CTD data collected during MOCNESS-10 deployments from ARSV Laurence M. Gould LMG0602 in the Southern Ocean from February to March 2006 (SouthernSalps project)

Website: https://www.bco-dmo.org/dataset/2918
Data Type: Cruise Results
Version: Final
Version Date: 2018-03-27

» Salpa Thompsoni in the Southern Ocean: Bioenergetics, Population Dynamics and Biogeochemical Impact (SouthernSalps)
Madin, Laurence P.Woods Hole Oceanographic Institution (WHOI)Chief Scientist
Horgan, ErichWoods Hole Oceanographic Institution (WHOI)Co-Principal Investigator
Allison, DickyWoods Hole Oceanographic Institution (WHOI BCO-DMO)BCO-DMO Data Manager


Spatial Extent: N:-62.3433 E:-64.2567 S:-63.95 W:-66.85
Temporal Extent: 2006-02-20 - 2006-03-08

Dataset Description

CTD data collected during MOCNESS-10 deployments. CTD attached to MOCNESS-10 frame.

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cruiseidcruise identification, e.g. NBP0202, for RVIB Palmer cruise 0202
temptemperature of water degrees C
datatypesampling method - instrument type, e.g. MOCNESS-1 or MOCNESS-10
towtow number
day_localday of month, local time, 1-31
month_localmonth of year, local time, 1 - 12
yrday_localyear day as a decimal, based on Julian calendar, local;  includes time due to precision YYY.Yyyyyy
time_localtime, local using 24 hour clock to decimal minutes HHmm.m
pressdepth of observation or sample meters
potemppotential temperature or theta1 ¹Fofonoff and Millard, 1983, UNESCO technical papers in Marine Sciences, #44
salsalinity calculated from conductivity, bad values are set to 50
sigma_0potential density1 ¹Fofonoff and Millard, 1983, UNESCO technical papers in Marine Sciences, #44
angleangle of net frame relative to vertical (0-89 degrees) degrees
flowconsecutive flow counts
hzvelhorizontal net velocity m/min
vtvelvertical net velocity m/min
vol_filtvolume filtered meters3
netMOCNESS net number, (00-08)
latlatitude, negative = South DD.D
lonlongitude, negative = West DDD.D
stationStation number where tow was done. text
flvoltfluorescence in volts volts

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Dataset-specific Instrument Name
Conductivity, Temperature, Depth
Generic Instrument Name
CTD profiler
Generic Instrument Description
The Conductivity, Temperature, Depth (CTD) unit is an integrated instrument package designed to measure the conductivity, temperature, and pressure (depth) of the water column. The instrument is lowered via cable through the water column and permits scientists observe the physical properties in real time via a conducting cable connecting the CTD to a deck unit and computer on the ship. The CTD is often configured with additional optional sensors including fluorometers, transmissometers and/or radiometers. It is often combined with a Rosette of water sampling bottles (e.g. Niskin, GO-FLO) for collecting discrete water samples during the cast. This instrument designation is used when specific make and model are not known.

Dataset-specific Instrument Name
Generic Instrument Name
Generic Instrument Description
The CTD part of the MOCNESS includes 1) a pressure (depth) sensor which is a thermally isolated titanium strain gauge with a standard range of 0-5000 decibars full scale, 2) A Sea Bird temperature sensor whose frequency output is measured and sent to the surface for logging and conversion to temperature by the software in the MOCNESS computer (The system allows better than 1 milli-degree resolution at 10 Hz sampling rate), and 3) A Sea Bird conductivity sensor whose output frequency is measured and sent to the surface for logging and conversion to conductivity by the software in the computer (The system allows better than 1 micro mho/cm at 10 Hz sampling rate). The data rate depends on the speed of the computer and the quality of the cable. With a good cable, the system can operate at 2400 baud, sampling all variables at 2 times per second. One sample every 4 seconds is the default, although the hardware can operate much faster. (From The MOCNESS Manual)

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ARSV Laurence M. Gould
Start Date
End Date
The goal of the LMG06-02 cruise was to continue the studies begun in 2004 (LMG04-14) on the population biology, feeding, and energetics of Salpa thompsoni in the waters near the Antarctic Peninsula.

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Project Information

Salpa Thompsoni in the Southern Ocean: Bioenergetics, Population Dynamics and Biogeochemical Impact (SouthernSalps)

Coverage: Southern Ocean

This project is also referred to as "B-307:  Salpa thompsoni in the Southern Ocean". (B-307 was the USAP project/event number).

NSF Award Abstract:
Salps are planktonic grazers that have a life history, feeding biology and population dynamic strikingly different from krill, copepods or other crustacean zooplankton. Salps can occur in very dense population blooms that cover large areas and have been shown to have major impacts due to the their grazing and the production of fast-sinking fecal pellets. Although commonly acknowledged as a major component of the Southern Ocean zooplankton community, often comparable in biomass and distribution to krill, salps have received relatively little attention. Although extensive sampling has documented the seasonal abundance of salps in the Southern Ocean, there is a paucity of data on important rates that determine population growth and the role of this species in grazing and vertical flux of particulates. This proposed study will include: measurements of respiration and excretion rates for solitary and aggregate salps of all sizes; measurements of ingestion rates, including experiments to determine the size or concentration of particulates that can reduce ingestion; and determination of growth rates of solitaries and aggregates. In addition to the various rate measurements, this study will include quantitative surveys of salp horizontal and vertical distribution to determine their biomass and spatial distribution, and to allow a regional assessment of their effects. Measurements of the physical characteristics of the water column and the quantity and quality of particulate food available for the salps at each location will also be made. Satellite imagery and information on sea-ice cover will be used to test hypotheses about conditions that result in high densities of salps. Results will be used to construct a model of salp population dynamics, and both experimental and modeling results will be interpreted within the context of the physical and nutritional conditions to which the salps are exposed. This integrated approach will provide a good basis for understanding the growth dynamics of salp blooms in the Southern Ocean. Two graduate students will be trained on this project, and cruise and research experience will be provided for two undergraduate students. A portion of a website allowing students to be a virtual participant in the research will be created to strengthen students' quantitative skills. Both PI's will participate in teacher-researcher workshops, and collaboration with a regional aquarium will be developed in support of public education.

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Funding SourceAward
NSF Antarctic Sciences (NSF ANT)

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