Dataset: CTD_MOCNESS10
Deployment: NBP0204

CTD data collected during MOCNESS hauls

Principal Investigator:

Peter H. Wiebe (Woods Hole Oceanographic Institution, WHOI)

Technician:

Nancy Copley (Woods Hole Oceanographic Institution, WHOI)

BCO-DMO Data Manager:

Ms Dicky Allison (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Project:

U.S. GLOBEC Southern Ocean (SOGLOBEC)

Deployment Synonyms:

GLOBECIV

Coordinated Deployments:

LMG0205

Data URL:

https://www.bco-dmo.org/dataset-deployment/450385/data

Expand/Collapse All

Description

CTD observations taken simultaneously during MOCNESS tows,
plus MOCNESS sampling conditions

Note: Some variables have been eliminated from the display but are nevertheless available. These variables include: oxycurrent, oxytemp, tempco, and echo.

The MOCNESS is based on the Tucker Trawl principle (Tucker, 1951). The particular MOCNESS system from which these CTD data came is one of two net systems. The MOCNESS-1 has nine rectangular nets (1m x 1.4 m) which are opened and closed sequentially by commands through conducting cable from the surface (Wiebe et al., 1976). The MOCNESS-10 (with 10 m² nets)carries 6 nets of 3.0-mm circular mesh. In both systems, "the underwater unit sends a data frame, comprised of temperature, depth, conductivity, net-frame angle, flow count, time, number of open net, and net opening/closing, to the deck unit in a compressed hexadecimal format every 2 seconds and from the deck unit to a microcomputer every 4 seconds... Temperature (to approximately 0.01 deg C) and conductivity are measured with SEABIRD sensors. Normally, a modified T.S.K.-flowmeter is used... Both the temperature and conductivity sensors and the flow meter are mounted on top of the frame so that they face horizontally when the frame is at a towing angle of 45deg... Calculations of salinity (to approximately 0.01 o/oo S), potential temperature (theta), potential density (sigma), the oblique and vertical velocities of the net, and the approximate volume filtered by each net are made after each string of data has been received by the computer." (Wiebe et al., 1985) In addition, data were collected from four other sensors attached to the frame: the Transmissometer, the Fluorometer, the Down welling light sensor, and the Oxygen sensor. A SeaBird underwater pump was also included in the sensor suite.

It should be noted that due to Antarctic cold, the first few minutes of data are often of questionable value as they are extremely variable and have a high frequency of '50.000' (indicating 'bad values') in the temp, theta and sal fields. Once the sensors encounter deeper, warmer water, they start recording good values.

For additional information, contact the chief scientist for the cruise.

References

¹Fofonoff and Millard, 1983, UNESCO technical papers in Marine Sciences, #44

Tucker, G.H., 1951. Relation of fishes and other organisms to the scattering of underwater sound. Journal of Marine Research, 10: 215-238.

Wiebe, P.H., K.H. Burt, S. H. Boyd, A.W. Morton, 1976. The multiple opening/closing net and environmental sensing system for sampling zooplankton. Journal of Marine Research, 34(3): 313-326

Wiebe, P.H., A.W. Morton, A.M. Bradley, R.H. Backus, J.E. Craddock, V. Barber, T.J. Cowles and G.R. Flierl, 1985. New developments in the MOCNESS, an apparatus for sampling zooplankton and micronekton. Marine Biology, 87: 313-323.

last updated January 10, 2006; gfh

Methods & Sampling

Dataset acquisition description

The MOCNESS is based on the Tucker Trawl principle (Tucker, 1951). The particular MOCNESS system from which these CTD data came is one of two net systems. The MOCNESS-1 has nine rectangular nets (1m x 1.4 m) which are opened and closed sequentially by commands through conducting cable from the surface (Wiebe et al., 1976). The MOCNESS-10 (with 10 m2 nets)carries 6 nets of 3.0-mm circular mesh. In both systems, 'the underwater unit sends a data frame, comprised of temperature, depth, conductivity, net-frame angle, flow count, time, number of open net, and net opening/closing, to the deck unit in a compressed hexadecimal format every 2 seconds and from the deck unit to a microcomputer every 4 seconds... Temperature (to approximately 0.01 deg C) and conductivity are measured with SEABIRD sensors. Normally, a modified T.S.K.-flowmeter is used... Both the temperature and conductivity sensors and the flow meter are mounted on top of the frame so that they face horizontally when the frame is at a towing angle of 45deg... Calculations of salinity (to approximately 0.01 o/oo S), potential temperature (theta), potential density (sigma), the oblique and vertical velocities of the net, and the approximate volume filtered by each net are made after each string of data has been received by the computer.' (Wiebe et al., 1985) In addition, data were collected from four other sensors attached to the frame: the Transmissometer, the Fluorometer, the Down welling light sensor, and the Oxygen sensor. A SeaBird underwater pump was also included in the sensor suite.

Deployment-specific acquisition description

The MOCNESS is based on the Tucker Trawl principle (Tucker, 1951). The particular MOCNESS system from which these CTD data came is one of two net systems. The MOCNESS-1 has nine rectangular nets (1m x 1.4 m) which are opened and closed sequentially by commands through conducting cable from the surface (Wiebe et al., 1976). The MOCNESS-10 (with 10 m2 nets)carries 6 nets of 3.0-mm circular mesh. In both systems, 'the underwater unit sends a data frame, comprised of temperature, depth, conductivity, net-frame angle, flow count, time, number of open net, and net opening/closing, to the deck unit in a compressed hexadecimal format every 2 seconds and from the deck unit to a microcomputer every 4 seconds... Temperature (to approximately 0.01 deg C) and conductivity are measured with SEABIRD sensors. Normally, a modified T.S.K.-flowmeter is used... Both the temperature and conductivity sensors and the flow meter are mounted on top of the frame so that they face horizontally when the frame is at a towing angle of 45deg... Calculations of salinity (to approximately 0.01 o/oo S), potential temperature (theta), potential density (sigma), the oblique and vertical velocities of the net, and the approximate volume filtered by each net are made after each string of data has been received by the computer.' (Wiebe et al., 1985) In addition, data were collected from four other sensors attached to the frame: the Transmissometer, the Fluorometer, the Down welling light sensor, and the Oxygen sensor. A SeaBird underwater pump was also included in the sensor suite.

Data Processing Description

Dataset Processing Description

For additional information, contact the chief scientist for the cruise.

Deployment-specific processing description

<p> It should be noted that due to Antarctic cold, the first few minutes of
data are often of questionable value as they are extremely variable and have a high
frequency of '50.000' (indicating 'bad values') in the temp, theta and sal
fields. Once the sensors encounter deeper, warmer water, they start recording
good values.
</p>

<p>For additional information,
contact the
<a href="/jg/serv/globec/soglobec/inventory.html0?project,name_prin">
chief scientist</a> for the cruise.

More information about this dataset deployment

Funding

Award Number	Funding Source
unknown SOGLOBEC NSF ANT	NSF Antarctic Sciences

Instruments

MOCNESS1

Supplied Description:

Instrument Type

Generic Name: MOCNESS1

Acronym: MOC1

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/NETT0097/

Generic Description:

The Multiple Opening/Closing Net and Environmental Sensing System or MOCNESS is a family of net systems based on the Tucker Trawl principle. The MOCNESS-1 carries nine 1-m2 nets usually of 335 micrometer mesh and is intended for use with the macrozooplankton. All nets are black to reduce contrast with the background. A motor/toggle release assembly is mounted on the top portion of the frame and stainless steel cables with swaged fittings are used to attach the net bar to the toggle release. A stepping motor in a pressure compensated case filled with oil turns the escapement crankshaft of the toggle release which sequentially releases the nets to an open then closed position on command from the surface. -- from the MOCNESS Operations Manual (1999 + 2003).

MOCNESS10

Supplied Description:

The MOCNESS is based on the Tucker Trawl principle (Tucker, 1951). The particular MOCNESS system from which these CTD data came is one of two net systems. The MOCNESS-10 (with 10 m2 nets)carries 6 nets of 3.0-mm circular mesh. In both systems, "the underwater unit sends a data frame, comprised of temperature, depth, conductivity, net-frame angle, flow count, time, number of open net, and net opening/closing, to the deck unit in a compressed hexadecimal format every 2 seconds and from the deck unit to a microcomputer every 4 seconds... Temperature (to approximately 0.01 deg C) and conductivity are measured with SEABIRD sensors. Normally, a modified T.S.K.-flowmeter is used... Both the temperature and conductivity sensors and the flow meter are mounted on top of the frame so that they face horizontally when the frame is at a towing angle of 45deg... Calculations of salinity (to approximately 0.01 o/oo S), potential temperature (theta), potential density (sigma), the oblique and vertical velocities of the net, and the approximate volume filtered by each net are made after each string of data has been received by the computer." (Wiebe et al., 1985)

Instrument Type

Generic Name: MOCNESS10

Acronym: MOC10

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/NETT0097/

Generic Description:

The Multiple Opening/Closing Net and Environmental Sensing System (MOCNESS) is based on the Tucker Trawl principle (Tucker, 1951). The MOCNESS-10 (with 10 m^2 nets) carries 6 nets of 3.0-mm circular mesh which are opened and closed sequentially by commands through conducting cable from the surface (Wiebe et al., 1976). In this system, "the underwater unit sends a data frame, comprising temperature, depth, conductivity, net-frame angle, flow count, time, number of open net, and net opening/closing, to the deck unit in a compressed hexadecimal format every 2 seconds and from the deck unit to a microcomputer every 4 seconds" (Wiebe et al., 1985).

Parameters

Supplied Name	Supplied description	Supplied Units	Standard Name
datatype	sampling method - instrument type, e.g. MOCNESS-1 or MOCNESS-10		datatype
cruiseid	cruise identification, e.g. NBP0202, for RVIB Palmer cruise 0202		cruiseid
year	year		year
brief_desc	brief cruise description, such as process or mooring		brief_desc
tow	tow number		tow
day_gmt	day of month, GMT, 1 - 31		day_gmt
month_gmt	month of year, GMT, 1 - 12		month_gmt
station	station number, from event log		station
station_std	standard station number, from event log		station_std
yrday_gmt	year day as a decimal, based on Julian calendar, GMT	YYY.Y	yrday_gmt
time_gmt	time, GMT using 24 hour clock to decimal minutes	HHmm.m	time_gmt
press	depth of observation or sample	meters	press
temp	temperature of water	degrees C	temp
potemp	potential temperature or theta¹	degrees C	potemp
sal	salinity calculated from conductivity, bad values are set to 50		sal
sigma_0	potential density¹	kg/m<sup>3</sup>	sigma_0
flvolt	relative fluorescence (0-5 volts)	volts	flvolt
angle	angle of net frame relative to vertical (0-89 degrees)	degrees	tow_angle
flow	consecutive flow counts		flow
hzvel	horizontal net velocity	m/min	hzvel
vtvel	vertical net velocity	m/min	vtvel
vol_filt	volume filtered	meters³	vol_filt
trans_v	transmissometry or light transmission, (0-5 volts)	volts	trans_v
o2	dissolved oxygen	ml/liter	O2
lite	down welling light	volts	no_bcodmo_term
net	MOCNESS net number, (00-08)		net
lat	latitude, negative = South	DD.D	lat
lon	longitude, negative = West	DDD.D	lon

Database

Contribute Data

Dataset: CTD_MOCNESS10
Deployment: NBP0204

CTD observations taken simultaneously during MOCNESS tows,
plus MOCNESS sampling conditions

References

Dataset acquisition description

Deployment-specific acquisition description

Dataset Processing Description

Deployment-specific processing description

Database

Contribute Data

Dataset: CTD_MOCNESS10Deployment: NBP0204

CTD observations taken simultaneously during MOCNESS tows, plus MOCNESS sampling conditions

References

Dataset acquisition description

Deployment-specific acquisition description

Dataset Processing Description

Deployment-specific processing description

Dataset: CTD_MOCNESS10
Deployment: NBP0204

CTD observations taken simultaneously during MOCNESS tows,
plus MOCNESS sampling conditions