| Contributors | Affiliation | Role |
|---|---|---|
| Babbin, Andrew R. | Massachusetts Institute of Technology (MIT) | Principal Investigator, Contact |
| Casciotti, Karen L. | Stanford University | Principal Investigator |
| Woosley, Ryan | Massachusetts Institute of Technology (MIT) | Co-Principal Investigator |
| Soenen, Karen | Woods Hole Oceanographic Institution (WHOI BCO-DMO) | BCO-DMO Data Manager |
The samples were taken using a 24-bottle CTD rosette with 12L bottles. Depths varied per station but were focused in the upper 1000m. 19 stations were sampled with 22 casts total.
Samples were drawn in order: pH, alkalinity, NH4, nutrients (NOx, PO4, NO2). pH, NH4, PO4, NO2 were measured within 3 hours of collection onboard. NOx were filtered (0.22um Sterivex) and frozen. NOx is generally a mean of 3 measurements. Alkalinity were poisoned with a saturated HgCl2 solution and preserved in 160mL crimped serum bottles.
The samples were analysed using the following instruments:
BCO-DMO processing notes:
| File |
|---|
bottle_data.csv (Comma Separated Values (.csv), 111.47 KB) MD5:fadd5e6bf1f6ff7cc17732b5162ab9ad Primary data file for dataset ID 832389 |
| Parameter | Description | Units |
| CRUISEID | cruide identifier | unitless |
| EXPOCODE | cruise EXPO code | unitless |
| STNNBR | station number | unitless |
| CASTNO | cast number | unitless |
| SAMPNO | sample number | unitless |
| DATE | sampling date in pacific daylight time (PDT), format:dd-mm-yyy | unitless |
| TIME | time in pacific daylight time (PDT), format: hh:mm:ss | unitless |
| LATITUDE | latitude, south is negative | decimal degrees |
| LONGITUDE | longitude, west is negative | decimal degrees |
| BOTTOM_DEPTH | bottom depth of ocean | meters (m) |
| CTDPRS | CTD pressure | decibar (dbar) |
| CTDTMP | CTD temperature, International Temperature Scale of 1990 (ITS-90) | degrees Celsius (°C) |
| CTDSAL | CTD salinity, Practical Salinity Scale - 1978 | PSU |
| CTDS_FLAG_W | CTD salinity flag. WOCE standard, with 2 = good, 3 = questionable, 6 = mean of replicates, 9 = sample not drawn | unitless |
| CTDOXY | CTD oxygen | micromoles per liters (umol/l) |
| CTDOXY_FLAG_W | oxygen flag. WOCE standard, with 2 = good, 3 = questionable, 6 = mean of replicates, 9 = sample not drawn | unitless |
| FLOR | calibrated fluoresence from CTD | micrograms per liters (ug/l) |
| FLOR_FLAG_W | fluoresence flag. WOCE standard, with 2 = good, 3 = questionable, 6 = mean of replicates, 9 = sample not drawn. | unitless |
| NOx | nitrate + nitrite | micromoles per liters (umol/l) |
| NOx_FLAG_W | total NOx flag. WOCE standard, with 2 = good, 3 = questionable, 6 = mean of replicates, 9 = sample not drawn. | unitless |
| NOx_stdev | standard deviation of NOx | micromoles per liters (umol/l) |
| NOx_STD_FLAG_W | flag. WOCE standard, with 2 = good, 3 = questionable, 6 = mean of replicates, 9 = sample not drawn. | unitless |
| NITRIT_BabLab | nitrite | micromoles per liters (umol/l) |
| NITRIT_FLAG_W | nitrite flag. WOCE standard, with 2 = good, 3 = questionable, 6 = mean of replicates, 9 = sample not drawn. | unitless |
| PHSPHT | phosphate | micromoles per liters (umol/l) |
| PHSPHT_FLAG_W | phosphate flag. WOCE standard, with 2 = good, 3 = questionable, 6 = mean of replicates, 9 = sample not drawn. | unitless |
| NH4 | ammonium | micromoles per liters (umol/l) |
| NH4_FLAG_W | ammonium flag. WOCE standard, with 2 = good, 3 = questionable, 6 = mean of replicates, 9 = sample not drawn. | unitless |
| PH_TOT | pH on the total scale at 25C | unitless |
| PH_TOT_FLAG_W | pH flag | unitless |
| PH_TEMP | temperature of pH measurements | degrees Celsius (°C) |
| TA | total alkalinity | micromoles per kilograms (umol/kg) |
| TA_FLAG_W | total alkalinity flag. WOCE standard, with 2 = good, 3 = questionable, 6 = mean of replicates, 9 = sample not drawn. | unitless |
| ISO_DateTime_UTC | Date and time of sample and data collection in UTC, standard ISO format (yyyy-mm-ddThh:mmZ) | unitless |
| Dataset-specific Instrument Name | Custom total alkalinity titrator |
| Generic Instrument Name | Automatic titrator |
| Dataset-specific Description | Custom total alkalinity titrator built by the lab of Andrew Dickson, UCSD-Scripps |
| Generic Instrument Description | Instruments that incrementally add quantified aliquots of a reagent to a sample until the end-point of a chemical reaction is reached. |
| Dataset-specific Instrument Name | Teledyne T200 NOx analyzer |
| Generic Instrument Name | Chemiluminescence NOx Analyzer |
| Dataset-specific Description | NOx: Teledyne T200 NOx analyzer with custom front end for vanadium reduction. |
| Generic Instrument Description | The chemiluminescence method for gas analysis of oxides of nitrogen relies on the measurement of light produced by the gas-phase titration of nitric oxide and ozone. A chemiluminescence analyzer can measure the concentration of NO/NO2/NOX.
One example is the Teledyne Model T200: https://www.teledyne-api.com/products/nitrogen-compound-instruments/t200 |
| Dataset-specific Instrument Name | Ocean Optics QEPRO spectrophotometer |
| Generic Instrument Name | Spectrophotometer |
| Dataset-specific Description | NO2, PO4: Ocean Optics QEPRO spectrophotometer with 10cm Starna flow through quartz cell |
| Generic Instrument Description | An instrument used to measure the relative absorption of electromagnetic radiation of different wavelengths in the near infra-red, visible and ultraviolet wavebands by samples. |
| Dataset-specific Instrument Name | Agilent 8454 spectrophotometer |
| Generic Instrument Name | Spectrophotometer |
| Dataset-specific Description | pH: Agilent 8454 spectrophotometer with custom front end for automated syringe injection |
| Generic Instrument Description | An instrument used to measure the relative absorption of electromagnetic radiation of different wavelengths in the near infra-red, visible and ultraviolet wavebands by samples. |
| Website | |
| Platform | R/V Falkor |
| Start Date | 2018-06-24 |
| End Date | 2018-07-15 |
Phytoplankton form the base of the marine food web. These microscopic, single-celled organisms float in seawater, taking in carbon dioxide and using light energy to make carbohydrates. Like land plants, phytoplankton need other elements and compounds (fertilizer) to perform photosynthesis in order to survive and thrive: Nitrogen is one of these key ingredients for phytoplankton growth.
Nitrogen is fascinating and somewhat unique because it cycles through many oxygenation states. This means that there is plenty of energy for organisms to harness and the nitrogen cycle can be used as a lens to understand microbial communities. The quantity of “fixed nitrogen” in the ocean, usually nitrate (NO3–) and ammonium (NH4+), is critical for the existence and development of phytoplankton, and plays a role in the biological carbon pump sequestering carbon dioxide from the atmosphere.
Being able to recognize the role of fixed nitrogen in ocean processes is important for understanding low-oxygen areas in the world’s oceans. Insight into microbial interactions in oxygen deficient waters will allow researchers to better predict the marine response to increased nutrient runoff, eutrophication, and hypoxia – all of which currently threaten the livelihoods of many coastal communities as a warming climate leads to the expansion of low oxygen “dead” zones.
Data Management Plan: The resulting shipboard dataset is being archived at Rolling Deck to Repository and is now available. ADCP data is curated and processed by University of Hawaii.Iodine Speciation measurements are archived in BCO-DMO
| Funding Source | Award |
|---|---|
| Schmidt Ocean Institute (SOI) |