Dataset: CTD

Name: CTD data from R/V Atlantic Explorer X0606, X0705, AE0810 in the Western Sargasso Sea roughly 38-20N and 66-43W from 2006-2008 (ATP3 project)
Published: 2011-12-06
Keywords: oceans

Cite This Dataset

Spatial Extent: N:37.4998367 E:-44.7395 S:19.6498333 W:-66.0970553

Project:

DOP Utilization in the Sargasso Sea: Quantifying Taxon-specific Rates of Hydrolysis and Uptake (ATP3)

Principal Investigator:

Michael W. Lomas (Bermuda Institute of Ocean Sciences, BIOS)

Co-Principal Investigator:

James Ammerman (Sea Grant, SGNY)

Sonya T. Dyhrman (Woods Hole Oceanographic Institution, WHOI)

Contact:

Michael W. Lomas (Bermuda Institute of Ocean Sciences, BIOS)

BCO-DMO Data Manager:

Stephen R. Gegg (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

06 December 2011

Version Date:

2011-12-06

Validated:

Yes

Current State:

Final no updates expected

CTD data from R/V Atlantic Explorer X0606, X0705, AE0810 in the Western Sargasso Sea roughly 38-20N and 66-43W from 2006-2008 (ATP3 project)

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Description

DOP Utilization (ATP3, DOP) CTD data
Biogeochemical data collected on transect cruises studying
Dissolved Organic Phosphorus throughout the western Sargasso Sea.
Data are from several cruises over the span 2006 to 2008.

Note the cruise identifiers for the Atlantic Explorer were originally formatted as XYY## (e.g. X0806 was the 6th cruise in 2008). The data files include cruise IDs of this type. The vessel operator changed the cruise ID syntax several years after the cruise and the official cruise ID syntax was changed to AEYY##. For example, AE0810 should be the same cruise as X0810. One exception for this dataset is that X0804 is cruise ID AE0810.

Related files and references:
Detailed information on analyses:
Lomas, M.W., Burke, A., Lomas, D.A., Bell, D.W., Shen, C., Ammerman, J.W., Dyhrman, S.T. 2010.
Sargasso Sea phosphorus biogeochemistry: An important role for dissolved organic phosphorus (DOP).
Biogeosciences 7: 695-710.

Other published work:
Michelou, V.K., Lomas, M.W., Kirchman, D.L. Phosphate and ATP uptake by cyanobacteria and heterotrophic
bacteria in the Sargasso Sea. Limnology and Oceanography, in press.

McLaughlin, K., Sohm, J.A., Cutter, G.A., Lomas, M.W., Paytan, A. 2010. Phosphate cycling in the Sargasso Sea:
Investigation using the oxygen isotopic composition of phosphate, enzyme labeled fluorescence, and turnover times.
Journal of Geophysical Research - Biogeosciences, in press.

Longnecker, K., Lomas, M.W., and Van Mooy, B.A.S. 2010. Characterizing the abundance and diversity of
heterotrophic bacterial cells assimilating phosphate in the sub-tropical North Atlantic Ocean.
Environmental Microbiology, in press.

Orchard, E.D., Ammerman, J.W., Lomas, M.W., Dyhrman, S.T. 2010. Dissolved inorganic and organic phosphorus
uptake in Trichodesmium and the microbial community: The importance of phosphorus ester in the Sargasso Sea.
Limnology and Oceanography, 55:1390-1399.

Casey, J., Lomas, M.W., Michelou, V., Orchard, E.D., Dyhrman, S.T., Ammerman, J.W., and Sylvan, J. 2009.
Phytoplankton taxon-specific orthophosphate (Pi) and ATP uptake in the northwestern Atlantic subtropical gyre.
Aquatic Microbial Ecology, 58:31-44.

Van Mooy, B.A.S., Fredricks, H.F., Pedler, B.F., Dyhrman, S.T., Karl, D.M., Koblizek, M., Lomas, M.W., Moore,
L.R., Moutin, T., Rappé, M.S., and Webb, E.A. 2009. Phytoplankton in the oligotrophic ocean use non-phosphorus
lipids in response to phosphorus scarcity.
Nature Geosciences, doi:10.1038/nature07659.

Methods & Sampling

Sampling and Analytical Methodology:
Detailed methods for all data collected as part of this study can be found in the publications
arising from this study (references given below). This contains information on analytical
machines and certified standards where applicable.

Sample QA/QC procedures followed those of the Bermuda Atlantic Time-series Study (BATS).
At the point of collection, any leaking niskin bottles were noted on the master cast sheets
and samples were taken from a different niskin fired at the same depth as the leaking bottle.
No data are reported for leaking Niskin bottles. During sample analysis standard curves
and/or certified standards were carefully examined to ensure that they were consistent with
expectations and accurate. If nothing was found, then we examined other data from that
niskin to see if other samples are in question. If no obvious error or problem was found,
the data were considered OK and in the range of environmental data that this study hoped
to observe.

Sample accuracy and precision:
Sample accuracy was assessed by using certified standards, for those measurements where
standards are available (dissolved oxygen, nutrients, salinity). Certified standards were
run with each analytical run and compared to long term control charts for respective analyses.
Samples were not run until certified standards were shown to be accurate for that analytical
run. Sample precision was determined by analyzing replicate samples (not replicate analyses
on the same sample) and therefore is higher than analytical precision due to the inclusion
of sampling error. At the concentrations observed during this study, sample precision was
<5% for stock measurements and <10% for rate measurements. Some analyses, namely dissolved

oxygen and salinity, were much better and often had a sample precisions <1%. These precision

estimates are consistent with the long term QA/QC seen with the BATS program.

The provided data files are complete matrices and therefore not every sample (columns) will be
taken from every Niskin fired (rows). Data that were either not collected, or were associated
with leaking Niskins, or were found to be in error for other reasons are denoted by "nd" in the
spreadsheets.

Data Processing Description

Data Processing:
Most of the data given in this dataset are not derived variables and are calculated using
reasonably standard equations as given in the appropriate reference above. The one exception
is CTD data. Raw CTD data were processed using SBE-Data Processing software using configuration
and calibration files provided by the Shipboard Science technician. Sensors were calibrated
every 6 months. Manual determinations of dissolved oxygen, salinity and HPLC Chlorophyll a,
once passing the above QA/QC steps, were taken as correct. CTD sensor data was regressed against
the appropriate manual variable. In all cases, regression statistics were very strong and linear.
CTD data were corrected to manual measurements using the regression data and it is this corrected
data that is given in the associated data files.

Only nutrient analyses were close to analytical method detection limits (MDL). MDLs were estimated
as 3x the standard deviation of the lowest standard used for the analysis and are ~30nM for nitrate
and phosphate using a standard autoanalyzer. We used the MAGIC co-precipitation method for phosphate
which lowered our MDL to ~1.5nM. Samples below the MDL are reported as calculated for the reason
that they are somewhere between the MDL and a true zero; we consider listing them as either to be
incorrect.

BCO-DMO Edits
- Parameter names modified to conform to BCO-DMO convention
- date reformatted to YYYYMMDD
- time reformatted to HHMM
- lat/lon padded to 7 decimal places
- added CruiseId column and combined all CTD data into one dataset
- X0606 station 7 year corrected from 2007 to 2006
- Lat/Lons for X0606 standardized to positions from BGC data

Data Files

File
CTD.csv (Comma Separated Values (.csv), 4.53 MB) MD5:c36a0e2523cdbee021112c536c5713d0 Primary data file for dataset ID 3355

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Division of Ocean Sciences	OCE-0453023

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
AE0810	ATP3 DOP X0804 233	2008-05-03	R/V Atlantic Explorer	Michael W. Lomas (Chief Scientist)	data info
X0606	ATP3 DOP AE0606	2006-05-19	R/V Atlantic Explorer	Michael W. Lomas (Chief Scientist)	data info
X0705	ATP3 DOP AE0705	2007-06-02	R/V Atlantic Explorer	Michael W. Lomas (Chief Scientist)	data info

Instruments

CTD Sea-Bird 911

Supplied Description:

1.0 CTD

1.1 Seabird Electronics SBE 9/11+ Max Depth is 6800m for all CTD sensors except

Chelsea Fluorometer, Wetlabs Transmissometer and Altimeter which are all

6000m. Aluminum frame holds 24 12 liter water samplers.

1.2 Sensors include Seabird SBE 9/11+, Dual pumped Temperature, conductivity

and Dissolved Oxygen. Chelsea Aquatracka III Flourometer, Wetlabs SeaStar

25cm/660nm Transmissometer, Benthos PSA9000 Altimeter. All data logged with

Seabird Software.

1.3 Water Samplers - 24x12 liter Ocean Test Equipment (OTE) Niskin Water

samplers and 4x10 liter OTE Go-Flo's.

Instrument Type

Generic Name: CTD Sea-Bird 911

Acronym: CTD SBE 911

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0035/

Generic 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.

Parameters

Date and time formats are described in python strftime() syntax.

Supplied Name	Supplied description	Supplied Units	Standard Name
CruiseId	Cruise Id	text	cruiseid
Station	Station Id	integer	station
Cast	CTD drop number	integer	cast
date	date of operation (GMT)	YYYYMMDD	date
time	time of operation (GMT)	HHMM	time
lon	Longitude position West is negative	decimal degrees	lon
lat	Latitude position South is negative	decimal degrees	lat
Depth	depth	meters	depth
Depth_actual	depth retrieved from CTD pressure sensor	meters	depth
Temp_1	primary temperature sensor	degrees celsius	temp
Temp_2	secondary temperature sensor	degrees celsius	temp
Salinity_1	primary conductivity sensor	dimensionless	sal
Salinity_2	secondary conductivity sensor	dimensionless	sal
Sigma_theta_1	density derived from primary sensors	kg/m3	sigma_theta
Sigma_theta_2	density derived from secondary sensors	kg/m3	sigma_theta
Fluorescence	CTD Fluormeter	relative	fluor
DO_1	primary dissolved oxygen sensor	umol/kg	O2
DO_2	secondary dissolved oxygen sensor	umol/kg	O2

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Dataset: CTD