http://lod.bco-dmo.org/id/dataset/2530
eng; USA
utf8
dataset
Highest level of data collection, from a common set of sensors or instrumentation, usually within the same research project
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
2010-06-16
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Mixed layer depths from R/V Thomas G. Thompson TT043, TT045, TT049, TT050, TT053, TT054 cruises in the Arabian Sea in 1995 (U.S. JGOFS Arabian Sea project)
2002-06-06
publication
2002-06-06
revision
BCO-DMO Linked Data URI
2002-06-06
creation
http://lod.bco-dmo.org/id/dataset/2530
Wilford D. Gardner
Texas A&M University
principalInvestigator
John M. Morrison
North Carolina State University - Marine, Earth and Atmospheric Sciences
principalInvestigator
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
publisher
Cite this dataset as: Gardner, W. D., Morrison, J. M. (2002) Mixed layer depths from R/V Thomas G. Thompson TT043, TT045, TT049, TT050, TT053, TT054 cruises in the Arabian Sea in 1995 (U.S. JGOFS Arabian Sea project). Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version June 6, 2002) Version Date 2002-06-06 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/2530 [access date]
Mixed layer depths Dataset Description: <pre>
<b>PI:</b> Wilford Gardner (Texas A&M University),
Jan Gundersen (Texas A&M University)
John Morrison (North Carolina University)
<b>dataset:</b> Mixed layer depths
<b>dates:</b> January 08, 1995 to December 26, 1995
<b>location:</b> N: 22.5 S: 10 W: 57.3 E: 68.75
<b>project/cruise:</b> Arabian Sea - All Process Cruises
<b>ship:</b> Thomas Thompson
Wilford Gardner - based on temperature changes
John Morrison - based on density changes
Arabian Sea Mixed Layer Depths - all process cruises
<a href="http://usjgofs.whoi.edu/PI-NOTES/arabian/Gardner_mixed.html">PI Notes</a>
<a href="http://usjgofs.whoi.edu/PI-NOTES/arabian/Gardner-mixlayer-update.html">PI Notes on density vs. temperature calculation</a>
Mixed layer depths are based on a temperature increase of 0.1 and 0.5
degrees C from the second temperature value listed in the CTD files, which
corresponds roughly to a density increase of 0.03 and 0.125 density units.
The second TEMPERATURE value was used because there occasionally appeared to
be questionable numbers as the first value. The temperature change of 0.1
degree C was recommended by Dr. Craig Lee (WHOI) after looking at the data
and the 0.5 degree C value is the Levitus standard used in his NOAA global
atlases. These are also the values used in the US JGOFS EqPac program.
<b>Please note variable initial (starting) depths.</b>
Calculations were made by Jan Gundersen. (TAMU).
Wilford D. Gardner
Dept. of Oceanography
Texas A&M University
College Station, TX 77843-3146
</pre>
<h2>From Wilf Gardner, Texas A & M University, August 8, 1997</h2>
<b>to Arabian Sea investigators and all interested others</b>
<hr>
<pre>
Since the New Hampshire meeting [July, 1997], we have compared the MLD
based on the temperature criteria of 0.1 and 0.5 degrees C compared with
the density differences of 0.03 and 0.125 density units. About 75% of
the time the values are identical. There are other occasions, however,
where there are significant differences, especially for the 0.1 degrees
C/0.03 comparison. When there is a difference, the temperature
calculations generally give deeper MLDs than density calculations.
Differences most often occur when there is a salinity increase below
the surface. Temperature criteria are often used for MLDs on moored
data as salinity sensors are sometimes subject to greater drift than
temperature sensors.
None of the above criteria identify the "mixed-layer depth" perfectly in
all cases, but examination of depth plots where there are differences
suggest that the density criteria more reliably identify the depth of most
recent mixing. For consistency, we recommend that the MLDs based on
density be used when you are trying to calculate mass budgets. In some
situations, such as sometimes during the TN045 intermonsoon period, there
is no true mixed layer - just a depth at which the MLD criteria are finally
exceeded. We suggest that you look at an expanded plot of the density
profile if your calculations are critical.
</pre> Methods and Sampling: <p>See Platform deployments for cruise specific documentation</p>
Funding provided by Office of Naval Research (ONR) Award Number: unknown Arabian Sea ONR
Funding provided by National Science Foundation (NSF) Award Number: unknown Arabian Sea NSF
completed
Wilford D. Gardner
Texas A&M University
Dept. of Oceanography
College Station
TX
77843-3146
USA
wgardner@ocean.tamu.edu
pointOfContact
John M. Morrison
North Carolina State University - Marine, Earth and Atmospheric Sciences
910-962-2304
Center for Marine Science 5600 Marvin K. Moss Lane
Wilmington
NC
28409
USA
morrisonj@uncw.edu
pointOfContact
asNeeded
Dataset Version: June 6, 2002
Unknown
event
sta_std
sta
cast
MLD_0d1_t
MLD_0d5_t
depth_start_temp
MLD_0d03_dp
MLD_0d05_dp
MLD_0d125_dp
LD_0d25_dp
depth_start_dens
MLD_0d25_dp
Conductivity, Temperature, Depth
theme
None, User defined
event
No BCO-DMO term
cast
featureType
BCO-DMO Standard Parameters
CTD - profiler
instrument
BCO-DMO Standard Instruments
TT043
TT045
TT049
TT050
TT053
TT054
service
Deployment Activity
U.S. JGOFS Arabian Sea
place
Locations
otherRestrictions
otherRestrictions
Access Constraints: none. Use Constraints: Please follow guidelines at: http://www.bco-dmo.org/terms-use Distribution liability: Under no circumstances shall BCO-DMO be liable for any direct, incidental, special, consequential, indirect, or punitive damages that result from the use of, or the inability to use, the materials in this data submission. If you are dissatisfied with any materials in this data submission your sole and exclusive remedy is to discontinue use.
U.S. Joint Global Ocean Flux Study
http://usjgofs.whoi.edu/
U.S. Joint Global Ocean Flux Study
The United States Joint Global Ocean Flux Study was a national component of international JGOFS and an integral part of global climate change research.
The U.S. launched the Joint Global Ocean Flux Study (JGOFS) in the late 1980s to study the ocean carbon cycle. An ambitious goal was set to understand the controls on the concentrations and fluxes of carbon and associated nutrients in the ocean. A new field of ocean biogeochemistry emerged with an emphasis on quality measurements of carbon system parameters and interdisciplinary field studies of the biological, chemical and physical process which control the ocean carbon cycle. As we studied ocean biogeochemistry, we learned that our simple views of carbon uptake and transport were severely limited, and a new "wave" of ocean science was born. U.S. JGOFS has been supported primarily by the U.S. National Science Foundation in collaboration with the National Oceanic and Atmospheric Administration, the National Aeronautics and Space Administration, the Department of Energy and the Office of Naval Research. U.S. JGOFS, ended in 2005 with the conclusion of the Synthesis and Modeling Project (SMP).
U.S. JGOFS
largerWorkCitation
program
U.S. JGOFS Arabian Sea
http://usjgofs.whoi.edu/research/arabian.html
U.S. JGOFS Arabian Sea
<p>The U.S. Arabian Sea Expedition which began in September 1994 and ended in January 1996, had three major components: a U.S. JGOFS Process Study, supported by the National Science Foundation (NSF); Forced Upper Ocean Dynamics, an Office of Naval Research (ONR) initiative; and shipboard and aircraft measurements supported by the National Aeronautics and Space Administration (NASA). The Expedition consisted of 17 cruises aboard the R/V Thomas Thompson, year-long moored deployments of five instrumented surface buoys and five sediment-trap arrays, aircraft overflights and satellite observations. Of the seventeen ship cruises, six were allocated to repeat process survey cruises, four to SeaSoar mapping cruises, six to mooring and benthic work, and a single calibration cruise which was essentially conducted in transit to the Arabian Sea.</p>
Arabian Sea
largerWorkCitation
project
eng; USA
oceans
U.S. JGOFS Arabian Sea
2002-06-06
Arabian Sea
0
BCO-DMO catalogue of parameters from Mixed layer depths from R/V Thomas G. Thompson TT043, TT045, TT049, TT050, TT053, TT054 cruises in the Arabian Sea in 1995 (U.S. JGOFS Arabian Sea project)
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
http://lod.bco-dmo.org/id/dataset-parameter/10192.rdf
Name: event
Units: dimensionless
Description: <p>event number, from event log</p>
http://lod.bco-dmo.org/id/dataset-parameter/10193.rdf
Name: sta_std
Units: unknown
Description: <p>Arabian Sea standard station identifier</p>
http://lod.bco-dmo.org/id/dataset-parameter/10194.rdf
Name: sta
Units: unknown
Description: <p>station number</p>
http://lod.bco-dmo.org/id/dataset-parameter/10195.rdf
Name: cast
Units: dimensionless
Description: <p>CTD cast number</p>
http://lod.bco-dmo.org/id/dataset-parameter/10196.rdf
Name: MLD_0d1_t
Units: meters
Description: <p>depth of mixed layer based on a .1 deg. C change in temperature</p>
http://lod.bco-dmo.org/id/dataset-parameter/10197.rdf
Name: MLD_0d5_t
Units: meters
Description: <p>depth of mixed layer based on a .5 deg. C change in temperature</p>
http://lod.bco-dmo.org/id/dataset-parameter/10198.rdf
Name: depth_start_temp
Units: meters
Description: <p>starting depth used in computation based on temperature</p>
http://lod.bco-dmo.org/id/dataset-parameter/10199.rdf
Name: MLD_0d03_dp
Units: decibars
Description: <p>depth of mixed layer based on a .03kg/m^3 change in density</p>
http://lod.bco-dmo.org/id/dataset-parameter/10200.rdf
Name: MLD_0d05_dp
Units: decibars
Description: <p>depth of mixed layer based on a .05kg/m^3 change in density</p>
http://lod.bco-dmo.org/id/dataset-parameter/10201.rdf
Name: MLD_0d125_dp
Units: decibars
Description: <p>depth of mixed layer based on a .125kg/m^3 change in density</p>
http://lod.bco-dmo.org/id/dataset-parameter/10202.rdf
Name: LD_0d25_dp
Units: decibars
Description: <p>depth of mixed layer based on a .25kg/m^3 change in density</p>
http://lod.bco-dmo.org/id/dataset-parameter/10203.rdf
Name: depth_start_dens
Units: decibars
Description: <p>starting depth used in computation based on density</p>
http://lod.bco-dmo.org/id/dataset-parameter/10204.rdf
Name: MLD_0d25_dp
Units: decibars
Description: <p>depth of mixed layer based on a .25kg/m^3 change in density</p>
GB/NERC/BODC > British Oceanographic Data Centre, Natural Environment Research Council, United Kingdom
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
50021
https://datadocs.bco-dmo.org/file/jAABwmot3wAn2Z/mixed_layer.csv
mixed_layer.csv
Primary data file for dataset ID 2530
download
https://osprey.bco-dmo.org/dataset/2530/data/download
download
onLine
dataset
<p>See Platform deployments for cruise specific documentation</p>
from Cruise: TT043 <pre>
<b>PI:</b> Wilford Gardner (Texas A&M University),
Jan Gunderson (Texas A&M University) and
John Morrison (North Carolina State University)
<b>dataset:</b> Mixed layer depths
<b>dates:</b> January 08, 1995 to February 01, 1995
<b>location:</b> N: 22.483 S: 9.9826 W: 57.2999 E: 68.75
<b>project/cruise:</b> Arabian Sea Process Cruise 1, TTN-043 (Late NE Monsoon)
<b>ship:</b> Thomas Thompson
</pre>
<pre>
Mixed layer depths are based on a temperature increase of 0.1 and 0.5
degrees C from the second temperature value listed in the CTD files, which
corresponds roughly to a density increase of 0.03 and 0.125 density units.
The second TEMPERATURE value was used because there occasionally appeared to
be questionable numbers as the first value. The temperature change of 0.1
degree C was recommended by Dr. Craig Lee (WHOI) after looking at the data
and the 0.5 degree C value is the Levitus standard used in his NOAA global
atlases. These are also the values used in the US JGOFS EqPac program.
<b>Please note variable initial (starting) depths.</b>
Calculations were made by Jan Gundersen. (TAMU).
Wilford D. Gardner
Dept. of Oceanography
Texas A&M University
College Station, TX 77843-3146
</pre>
<h2>From Wilf Gardner, Texas A & M University, August 8, 1997</h2>
<b>to Arabian Sea investigators and all interested others</b>
<hr>
<pre>
Since the New Hampshire meeting [July, 1997], we have compared the MLD
based on the temperature criteria of 0.1 and 0.5 degrees C compared with
the density differences of 0.03 and 0.125 density units. About 75% of
the time the values are identical. There are other occasions, however,
where there are significant differences, especially for the 0.1 degrees
C/0.03 comparison. When there is a difference, the temperature
calculations generally give deeper MLDs than density calculations.
Differences most often occur when there is a salinity increase below
the surface. Temperature criteria are often used for MLDs on moored
data as salinity sensors are sometimes subject to greater drift than
temperature sensors.
None of the above criteria identify the "mixed-layer depth" perfectly in
all cases, but examination of depth plots where there are differences
suggest that the density criteria more reliably identify the depth of most
recent mixing. For consistency, we recommend that the MLDs based on
density be used when you are trying to calculate mass budgets. In some
situations, such as sometimes during the TN045 intermonsoon period, there
is no true mixed layer - just a depth at which the MLD criteria are finally
exceeded. We suggest that you look at an expanded plot of the density
profile if your calculations are critical.
</pre>
from Cruise: TT045 <pre>
<b>PI:</b> Wilford Gardner (Texas A&M University),
Jan Gunderson (Texas A&M University) and
John Morrison (North Carolina State University)
<b>dataset:</b> Mixed layer depths
<b>dates:</b> January 08, 1995 to February 01, 1995
<b>location:</b> N: 22.483 S: 9.9826 W: 57.2999 E: 68.75
<b>project/cruise:</b> Arabian Sea Process Cruise 2, TTN-045 (Spring InterMonsoon)
<b>ship:</b> Thomas Thompson
</pre>
<pre>
Mixed layer depths are based on a temperature increase of 0.1 and 0.5
degrees C from the second temperature value listed in the CTD files, which
corresponds roughly to a density increase of 0.03 and 0.125 density units.
The second TEMPERATURE value was used because there occasionally appeared to
be questionable numbers as the first value. The temperature change of 0.1
degree C was recommended by Dr. Craig Lee (WHOI) after looking at the data
and the 0.5 degree C value is the Levitus standard used in his NOAA global
atlases. These are also the values used in the US JGOFS EqPac program.
<b>Please note variable initial (starting) depths.</b>
Calculations were made by Jan Gundersen. (TAMU).
Wilford D. Gardner
Dept. of Oceanography
Texas A&M University
College Station, TX 77843-3146
</pre>
<h2>From Wilf Gardner, Texas A & M University, August 8, 1997</h2>
<b>to Arabian Sea investigators and all interested others</b>
<hr>
<pre>
Since the New Hampshire meeting [July, 1997], we have compared the MLD
based on the temperature criteria of 0.1 and 0.5 degrees C compared with
the density differences of 0.03 and 0.125 density units. About 75% of
the time the values are identical. There are other occasions, however,
where there are significant differences, especially for the 0.1 degrees
C/0.03 comparison. When there is a difference, the temperature
calculations generally give deeper MLDs than density calculations.
Differences most often occur when there is a salinity increase below
the surface. Temperature criteria are often used for MLDs on moored
data as salinity sensors are sometimes subject to greater drift than
temperature sensors.
None of the above criteria identify the "mixed-layer depth" perfectly in
all cases, but examination of depth plots where there are differences
suggest that the density criteria more reliably identify the depth of most
recent mixing. For consistency, we recommend that the MLDs based on
density be used when you are trying to calculate mass budgets. In some
situations, such as sometimes during the TN045 intermonsoon period, there
is no true mixed layer - just a depth at which the MLD criteria are finally
exceeded. We suggest that you look at an expanded plot of the density
profile if your calculations are critical.
</pre>
from Cruise: TT049 <pre>
<b>PI:</b> Wilford Gardner (Texas A&M University),
Jan Gundersen-temperature-based (Texas A&M University) and
John Morrison-density-based (North Carolina State University)
<b>dataset:</b> Mixed layer depths
<b>dates:</b> July 18, 1995 to August 13, 1995
<b>location:</b> N: 22.5268 S: 9.911 W: 57.2997 E: 68.7507
<b>project/cruise:</b> Arabian Sea Process Cruise 4, TTN-049 (Middle SW Monsoon)
<b>ship:</b> Thomas Thompson
</pre>
<pre>
Mixed layer depths are based on a temperature increase of 0.1 and 0.5
degrees C from the second temperature value listed in the CTD files, which
corresponds roughly to a density increase of 0.03 and 0.125 density units.
The second TEMPERATURE value was used because there occasionally appeared to
be questionable numbers as the first value. The temperature change of 0.1
degree C was recommended by Dr. Craig Lee (WHOI) after looking at the data
and the 0.5 degree C value is the Levitus standard used in his NOAA global
atlases. These are also the values used in the US JGOFS EqPac program.
<b>Please note variable initial (starting) depths.</b>
Calculations were made by Jan Gundersen. (TAMU).
Wilford D. Gardner
Dept. of Oceanography
Texas A&M University
College Station, TX 77843-3146
</pre>
<h2>From Wilf Gardner, Texas A & M University, August 8, 1997</h2>
<b>to Arabian Sea investigators and all interested others</b>
<hr>
<pre>
Since the New Hampshire meeting [July, 1997], we have compared the MLD
based on the temperature criteria of 0.1 and 0.5 degrees C compared with
the density differences of 0.03 and 0.125 density units. About 75% of
the time the values are identical. There are other occasions, however,
where there are significant differences, especially for the 0.1 degrees
C/0.03 comparison. When there is a difference, the temperature
calculations generally give deeper MLDs than density calculations.
Differences most often occur when there is a salinity increase below
the surface. Temperature criteria are often used for MLDs on moored
data as salinity sensors are sometimes subject to greater drift than
temperature sensors.
None of the above criteria identify the "mixed-layer depth" perfectly in
all cases, but examination of depth plots where there are differences
suggest that the density criteria more reliably identify the depth of most
recent mixing. For consistency, we recommend that the MLDs based on
density be used when you are trying to calculate mass budgets. In some
situations, such as sometimes during the TN045 intermonsoon period, there
is no true mixed layer - just a depth at which the MLD criteria are finally
exceeded. We suggest that you look at an expanded plot of the density
profile if your calculations are critical.
</pre>
from Cruise: TT050 <pre>
<b>PI:</b> Wilford Gardner (Texas A&M University),
Jan Gundersen-temperature-based (Texas A&M University) and
John Morrison-density-based (North Carolina State University)
<b>dataset:</b> Mixed layer depths
<b>dates:</b> August 18, 1995 to September 13, 1995
<b>location:</b> N: 22.4998 S: 9.9125 W: 57.3004 E: 68.7527
<b>project/cruise:</b> Arabian Sea Process Cruise 5, TTN-050 (Late SW Monsoon)
<b>ship:</b> Thomas Thompson
</pre>
<pre>
Mixed layer depths are based on a temperature increase of 0.1 and 0.5
degrees C from the second temperature value listed in the CTD files, which
corresponds roughly to a density increase of 0.03 and 0.125 density units.
The second TEMPERATURE value was used because there occasionally appeared to
be questionable numbers as the first value. The temperature change of 0.1
degree C was recommended by Dr. Craig Lee (WHOI) after looking at the data
and the 0.5 degree C value is the Levitus standard used in his NOAA global
atlases. These are also the values used in the US JGOFS EqPac program.
<b>Please note variable initial (starting) depths.</b>
Calculations were made by Jan Gundersen. (TAMU).
Wilford D. Gardner
Dept. of Oceanography
Texas A&M University
College Station, TX 77843-3146
</pre>
<h2>From Wilf Gardner, Texas A & M University, August 8, 1997</h2>
<b>to Arabian Sea investigators and all interested others</b>
<hr>
<pre>
Since the New Hampshire meeting [July, 1997], we have compared the MLD
based on the temperature criteria of 0.1 and 0.5 degrees C compared with
the density differences of 0.03 and 0.125 density units. About 75% of
the time the values are identical. There are other occasions, however,
where there are significant differences, especially for the 0.1 degrees
C/0.03 comparison. When there is a difference, the temperature
calculations generally give deeper MLDs than density calculations.
Differences most often occur when there is a salinity increase below
the surface. Temperature criteria are often used for MLDs on moored
data as salinity sensors are sometimes subject to greater drift than
temperature sensors.
None of the above criteria identify the "mixed-layer depth" perfectly in
all cases, but examination of depth plots where there are differences
suggest that the density criteria more reliably identify the depth of most
recent mixing. For consistency, we recommend that the MLDs based on
density be used when you are trying to calculate mass budgets. In some
situations, such as sometimes during the TN045 intermonsoon period, there
is no true mixed layer - just a depth at which the MLD criteria are finally
exceeded. We suggest that you look at an expanded plot of the density
profile if your calculations are critical.
</pre>
from Cruise: TT053 <pre>
<b>PI:</b> Wilford Gardner (Texas A&M University),
Jan Gundersen-temperature-based (Texas A&M University) and
John Morrison-density-based (North Carolina State University)
<b>dataset:</b> Mixed layer depths
<b>dates:</b> October 29, 1995 to November 25, 1995
<b>location:</b> N: 24.3329 S: 10.0823 W: 56.4858 E: 67.1784
<b>project/cruise:</b> Arabian Sea Process Cruise 6, TTN-053 (bio-optics)
<b>ship:</b> Thomas Thompson
</pre>
<pre>
Mixed layer depths are based on a temperature increase of 0.1 and 0.5
degrees C from the second temperature value listed in the CTD files, which
corresponds roughly to a density increase of 0.03 and 0.125 density units.
The second TEMPERATURE value was used because there occasionally appeared to
be questionable numbers as the first value. The temperature change of 0.1
degree C was recommended by Dr. Craig Lee (WHOI) after looking at the data
and the 0.5 degree C value is the Levitus standard used in his NOAA global
atlases. These are also the values used in the US JGOFS EqPac program.
<b>Please note variable initial (starting) depths.</b>
Calculations were made by Jan Gundersen. (TAMU).
Wilford D. Gardner
Dept. of Oceanography
Texas A&M University
College Station, TX 77843-3146
</pre>
<h2>From Wilf Gardner, Texas A & M University, August 8, 1997</h2>
<b>to Arabian Sea investigators and all interested others</b>
<hr>
<pre>
Since the New Hampshire meeting [July, 1997], we have compared the MLD
based on the temperature criteria of 0.1 and 0.5 degrees C compared with
the density differences of 0.03 and 0.125 density units. About 75% of
the time the values are identical. There are other occasions, however,
where there are significant differences, especially for the 0.1 degrees
C/0.03 comparison. When there is a difference, the temperature
calculations generally give deeper MLDs than density calculations.
Differences most often occur when there is a salinity increase below
the surface. Temperature criteria are often used for MLDs on moored
data as salinity sensors are sometimes subject to greater drift than
temperature sensors.
None of the above criteria identify the "mixed-layer depth" perfectly in
all cases, but examination of depth plots where there are differences
suggest that the density criteria more reliably identify the depth of most
recent mixing. For consistency, we recommend that the MLDs based on
density be used when you are trying to calculate mass budgets. In some
situations, such as sometimes during the TN045 intermonsoon period, there
is no true mixed layer - just a depth at which the MLD criteria are finally
exceeded. We suggest that you look at an expanded plot of the density
profile if your calculations are critical.
</pre>
from Cruise: TT054 <pre>
<b>PI:</b> Wilford Gardner (Texas A&M University),
Jan Gundersen-temperature-based (Texas A&M University) and
John Morrison-density-based (North Carolina State University)
<b>dataset:</b> Mixed layer depths
<b>dates:</b> November 30, 1995 to December 26, 1995
<b>location:</b> N: 22.5171 S: 9.9673 W: 57.2992 E: 68.7849
<b>project/cruise:</b> Arabian Sea Process Cruise 7, TTN-054 (Early NE Monsoon)
<b>ship:</b> Thomas Thompson
</pre>
<pre>
Mixed layer depths are based on a temperature increase of 0.1 and 0.5
degrees C from the second temperature value listed in the CTD files, which
corresponds roughly to a density increase of 0.03 and 0.125 density units.
The second TEMPERATURE value was used because there occasionally appeared to
be questionable numbers as the first value. The temperature change of 0.1
degree C was recommended by Dr. Craig Lee (WHOI) after looking at the data
and the 0.5 degree C value is the Levitus standard used in his NOAA global
atlases. These are also the values used in the US JGOFS EqPac program.
<b>Please note variable initial (starting) depths.</b>
Calculations were made by Jan Gundersen. (TAMU).
Wilford D. Gardner
Dept. of Oceanography
Texas A&M University
College Station, TX 77843-3146
</pre>
<h2>From Wilf Gardner, Texas A & M University, August 8, 1997</h2>
<b>to Arabian Sea investigators and all interested others</b>
<hr>
<pre>
Since the New Hampshire meeting [July, 1997], we have compared the MLD
based on the temperature criteria of 0.1 and 0.5 degrees C compared with
the density differences of 0.03 and 0.125 density units. About 75% of
the time the values are identical. There are other occasions, however,
where there are significant differences, especially for the 0.1 degrees
C/0.03 comparison. When there is a difference, the temperature
calculations generally give deeper MLDs than density calculations.
Differences most often occur when there is a salinity increase below
the surface. Temperature criteria are often used for MLDs on moored
data as salinity sensors are sometimes subject to greater drift than
temperature sensors.
None of the above criteria identify the "mixed-layer depth" perfectly in
all cases, but examination of depth plots where there are differences
suggest that the density criteria more reliably identify the depth of most
recent mixing. For consistency, we recommend that the MLDs based on
density be used when you are trying to calculate mass budgets. In some
situations, such as sometimes during the TN045 intermonsoon period, there
is no true mixed layer - just a depth at which the MLD criteria are finally
exceeded. We suggest that you look at an expanded plot of the density
profile if your calculations are critical.
</pre>
Specified by the Principal Investigator(s)
asNeeded
7.x-1.1
Biological and Chemical Oceanography Data Management Office (BCO-DMO)
Unavailable
508-289-2009
WHOI MS#36
Woods Hole
MA
02543
USA
info@bco-dmo.org
http://www.bco-dmo.org
Monday - Friday 8:00am - 5:00pm
For questions regarding this resource, please contact BCO-DMO via the email address provided.
pointOfContact
Conductivity, Temperature, Depth
Conductivity, Temperature, Depth
PI Supplied Instrument Name: Conductivity, Temperature, Depth PI Supplied Instrument Description:CTD measurements taken, CTD unit unidentified Instrument Name: CTD - profiler Instrument Short Name: 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. It permits scientists to observe the physical properties in real-time via a conducting cable, which is typically connected to a CTD to a deck unit and computer on a 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 term applies to profiling CTDs. For fixed CTDs, see https://www.bco-dmo.org/instrument/869934. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/130/
Cruise: TT043
TT043
R/V Thomas G. Thompson
Community Standard Description
International Council for the Exploration of the Sea
R/V Thomas G. Thompson
vessel
TT043
Michael R. Roman
University of Maryland Center for Environmental Science
http://osprey.bcodmo.org/datasetDeployment.cfm?ddid=2580&did=353&flag=view
Report describing TT043
Cruise: TT045
TT045
R/V Thomas G. Thompson
Community Standard Description
International Council for the Exploration of the Sea
R/V Thomas G. Thompson
vessel
TT045
John F. Marra
Lamont-Doherty Earth Observatory
Cruise: TT049
TT049
R/V Thomas G. Thompson
Community Standard Description
International Council for the Exploration of the Sea
R/V Thomas G. Thompson
vessel
TT049
Richard Barber
Duke University
Cruise: TT050
TT050
R/V Thomas G. Thompson
Community Standard Description
International Council for the Exploration of the Sea
R/V Thomas G. Thompson
vessel
TT050
Sharon L. Smith
University of Miami
Cruise: TT053
TT053
R/V Thomas G. Thompson
Community Standard Description
International Council for the Exploration of the Sea
R/V Thomas G. Thompson
vessel
TT053
William M. Balch
University of Miami
Cruise: TT054
TT054
R/V Thomas G. Thompson
Community Standard Description
International Council for the Exploration of the Sea
R/V Thomas G. Thompson
vessel
TT054
Wilford D. Gardner
Texas A&M University
R/V Thomas G. Thompson
Community Standard Description
International Council for the Exploration of the Sea
R/V Thomas G. Thompson
vessel