Contributors | Affiliation | Role |
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Roberts, Brian | Louisiana Universities Marine Consortium (LUMCON) | Principal Investigator |
Rauch, Shannon | Woods Hole Oceanographic Institution (WHOI BCO-DMO) | BCO-DMO Data Manager |
Usage note: Time zone information was not received by BCO-DMO so it is unknown if the dates and times in this dataset are local or UTC. Please contact the dataset PI if you have questions about this.
Conductivity, Temperature and Depth (CTD) data and water samples were collected at various depths across 102 stations (total n = 471) in the Gulf of Mexico on the R/V Pelican between September 28, 2017 and September 19, 2017. At all stations, a vertical profile of salinity, dissolved oxygen concentration and temperature was collected using a Seabird SBE 911 CTD instrument package mounted onto a rosette containing 12, 5L Niskin bottles for collecting aqueous samples at specific depths. Water samples were collected using a single Niskin bottle per depth and were analyzed across various analytical instruments for nutrient concentrations.
Water samples were collected using a single Niskin bottle per depth on the CTD rosette. Samples for dissolved inorganic nutrients and dissolved organic carbon / total nitrogen were analyzed following the methods detailed in Roberts and Doty (2015) and Mason et al. (2016). Specifically, one niskin bottle, water samples for dissolved inorganic nutrients (NO₃⁻ + NO₂⁻, NO₂⁻, PO₄³−, SiO₂, and NH₄⁺) were analyzed in duplicate using a Lachat Instruments QuikChem FIA+ 8000 Series Automated Ion Analyzer with an ASX-400 Series XYZ autosampler after being filtered through acid-cleaned (10% HCl), 47 mm diameter, 0.2 µm pore size, membrane filters (Pall SuporR-200) under low vacuum pressure. Samples were analyzed for dissolved NO₃⁻ + NO₂⁻ (by Cu-Cd reduction followed by azo dye colorimetry), PO₄³− (by the automated ascorbic acid reduction method), SiO₂⁻, and dissolved NH₄⁺ (by phenate colorimetry) (APHA, 1992). Dissolved NO₂⁻ was determined separately by azo dye colorimetry (without Cu−Cd reduction). Standard curves were prepared using certified standard stock solutions (Hach, Loveland CO) and yielded r² values of ≥ 0.999. NO₃⁻ concentration was determined by difference between NO₃⁻ + NO₂⁻ and NO₂⁻.
Dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) concentrations were measured at least in triplicate on a Shimadzu TOC-VCSH Analyzer with TNM-1 Module (MDL 1.5 μmol C L−1, 0.3 μmol N L−1; Shimadzu Scientific Instruments, Columbia, MD) after being filtered through combusted (450°C), 47mm diameter Whatman GF/F filters under low vacuum pressure. Concentrations of dissolved organic nitrogen (DON) were determined by difference [DON=TDN−DIN].
All water chemistry data went through quality control checks. CTD instrument probes were calibrated prior to cruise departure.
CTD data were processed on Seabird's SBEDataProcessing-Win32.
BCO-DMO Processing:
- renamed fields to conform with BCO-DMO naming conventions.
File |
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oct_2017_discrete.csv (Comma Separated Values (.csv), 84.75 KB) MD5:a0375b3277142da3bac9d75e353fb128 Primary data file for dataset ID 844721 |
Parameter | Description | Units |
Cruise | Cruise identification | unitless |
Type | Type of cast (CTD) | unitless |
DateTime | Date and time of sample collection | unitless |
Date | Date of sample collection | unitless |
Time | Time of sample collection | unitless |
Station | Location of sample collection | unitless |
Bottle_Depth | Depth of the sample bottle at collection | meters (m) |
Longitude | Longitude, west is negative | decimal degrees North |
Latitude | Latitude, south is negative | decimal degrees East |
Seafloor_Depth | Depth of seafloor below water surface | meters (m) |
Bottle | Bottle number on the CTD | unitless |
Depth | Depth of CTD at sample collection | meters (m) |
Temperature | CTD water temperature in degrees Celsius | degrees C |
Salinity | CTD salinity in practical salinity units (PSU) | PSU |
OxygenSBE | CTD dissolved oxygen concentration | micromoles per kilogram (umol/kg) |
wetCDOM | wet colored dissolved organic matter concentration | milligrams per cubic meter (mg/m^3) |
SPAR | surface photosynthetically active radiation | micromoles photons per square meter per second (umol/m2/s) |
PAR | Photosynthetically active radiation | micromoles photons per square meter per second (umol/m2/s) |
Turbidity | CTD turbidity in Formazin Turbidity Units (FTU) | FTU |
NO3_NO2 | Sample nitrate and nitrite concentration | micromoles per liter (umol N/L) |
NO2 | Sample nitrate concentration | micromoles per liter (umol N/L) |
NO3_calculated | Calculated sample nitrate concentration | micromoles per liter (umol N/L) |
NH4 | Sample ammonium concentration | micromoles per liter (umol N/L) |
DIN_calculated | Calculated dissolved inorganic nitrogen concentration | micromoles per liter (umol N/L) |
PO4 | Sample phosphate concentration | micromoles per liter (umol P/L) |
SiO2 | Sample silicate concentration | micromoles per liter (umol Si/L) |
DOC | Sample dissolved organic carbon concentration | micromoles per liter (umol C/L) |
TDN | Sample total dissolved nitrogen concentration | micromoles per liter (umol N/L) |
DON_calculated | Calculated dissolved organic nitrogen concentration | micromoles per liter (umol N/L) |
Dataset-specific Instrument Name | Sea-Bird SBE 911 CTD |
Generic Instrument Name | CTD Sea-Bird 911 |
Dataset-specific Description | At all stations, vertical profiles were taken with the Sea-Bird SBE 911 CTD instrument package. The SBE 911 includes the SBE 9 Underwater Unit and the SBE 11 Deck Unit (for real-time readout using conductive wire) for deployment from a vessel. The combination of the SBE 9 and SBE 11 is called a SBE 911. The SBE 9 uses Sea-Bird's standard modular temperature and conductivity sensors (SBE 3 and SBE 4). The SBE 9 CTD can be configured with auxiliary sensors to measure other parameters including dissolved oxygen, pH, turbidity, fluorescence, light (PAR), light transmission, etc.). |
Generic Instrument Description | The Sea-Bird SBE 911 is a type of CTD instrument package. The SBE 911 includes the SBE 9 Underwater Unit and the SBE 11 Deck Unit (for real-time readout using conductive wire) for deployment from a vessel. The combination of the SBE 9 and SBE 11 is called a SBE 911. The SBE 9 uses Sea-Bird's standard modular temperature and conductivity sensors (SBE 3 and SBE 4). The SBE 9 CTD can be configured with auxiliary sensors to measure other parameters including dissolved oxygen, pH, turbidity, fluorescence, light (PAR), light transmission, etc.). More information from Sea-Bird Electronics. |
Dataset-specific Instrument Name | Lachat Instruments QuikChem® FIA+ 8000 Series Automated Ion Analyzer |
Generic Instrument Name | Flow Injection Analyzer |
Dataset-specific Description | Water samples were analyzed for NO₃⁻ + NO₂⁻, NO₂⁻, PO₄³−, SiO₂, and NH₄⁺ using a Lachat Instruments QuikChem® FIA+ 8000 Series Automated Ion Analyzer with an ASX-400 Series XYZ autosampler. |
Generic Instrument Description | An instrument that performs flow injection analysis. Flow injection analysis (FIA) is an approach to chemical analysis that is accomplished by injecting a plug of sample into a flowing carrier stream. FIA is an automated method in which a sample is injected into a continuous flow of a carrier solution that mixes with other continuously flowing solutions before reaching a detector. Precision is dramatically increased when FIA is used instead of manual injections and as a result very specific FIA systems have been developed for a wide array of analytical techniques. |
Dataset-specific Instrument Name | 5 L Niskin bottles |
Generic Instrument Name | Niskin bottle |
Dataset-specific Description | Water samples were collected from a rosette containing 12, 5L Niskin bottles that had the CTD instrument package mounted below it. |
Generic Instrument Description | A Niskin bottle (a next generation water sampler based on the Nansen bottle) is a cylindrical, non-metallic water collection device with stoppers at both ends. The bottles can be attached individually on a hydrowire or deployed in 12, 24, or 36 bottle Rosette systems mounted on a frame and combined with a CTD. Niskin bottles are used to collect discrete water samples for a range of measurements including pigments, nutrients, plankton, etc. |
Dataset-specific Instrument Name | Shimazdu Instruments TOC-VCSH and TNM-1 |
Generic Instrument Name | Total Organic Carbon Analyzer |
Dataset-specific Description | Water samples were analyzed for dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) content using a Shimazdu Instruments TOC-VCSH and TNM-1 with attached ASI-V auto sampler. |
Generic Instrument Description | A unit that accurately determines the carbon concentrations of organic compounds typically by detecting and measuring its combustion product (CO2). See description document at: http://bcodata.whoi.edu/LaurentianGreatLakes_Chemistry/bs116.pdf |
Website | |
Platform | R/V Pelican |
Start Date | 2017-09-28 |
End Date | 2017-10-11 |
Description | Additional cruise information is available from the Rolling Deck to Repository (R2R): https://www.rvdata.us/search/cruise/PE18-11 |
NSF Award Abstract:
Understanding how extreme events, like hurricanes, impact coastal ecosystems and the cycling of elements like carbon and oxygen, is important for improving our ability to predict how the global carbon cycle will respond to climate. This team of investigators, who have already been working together on understanding the carbon cycle in the Gulf of Mexico continental shelves, have important recent data against which to measure the effects of the passage of Hurricane Harvey in August, 2017. They will sample the waters and sediments of the northwestern Gulf of Mexico in September, October, and January to assess Harvey's impacts on a timescale of weeks to months.
The researchers pose three specific questions: 1. Will the region become a major source of carbon dioxide to the atmosphere, releasing carbon accumulated in the bottom water and sediments, and will this potential impact be faster and greater than during normal fall and winter mixing events? Will this process acidify the surface water and for how long? 2. Will the metabolic balance be substantially pushed toward net heterotrophy as a result of the storm in comparison to other years? 3. Can the amount of material delivered or redeposited across the continental shelf by a tropical cyclone be considerably larger than that related to winter storm systems? The PIs will measure water column nutrients, oxygen, organic carbon, and inorganic carbon system parameters; determine water column and benthic metabolic and nutrient flux rates; and sediment organic matter deposition rates. They will also collect end member river samples. They will compare the immediate (mid-Sept) but limited post-hurricane data and one-month post-hurricane, more detailed data with those collected in July and April to study the impacts of the storms. they will also compare 2017-2018 seasonal data to seasonal data over the same region collected in the past (2006-2008 and 2009-2010). They will also compare the impacts of Hurricane Harvey to those of Hurricanes Katrina and Rita (2005) and Tropical Storm Cindy (June 2017). The project will involve graduate and postdoctoral research and work to communicate results to the public.
Funding Source | Award |
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NSF Division of Ocean Sciences (NSF OCE) |