Abundance of ammonia oxidizing bacteria and archaea that were collected on LMG 06-01 (archaea) at discrete depths, 2006.

Summary:
The Palmer, Antarctica, Long-Term Ecological Research project is a member site of the Long-Term Ecological Research program, a network of sites investigating diverse biomes.  A team of researchers seeks to understand the structure and function of the Western Antarctic Peninsula's marine and terrestrial ecosystems in the context of seasonal-to-interannual atmospheric and sea ice dynamics, as well as long-term climate change. The PAL measurement system (or grid) is designed to study marine and terrestrial food webs consisting principally of diatom primary producers, the dominant herbivore Antarctic krill, and the apex predator Adelie penguin. An attenuated microbial food web is also a focus. PAL studies these ecosystems annually over a regional scale grid of oceanographic stations and seasonally at Palmer Station. \n\nPalmer Station is located on Anvers Island west of the Antarctic Peninula. The peninsula runs perpendicular to a strong climatic gradient between the cold, dry continental regime to the south, characteristic of the Antarctic interior, and the warm, moist, maritime regime to the north. North-south shifts in the gradient give rise to large environmental variability to climate change. Sea ice extent and variability affects ecosystem changes at all trophic levels.  In addition to the long-term field and research activities, information management, graduate student training,  education and outreach are an integral part of the program.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
time (seconds since 1970-01-01T00:00:00Z)
depth (m)
latitude (degrees_north)
longitude (degrees_east)
event
station
bottle
eub_16s_gene_copies (L-1)
aob_165_gene_copies (L-1)
archaea_16s_gene_copies (L-1)
cren_16s_gene_copies (L-1)
... (10 more variables)


Adelie penguin 1:2 chick nest ratio, 1991, present.

Summary:
Adelie penguin 1:2 chick nest ratio, 1991 - present. The fundamental long-term objective of the seabird component of the Palmer LTER (PAL) has been to identify and understand the mechanistic processes that regulate the mean fitness (population growth rate) of regional penguin populations.  Two hypotheses have guided this research, with one suggesting that population mean fitness is best explained by changes in regional krill biomass, and the other proposing that long-term changes in sea ice affects mean fitness by tipping the balance in favor of one species over another in accordance with species-specific evolved life history affinities to sea ice.  Although these hypotheses are not mutually exclusive, current evidence in the PAL region tends to favor the latter over the former.  Since the inception of PAL, Adélie penguin populations have effectively collapsed, while those of gentoo and chinstrap penguins have increased dramatically, trends that are spatially and temporally coherent with decreasing regional sea ice duration. Adélie penguins are an ice-obligate polar species whose life history is intimately linked to the presence of sea ice, while chinstrap and gentoo penguins are ice-intolerant species whose life histories evolved in the sub-Antarctic, where sea ice is a less permanent feature of the marine ecosystem.  In contrast, although krill constitute the most important component of the summer diets by mass of these three penguin species, changes in PAL krill abundances have exhibited no long-term trends, and thus fail to explain the divergent patterns in penguin populations evident in our time series.     \n\nThe PAL study region includes five main islands on which Adélie penguin colonies have historically occurred, and typically during the first week of January when chicks are in the guard stage (thus visible because they are no longer being brooded), these colonies are censused to determine the ratio of 1-chick to 2-chick nests.  This census is restricted to nests that are no more than one meter in from the colony perimeter, and therefore tend to be more vulnerable to predation and other factors such as snow deposition that tend to affect the more marginal sectors of the colonies.  The 1:2 chick ratio is thus highly sensitive to perturbations that are not necessarily evident in more optimal breeding habitats, and has provided important insights on the effects that breeding landscape quality has on reproductive success.   \n

cdm_data_type = Other
VARIABLES:
study_name (Study)
time (seconds since 1970-01-01T00:00:00Z)
... (6 more variables)


Adelie penguin area-wide breeding population census, 1991, present.

Summary:
Adelie penguin area-wide breeding population census, 1991 - present. The fundamental long-term objective of the seabird component of the Palmer LTER (PAL) has been to identify and understand the mechanistic processes that regulate the mean fitness (population growth rate) of regional penguin populations.  Two hypotheses have guided this research, with one suggesting that population mean fitness is best explained by changes in regional krill biomass, and the other proposing that long-term changes in sea ice affects mean fitness by tipping the balance in favor of one species over another in accordance with species-specific evolved life history affinities to sea ice.  Although these hypotheses are not mutually exclusive, current evidence in the PAL region tends to favor the latter over the former.  Since the inception of PAL, Adélie penguin populations have effectively collapsed, while those of gentoo and chinstrap penguins have increased dramatically, trends that are spatially and temporally coherent with decreasing regional sea ice duration. Adélie penguins are an ice-obligate polar species whose life history is intimately linked to the presence of sea ice, while chinstrap and gentoo penguins are ice-intolerant species whose life histories evolved in the sub-Antarctic, where sea ice is a less permanent feature of the marine ecosystem.  In contrast, although krill constitute the most important component of the summer diets by mass of these three penguin species, changes in PAL krill abundances have exhibited no long-term trends, and thus fail to explain the divergent patterns in penguin populations evident in our time series.     \n\nThe PAL study region includes five main islands on which Adélie penguin colonies have historically occurred.  These are censused synoptically once a year to determine the overall size of the breeding population.  The optimal census date may vary by a few days each season, but ultimately tries to capture the week following peak egg laying when the total number of breeding pairs reaches a maximum.  The timing of this census is assisted by the REPRO and HUMPOP data, which provide a daily to weekly rate of change in breeding adult population numbers as new nests are initiated.  This census is useful for a number of assessments, one of the most critical being that it directly reflects the effects of environmental variability on adult overwinter survival.\n

cdm_data_type = Other
VARIABLES:
study_name (Study)
time (Date GMT, seconds since 1970-01-01T00:00:00Z)
island_name (Island)
colony_code (Colony)
num_breeding_pairs (Breeding Pairs)


Adelie penguin breeding population arrival chronology on Humble Island, 1991, present.\t

Summary:
Adelie penguin breeding population arrival chronology on Humble Island, 1991 - present.\t. The fundamental long-term objective of the seabird component of the Palmer LTER (PAL) has been to identify and understand the mechanistic processes that regulate the mean fitness (population growth rate) of regional penguin populations.  Two hypotheses have guided this research, with one suggesting that population mean fitness is best explained by changes in regional krill biomass, and the other proposing that long-term changes in sea ice affects mean fitness by tipping the balance in favor of one species over another in accordance with species-specific evolved life history affinities to sea ice.  Although these hypotheses are not mutually exclusive, current evidence in the PAL region tends to favor the latter over the former.  Since the inception of PAL, Adélie penguin populations have effectively collapsed, while those of gentoo and chinstrap penguins have increased dramatically, trends that are spatially and temporally coherent with decreasing regional sea ice duration. Adélie penguins are an ice-obligate polar species whose life history is intimately linked to the presence of sea ice, while chinstrap and gentoo penguins are ice-intolerant species whose life histories evolved in the sub-Antarctic, where sea ice is a less permanent feature of the marine ecosystem.  In contrast, although krill constitute the most important component of the summer diets by mass of these three penguin species, changes in PAL krill abundances have exhibited no long-term trends, and thus fail to explain the divergent patterns in penguin populations evident in our time series.     \n\nThe arrival chronology of adult Adélie penguins on Humble Island is documented annually through island-wide censuses performed as ice and weather conditions permit.  Recorded data (numbers of adults present) provide a measure of the number of adults arriving daily at the breeding colonies, a metric that is sensitive to environmental conditions such as sea ice extent during late winter and early spring.  These data are also used in combination with other metrics to determine the optimal window for other, more extensive area-wide breeding population censuses (see CENSUS). \n

cdm_data_type = Other
VARIABLES:
study_name (Study)
time (Date GMT, seconds since 1970-01-01T00:00:00Z)
island_name (Island)
colony_code (Colony)
num_breeding_pairs (Adults)


Adelie penguin chick fledging weights, 1991, present.\t

Summary:
Adelie penguin chick fledging weights, 1991 - present.\t. The fundamental long-term objective of the seabird component of the Palmer LTER (PAL) has been to identify and understand the mechanistic processes that regulate the mean fitness (population growth rate) of regional penguin populations.  Two hypotheses have guided this research, with one suggesting that population mean fitness is best explained by changes in regional krill biomass, and the other proposing that long-term changes in sea ice affects mean fitness by tipping the balance in favor of one species over another in accordance with species-specific evolved life history affinities to sea ice.  Although these hypotheses are not mutually exclusive, current evidence in the PAL region tends to favor the latter over the former.  Since the inception of PAL, Adélie penguin populations have effectively collapsed, while those of gentoo and chinstrap penguins have increased dramatically, trends that are spatially and temporally coherent with decreasing regional sea ice duration. Adélie penguins are an ice-obligate polar species whose life history is intimately linked to the presence of sea ice, while chinstrap and gentoo penguins are ice-intolerant species whose life histories evolved in the sub-Antarctic, where sea ice is a less permanent feature of the marine ecosystem.  In contrast, although krill constitute the most important component of the summer diets by mass of these three penguin species, changes in PAL krill abundances have exhibited no long-term trends, and thus fail to explain the divergent patterns in penguin populations evident in our time series.     \n\nAdélie penguin chick fledging weights are obtained every two days (or as ice and weather conditions permit) at three beaches on Humble Island beginning when the first fledglings appear on any one of these beaches, and continuing until the last fledglings depart.  These data are generally collected during the first three weeks of February by first censusing the total number of chicks present on each beach, and then sub-sampling 30% of the censused population.  The metric of interest is the weight (in grams) of individual chicks, which is an important predictor of overwinter survival and thus future recruitment into the population as breeding adults.  \n

cdm_data_type = Other
VARIABLES:
study_name (Study)
time (Date GMT, seconds since 1970-01-01T00:00:00Z)
island_name (Island)
colony_code (Colony)
band_number
weight (gram)


Adelie penguin colony-specific chick production, 1991, present.

Summary:
Adelie penguin colony-specific chick production, 1991 - present. The fundamental long-term objective of the seabird component of the Palmer LTER (PAL) has been to identify and understand the mechanistic processes that regulate the mean fitness (population growth rate) of regional penguin populations.  Two hypotheses have guided this research, with one suggesting that population mean fitness is best explained by changes in regional krill biomass, and the other proposing that long-term changes in sea ice affects mean fitness by tipping the balance in favor of one species over another in accordance with species-specific evolved life history affinities to sea ice.  Although these hypotheses are not mutually exclusive, current evidence in the PAL region tends to favor the latter over the former.  Since the inception of PAL, Adélie penguin populations have effectively collapsed, while those of gentoo and chinstrap penguins have increased dramatically, trends that are spatially and temporally coherent with decreasing regional sea ice duration. Adélie penguins are an ice-obligate polar species whose life history is intimately linked to the presence of sea ice, while chinstrap and gentoo penguins are ice-intolerant species whose life histories evolved in the sub-Antarctic, where sea ice is a less permanent feature of the marine ecosystem.  In contrast, although krill constitute the most important component of the summer diets by mass of these three penguin species, changes in PAL krill abundances have exhibited no long-term trends, and thus fail to explain the divergent patterns in penguin populations evident in our time series.     \n\nThe PAL study region includes five main islands on which Adélie penguin colonies have historically occurred.  These are censused synoptically once a year to determine the total number of chicks produced in the area.  The optimal date for this census may vary by a few days each season, but ultimately tries to capture the week following the time when approximately 2/3 of the chicks have crèched.  The timing of this census is assisted by the REPRO data, which provide a daily to weekly rate of change in the number of crèched chicks.  Because the colonies used in this area-wide census are the same as those used to determine the overall annual breeding population, one of the key metrics obtained is an integrated number of breeding success (chicks crèched/breeding pair).  These data have provided valuable insights into the marine and terrestrial factors that influence Adélie penguin mean population fitness.  \n

cdm_data_type = Other
VARIABLES:
study_name (Study)
... (6 more variables)


Adelie penguin diet composition, fish species and numbers, 1991, present.

Summary:
Adelie penguin diet composition, fish species and numbers, 1991 - present. The fundamental long-term objective of the seabird component of the Palmer LTER (PAL) has been to identify and understand the mechanistic processes that regulate the mean fitness (population growth rate) of regional penguin populations.  Two hypotheses have guided this research, with one suggesting that population mean fitness is best explained by changes in regional krill biomass, and the other proposing that long-term changes in sea ice affects mean fitness by tipping the balance in favor of one species over another in accordance with species-specific evolved life history affinities to sea ice.  Although these hypotheses are not mutually exclusive, current evidence in the PAL region tends to favor the latter over the former.  Since the inception of PAL, Adélie penguin populations have effectively collapsed, while those of gentoo and chinstrap penguins have increased dramatically, trends that are spatially and temporally coherent with decreasing regional sea ice duration. Adélie penguins are an ice-obligate polar species whose life history is intimately linked to the presence of sea ice, while chinstrap and gentoo penguins are ice-intolerant species whose life histories evolved in the sub-Antarctic, where sea ice is a less permanent feature of the marine ecosystem.  In contrast, although krill constitute the most important component of the summer diets by mass of these three penguin species, changes in PAL krill abundances have exhibited no long-term trends, and thus fail to explain the divergent patterns in penguin populations evident in our time series.     \n\n\nFish occur frequently in Adélie penguin diets but rarely as whole specimens, hence recording their presence in sorted subsamples (see DIET) is generally limited to noting the incidence of skin, flesh, bones, eyes and especially otoliths.  With the exception of otoliths, the weights of these items are obtained if warranted by the sample size.  Otoliths can be used to identify individual fish species, and in combination with regression equations based on otolith length and width, can also be used to reconstitute fish length and mass.  However, because the expertise needed to identify fish from otoliths does not exist within the PAL program, otolith identification is performed by off-site experts as time and funding allow.  This results in long lags between the time otoliths are collected and integrated with the appropriate databases, meaning that understanding the role of fish in Adélie penguin diets still remains a longer-term objective of PAL.   \n

cdm_data_type = Other
VARIABLES:
study_name (Study)
... (12 more variables)


Adelie penguin diet composition, krill size-frequency distribution, 1991, present.

Summary:
Adelie penguin diet composition, krill size-frequency distribution, 1991 - present. The fundamental long-term objective of the seabird component of the Palmer LTER (PAL) has been to identify and understand the mechanistic processes that regulate the mean fitness (population growth rate) of regional penguin populations.  Two hypotheses have guided this research, with one suggesting that population mean fitness is best explained by changes in regional krill biomass, and the other proposing that long-term changes in sea ice affects mean fitness by tipping the balance in favor of one species over another in accordance with species-specific evolved life history affinities to sea ice.  Although these hypotheses are not mutually exclusive, current evidence in the PAL region tends to favor the latter over the former.  Since the inception of PAL, Adélie penguin populations have effectively collapsed, while those of gentoo and chinstrap penguins have increased dramatically, trends that are spatially and temporally coherent with decreasing regional sea ice duration. Adélie penguins are an ice-obligate polar species whose life history is intimately linked to the presence of sea ice, while chinstrap and gentoo penguins are ice-intolerant species whose life histories evolved in the sub-Antarctic, where sea ice is a less permanent feature of the marine ecosystem.  In contrast, although krill constitute the most important component of the summer diets by mass of these three penguin species, changes in PAL krill abundances have exhibited no long-term trends, and thus fail to explain the divergent patterns in penguin populations evident in our time series.     \n\nThree species of krill occur in Adélie penguin diet samples, Antarctic krill (Euphausia superba), crystal krill (E. crystallorophias) and Thysanoessa macrura (no common name), but beyond obtaining whole subsample weights following sorting (see DIET), only E. superba is subjected to further analysis.  In this case, the original subsample from each individual penguin is searched with the objective of obtaining a minimum of 50 whole krill that when measured (in millimeters) provide an index of within and between season variability in population size-frequency distributions.  These data have provided critical insights into a number of ecological processes, including in particular how sea ice affects krill recruitment and, in turn, how krill recruitment impacts Adélie penguin foraging efforts.  \n

cdm_data_type = Other
VARIABLES:
study_name (Study)
time (seconds since 1970-01-01T00:00:00Z)
... (12 more variables)


Adelie penguin diet composition, preliminary analyses of whole lavaged samples, 1991, present.

Summary:
Adelie penguin diet composition, preliminary analyses of whole lavaged samples, 1991 - present. The fundamental long-term objective of the seabird component of the Palmer LTER (PAL) has been to identify and understand the mechanistic processes that regulate the mean fitness (population growth rate) of regional penguin populations.  Two hypotheses have guided this research, with one suggesting that population mean fitness is best explained by changes in regional krill biomass, and the other proposing that long-term changes in sea ice affects mean fitness by tipping the balance in favor of one species over another in accordance with species-specific evolved life history affinities to sea ice.  Although these hypotheses are not mutually exclusive, current evidence in the PAL region tends to favor the latter over the former.  Since the inception of PAL, Adélie penguin populations have effectively collapsed, while those of gentoo and chinstrap penguins have increased dramatically, trends that are spatially and temporally coherent with decreasing regional sea ice duration. Adélie penguins are an ice-obligate polar species whose life history is intimately linked to the presence of sea ice, while chinstrap and gentoo penguins are ice-intolerant species whose life histories evolved in the sub-Antarctic, where sea ice is a less permanent feature of the marine ecosystem.  In contrast, although krill constitute the most important component of the summer diets by mass of these three penguin species, changes in PAL krill abundances have exhibited no long-term trends, and thus fail to explain the divergent patterns in penguin populations evident in our time series.     \n\nAdélie penguin diet samples obtained in the field (see HEADER) are initially drained and weighed and returned to laboratories for further processing.  This includes resuspension of the samples in fresh water to release fish otoliths, squid beaks and other prey hard parts, and then draining to a consistency that facilitates separating the diet samples into subsamples of primary and secondary prey components.  Primary prey components include krill and fish, and secondary prey components include octopus, squid amphipods, mysid shrimp, limpets and small clams.  Each prey component is weighed (total weight) and, if possible, sorted according to species for further analyses.  Variability in diets within and between seasons is strongly linked to variability in the marine environment such as the presence or absence of sea ice and the timing and persistence of phytoplankton blooms, and thus affects a host of Adélie penguin life history parameters.    \n

cdm_data_type = Other
VARIABLES:
study_name (Study)
... (9 more variables)


Adelie penguin diet composition, secondary prey items, 1991, present.\t

Summary:
Adelie penguin diet composition, secondary prey items, 1991 - present.\t. The fundamental long-term objective of the seabird component of the Palmer LTER (PAL) has been to identify and understand the mechanistic processes that regulate the mean fitness (population growth rate) of regional penguin populations.  Two hypotheses have guided this research, with one suggesting that population mean fitness is best explained by changes in regional krill biomass, and the other proposing that long-term changes in sea ice affects mean fitness by tipping the balance in favor of one species over another in accordance with species-specific evolved life history affinities to sea ice.  Although these hypotheses are not mutually exclusive, current evidence in the PAL region tends to favor the latter over the former.  Since the inception of PAL, Adélie penguin populations have effectively collapsed, while those of gentoo and chinstrap penguins have increased dramatically, trends that are spatially and temporally coherent with decreasing regional sea ice duration. Adélie penguins are an ice-obligate polar species whose life history is intimately linked to the presence of sea ice, while chinstrap and gentoo penguins are ice-intolerant species whose life histories evolved in the sub-Antarctic, where sea ice is a less permanent feature of the marine ecosystem.  In contrast, although krill constitute the most important component of the summer diets by mass of these three penguin species, changes in PAL krill abundances have exhibited no long-term trends, and thus fail to explain the divergent patterns in penguin populations evident in our time series.     \n\nBesides krill and fish, a number of secondary prey items (see DIET) can be found in Adélie penguin diets, including octopus, squid, amphipods, mysid shrimp, limpets and small clams.  One or more of these prey types may occur frequently in the samples, but very rarely in abundance, hence recorded metrics are limited to detailing the number of specimens observed and obtaining weights if warranted by the sample size.  One exception concerns squid and octopus beaks, which like fish otoliths can be identified to species and the size and mass of individuals reconstituted based on regressions that use beak length to determine relational metrics.  Like otoliths, beaks are also processed by experts outside PAL (see FISH), hence similar time lags exist in database integration.  What role these less abundant prey items have in  Adélie penguin diets is unknown, but paleoecological evidence suggests that squid in particular were once consumed much more frequently in the PAL region than they are now.\n

cdm_data_type = Other
VARIABLES:
study_name (Study)
... (11 more variables)


Adelie penguin diet metadata, 1991, present.

Summary:
Adelie penguin diet metadata, 1991 - present. The fundamental long-term objective of the seabird component of the Palmer LTER (PAL) has been to identify and understand the mechanistic processes that regulate the mean fitness (population growth rate) of regional penguin populations.  Two hypotheses have guided this research, with one suggesting that population mean fitness is best explained by changes in regional krill biomass, and the other proposing that long-term changes in sea ice affects mean fitness by tipping the balance in favor of one species over another in accordance with species-specific evolved life history affinities to sea ice.  Although these hypotheses are not mutually exclusive, current evidence in the PAL region tends to favor the latter over the former.  Since the inception of PAL, Adélie penguin populations have effectively collapsed, while those of gentoo and chinstrap penguins have increased dramatically, trends that are spatially and temporally coherent with decreasing regional sea ice duration. Adélie penguins are an ice-obligate polar species whose life history is intimately linked to the presence of sea ice, while chinstrap and gentoo penguins are ice-intolerant species whose life histories evolved in the sub-Antarctic, where sea ice is a less permanent feature of the marine ecosystem.  In contrast, although krill constitute the most important component of the summer diets by mass of these three penguin species, changes in PAL krill abundances have exhibited no long-term trends, and thus fail to explain the divergent patterns in penguin populations evident in our time series.     \n\n\nAdélie penguin diet samples are obtained during the chick-rearing phase of the breeding season (January -February) using stomach lavage (water off-loading method).  Five adult penguins are typically sampled every 5-7 days (weather permitting) during this period by capturing birds near their breeding colonies as they return from foraging in the evenings.  Before lavaging, birds are weighed and measured to obtain an index of gender and condition, and are then released at the site where they were initially captured.  Variability in adult condition within and between seasons provides an important index of foraging effort and other related metrics.      \n

cdm_data_type = Other
VARIABLES:
study_name (Study)
time (Sample Date/Time, seconds since 1970-01-01T00:00:00Z)
island_name (Island)
colony_code (Colony)
... (5 more variables)


Adelie penguin flipper band resightings, 1991, 2006.

Summary:
Adelie penguin flipper band resightings, 1991 - 2006. The fundamental long-term objective of the seabird component of the Palmer LTER (PAL) has been to identify and understand the mechanistic processes that regulate the mean fitness (population growth rate) of regional penguin populations.  Two hypotheses have guided this research, with one suggesting that population mean fitness is best explained by changes in regional krill biomass, and the other proposing that long-term changes in sea ice affects mean fitness by tipping the balance in favor of one species over another in accordance with species-specific evolved life history affinities to sea ice.  Although these hypotheses are not mutually exclusive, current evidence in the PAL region tends to favor the latter over the former.  Since the inception of PAL, Adélie penguin populations have effectively collapsed, while those of gentoo and chinstrap penguins have increased dramatically, trends that are spatially and temporally coherent with decreasing regional sea ice duration. Adélie penguins are an ice-obligate polar species whose life history is intimately linked to the presence of sea ice, while chinstrap and gentoo penguins are ice-intolerant species whose life histories evolved in the sub-Antarctic, where sea ice is a less permanent feature of the marine ecosystem.  In contrast, although krill constitute the most important component of the summer diets by mass of these three penguin species, changes in PAL krill abundances have exhibited no long-term trends, and thus fail to explain the divergent patterns in penguin populations evident in our time series.     \n\n Annually between 1991 and 1998, a subsample of 1000 Adélie penguin crèche-age chicks were flipper-banded on Humble Island as part of demographic studies to determine long-term survival and recruitment.  This was achieved through resighting efforts in the years that followed the banding work through 2006 when the last banded bird was observed.  The decision to end the banding studies is in concordance with other national and international efforts to limit this work due to evidence that flipper- banding penguins may affect survival.   \n

cdm_data_type = Other
VARIABLES:
index
study_name (Study)
time (Date GMT, seconds since 1970-01-01T00:00:00Z)
island_name (Island)
colony_code (Colony)
... (5 more variables)


Annual counts of penguin breeding pairs near Palmer Station, Antarctica 1970, 2006.

Summary:
Annual counts of penguin breeding pairs near Palmer Station, Antarctica 1970 - 2006. Penguin populations are in the vicinity of Palmer Station, Anvers Island, Antarctica. The Adelie penguin, (Pygoscelis adeliae), one of two true sea ice-obligate Antarctic penguins are in decline near Palmer. Two lower-latitude species (Chinstrap and Gentoo penguins) are now rapidly colonizing the region.

cdm_data_type = Other
VARIABLES:
study_name (Study)
time (seconds since 1970-01-01T00:00:00Z)
year (seconds since 1970-01-01T00:00:00Z)
chinstrap_num_breeding_pairs
adelie_num_breeding_pairs
gentoo_num_breeding_pairs


At-sea seabird censuses. Data on the species encountered (including marine mammals), their abundance, distribution and behavior. Data collected aboard cruises off the coast of the Western Antarctic Penninsula, 1993, 1999 and 2001.

Summary:
The objectives of the LTER seabird component during the 92-93 season cruises were similar.  These objectives included 1) determining the pelagic abundance and distribution of Adelie Penguins, 2) examining how the physical and biological characteristics of the marine environment influence these parameters and, 3) using these data to identify foraging areas that may be important to Adelie populations being studied as part of land-based  work at Palmer Station.  Secondary objectives included documenting the abundance and distribution of other seabirds and marine mammals within the LTER study area.  The focus of the January cruise was the nearshore foraging habitat,which required sampling at smaller scales.  All seabird censuses were thus conducted within approximately 100 kms of Palmer Station while traversing a sampling grid with stations at 10km intervals.  The first two days (18-20 January) of this cruise were spent covering the selected grid as rapidly as possible resulting in 45 transects spaced at 45-60 minute intervals.  There were no stops at the 10km stations during this Fast Grid phase.  Upon completion of the Fast Grid, a force 12 gale suspended data collection for 24 hours.  From January 22-25 the grid direction was reversed and the grid repeated.  During this Slow Grid phase, 2-M net tows were done at 10km intervals and BOPS and 1-M and 2-M net tows every 20 km.  All seabird censusesduring the cruise were done using the procedures outlined in theprevious paragraph.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
event
time (seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
lat_end (Latitude, degrees_north)
lon_end (Longitude, degrees_east)
depth (m)
cruise_name
start_station
end_station
duration (minutes)
... (14 more variables)


Summary:
The objectives of the LTER seabird component during the 92-93 season cruises were similar.  These objectives included 1) determining the pelagic abundance and distribution of Adelie Penguins, 2) examining how the physical and biological characteristics of the marine environment influence these parameters and, 3) using these data to identify foraging areas that may be important to Adelie populations being studied as part of land-based  work at Palmer Station.  Secondary objectives included documenting the abundance and distribution of other seabirds and marine mammals within the LTER study area.  The focus of the January cruise was the nearshore foraging habitat,which required sampling at smaller scales.  All seabird censuses were thus conducted within approximately 100 kms of Palmer Station while traversing a sampling grid with stations at 10km intervals.  The first two days (18-20 January) of this cruise were spent covering the selected grid as rapidly as possible resulting in 45 transects spaced at 45-60 minute intervals.  There were no stops at the 10km stations during this Fast Grid phase.  Upon completion of the Fast Grid, a force 12 gale suspended data collection for 24 hours.  From January 22-25 the grid direction was reversed and the grid repeated.  During this Slow Grid phase, 2-M net tows were done at 10km intervals and BOPS and 1-M and 2-M net tows every 20 km.  All seabird censusesduring the cruise were done using the procedures outlined in theprevious paragraph.

cdm_data_type = Trajectory
VARIABLES:
event
cruise_id
study_name (Study)
depth (m)
latitude (degrees_north)
longitude (degrees_east)
time (seconds since 1970-01-01T00:00:00Z)
station
grid_line (km)
grid_station (km)
sea_state
salinity (Sea Water Practical Salinity, 1)
... (14 more variables)


At-sea seabird censuses. Data on the species encountered (including marine mammals), their abundance, distribution and behavior. Data collected aboard cruises off the coast of the Western Antarctic Penninsula, 1993, 2018.

Summary:
At-sea seabird censuses. Data on the species encountered (including marine mammals), their abundance, distribution and behavior. Data collected aboard cruises off the coast of the Western Antarctic Penninsula, 1993 - 2018. The objectives of the LTER seabird component during the 92-93 season cruises were similar.  These objectives included 1) determining the  pelagic abundance and distribution of Adelie Penguins, 2) examining  how the physical and biological characteristics of the marine  environment influence these parameters and, 3) using these data to  identify foraging areas that may be important to Adelie populations  being studied as part of land-based  work at Palmer Station.   Secondary objectives included documenting the abundance and  distribution of other seabirds and marine mammals within the LTER  study area.  The focus of the January cruise was the nearshore foraging habitat, which required sampling at smaller scales.  All seabird censuses  were thus conducted within approximately 100 kms of Palmer Station  while traversing a sampling grid with stations at 10km intervals.   The first two days (18-20 January) of this cruise were spent covering  the selected grid as rapidly as possible resulting in 45 transects  spaced at 45-60 minute intervals.  There were no stops at the 10km  stations during this Fast Grid phase.  Upon completion of the Fast Grid,  a force 12 gale suspended data collection for 24 hours.  From  January 22-25 the grid direction was reversed and the grid repeated.   During this Slow Grid phase, 2-M net tows were done at 10km intervals  and BOPS and 1-M and 2-M net tows every 20 km.  All seabird censuses during the cruise were done using the procedures outlined in the previous paragraph.\n\nSeventy-two 30-minute transects and 15 station censuses were completed during the January cruise.  Athough seabirds were widely  distributed  throughout the  study  area,  the highest  densities and  greatest  biomass occurred consistently within 2-5 km of Anvers Island and  several major  island  groups to the south and \nwest  near  the  Antarctic Peninsula.   Adelie Penguins were the  dominant component of  this seabird  assemblage  in  terms of  both   abundance  and  biomass.  South Polar Skuas ranked second and Black-browed Albatross third, with the latter becoming the dominant assemblage member at distances greater than 10km from land.  Although  \nSouth Polar Skuas had been expected to occur in more pelagic  habitats, few were censused at distances greater than 10km from land.   The presence  of  both  skuas  and penguins  so close  to  land  was unexpected.  The  most  important  variable accounting for  variation  in  the distribution  and  abundance  of  seabirds  appeared  to  \nbe  the location  of  the 200m contour, which throughout the  study  area occurred 2-5km from the adjoining land masses.  Approximately 65% of the seabirds censused during this cruise (85% of the  biomass) occurred  in  association with this contour.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
... (25 more variables)


At-sea seabird censuses. Data on the species encountered (including marine mammals), their abundance, distribution and behavior. Data collected aboard cruises off the coast of the Western Antarctic Penninsula, 1993, present.

Summary:
At-sea seabird censuses. Data on the species encountered (including marine mammals), their abundance, distribution and behavior. Data collected aboard cruises off the coast of the Western Antarctic Penninsula, 1993 - present. The objectives of the LTER seabird component during the 92-93 season cruises were similar.  These objectives included 1) determining the pelagic abundance and distribution of Adelie Penguins, 2) examining how the physical and biological characteristics of the marine environment influence these parameters and, 3) using these data to identify foraging areas that may be important to Adelie populations being studied as part of land-based  work at Palmer Station.  Secondary objectives included documenting the abundance and distribution of other seabirds and marine mammals within the LTER study area.  The focus of the January cruise was the nearshore foraging habitat,which required sampling at smaller scales.  All seabird censuses were thus conducted within approximately 100 kms of Palmer Station while traversing a sampling grid with stations at 10km intervals.  The first two days (18-20 January) of this cruise were spent covering the selected grid as rapidly as possible resulting in 45 transects spaced at 45-60 minute intervals.  There were no stops at the 10km stations during this Fast Grid phase.  Upon completion of the Fast Grid, a force 12 gale suspended data collection for 24 hours.  From January 22-25 the grid direction was reversed and the grid repeated.  During this Slow Grid phase, 2-M net tows were done at 10km intervals and BOPS and 1-M and 2-M net tows every 20 km.  All seabird censusesduring the cruise were done using the procedures outlined in theprevious paragraph.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
time (Date/Time, seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
lat_end (Latitude, degrees_north)
lon_end (Longitude, degrees_east)
depth (m)
event
cruise_id
start_station
... (16 more variables)


Bacterial abundance and produciton at the Palmer Station LTER sites B and E in May 2011 and 2012

Summary:
The data described here were collected as part of a study of photoheterotrophic microbes in Antarctic waters (National Science Foundation (NSF) OPP 0838830).  This sampling was conducted in May outside of the LTER sampling season at Palmer Station.  Samplng was conducted by pumping water from a depth of 1 m into carboys that were returned to the lab..The data described here were collected as part of a study of photoheterotrophic microbes in Antarctic waters (NSF OPP 0838830).  This sampling was conducted in May outside of the LTER sampling season at Palmer Station.  Samplng was conducted by pumping water from a depth of 1 m into carboys that were returned to the lab.

cdm_data_type = Other
VARIABLES:
study_name (Study)
time (seconds since 1970-01-01T00:00:00Z)
station
depth (m)
salinity (Sea Water Practical Salinity, 1)
temperature (Sea Water Temperature, degree_C)
chlorophyll_a (Mass Concentration Of Chlorophyll A In Sea Water, ug L-1)
chlorophyll_a_standard_deviation (ug L-1)
leucine_incorporation (picomoles L-1 hr-1)
leucine_incorporation_stdev (picomoles L-1 hr-1)
thymidine_incorporation (picomoles L-1 hr-1)
thymidine_incorporation_stdev (picomoles L-1 hr-1)
bacterial_abundance
bacterial_abundance_stdev


Bacterial properties in discrete water column samples at selected depths, collected aboard Palmer LTER annual cruises off the coast of the Western Antarctica Peninsula, 2003, 2019.

Summary:
Bacterial properties in discrete water column samples at selected depths, collected aboard Palmer LTER annual cruises off the coast of the Western Antarctica Peninsula, 2003 - 2019. The microbial biogeochemistry component of PAL focuses on marine bacterioplankton, and is thus a counterpart to the phytoplankton and zooplankton components, which together provide a detailed and comprehensive description of plankton ecology in PAL-LTER. Bacteria and Archaea (hereafter called "bacteria") are taxonomically and metabolically diverse. In coastal and offshore surface waters Bacteria generally predominate over Archaea, but Archaea are equal or greater in abundance in the mesopelagic layer below the euphoric zone. We focus on aerobic, heterotrophic bacteria in the upper 100 m on the annual summer cruise. These bacteria oxidize recently-produced low molecular weight dissolved organic compounds released by phytoplankton and zooplankton, decomposing them back into CO2 and inorganic nutrients. Globally, marine bacteria respire an amount of carbon roughly equal to about half the daily photosynthetic production. In cold polar waters, relative bacterial activity is lower, with bacterial biomass production being equal to <5% of the daily photosynthesis. The ratio at lower latitudes is 10-20%. The factors responsible for this contrast are not entirely clear. Resolving this pattern is a key aim of the PAL microbial component. Bacterial production is generally low across the grid, relative to primary production, but with considerable spatial and annual variability. Discrete BP can reach >200mgC/m2/d following bloom-fueled high organic matter events. Across the grid and over years, BP is highly correlated with chlorophyll, highlighting the close relationship with phytoplanktonic organic matter production.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
event (Event Number)
station (Station Name)
bottle (Bottle Number)
time (Datetime GMT, seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
depth (m)
bacterial_cell_count (Abundance, count L-1)
... (5 more variables)


Bacterial properties in discrete water column samples collected during Palmer LTER station seasons at Palmer Station Antarctica, 2002, 2019.

Summary:
Bacterial properties in discrete water column samples collected during Palmer LTER station seasons at Palmer Station Antarctica, 2002 - 2019. The microbial biogeochemistry component of PAL focuses on marine bacterioplankton, and is thus a counterpart to the phytoplankton and zooplankton components, which together provide a detailed and comprehensive description of plankton ecology in PAL-LTER. Bacteria and Archaea (hereafter called "bacteria") are taxonomically and metabolically diverse. In coastal and offshore surface waters Bacteria generally predominate over Archaea, but Archaea are equal or greater in abundance in the mesopelagic layer below the euphoric zone. We focus on aerobic, heterotrophic bacteria in the upper 65 m at Palmer Station which oxidize recently-produced low molecular weight dissolved organic compounds released by phytoplankton and zooplankton, decomposing them back into CO2 and inorganic nutrients. Globally, marine bacteria respire an amount of carbon roughly equal to about half the daily photosynthetic production. In cold polar waters, relative bacterial activity is lower, with bacterial biomass production being equal to <5% of the daily photosynthesis. The ratio at lower latitudes is 10-20%. The factors responsible for this contrast are not entirely clear. Resolving this pattern is a key aim of the PAL microbial component. At Palmer Station, bacterial production is low (< 10 mgC/m2/d) in the winter (polar night) when there is little if any photosynthesis. There is a climatological (2003-14 average) summer peak of 50-60 mgC/m2/d in January-February but with considerable seasonal and annual variability. \n\nThe 2016/2017 season data contains bacteria abundances for preserved samples for comparison to abundances from live samples. See the documentation for this in the accompanying file, 2016_live_vs_preserved.pdf.

cdm_data_type = TimeSeries
VARIABLES:
study_name (Study)
time (Date GMT, seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
event (Event Number)
station (Station Name)
depth (m)
bacterial_cell_count (Abundance, count L-1)
... (5 more variables)


Chlorophyll and phaeopigments from water column samples, collected at selected depths aboard Palmer LTER annual cruises off the coast of the Western Antarctic Peninsula, 1991 - 2019.

Summary:
Phytoplankton chlorophyll sampling was led by Smith from 1991-2002, and then by Vernet from 2003-2008. Schofield is the third, and current lead, beginning in 2009. Methods have been kept consistent as much as possible over the full time series and different Principal Investigators. Chlorophyll a (Chl a) is the principal photosynthetic pigment of phytoplankton, and is used as a proxy measurement for estimating phytoplankton biomass in water samples. Chl a concentrations reflect the distribution of active phytoplankton spatially and with depth in the water column and their changes over time. Phaeopigments are non-photosynthetic pigments that are degradation products of phytoplankton chlorophylls which form during and after phytoplankton blooms. Water samples are collected throughout the water column along the Western Antarctic Peninsula at regular LTER grid stations where Conductivity, Temperature, Depth (CTD) casts are preformed and in surface waters at underway stations, where CTD casts are not done, using the ship's flow-through seawater system. Water samples are filtered onto GF/F filters, and filters kept frozen at -80°C until analysis at Palmer Station following the completion of the cruise. Fluorometric chlorophyll and phaeopigment analysis is conducted at Palmer Station through acetone extraction of the GF/F filters and measurement of the extract on a Turner 10AU Fluorometer. The primary source of error for phaeopigment measurement is Chlorophyll b. If high amounts of Chlorophyll b are present in the sample, phaeopigments may be overestimated.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
chlorophyll_a (mass_concentration_of_chlorophyll_a_in_sea_water, mg m-3)
phaeopigment (mg m-3)
event
bottle
time (seconds since 1970-01-01T00:00:00Z)
grid_line
grid_station
latitude (degrees_north)
longitude (degrees_east)
depth (m)
... (7 more variables)


Conductivity Temperature Depth (CTD) sensor profile data binned by depth from PAL LTER annual cruises, 1991, 2017 (ongoing).

Summary:
Conductivity Temperature Depth (CTD) sensor profile data binned by depth from PAL LTER annual cruises, 1991 - 2017 (ongoing). Since 1991 (and ongoing), the PAL LTER program has deployed a SeaBird 911+ CTD mounted on a 24-bottle rosette during annual (Austral Summer) cruises plus a few supplemental cruises at other times of the year. An equal area grid oriented parallel to the average coast provides the basis for sampling, as well as specific process studies and on-the-fly scientific needs. The CTD-rosette is lowered into the ocean (usually to just above the sea-floor) using the ship's conductive-wire winch. Data is collected and displayed real-time to ensure quality and make decisions about where to collect seawater with the bottles. Bottle data is typically collected extensively in the seasaonal mixed layer and pycnocline, plus at Tmin, in the permament pycnolcine and at Tmax and Smax, as well as near the bottom. Bottle data allows measurement adn calculation of additional variables and helps ensure quality data collected via sensors. Sensors include: Pressure, Conductivity (for Salinity), Temperature, Oxygen, Transmissometer, Flourometer, Photosynthetically Available Radiation (PAR/Irrandiance). Additional Bottle Data Variables include: Phosphate, Silicate, Nitrite, Nitrate, Ammonium.  After each cruise, Temperature, Conductivity and Oxygen sensors are calibrated and post-crusie processing is applied, making use of pre- and post- cruise calibrations as well as SeaBird software and algorithms for getting the best quality data. Each profile is then inspected for any issues and if needed, suitable corrections are made such as using secondary sensors (temperature, conductivity and oxygen all currently measured in duplicate), using the upcast, or flagging the data as bad.

cdm_data_type = TrajectoryProfile
VARIABLES:
study_name (Cruise Name)
time (Datetime UTC, seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
depth (m)
pressure (dbar)
temperature (degree_C)
salinity (1)
sigmat (Sigma-Theta, kg m-3)
... (5 more variables)


Daily averaged weather timeseries (air temperature, pressure, wind speed, wind direction, precipitation, sky cover) at Palmer Station, Antarctica combining manual observations (1989, Dec 12, 2003) and PALMOS automatic weather station measurements (Dec 13, 2003, March 2019).

Summary:
Daily averaged weather timeseries (air temperature, pressure, wind speed, wind direction, precipitation, sky cover) at Palmer Station, Antarctica combining manual observations (1989 - Dec 12, 2003) and PALMOS automatic weather station measurements (Dec 13, 2003 - March 2019). Weather data acquisition was originally by manual observation and continued with an automated system installed in Nov 2001. Measurements began shifting from manual to automated observations in June 2003 until the manual observations were ended on December 12, 2003. Data are collected, compiled, and distributed by the US Antarctic polar contractor. Electronic distributed occurs monthly from Palmer station via internet and are available at University of Wisconsin weather archive: ftp://amrc.ssec.wisc.edu/pub/palmer/climatology/.Weather data acquisition was originally by manual observation and continued with an automated system installed in Nov 2001. Measurements began shifting from manual to automated observations in June 2003 until the manual observations were ended on December 12, 2003. Data are collected, compiled, and distributed by the US Antarctic polar contractor. Electronic distributed occurs monthly from Palmer station via internet and are available at University of Wisconsin weather archive: ftp://amrc.ssec.wisc.edu/pub/palmer/climatology/

cdm_data_type = TimeSeries
VARIABLES:
time (seconds since 1970-01-01T00:00:00Z)
station_id
latitude (degrees_north)
longitude (degrees_east)
high_temperature (Air Temperature, degree_C)
low_temperature (degree_C)
avg_temperature (degree_C)
sea_surface_temperature (degree_C)
sea_ice
high_pressure (Air Pressure, mbar)
low_pressure (mbar)
avg_pressure (mbar)
peak_windspeed (Wind Speed, m s-1)
... (14 more variables)


Dissolved inorganic carbon and alkalinity of discrete water column samples, collected aboard Palmer LTER annual cruises of the Western Antarctic Peninsula, 1993, 2018.

Summary:
Dissolved inorganic carbon and alkalinity of discrete water column samples, collected aboard Palmer LTER annual cruises of the Western Antarctic Peninsula, 1993 - 2018. There is a temporal uncoupling between Antarctic phytoplankton and bacterial processes.  This affects the coastal ecosystem carbon cycle. Our sampling strategy and experiments are designed to evaluate the hypotheses that this uncoupling is caused by:1) dissolved organic carbon - bacterial interactions,2) temperature effects, and 3) direct competition and chemical antagonism.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
event (Event Number)
bottle (Bottle Number)
grid_station
cast_number (Cast)
grid_line (Line)
station
time (Datetime GMT, seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
depth (m)
dissolved_inorganic_carbon1 (DIC 1, micromoles kg-1)
dissolved_inorganic_carbon2 (DIC 2, micromoles kg-1)
alkalinity1 (Alkalinity 1)
alkalinity2 (Alkalinity 2)
temperature (degree_C)
salinity (1)
notes


Dissolved inorganic nutrients including 5 macro nutrients: silicate, phosphate, nitrate, nitrite, and ammonium from water column bottle samples collected during annual cruise along western Antarctic Peninsula, 1991, 2019.

Summary:
Dissolved inorganic nutrients including 5 macro nutrients: silicate, phosphate, nitrate, nitrite, and ammonium from water column bottle samples collected during annual cruise along western Antarctic Peninsula, 1991 - 2019. The inorganic plant macronutrients dissolved phosphate, silicate, nitrate, nitrite and ammonium are the major sources of nutrition for phytoplankton growth in seawater (with sunlight and inorganic carbon). Macronutrient distributions reflect the large-scale circulation patterns in the oceans and are useful properties to delineate water masses. Dissolved inorganic nutrients samples are typically collected in every Conductivity, Temperature, Depth (CTD)/Rosette cast performed on the annual LTER cruises along the western Antarctic Peninsula. Water samples are analyzed for dissolved nutrients with recognized standard oceanographic protocols for nutrient autoanalyzers (continuous flow analyzers). In Antarctic waters, dissolved inorganic macronutrients are seldom depleted to limiting concentrations except during heavy prolonged phytoplankton blooms. This is due to the fact that phytoplankton growth is more often limited by light or iron, and to the short growing season. .The inorganic plant macronutrients dissolved phosphate, silicate, nitrate, nitrite and ammonium are the major sources of nutrition for phytoplankton growth in seawater (with sunlight and inorganic carbon). Macronutrient distributions reflect the large-scale circulation patterns in the oceans and are useful properties to delineate water masses. Dissolved inorganic nutrients samples are typically collected in every CTD/Rosette cast performed on the annual LTER cruises along the western Antarctic Peninsula. Water samples are analyzed for dissolved nutrients with recognized standard oceanographic protocols for nutrient autoanalyzers (continuous flow analyzers). In Antarctic waters, dissolved inorganic macronutrients are seldom depleted to limiting concentrations except during heavy prolonged phytoplankton blooms. This is due to the fact that phytoplankton growth is more often limited by light or iron, and to the short growing season. .The inorganic plant macronutrients dissolved phosphate, silicate, nitrate, nitrite and ammonium are the major sources of nutrition for phytoplankton growth in seawater (with sunlight and inorganic carbon). Macronutrient distributions reflect the large-scale circulation patterns in the oceans and are useful properties to delineate water masses. Dissolved inorganic nutrients samples are typically collected in every CTD/Rosette cast performed on the annual LTER cruises along the western Antarctic Peninsula. Water samples are analyzed for dissolved nutrients with recognized standard oceanographic protocols for nutrient autoanalyzers (continuous flow analyzers). In Antarctic waters, dissolved inorganic macronutrients are seldom depleted to limiting concentrations except during heavy prolonged phytoplankton blooms. This is due to the fact that phytoplankton growth is more often limited by light or iron, and to the short growing season.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
... (17 more variables)


Dissolved organic carbon (DOC) taken from discrete water column samples collected during annual cruise along western Antarctic Peninsula, 2003-2012.

Summary:
Dissolved organic carbon (Department of Commerce (DOC)) is a poorly-characterized but large and dynamic pool of actively-cycling carbon in the oceans, and one of the largest organic carbon pools on the planet. The total DOC pool consists of three major fractions: refractory DOC resistant to microbial oxidation with a turnover time of millennia; semi-labile DOC, produced and decomposed on seasonal timescales, and labile DOC, consisting of simple, recently-produced compounds with nanomolar concentrations, and turnover times of minutes-days. The background concentration of refractory DOC in the deep ocean is 35-45 micromolar. DOC concentration in the upper 100-200 meters is enhanced by 10-50 micromolar with the addition of semilabile DOC. In subtropical and temperate oceans, semilabile DOC can form an important part of the carbon export by deep vertical mixing into the oceanic mid-depths. Concentrations of semilabile DOC are lower in the polar Southern Ocean than in most other regions.

cdm_data_type = Other
VARIABLES:
study_name (Study)
time (Datetime GMT, seconds since 1970-01-01T00:00:00Z)
grid_line (Grid Line Intended)
grid_station (Grid Station Intended)
station (Station Name)
bottle (Bottle Number)
depth (m)
dissolved_organic_carbon (DOC, micromoles L-1)
event (Event Number)
notes


Dissolved oxygen of discrete water column samples at selected depths collected aboard Palmer LTER annual cruises off the coast of the Western Antarctic Peninsula, 1993, 2012.

Summary:
Dissolved oxygen of discrete water column samples at selected depths collected aboard Palmer LTER annual cruises off the coast of the Western Antarctic Peninsula, 1993 - 2012. Oxygen is produced by phytoplankton photosynthesis and consumed by respiration of phytoplankton, zooplankton and bacteria. Oxygen also enters and exits the ocean via physical exchange with the atmosphere. Oxygen concentrations in the surface ocean may be supersaturated by photosynthesis and turbulence enhancing air-sea exchange via bubble injection; or undersaturated due to excess respiration. In cases where exchange with the atmosphere is limited, and/or respiration exceeds photosynthesis, oxygen concentration can be reduced to very low levels (hypoxia) or entirely depleted (anoxia). This is uncommon in cold Antarctic Seas where respiration is depressed and oxygen solubility is enhanced by low temperature. Different water masses have characteristic oxygen concentrations which serve as tracers for diagnosing physical mixing and advection. Dissolved oxygen was analyzed by Winkler Titration (see Methods) in Conductivity, Temperature, Depth (CTD)-Rosette bottle samples at all depths sampled until 2012. This measurement was discontinued in 2013. The CTD has duplicate oxygen electrodes that provide continuous vertical profiles of oxygen concentration at all depths on all casts. The vessel also has continuous underway, Optode determination of dissolved oxygen in the surface (ship's intake at 6 meters depth) on all cruises. Finally we now routinely measure net community production by Equilibrator Inlet Mass Spectroscopy (EIMS) on LTER cruises

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
time (seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
depth (m)
event
grid_line
grid_station
bottle
oxygen_concentration (mL L-1)
oxygen_concentration_moles (micromoles L-1)
comments


Inherent optical properties measured at selected water-column depths, collected aboard Palmer LTER Annual cruises off the coast of the Western Antarctic Penninsula, 2009.

Summary:
The Palmer, Antarctica, Long-Term Ecological Research project is a member site of the Long-Term Ecological Research program, a network of sites investigating diverse biomes.  A team of researchers seeks to understand the structure and function of the Western Antarctic Peninsula's marine and terrestrial ecosystems in the context of seasonal-to-interannual atmospheric and sea ice dynamics, as well as long-term climate change. The PAL measurement system (or grid) is designed to study marine and terrestrial food webs consisting principally of diatom primary producers, the dominant herbivore Antarctic krill, and the apex predator Adelie penguin. An attenuated microbial food web is also a focus. PAL studies these ecosystems annually over a regional scale grid of oceanographic stations and seasonally at Palmer Station. \n\nPalmer Station is located on Anvers Island west of the Antarctic Peninula. The peninsula runs perpendicular to a strong climatic gradient between the cold, dry continental regime to the south, characteristic of the Antarctic interior, and the warm, moist, maritime regime to the north. North-south shifts in the gradient give rise to large environmental variability to climate change. Sea ice extent and variability affects ecosystem changes at all trophic levels.  In addition to the long-term field and research activities, information management, graduate student training,  education and outreach are an integral part of the program.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
event
time (seconds since 1970-01-01T00:00:00Z)
grid_line
grid_station
station
latitude (degrees_north)
longitude (degrees_east)
depth (m)
salinity (Sea Water Practical Salinity, 1)
temperature (Sea Water Temperature, degree_C)
conductivity (Sea Water Electrical Conductivity, mS cm-1)
... (24 more variables)


Inherent optical properties measured at selected water-column depths, collected at Palmer Station Antarctica, 2008/2009 field season.

Summary:
The Palmer, Antarctica, Long-Term Ecological Research project is a member site of the Long-Term Ecological Research program, a network of sites investigating diverse biomes.  A team of researchers seeks to understand the structure and function of the Western Antarctic Peninsula's marine and terrestrial ecosystems in the context of seasonal-to-interannual atmospheric and sea ice dynamics, as well as long-term climate change. The PAL measurement system (or grid) is designed to study marine and terrestrial food webs consisting principally of diatom primary producers, the dominant herbivore Antarctic krill, and the apex predator Adelie penguin. An attenuated microbial food web is also a focus. PAL studies these ecosystems annually over a regional scale grid of oceanographic stations and seasonally at Palmer Station. \n\nPalmer Station is located on Anvers Island west of the Antarctic Peninula. The peninsula runs perpendicular to a strong climatic gradient between the cold, dry continental regime to the south, characteristic of the Antarctic interior, and the warm, moist, maritime regime to the north. North-south shifts in the gradient give rise to large environmental variability to climate change. Sea ice extent and variability affects ecosystem changes at all trophic levels.  In addition to the long-term field and research activities, information management, graduate student training,  education and outreach are an integral part of the program.

cdm_data_type = TimeSeries
VARIABLES:
study_name (Study)
event
time (seconds since 1970-01-01T00:00:00Z)
station
latitude (degrees_north)
longitude (degrees_east)
depth (m)
salinity (1)
temperature (degree_C)
conductivity (ms cm-1)
a412 (m-1)
a440 (m-1)
... (22 more variables)


Isotopic signatures of diet provisioned to 15 day old chick Pygoscelis penguins reared along the Palmer Archipelago near Palmer Station, 2007-2009

Summary:
We evaluated regional variation in reproductive isotopic niche among breeding populations of AdÃ©lie (Pygoscelis adeliae), chinstrap (P. antarctica), and gentoo (P. papua) penguins west of the Antarctic Peninsula (AP) to test a hypothesis for sea ice-associated food-web correlates of breeding population change. We rely on signatures of naturally occurring carbon (13C/12C, Î´13C) and nitrogen (15N/14N, Î´15N) stable isotopes (SI) as integrated proxies of penguin trophic foraging and food-web structure. Each season, study nests, where pairs of adults were present, were individually marked and chosen before the onset of egg-laying, and consistently monitored. When study nests were found at the one-egg stage, both adults were captured to obtain blood samples used for molecular sexing and stable isotope analyses, and measurements of structural size and body mass. At the time of capture, each adult penguin was quickly blood sampled (~1 ml) from the brachial vein. After handling, individuals at study nests were further monitored to ensure the pair reached clutch completion, i.e., two eggs. At approximate an average nest age of five and 15 days, offspring from study nests were captured and quickly blood sampled (<= ~500 Âµl for day five chicks, and <= ~1 ml for day 15 chicks) from the tarsus vein using a sterile needle and heparinized capillary tubes for day five chicks, and a sterile 3 ml syringe and heparinized infusion needle for day 15 chicks, again to obtain blood tissue for SI analyses. Study nests were monitored for chick survival to 25 days. At five weeks into chick-rearing, older crÃ¨ched chicks of all three species were captured and quickly blood sampled from study rookeries near Anvers Island. Handling of crÃ¨ched chicks occurred over a one or two day period, which varied seasonally and by species depending on nest initiation dates. AdÃ©lie penguin chicks at Avian Island were sampled on the same day Anvers Island AdÃ©lie penguin chicks were sampled. AdÃ©lie penguin chicks at Charcot Island, sampled during one season only on 25 January 2010, were handled three days after Anvers Island and Avian Island AdÃ©lie penguin chicks were sampled that year, i.e., 22 January 2010. Blood samples from crÃ¨ched chicks (~1 ml) were taken from the brachial vein using a sterile 3 ml syringe and heparinized infusion needle following sampling procedures used for adult penguins to obtain blood tissue for SI analyses. Stable isotope analyses were conducted at the Stable Isotope Facility at the University of California, Davis using an elemental analyzer interfaced with an isotope ratio mass spectrometer

cdm_data_type = Other
VARIABLES:
time (Date Day 15 Chicks Observed, seconds since 1970-01-01T00:00:00Z)
... (11 more variables)


Isotopic signatures of diet provisioned to 5 day old chick Pygoscelis penguins reared along the Palmer Archipelago near Palmer Station, 2007-2009

Summary:
We evaluated regional variation in reproductive isotopic niche among breeding populations of AdÃ©lie (Pygoscelis adeliae), chinstrap (P. antarctica), and gentoo (P. papua) penguins west of the Antarctic Peninsula (AP) to test a hypothesis for sea ice-associated food-web correlates of breeding population change. We rely on signatures of naturally occurring carbon (13C/12C, Î´13C) and nitrogen (15N/14N, Î´15N) stable isotopes (SI) as integrated proxies of penguin trophic foraging and food-web structure. Each season, study nests, where pairs of adults were present, were individually marked and chosen before the onset of egg-laying, and consistently monitored. When study nests were found at the one-egg stage, both adults were captured to obtain blood samples used for molecular sexing and stable isotope analyses, and measurements of structural size and body mass. At the time of capture, each adult penguin was quickly blood sampled (~1 ml) from the brachial vein. After handling, individuals at study nests were further monitored to ensure the pair reached clutch completion, i.e., two eggs. At approximate an average nest age of five and 15 days, offspring from study nests were captured and quickly blood sampled (<= ~500 Âµl for day five chicks, and <= ~1 ml for day 15 chicks) from the tarsus vein using a sterile needle and heparinized capillary tubes for day five chicks, and a sterile 3 ml syringe and heparinized infusion needle for day 15 chicks, again to obtain blood tissue for SI analyses. Study nests were monitored for chick survival to 25 days. At five weeks into chick-rearing, older crÃ¨ched chicks of all three species were captured and quickly blood sampled from study rookeries near Anvers Island. Handling of crÃ¨ched chicks occurred over a one or two day period, which varied seasonally and by species depending on nest initiation dates. AdÃ©lie penguin chicks at Avian Island were sampled on the same day Anvers Island AdÃ©lie penguin chicks were sampled. AdÃ©lie penguin chicks at Charcot Island, sampled during one season only on 25 January 2010, were handled three days after Anvers Island and Avian Island AdÃ©lie penguin chicks were sampled that year, i.e., 22 January 2010. Blood samples from crÃ¨ched chicks (~1 ml) were taken from the brachial vein using a sterile 3 ml syringe and heparinized infusion needle following sampling procedures used for adult penguins to obtain blood tissue for SI analyses. Stable isotope analyses were conducted at the Stable Isotope Facility at the University of California, Davis using an elemental analyzer interfaced with an isotope ratio mass spectrometer

cdm_data_type = Other
VARIABLES:
time (Date Day 5 Chicks Observed, seconds since 1970-01-01T00:00:00Z)
... (11 more variables)


Isotopic signatures of diet provisioned to 5 week old chick Pygoscelis penguins reared along the western Antarctic Peninsula, 2007-2009

Summary:
We evaluated regional variation in reproductive isotopic niche among breeding populations of AdÃ©lie (Pygoscelis adeliae), chinstrap (P. antarctica), and gentoo (P. papua) penguins west of the Antarctic Peninsula (AP) to test a hypothesis for sea ice-associated food-web correlates of breeding population change. We rely on signatures of naturally occurring carbon (13C/12C, Î´13C) and nitrogen (15N/14N, Î´15N) stable isotopes (SI) as integrated proxies of penguin trophic foraging and food-web structure. Each season, study nests, where pairs of adults were present, were individually marked and chosen before the onset of egg-laying, and consistently monitored. When study nests were found at the one-egg stage, both adults were captured to obtain blood samples used for molecular sexing and stable isotope analyses, and measurements of structural size and body mass. At the time of capture, each adult penguin was quickly blood sampled (~1 ml) from the brachial vein. After handling, individuals at study nests were further monitored to ensure the pair reached clutch completion, i.e., two eggs. At approximate an average nest age of five and 15 days, offspring from study nests were captured and quickly blood sampled (<= ~500 Âµl for day five chicks, and <= ~1 ml for day 15 chicks) from the tarsus vein using a sterile needle and heparinized capillary tubes for day five chicks, and a sterile 3 ml syringe and heparinized infusion needle for day 15 chicks, again to obtain blood tissue for SI analyses. Study nests were monitored for chick survival to 25 days. At five weeks into chick-rearing, older crÃ¨ched chicks of all three species were captured and quickly blood sampled from study rookeries near Anvers Island. Handling of crÃ¨ched chicks occurred over a one or two day period, which varied seasonally and by species depending on nest initiation dates. AdÃ©lie penguin chicks at Avian Island were sampled on the same day Anvers Island AdÃ©lie penguin chicks were sampled. AdÃ©lie penguin chicks at Charcot Island, sampled during one season only on 25 January 2010, were handled three days after Anvers Island and Avian Island AdÃ©lie penguin chicks were sampled that year, i.e., 22 January 2010. Blood samples from crÃ¨ched chicks (~1 ml) were taken from the brachial vein using a sterile 3 ml syringe and heparinized infusion needle following sampling procedures used for adult penguins to obtain blood tissue for SI analyses. Stable isotope analyses were conducted at the Stable Isotope Facility at the University of California, Davis using an elemental analyzer interfaced with an isotope ratio mass spectrometer

cdm_data_type = Other
VARIABLES:
time (Date Week 5 Chicks Observed, seconds since 1970-01-01T00:00:00Z)
... (11 more variables)


Isotopic signatures of foraging among adult Pygoscelis penguins nesting along the Palmer Archipelago near Palmer Station, 2007-2009

Summary:
We evaluated regional variation in reproductive isotopic niche among breeding populations of AdÃ©lie (Pygoscelis adeliae), chinstrap (P. antarctica), and gentoo (P. papua) penguins west of the Antarctic Peninsula (AP) to test a hypothesis for sea ice-associated food-web correlates of breeding population change. We rely on signatures of naturally occurring carbon (13C/12C, Î´13C) and nitrogen (15N/14N, Î´15N) stable isotopes (SI) as integrated proxies of penguin trophic foraging and food-web structure. Each season, study nests, where pairs of adults were present, were individually marked and chosen before the onset of egg-laying, and consistently monitored. When study nests were found at the one-egg stage, both adults were captured to obtain blood samples used for molecular sexing and stable isotope analyses, and measurements of structural size and body mass. At the time of capture, each adult penguin was quickly blood sampled (~1 ml) from the brachial vein. After handling, individuals at study nests were further monitored to ensure the pair reached clutch completion, i.e., two eggs. At approximate an average nest age of five and 15 days, offspring from study nests were captured and quickly blood sampled (<= ~500 Âµl for day five chicks, and <= ~1 ml for day 15 chicks) from the tarsus vein using a sterile needle and heparinized capillary tubes for day five chicks, and a sterile 3 ml syringe and heparinized infusion needle for day 15 chicks, again to obtain blood tissue for SI analyses. Study nests were monitored for chick survival to 25 days. At five weeks into chick-rearing, older crÃ¨ched chicks of all three species were captured and quickly blood sampled from study rookeries near Anvers Island. Handling of crÃ¨ched chicks occurred over a one or two day period, which varied seasonally and by species depending on nest initiation dates. AdÃ©lie penguin chicks at Avian Island were sampled on the same day Anvers Island AdÃ©lie penguin chicks were sampled. AdÃ©lie penguin chicks at Charcot Island, sampled during one season only on 25 January 2010, were handled three days after Anvers Island and Avian Island AdÃ©lie penguin chicks were sampled that year, i.e., 22 January 2010. Blood samples from crÃ¨ched chicks (~1 ml) were taken from the brachial vein using a sterile 3 ml syringe and heparinized infusion needle following sampling procedures used for adult penguins to obtain blood tissue for SI analyses. Stable isotope analyses were conducted at the Stable Isotope Facility at the University of California, Davis using an elemental analyzer interfaced with an isotope ratio mass spectrometer

cdm_data_type = Other
VARIABLES:
time (seconds since 1970-01-01T00:00:00Z)
... (12 more variables)


Isotopic signatures of penguin food-web components along the western Antarctic Peninsula, 2009-2011

Summary:
We evaluated regional variation in reproductive isotopic niche among breeding populations of AdÃ©lie (Pygoscelis adeliae), chinstrap (P. antarctica), and gentoo (P. papua) penguins west of the Antarctic Peninsula (AP) to test a hypothesis for sea ice-associated food-web correlates of breeding population change. We rely on signatures of naturally occurring carbon (13C/12C, Î´13C) and nitrogen (15N/14N, Î´15N) stable isotopes (SI) as integrated proxies of penguin trophic foraging and food-web structure. Each season, study nests, where pairs of adults were present, were individually marked and chosen before the onset of egg-laying, and consistently monitored. When study nests were found at the one-egg stage, both adults were captured to obtain blood samples used for molecular sexing and stable isotope analyses, and measurements of structural size and body mass. At the time of capture, each adult penguin was quickly blood sampled (~1 ml) from the brachial vein. After handling, individuals at study nests were further monitored to ensure the pair reached clutch completion, i.e., two eggs. At approximate an average nest age of five and 15 days, offspring from study nests were captured and quickly blood sampled (<= ~500 Âµl for day five chicks, and <= ~1 ml for day 15 chicks) from the tarsus vein using a sterile needle and heparinized capillary tubes for day five chicks, and a sterile 3 ml syringe and heparinized infusion needle for day 15 chicks, again to obtain blood tissue for SI analyses. Study nests were monitored for chick survival to 25 days. At five weeks into chick-rearing, older crÃ¨ched chicks of all three species were captured and quickly blood sampled from study rookeries near Anvers Island. Handling of crÃ¨ched chicks occurred over a one or two day period, which varied seasonally and by species depending on nest initiation dates. AdÃ©lie penguin chicks at Avian Island were sampled on the same day Anvers Island AdÃ©lie penguin chicks were sampled. AdÃ©lie penguin chicks at Charcot Island, sampled during one season only on 25 January 2010, were handled three days after Anvers Island and Avian Island AdÃ©lie penguin chicks were sampled that year, i.e., 22 January 2010. Blood samples from crÃ¨ched chicks (~1 ml) were taken from the brachial vein using a sterile 3 ml syringe and heparinized infusion needle following sampling procedures used for adult penguins to obtain blood tissue for SI analyses. Stable isotope analyses were conducted at the Stable Isotope Facility at the University of California, Davis using an elemental analyzer interfaced with an isotope ratio mass spectrometer

cdm_data_type = Other
VARIABLES:
time (seconds since 1970-01-01T00:00:00Z)
... (16 more variables)


Length of Salpa thompsoni collected with a 2-m, 700-um net towed from surface to 120 m, collected aboard Palmer LTER annual cruises off the coast of the Western Antarctic Peninsula, 2009, 2019.

Summary:
Length of Salpa thompsoni collected with a 2-m, 700-um net towed from surface to 120 m, collected aboard Palmer LTER annual cruises off the coast of the Western Antarctic Peninsula, 2009 - 2019. Salps (Salpa thompsoni) are conspicuous gelatinous zooplankton capable of rapid population increases, enabling them to respond quickly to unpredictable phytoplankton blooms common in the Antarctic.  Body length was measured on salps collected from LTER zooplankton tows along the western Antarctic Peninsula.  Salps have amongst the highest filtration rates of all zooplankton, and package their waste into large, fast sinking fecal pellets.  These pellets provide a mechanism to export carbon fixed in the surface waters into the deep ocean.  Since filtration rates and pellet  size are positively related to the size of a salp, population estimates of grazing and exported carbon can be determined through length data.\n

cdm_data_type = Trajectory
VARIABLES:
cruise_tow_number
cruise_name
event
tow_number
grid_line
grid_station
time (Start Time, seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
end_time (seconds since 1970-01-01T00:00:00Z)
lat_end (Latitude, degrees_north)
lon_end (Longitude, degrees_east)
tow_duration (minutes)
heading (degrees)
speed_over_ground
depth (m)
wind_speed (m s-1)
wind_direction (Wind To Direction, degrees)
... (7 more variables)


Nitrate (15N) Uptake near Palmer Station, 2012-2013

Summary:
Nitrate uptake by the bulk phytoplankton community was determined using tracer (<10%) additions of labeled 15-NO3.  Samples were collected by Go-Flo from 5 depths 0, 5, 10, 20, 65 m and incubated for 24 h at light levels of 100%, 50%, 25%, 10%, and 0% surface irradiance, respectively.

cdm_data_type = Other
VARIABLES:
study_name (Study)
time (seconds since 1970-01-01T00:00:00Z)
station
date (seconds since 1970-01-01T00:00:00Z)
incubation_start_time (seconds since 1970-01-01T00:00:00Z)
depth (m)
incubation_light_level
nitrate (Mole Concentration Of Nitrate In Sea Water, micromoles L-1)
nitrate_uptake (Mole Concentration Of Nitrate In Sea Water, micromoles L-1 day-1)


Nuclear genetic markers used to infer population genetic structure among breeding Adelie penguins from four regional rookeries along the western Antarctic Peninsula, 2008-2011.\n

Summary:
We used nuclear and mitochondrial DNA (mtDNA, data archived in GenBank) markers to better understand historical population genetic structure and gene flow given relatively recent and ongoing reductions in sea ice habitats and changes in numbers of breeding adult Adelie penguins at regional rookeries along the western Antarctic Peninsula. Study nests near Anvers Island, where pairs of adults were present, were individually marked and chosen before the onset of egg-laying, and consistently monitored each season (2008-2009). When study nests were found at the one-egg stage, both adults were captured to obtain blood samples used for population genetic analyses. At the time of capture, each adult penguin was quickly blood sampled (~1 ml) from the brachial vein using a and non-heparinized, sterile 3 ml syringe infusion needle. After handling, individuals at study nests were further monitored to ensure the pair reached clutch completion, i.e., two eggs. AdÃ©lie penguin chicks at Avian Island were sampled over two years (2009-2010), Adelie chicks as Prospect Point were sampled during one year (2011), while chicks at Charcot Island were sampled during two seasons (2010-2011). Blood samples from crÃ¨ched chicks (~1 ml) were taken from the brachial vein using a sterile 3 ml syringe and infusion needle following sampling procedures used for adult penguins. Genetic analyses were conducted at the wildlife genetics laboratory, Alaska Science Center - United States Geological Survey (USGS), under the supervision of geneticist Dr. S.L. Talbot.\n\nData presented here are raw data only and do not include any derived data products. For any meta-analyses with other microsatellite data, proper calibration across labs must be completed. Data were produced at the Alaska Science Center, USGS wildlife genetics laboratory under the supervision of Dr. Sandra Talbot (stalbot@usgs.gov). Questions regarding data or any laboratory cross-validation should be directed to Dr. Kristen Gorman (kgorman@sfu.ca).

cdm_data_type = Other
VARIABLES:
study_name (Study)
sample_number
sample_number_region
species
region
reproductive_stage
individual_id
... (21 more variables)


Palmer (PAL) log of events aboard Palmer LTER cruises off the coast of the Western Antarctic Peninsula (cruise happenings ordered by time) is a meta dataset, including lat-lon, datetime, activity, events, etc, 1991, 2019.

Summary:
Palmer (PAL) log of events aboard Palmer LTER cruises off the coast of the Western Antarctic Peninsula (cruise happenings ordered by time) is a meta dataset, including lat-lon, datetime, activity, events, etc, 1991 - 2019. The event log for the Palmer LTER research cruises provides a mapping of sampling and other research activities to spatial, temporal and other variables. Event numbers are used to coordinate relational indexes and provide users of the data with a high-level index for relating measurements across research components.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
time (seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
event
event_group
cast_number
event_name
grid_station
station
grid_line
calculated_grid_station
comments
notes


Palmer Station VERTEX-style Sediment Trap measurements, 50 m depth, 2012-2013

Summary:
Measurements were made using moored VERTEX-style particle interceptor tube (PIT) sediment traps deployed at a depth of 50-m at stations B and E near Palmer Station between Nov. 2012 and Apr. 2013.  Sediment trap contents was measured to determine fluxes of POC, PN, and Th-234 on two size fractions (>200 and <200 micron).  Note that these are operational size classes and may not directly coincide with the size of aggregates that may have been sinking in the water column.  For more details, please see Stukel et al. (in review, Global Biogeochemical Cycles)..Measurements were made using moored VERTEX-style particle interceptor tube (PIT) sediment traps deployed at a depth of 50-m at stations B and E near Palmer Station between Nov. 2012 and Apr. 2013.  Sediment trap contents was measured to determine fluxes of POC, PN, and Th-234 on two size fractions (>200 and <200 micron).  Note that these are operational size classes and may not directly coincide with the size of aggregates that may have been sinking in the water column.  For more details, please see Stukel et al. (in review, Global Biogeochemical Cycles).

cdm_data_type = Other
VARIABLES:
study_name (Study)
station
time (Deployment Date, seconds since 1970-01-01T00:00:00Z)
recovery_date (seconds since 1970-01-01T00:00:00Z)
poc_flux (mg m-2 day-1)
carbon_flux_std (mg m-2 day-1)
particulate_nitrogen_flux (mg m-2 day-1)
particulate_nitrogen_flux_std (mg m-2 day-1)
organic_carbon_flux_less_than_200 (mg m-2 day-1)
organic_carbon_flux_less_than_200_stdev (mg m-2 day-1)
organic_carbon_flux_greater_than_200 (mg m-2 day-1)
organic_carbon_flux_greater_than_200_stdev (mg m-2 day-1)
nitrogen_flux_less_than_200 (mg m-2 day-1)
nitrogen_flux_less_than_200_stdev (mg m-2 day-1)
nitrogen_flux_greater_than_200 (mg m-2 day-1)
nitrogen_flux_greater_than_200_stdev (mg m-2 day-1)
th234_flux
th234_flux_uncertainty_stdev


Particulate organic carbon and nitrogen measurements from water column sample bottles, collected aboard Palmer LTER annual cruises off the Western Antarctic Peninsula, 1991, 2018. Cruise PD94-01 not included in time series for lack of samples

Summary:
Particulate organic carbon and nitrogen measurements from water column sample bottles, collected aboard Palmer LTER annual cruises off the Western Antarctic Peninsula, 1991 - 2018. Cruise PD94-01 not included in time series for lack of samples. All organisms are composed of organic matter. Organic matter is synthesized from dissolved inorganic carbon (dissolved CO2) and inorganic nutrients by phytoplankton photosynthesis, and consumed (oxidized) by respiration by heterotrophs (zooplankton and bacteria). The organic matter in seawater is a variable mixture of dissolved and particulate organic matter (DOM and Princeton Ocean Model (POM)). Typically DOM predominates over POM by an order of magnitude, but the relative amount of POM can be highly enhanced during large phytoplankton blooms. The principal elemental components of POM include organic carbon (POC), organic nitrogen (PN), there is no particulate inorganic N) and phosphorus (POP). These elements exist in a relatively stable, characteristic ratio of 106:6:1 (C:N:P) in seawater, known as the Redfield Ratio. Marine particulate matter is a complex mixture of live and dead plankton and detritus, and of carbohydrates, proteins, lipids and nucleic acids. POC and PN are enhanced in the euphoric zone, reflecting their origin by photosynthesis. The particulate pool is also a complex assemblage of particles of different sizes, shapes and densities. A simplified scheme divides the particles into large, rapidly sinking particles (10s - 100s of meters per day) and smaller, suspended particles. The transition between small particles and dissolved organic matter is typically specified by filtration through GF/F filters. POC and PN are analyzed for samples in the upper 100 meters on all regular grid samples.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
time (seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
depth (m)
grid_line
station (u2)
cast_number
bottle
... (5 more variables)


Photosynthesis-irradiance measurements collected during Palmer LTER station seasons at Palmer Station Antarctica, 1991, 1993.

Summary:
Photosynthesis-irradiance measurements collected during Palmer LTER station seasons at Palmer Station Antarctica, 1991 - 1993. Photosynthesis-irradiance measurements are used to derive P-I relationships and to calculate primary production for each discrete sample. Blue-green photosynthetron method described by Prezelin et al. (1994) were used to determine photosynthesis irradiance (P-I) relationships for collected samples. Non-linear cureve fits for the P-I data were calculated using the simplex method of Caceci & Cacheris (1984). Curve fitting provided estimates of Pmax (the light saturated rate of photosynthesis) and alpha (the affinity for photosynthesis at light-limited irradiances.

cdm_data_type = TimeSeries
VARIABLES:
study_name (Study)
event
time (seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
depth (m)
station
julian_day
bottle
chlorophyll_a (Mass Concentration Of Chlorophyll A In Sea Water, mg m-3)
incubation_hours (hours)
in_situ_temperature (degree_C)
incubation_temperature (degree_C)
pmax (mg m-3 hour-1)
alpha
beta
Ik (microeinstiens m-2 s-1)
It (microeinstiens m-2 s-1)
pmax_error (mg m-3 hour-1)
alpha_error
... (4 more variables)


Photosynthesis-irradiance measurements used to derive P-I relationships and to calculate primary production for each discrete sample. Samples collected aboard Palmer LTER annual cruises off the coast of the Western Antarctic Peninsula, 1991, 1993.

Summary:
Photosynthesis-irradiance measurements used to derive P-I relationships and to calculate primary production for each discrete sample. Samples collected aboard Palmer LTER annual cruises off the coast of the Western Antarctic Peninsula, 1991 - 1993. Photosynthesis-irradiance measurements are used to derive P-I relationships and to calculate primary production for each discrete sample. Blue-green photosynthetron method described by Prezelin et al. (1994) were used to determine photosynthesis irradiance (P-I) relationships for collected samples. Non-linear cureve fits for the P-I data were calculated using the simplex method of Caceci & Cacheris (1984). Curve fitting provided estimates of Pmax (the light saturated rate of photosynthesis) and alpha (the affinity for photosynthesis at light-limited irradiances.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
time (seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
event (Event Number)
julian_day
incubation_start_time (seconds since 1970-01-01T00:00:00Z)
grid_station
station
grid_line
bottle (Bottle Number)
depth (m)
chlorophyll_a (mg m-3)
incubation_hours (Incubation Hrs, hours)
in_situ_temperature (In Situ Water Temperature, degree_C)
incubation_temperature (Incubation Water Temperature, degree_C)
pmax (mg m-3 hour-1)
alpha
beta (percent)
... (8 more variables)


Photosynthetic pigments of water column samples analyzed using High Performance Liquid Chromatography (HPLC), sampled during the Palmer LTER field seasons at Palmer Station, Antarctica, 1991 - 2015.

Summary:
Phytoplankton pigment sampling was led by Prezelin from the 1991-1992 season through the 1993-1994 season, and then by Vernet from the 1994-1995 season through the 2006-2007 season. Schofield is the third, and current lead, beginning in the 2008-2009 season. Methods have been kept consistent as much as possible over the full time series and different Principal Investigators. Phytoplankton have a suite of accessory pigments in addition to Chlorophyll a, including other Chlorophyll's (e.g. Chlorophyll b), Xanthophylls, and Carotenes. These accessory pigments can be used as chemotaxonomic markers to assess the composition and distribution of the phytoplankton community. For example, Fucoxanthin is a marker pigment of Diatoms, whereas Alloxanthin is a marker pigment of Cryptophytes. Accessory pigments also assist in photoacclimation and photoprotective processes. Water samples are collected throughout the water column at stations within the Palmer LTER region (primarily B and E, to 50m and 65m respectively). Water samples are filtered onto GF/F filters, and filters kept frozen at -80C until analysis. HPLC analysis is completed following Wright et al (1991). Following the guidelines set by NASA SeaHARRE, we use an internal standard and replicate injects on the HPLC to track recovery and replicability of the pigment extraction methods. Data is unavailable for the Palmer 2009-2010 season due to instrumentation problems and for the Palmer 2011-2012 season due to a freezer failure which resulted in the loss of samples. \n

cdm_data_type = TimeSeries
VARIABLES:
study_name (Study)
time (seconds since 1970-01-01T00:00:00Z)
depth (m)
latitude (degrees_north)
longitude (degrees_east)
event
julian_day
station
irradiance (percent)
chlorophyllide_a (Concentration Of Chlorophyll In Sea Water, ug L-1)
chlorophyll_c3 (Concentration Of Chlorophyll In Sea Water, ug L-1)
chlorophyll_c2 (Concentration Of Chlorophyll In Sea Water, ug L-1)
... (25 more variables)


Photosynthetic pigments of water column samples and analyzed with High Performance Liquid Chromatography (HPLC), collected aboard Palmer LTER annual cruises off the coast of the Western Antarctica Peninsula, 1991, 2016.

Summary:
Photosynthetic pigments of water column samples and analyzed with High Performance Liquid Chromatography (HPLC), collected aboard Palmer LTER annual cruises off the coast of the Western Antarctica Peninsula, 1991 - 2016. Phytoplankton pigment sampling was led by Prezelin from 1991-1994, and then by Vernet from 1995-2008. Schofield is the third, and current lead, beginning in 2009. Methods have been kept consistent as much as possible over the full time series and different Principal Investigators. Phytoplankton have a suite of accessory pigments in addition to Chlorophyll a, including other Chlorophyll's (e.g. Chlorophyll b), Xanthophylls, and Carotenes. These accessory pigments can be used as chemotaxonomic markers to assess the composition and distribution of the phytoplankton community. For example, Fucoxanthin is a marker pigment of Diatoms, whereas Alloxanthin is a marker pigment of Cryptophytes. Accessory pigments also assist in photoacclimation and photoprotective processes. Water samples are collected throughout the water column along the Western Antarctic Peninsula at regular LTER grid stations where Conductivity, Temperature, Depth (CTD) casts are preformed and in surface waters at underway stations, where CTD casts are not done, using the ship's flow-through seawater system. Water samples are filtered onto GF/F filters, and filters kept frozen at -80C until analysis. HPLC analysis is completed following Wright et al (1991). Following the guidelines set by NASA SeaHARRE, we use an internal standard and replicate injects on the HPLC to track recovery and replicability of the pigment extraction methods and the HPLC. Data is unavailable for the LMG10-01 cruise due to instrumentation problems and for the LMG12-01 cruise due to a freezer failure which resulted in the loss of samples.

cdm_data_type = Trajectory
VARIABLES:
study_name (Study)
event
cast_number
bottle
time (seconds since 1970-01-01T00:00:00Z)
latitude (degrees_north)
longitude (degrees_east)
depth (m)
grid_line
... (29 more variables)


Sediment trap in nearshore waters collected during Palmer LTER station season at Palmer Station Antarctica, 1992, 1995.

Summary:
Sediment trap in nearshore waters collected during Palmer LTER station season at Palmer Station Antarctica, 1992 - 1995. Particulate organic matter is exported from the upper ocean euphotic zone in the form of large sinking particles and as dissolved material. Particle fluxes to depth link the surface and mesopelagic realm and supply food to the benthos. Sedimentation flux is typically measured with sediment traps of various designs. Sedimentation at the PAL site of the West Antarctic Peninsula demonstrates extreme seasonality, with a well-defined pulse in the Austral summer following sea ice retreat.

cdm_data_type = Other
VARIABLES:
study_name (Study)
experiment_name
time (Start Date, seconds since 1970-01-01T00:00:00Z)
end_date (seconds since 1970-01-01T00:00:00Z)
trap_id
cup_number
duration (days)
biomass (mg)
volume_filtered (mL)
total_mass (mg)
biomass_flux (mg m-2 day-1)
biomass_flux_mean (mg m-2 day-1)