| Contributors | Affiliation | Role |
|---|---|---|
| Yager, Patricia L. | University of Georgia (UGA) | Principal Investigator, Contact |
| Stammerjohn, Sharon E. | University of Colorado (UCo - INSTAAR) | Co-Principal Investigator |
| Mu, Linquan | University of Georgia (UGA) | Contact |
| Gegg, Stephen R. | Woods Hole Oceanographic Institution (WHOI BCO-DMO) | BCO-DMO Data Manager |
Underway shipboard data from uncontaminated seawater flowing continuously from intake at 5 m depth. Includes pCO2, dissolved oxygen, chlorophyll fluorescence, temperature, salinity, and wind speed data from the USAP RV Nathaniel B. Palmer during austral summer 2010-11 as it sampled the Amundsen Sea Polynya during the Amundsen Sea Polynya International Research Expedition.
Initial pCO2 data was processed at Lamont Doherty Earth Observatory and quality controlled according to Sutherland et al. (2011). We merged this data with the ship’s underway data stream and the underway oxygen optode data (see manuscript), and then removed observations during heavy sea ice conditions. Please see the attached manuscript for all equations and assumptions used in the calculations.
See: Spatial variability of surface pCO2 and air-sea CO2 flux in the Amundsen Sea Polynya, Antarctica
BCO-DMO Processing Notes
- Generated from MGDS:jgofs files dowloaded from MGDS data for NBP1005
- Awk routine generated to reformat original files into BCO-DMO servable file format
- Awk routine: "MGDS_Underway_jgofs_2_BCO-DMO.awk"
- Parameter names generated from: JGOFSDataFormat.pdf
- Parameter names edited to conform to BCO-DMO naming convention found at Choosing Parameter Name
- Date reformatted from DD-MM-YY to YYYYMMDD
- Time reformatted from HH:MM:SS to HHMMSS
- Records with Lat/Lon values of "NAN" deleted
- Tab separated data converted to comma separated data
| File |
|---|
Underway_Mu_etal.csv (Comma Separated Values (.csv), 1.01 MB) MD5:15347f6d5bcd85c07eb689f64e9e2288 Primary data file for dataset ID 540038 |
| Parameter | Description | Units |
| Julian_day | GMT time starting from January 1 2010 (day 1). E.g. December 31 2010 – day 365 and January 1 2011 – day 366. Hours and minutes are converted to decimal fractions of a day. | day |
| Latitude | Latitude (South is negative) | decimal degrees |
| Longitude | Longitude (West is negative) | decimal degrees |
| SST | abbreviation for Sea Surface Temperature in degrees C | deg C |
| Temp_eq | Temperature in the underway CO2 equilibrator where pCO2 is measured. Used to correct measured value back to SST. | deg C |
| SSS | abbreviation for Sea Surface Salinity (no units) | no units |
| density | sea surface density (kg L-1) | kg L−1 |
| sigma_theta | (Density – 1) x 1000 (unitless) | no units |
| Sc | Schmidt number – a parameter related to gas transfer velocity calculation (no units) (Wanninkhof 1992) | no units |
| Chl_a | sea surface chlorophyll a fluorescence (relative units) | relative units |
| ln_Beta | CO2 solubility (Weiss 1974) | no units |
| Beta_Ko | CO2 solubility (Weiss 1974) | mol kg−1 atm−1 |
| Wind | shipboard wind speed at 25 m height | m s−1 |
| Wind_cor | wind speed corrected to 10 m height | m s−1 |
| Wind_avr | cruise-averaged wind speed at 10 m height | m s−1 |
| k | CO2 gas transfer velocity (cm hr-1) | cm hr−1 |
| P_eq | atmospheric pressure inside of CO2 analyzer (kPa) | kPa |
| pCO2_w | partial pressure of CO2 in surface seawater (uatm) | uatm |
| pCO2_a | partial pressure of CO2 in atmosphere (uatm) | uatm |
| Delta_pCO2 | air-sea pCO2 gradient = pCO2(w) − pCO2(a) (uatm) | uatm |
| CO2_sat | saturation state for CO2 (%) | percentage |
| DO | dissolved oxygen concentration in the surface seawater (umol L-1) | umol L−1 |
| Cstar_DO | DO solubility (concentration in equilibrium with the atmosphere) | umol L−1 |
| DO_sat | saturation state for DO (%) | percentage |
| Flux | air-sea CO2 flux (mmol C m-2 d-1) | mmol C m−2 d−1 |
| Dataset-specific Instrument Name | GPS |
| Generic Instrument Name | Global Positioning System Receiver |
| Dataset-specific Description | This data set was acquired with a ship-based Navigation system |
| Generic Instrument Description | The Global Positioning System (GPS) is a U.S. space-based radionavigation system that provides reliable positioning, navigation, and timing services to civilian users on a continuous worldwide basis. The U.S. Air Force develops, maintains, and operates the space and control segments of the NAVSTAR GPS transmitter system. Ships use a variety of receivers (e.g. Trimble and Ashtech) to interpret the GPS signal and determine accurate latitude and longitude. |
| Dataset-specific Instrument Name | RVIB Nathaniel B. Palmer Underway Sampling Systems |
| Generic Instrument Name | Shipboard Surface Mapping System |
| Dataset-specific Description | RVIB Nathaniel B. Palmer Underway Sampling Systems |
| Generic Instrument Description | Surface Mapping System (SMS): The SMS records navigation, meteorological and sea surface data every 10 seconds. |
| Website | |
| Platform | RVIB Nathaniel B. Palmer |
| Start Date | 2010-11-26 |
| End Date | 2011-01-16 |
| Description | Expedition by the USAP RV Nathaniel B. Palmer during austral summer 2010-11 to sampled the Amundsen Sea Polynya during the Amundsen Sea Polynya International Research Expedition (ASPIRE). Also identified as OSO 2010-11 (Oden Southern Ocean – two vessel operation 2010-11)
The US Research Icebreaker Nathaniel B. Palmer was joined by the Swedish Icebreaker Oden for a two-vessel expedition to the Amundsen Sea. Scientists on the Palmer focused on understanding the climate-sensitive dynamics of the open water region, known as a "polynya." Oden scientists investigated the sea ice ecosystem nearby. The aim of both groups was to improve our understanding of how climate change will impact this important ecosystem.
Note R2R Link takes user to Marine Geoscience Data System (MGDS):
NBP1005
NBP1005A
Data at MGDS were available as NBP1005 and NBP1005A. The data are from the same expedition and are combined in BCO-DMO into the one deployment - NBP1005.
Nathaniel B. Palmer Systems and Specifications |
The Amundsen Sea Polynya is areally the most productive Antarctic polynya, exhibits higher chlorophyll levels during peak bloom and greater interannual variability than the better-studied Ross Sea Polynya ecosystem. Polynyas may be the key to understanding the future of polar regions as their extent is expected to increase with anthropogenic warming. The project will examine 1) sources of iron to the Amundsen Sea Polynya as a function of climate forcing, 2) phytoplankton community structure in relation to iron supply and mixed-layer depths, 3) the efficiency of the biological pump of carbon to depth and 4) the net flux of carbon as a function of climate and micronutrient forcing. The research also will compare results for the Amundsen Sea to existing data synthesis and modeling efforts for the Palmer LTER and Ross Sea. The project will 1) build close scientific collaborations between US and Swedish researchers; 2) investigate climate change implications with broad societal relevance; 3) train new researchers; 4) encourage participation in research science by underrepresented groups, and 5) involve broad dissemination of results via scientific literature and public outreach, including close interactions with NSF-supported PolarTrec and COSEE K-12 teachers.
This project brings together experienced US and Swedish investigators (trace metal and carbon chemists, phytoplankton physiologists, microbial and zooplankton ecologists, and physical oceanographers) to investigate climate controls on carbon dioxide uptake by one of the most productive ecosystems in the Antarctic.
The Amundsen Sea Polynya is the most productive Antarctic polynya per square meter, and exhibits higher chlorophyll levels during peak bloom and greater interannual variability than the better-studied Ross Sea polynya ecosystem to the west.
Polynyas, or recurring areas of seasonally open water surrounded by ice, are foci for energy and material transfer between the atmosphere, polar surface ocean and deep sea. Most help take up large amounts of carbon dioxide from the atmosphere.
These polar ecosystems are characterized by high biological productivity and intense biogeochemical cycling - a bit like an oasis. Polynyas may be the key to understanding the future of polar regions since their extent is expected to increase with anthropogenic warming. On the other hand, if seasonal sea ice disappears completely, the unique nature of polynyas may also be lost.
Regional reductions or growth in sea-ice over the past decade have been extensive and are coupled to climate-sensitive global cycles such as ENSO and the Southern Annular Mode. Without many historical measurements, this regional and interannual variability is our best present-day indication for what controls or “forces” these critical polar ecosystems and their sensitivity to future change.
Variability in the productivity of Antarctic polynyas is high for reasons the science community do not currently understand. The supply of trace metals such as iron is thought to determine phytoplankton community structure and production in the Southern Ocean, particularly in conjunction with mixed-layer depth controls on light limitation. A key question is whether interannual variability is driven by these two climate-sensitive factors, and whether we can expect climate-sensitive shifts in ecosystem function and carbon flux in the future. Understanding critical feedbacks between climate and the marine biosphere becomes increasingly urgent as we project rates of change into the future.
| Funding Source | Award |
|---|---|
| NSF Antarctic Sciences (NSF ANT) | |
| NSF Antarctic Sciences (NSF ANT) |