Dataset: moorings_currents 2001 -lowpass

Name: Southern Ocean 2001 moorings: LOW PASS current data from ARSV Laurence M. Gould LMG0103, LMG0201A in the Southern Ocean from 2001-2002 (SOGLOBEC project)
Published: 2009-11-10
Keywords: oceans

Cite This Dataset

Spatial Extent: N:-66.75003 E:-69.020283 S:-68.25575 W:-70.99985

Project:

U.S. GLOBEC Southern Ocean (SOGLOBEC)

Program:

U.S. GLOBal ocean ECosystems dynamics (U.S. GLOBEC)

Principal Investigator:

Robert C. Beardsley (Woods Hole Oceanographic Institution, WHOI)

Co-Principal Investigator:

Richard Limeburner (Woods Hole Oceanographic Institution, WHOI)

Student:

Carlos Moffat (Woods Hole Oceanographic Institution, WHOI)

BCO-DMO Data Manager:

Nancy Copley (Woods Hole Oceanographic Institution, WHOI BCO-DMO)

Version:

10 Nov. 2009

Version Date:

2009-11-10

Validated:

Yes

Current State:

Final no updates expected

Southern Ocean 2001 moorings: LOW PASS current data from ARSV Laurence M. Gould LMG0103, LMG0201A in the Southern Ocean from 2001-2002 (SOGLOBEC project)

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Description

"As part of the SO GLOBEC field program, the Woods Hole Oceanographic Institution (WHOI) deployed an array of instrumented subsurface moorings near Marguerite Bay during March 2001- March 2002 and a second array during March 2002-March 2003 (Figure 1). The moored measurements included pressure, temperature, conductivity, velocity, acoustic backscatter, and ice thickness. To monitor surface forcing during the moored array observations, two automatic weather stations (AWSs) were deployed on islands in Marguerite Bay and time series of wind, air temperature, pressure, and relative humidity were collected from May 2001 through March 2003.

The primary goals of this effort were to measure the temporal and spatial variability of currents and physical and biological water properties in the study area on time scales from hours to seasonal, improve our description and understanding of the regional general circulation, and identify and describe those physical processes that make this region well suited for krill production and survival." [from technical report WHOI-2005-07.pdf (10.2 MB)]

Methods & Sampling

See WHOI-2005-07.pdf (10.2 MB)]

Rotation angle (rotangle): The basic coordinate system is x(east) and y (north); the x and y velocity components are u and v. for some analysis, the coordinate and velocity are rotated into a local isobath coordinate system, where xr and yr are the rotated coordinates and ur and vr are the rotated velocity components. rotangle is the angle that the rotated xr and ur point in, measured in degrees counterclockwise from east. In the A1 case, rotangle = -152 degrees. Thus, the xr axis has been rotated 152 degrees clockwise (due to the negative sign on rotangle) from x (east). The governing complex equation (as it is written in matlab) is:

ur + i*vr = exp(i*pi*rotangle/180)*(u + i*v) where i = sqrt(-1).

Data Processing Description

See WHOI-2005-07.pdf (10.2 MB)]

Data Files

File
moor_so_lp_2001_uv.csv (Comma Separated Values (.csv), 156.75 MB) MD5:69511c4966935edcdf30f8e7121ebfbf Primary data file for dataset ID 3258

More Information about this dataset

Funding Sources

Funding Source	Award Number
NSF Antarctic Sciences	ANT-9910092

Deployments

Deployment	Synonyms	Start Date	Platform	Investigator
LMG0103		2001-03-18	ARSV Laurence M. Gould	Richard Limeburner (Chief Scientist)	data info
LMG0201A		2002-02-06	ARSV Laurence M. Gould	Robert C. Beardsley (Chief Scientist)	data info

Instruments

Acoustic Doppler Current Profiler

Supplied Description:

Instrument Type

Generic Name: Acoustic Doppler Current Profiler

Acronym: ADCP

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/115/

Generic Description:

The ADCP measures water currents with sound, using a principle of sound waves called the Doppler effect. A sound wave has a higher frequency, or pitch, when it moves to you than when it moves away. You hear the Doppler effect in action when a car speeds past with a characteristic building of sound that fades when the car passes. The ADCP works by transmitting "pings" of sound at a constant frequency into the water. (The pings are so highly pitched that humans and even dolphins can't hear them.) As the sound waves travel, they ricochet off particles suspended in the moving water, and reflect back to the instrument. Due to the Doppler effect, sound waves bounced back from a particle moving away from the profiler have a slightly lowered frequency when they return. Particles moving toward the instrument send back higher frequency waves. The difference in frequency between the waves the profiler sends out and the waves it receives is called the Doppler shift. The instrument uses this shift to calculate how fast the particle and the water around it are moving. Sound waves that hit particles far from the profiler take longer to come back than waves that strike close by. By measuring the time it takes for the waves to bounce back and the Doppler shift, the profiler can measure current speed at many different depths with each series of pings. (More from WHOI instruments listing).

CTD Sea-Bird MicroCAT 37

Supplied Name: MicroCat

Supplied Description:

Instrument Type

Generic Name: CTD Sea-Bird MicroCAT 37

Acronym: CTD MicroCAT 37

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/350/

Generic Description:

The Sea-Bird MicroCAT CTD unit is a high-accuracy conductivity and temperature recorder based on the Sea-Bird SBE 37 MicroCAT series of products. It can be configured with optional pressure sensor, internal batteries, memory, built-in Inductive Modem, integral Pump, and/or SBE-43 Integrated Dissolved Oxygen sensor. Constructed of titanium and other non-corroding materials for long life with minimal maintenance, the MicroCAT is designed for long duration on moorings.

In a typical mooring, a modem module housed in the buoy communicates with underwater instruments and is interfaced to a computer or data logger via serial port. The computer or data logger is programmed to poll each instrument on the mooring for its data, and send the data to a telemetry transmitter (satellite link, cell phone, RF modem, etc.). The MicroCAT saves data in memory for upload after recovery, providing a data backup if real-time telemetry is interrupted.

CTD Sea-Bird SEACAT

Supplied Name: Sea-Bird Seacat CTD

Supplied Description:

Instrument Type

Generic Name: CTD Sea-Bird SEACAT

Acronym: CTD SEACAT

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/350/

Generic Description:

The CTD SEACAT recorder is an instrument package manufactured by Sea-Bird Electronics. The first Sea-Bird SEACAT Recorder was the original SBE 16 SEACAT developed in 1987. There are several model numbers including the SBE 16plus (SEACAT C-T Recorder (P optional))and the SBE 19 (SBE 19plus SEACAT Profiler measures conductivity, temperature, and pressure (depth)). M ore information from Sea-Bird Electronics.

Ice Profiling Sonar

Supplied Name: ice profiler

Supplied Description:

Instrument Type

Generic Name: Ice Profiling Sonar

Acronym: Ice Profiler

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0292/

Generic Description:

The ASL Environmental Sciences (e.g. IPS4 or IPS5) ice profiler is an upward looking sonar device deployed on a mooring for measuring ice keel drafts. The distance between the instrument and the bottom of the ice is measured by sonar at an operating frequency of 420 kHz with a beam width of 1.8 degrees and sampling rate of up to 2Hz. Water depth is measured by a pressure sensor and ice draft is calculated by the difference.

Sea-Bird SBE 26 Wave and Tide Recorder

Supplied Name: SBE 26 SeaGauge

Supplied Description:

Instrument Type

Generic Name: Sea-Bird SBE 26 Wave and Tide Recorder

Acronym: SBE 26 SEAGAUGE

Community Identifier: http://vocab.nerc.ac.uk/collection/L22/current/TOOL0024/

Generic Description:

The Sea-Bird Electronics SBE 26 SEAGAUGE is a wave level and tide recorder with a pressure sensor, accurate clock, precision thermometer and optional SBE 4M conductivity sensor. Pressure data are integrated to give sea level or are burst recorded at rates up to 4 Hz to characterize waves. The standard pressure sensor is a 20 meter (45 psia) Quartzonix, with a temperature-compensated quartz element. Optionally, the SBE 26 can be configured with a Paroscientific Digiquartz pressure sensor with a temperature-compensated quartz element in 13 ranges, from 1 to 6800 meters (15 to 10,000 psia). more information from Sea-Bird Electronics

Vector Averaging Current Meter

Supplied Description:

Instrument Type

Generic Name: Vector Averaging Current Meter

Acronym: VACM

Community Identifier: http://vocab.nerc.ac.uk/collection/L05/current/114/

Generic Description:

Vector Averaging Current Meter

Parameters

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

Supplied Name	Supplied description	Supplied Units	Standard Name
day_gmt	day of month GMT (1-31)		day_gmt
depth	depth of instrument, negative = height above sea surf.	meters	depth
depth_w	water depth	meters	depth_w
hour_gmt	time GMT in hours (0-23)	whole hours	hour_gmt
lat	latitude, negative = South	decimal degrees	lat
lon	longitude, negative = West	decimal degrees	lon
minute_gmt	time GMT in minutes (0-59)	whole minutes	minute_gmt
month_gmt	month of year GMT (1-12)		month_gmt
mooring	mooring identification		mooring
rotangle	The angle that the rotated coordinates, xr, and the rotated velocity components, ur, point - measured in degrees counterclockwise from east (see more in Acquisition section, above)	degrees	no_bcodmo_term
u	eastward current	centimeters/second	curr_east
v	northward current	centimeters/second	curr_north
year	year		year
year_start	starting year of mooring deployment		year_start
yrday_gmt	GMT day and decimal time, as 326.5 for the 326th day of the year, or November 22 at 1200 hours (noon).		yrday_gmt

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Database

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Dataset: moorings_currents 2001 -lowpass