URLhttps://www.bco-dmo.org/dataset/757722
Download URLhttps://www.bco-dmo.org/dataset/757722/data/download
Media Typetext/tab-separated-values
CreatedMarch 6, 2019
ModifiedMarch 7, 2019
StateFinal no updates expected
Brief DescriptionCTD data from AT39-01 (North Pond 2017 expedition)

Acquisition Description

Software Version Seasave V 7.23.2

Processing Description

BCO-DMO Processing Notes:
- combined all files into one large file
- reformatted latitude and longitude into degrees
- reformatted date/time to ISO 8601 format
- appended lat, lon, time_ut, cast_id, and cast_no to the data from the headers
- added conventional header with dataset name, PI name, version date
- sorted by date/time and depth

Instruments

Sea-Bird SBE 9 [CTD Sea-Bird SBE 911plus]
Details
Instance Description (Sea-Bird SBE 9)

Sea-Bird SBE 9 Data File

The Sea-Bird SBE 911plus is a type of CTD instrument package for continuous measurement of conductivity, temperature and pressure. The SBE 911plus includes the SBE 9plus Underwater Unit and the SBE 11plus Deck Unit (for real-time readout using conductive wire) for deployment from a vessel. The combination of the SBE 9plus and SBE 11plus is called a SBE 911plus. The SBE 9plus uses Sea-Bird's standard modular temperature and conductivity sensors (SBE 3plus and SBE 4). The SBE 9plus CTD can be configured with up to eight auxiliary sensors to measure other parameters including dissolved oxygen, pH, turbidity, fluorescence, light (PAR), light transmission, etc.). more information from Sea-Bird Electronics
Details
Instance Description (WET Labs C Star)

WET Labs C Star
serial number: CST-854DR
caibration date: 8-Dec-16

A highly integrated opto-electronic design to provide a low cost, compact solution for underwater measurements of beam transmittance. The instrument is capable of either free space measurements, or through the use of an optical flow tube, flow-through sampling with a pump. It can be used in profiling, moored, or underway applications. more information from Wet Labs
WET Labs ECO-AFL/FL [Wet Labs ECO-AFL/FL Fluorometer]
Details
Instance Description (WET Labs ECO-AFL/FL)

WET Labs ECO-AFL/FL
Serial No.: FLTURT-964
Calibration Date: 22-Nov-16

The Environmental Characterization Optics (ECO) series of single channel fluorometers delivers both high resolution and wide ranges across the entire line of parameters using 14 bit digital processing. The ECO series excels in biological monitoring and dye trace studies. The potted optics block results in long term stability of the instrument and the optional anti-biofouling technology delivers truly long term field measurements. more information from Wet Labs
WET Labs, ECO-NTU [WETLabs ECO-FLNTU]
Details
Instance Description (WET Labs, ECO-NTU)

WET Labs, ECO-NTU
Serial no.: FLTURT-964
Calibration date: 22-Nov-16

The ECO FLNTU is a dual-wavelength, single-angle sensor for simultaneously determining both chlorophyll fluorescence and turbidity.

Parameters

press [pressure]
Details
press
Pressure. Originally named 'prDM'.
water pressure at measurement; depth reported as pressure; positive number increasing with water depth
Details
temp
Primary temperature measurement. Originally named 't090C'.
water temperature at measurement depth
temp_2 [temperature]
Details
temp_2
Secondary tempearture measurement. Originally named 't190C'.
water temperature at measurement depth
Details
cond
Primary conductivity measurement. Originally named 'c0S/m'.

Conductivity.  Units and collection methods may vary.  Often reported in Siemens/meter.

When used in a JGOFS/GLOBEC project this is the conductivity in Siemens/meter for the primary conductivity sensor on a CTD.

cond_2 [conductivity]
Details
cond_2
Secondary conductivity measurement. Originally named 'c1S/m'.

Conductivity.  Units and collection methods may vary.  Often reported in Siemens/meter.

When used in a JGOFS/GLOBEC project this is the conductivity in Siemens/meter for the primary conductivity sensor on a CTD.

trans [transmission]
Details
trans
Beam transmission expressed as percent. Originally named 'CStarTr0'.

light transmission, as percent

fluor [fluorescence]
Details
fluor
Fluorescence measured by WET Labs ECO-AFL/FL in milligrams per cubic meter. Originally named 'flECO-AFL'.

Fluorescence. Indirect measure of pigment concentration.

Units and collection method may vary. Units often reported in milligrams/meter^3 (mg/m3) or micromoles per liter (ug/L). Sometimes reported after being calibrated against extracted pigment concentrations.

In JGOFS/GLOBEC projects fluorescence is measured from CTD instrument sensor.

turbidity [turbidity]
Details
turbidity
Turbidity measured by WET Labs ECO. Originally named 'turbWetntu0'.

Turbidity is the cloudiness or haziness of a fluid caused by individual particles

Details
O2_v
Raw voltage from SBE43 oxygen sensor. Originally named 'Sbeox0V'.

dissolved oxygen concentration

depth [depth]
Details
depth

Depth. Originally named 'depSM'.

Observation/sample depth below the sea surface. Units often reported as: meters, feet.


When used in a JGOFS/GLOBEC dataset the depth is a best estimate; usually but not always calculated from pressure; calculated either from CTD pressure using Fofonoff and Millard (1982; UNESCO Tech Paper #44) algorithm adjusted for 1980 equation of state for seawater (EOS80) or simply equivalent to nominal depth as recorded during sampling if CTD pressure was unavailable.

density [density]
Details
density
Primary measure of density in kilograms per cubic meter. Originally named 'density00'.

density, in mass per unit volume

density_2 [density]
Details
density_2
Secondary measure of density in kilograms per cubic meter. Originally named 'density11'.

density, in mass per unit volume

sal [sal]
Details
sal
Primary salinity measurement. Originally named 'sal00'.

salinity, calculated from the CTD 'primary sensors' of conductivity and temperature, Practical Salinity Scale (PSS-78), dimensionless. Depending on the input source, salinity from the primary sensors can have a variety of names i.e. s0, s00, sal0, sal00.

sal_2 [sal]
Details
sal_2
Secondary salinity measurement. Originally named 'sal11'.

salinity, calculated from the CTD 'primary sensors' of conductivity and temperature, Practical Salinity Scale (PSS-78), dimensionless. Depending on the input source, salinity from the primary sensors can have a variety of names i.e. s0, s00, sal0, sal00.

sound_vel [sound_vel]
Details
sound_vel
Sound velocity in meters per second. Originally named 'svCM'.

sound velocity in sea water, in meters/second

sound_vel_2 [sound_vel]
Details
sound_vel_2
Sound velocity in meters per second from secondary sensor. Originally named 'svCM1'.

sound velocity in sea water, in meters/second

Details
O2

Oxygen concentration from SBE 43. Originally named 'sbeox0Mm/L'.

dissolved oxygen concentration

flag [flag]
Details
flag
Quality flag; bad flag = -9.99e-29.

Data flag. Multiple uses which are dataset dependent. Some uses: data quality, collection occurance or success, depth indicator. See dataset documentation for specific details

time_utc [ISO_DateTime_UTC]
Details
time_utc

date and time in ISO 8601 format yyyy-m-ddTHH:MM:SS

Date/Time (UTC) ISO formatted
This standard is based on ISO 8601:2004(E) and takes on any of the following forms:
2009-08-30T09:05:00[.xx] (local time)
2009-08-30T14:05:00[.xx]Z (UTC time)
2009-08-30T14:05:00[.xx]-05:00
The dashes and the colons can be dropped.
The T can also be dropped "by mutual agreement", but one needs the trailing Z if the time is UTC.

Sample ISO_datetime_utc:
2009-08-30T14:05:00[.xx]Z (UTC time)

Format: YYYY-mm-ddTHH:MM:SS[.xx]Z (UTC time)
cast_id [cast]
Details
cast_id
identifier for the cast

cast or profile number

cast_no [cast]
Details
cast_no
number for the cast

cast or profile number

Dataset Maintainers

NameAffiliationContact
Grieg StewardUniversity of Hawaii at Manoa (SOEST)
Mathew BiddleWoods Hole Oceanographic Institution (WHOI BCO-DMO)

BCO-DMO Project Info

Project TitleCollaborative Research: A multidimensional approach to understanding microbial carbon cycling beneath the seafloor during cool hydrothermal circulation
AcronymSubseafloor Microbial Carbon Cycling
URLhttps://www.bco-dmo.org/project/650059
CreatedJune 24, 2016
ModifiedNovember 29, 2017
Project Description

NSF abstract:

The global ocean comprises Earth’s largest microbiome, with at least half of the ocean’s microbial biomass occurring beneath the ocean floor. In particular, oceanic crust encompasses the largest aquifer on Earth, with a liquid volume equal to approximately 2% of the ocean’s volume. It also harbors a substantial reservoir of microbial life that may influence global-scale biogeochemical cycles. This project investigates this largest actively flowing aquifer system on Earth- the fluids circulating through oceanic crust underlying the oceans and sediments. Despite advancing knowledge about life in the deep ocean, the understanding of microorganisms in the rocky oceanic crust and the fluids flowing through it remains rudimentary. This project is focused on understanding the linkages between microbial activity and the cycling of carbon in the cool, subseafloor biosphere. The balance between organic carbon-consuming and organic carbon-producing metabolisms within the crustal biosphere will be determined using seafloor observatories put in place by the International Ocean Discovery Program (IODP) on the flanks of the Mid-Atlantic Ridge, likely representative of the majority of global hydrothermal fluid circulation. The rates of microbial transformations of carbon will be determined using both geochemical and biological approaches. Results will help establish the extent to which microbially-mediated processes in the subseafloor influence carbon cycling in the ocean. This work will represent the first comprehensive description of carbon cycling in the cold oxic crustal aquifer. Two female postdocs will be supported on the grant, and both high school and community college students will also be involved through collaborations with Cape Cod Community College and Cambridge-Rindge and Latin School. The goal is to promote science, technology, engineering and math literacy among high-school and community college students through hand-on research experiences, peer-to-peer mentoring, and professional development opportunities. 

The goal of the project is to answer the question "is the cool crustal subseafloor biosphere net autotrophic or net heterotrophic?" The focus of the effort is at North Pond, an isolated sediment pond located on ridge flank oceanic crust 7-8 million years old on the western side of the Mid-Atlantic Ridge. The two objectives of the project are to:

1. Characterize suspended particles in subseafloor fluids with respect to their inorganic and organic carbon content, and natural 14C and 13C isotopic ratios, to determine microbially-mediated fluxes and processes.

2. Characterize the net influence of particle-associated and free-living microbial communities on subseafloor fluid primary production and remineralization, as well as the taxon-specific contributions to these same processes.

The integration of isotope geochemical and molecular biological approaches represents a significant cross-disciplinary advance in the understanding of the microbial ecology and geochemistry of the subseafloor biosphere in young oceanic crust and their role in maintaining global deep-sea redox balance. Expected outcomes include identifying signatures of autotrophic and heterotrophic metabolism in particle-associated and free-living subseafloor microbial communities as well as quantification of autotrophic and heterotrophic metabolism and associated taxon-abundances to provide insights into the net and specific microbial processes in crustal fluids on carbon fluxes.

Project Maintainers
NameAffiliationRoleContact
Julie A. HuberWoods Hole Oceanographic Institution (WHOI)Lead Principal Investigator
Peter R. GirguisHarvard UniversityPrincipal Investigator
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