http://lod.bco-dmo.org/id/dataset/2562
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
2010-08-12
ISO 19115-2 Geographic Information - Metadata - Part 2: Extensions for Imagery and Gridded Data
ISO 19115-2:2009(E)
Aggregates from R/V Thomas G. Thompson TT050, TT054 cruises in the Arabian Sea in 1995 (U.S. JGOFS Arabian Sea project)
1999-01-26
publication
1999-01-26
revision
BCO-DMO Linked Data URI
1999-01-26
creation
http://lod.bco-dmo.org/id/dataset/2562
Wilford D. Gardner
Texas A&M University
principalInvestigator
Ian Walsh
Texas A&M University
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: Walsh, I., Gardner, W. D. (1999) Aggregates from R/V Thomas G. Thompson TT050, TT054 cruises in the Arabian Sea in 1995 (U.S. JGOFS Arabian Sea project). Biological and Chemical Oceanography Data Management Office (BCO-DMO). (Version 26 January 1999) Version Date 1999-01-26 [if applicable, indicate subset used]. http://lod.bco-dmo.org/id/dataset/2562 [access date]
Aggregates Dataset Description: <p>Aggregates with equivalent spherical diameters greater than .5 mm</p> Methods and Sampling: <p>See Platform deployments for cruise specific documentation</p>
<!-- data_object info file from
http://synthesis.whoi.edu/jg/info/jgofs/arabian/ttn-043/data_object -->
<h2>Large Aggregate Profiling System Protocol</h2>
<p>&nbsp;</p>
<p><strong>Ian D. Walsh, Wilford B. Gardner and Mary Jo Richardson</strong></p>
<p>Camera systems have been developed to characterize millimeter size particle distributions in the water column (Honjo etal, 1984; Asper, 1987; Gardner etal, 1988). It is conjectured that the millimeter size class range of particles, thought to be primarily composed of aggregates (``marine snow'') may dominate the total mass flux because of their abundance and high settling rates (Asper, 1987). Camera systems integrated with a CTD and transmissometer (such as the Walsh/Gardner Large Aggregate Profiling System (LAPS)) have the advantage of simultaneously collecting data on the distribution of suspended particles and aggregates along with the physical structure of the water column. This is important as previous work has shown that the distribution of aggregates at depth does not reflect the Suspended Particulate Matter (SPM) distribution, particularly in the case of intermediate depth layers of high aggregate abundance (Gardner and Walsh, 1990; Walsh 1990; Walsh and Gardner, in press). The continuous nature of the LAPS profile allows for the identification of mid-water aggregate nepheloid layers which might be missed by sediment traps or pumping because of low sampling density. This is particularly important to the success of the EQPAC program as the previous sediment trap moorings deployed in the area have shown mid-water column flux maximums (~1000--2000 m) on a yearly and seasonal basis except for a three month period at 11� N, 140� W during which the flux was dominated by a diatom bloom (Walsh <em> et al.</em>, 1988; Dymond and Collier, 1988).</p>
<p>The LAPS system as configured for the EQPAC program consists of a Deep-Sea Power and Light AVCS-101 Autonomous Video Camera (Sony CCD V801) synchronized with a high power strobe, and a Sea-Bird Seacat CTD coupled with a Sea Tech 25 cm pathlength deep transmissometer and a Sea Tech deep fluorometer. The strobe flash is contained and collimated using a stainless steel tube and a triple-lense Fresnel stack. PVC baffles on the lense stack can be set to produce a slab of light 5 to 10 cm thick, perpendicular to the camera. The illuminated imaging area can be varied using the zoom capability of the camera. For imaging the particle size range down to 0.5 mm, a 23 cm wide by 17.25 cm high image is acquired with a slab thickness of 10 cm. Calibration of the images is made by placing a target in the image volume during a preliminary cast and subsequent to all changes of the system parameters (e.g., image volume). Images from the camera are captured using a Data Translation frame capture board and NIH Image software on an Apple Macintosh IIci computer. Images are thresholded and particle counts made using the capabilities of the NIH Image program. Obvious zooplankton and nekton are excluded from the particle counts. Frames in the upper water column where sunlight is visible are excluded from the analysis because of potential ambiguity as to the water volume sampled (i.e., particles outside of the strobe illuminated volume may have been illuminated by sunlight). The strobe flash rate and lowering rate of the LAPS can be varied depending on the desired image density and the length of the cast. Generally the strobe interval is set for 6 seconds and the LAPS is lowered at 20 m/min yielding an image every 2 meters.</p>
<p>Each image is analyzed for the total number of particles and their maximum, minimum and equivalent circular diameters. The particles are binned into 0.5 mm size ranges based on the equivalent circular diameter starting at 0.5 mm. Particle volume is calculated assuming sphericity and diameters equal the means of the ranges.</p>
<p>The Seacat CTD will be factory calibrated prior to the EQPAC cruises. Transmissometer data reduction will be accomplished as outlined in the optics protocols.</p>
<h2>Literature Cited</h2>
<p>Asper, V.L. (1987).</p>
<p>Measuring the flux and sinking speed of marine snow aggregates. <em>Deep-Sea Research</em>, <strong>34</strong>(1A):1-17.</p>
<p>Dymond, J. and R. Collier (1988).</p>
<p>Biogenic particle fluxes in the equatorial Pacific: Evidence for both high and low productivity during the 1982-1983 El-Ni�o. <em>Global Bioceochemical Cycles</em>, <strong>2</strong>: 129-137.</p>
<p>Gardner, W.D. and I.D. Walsh (1990).</p>
<p>Distribution of macroaggregates and fine-grained particles across a continental margin and their potential role in fluxes. <em>Deep-Sea Research</em>, <strong>37</strong>: 401-412.</p>
<p>Gardner, W.D., I.D. Walsh, and V.L. Asper (1988).</p>
<p>Comparison of large-particle camera and transmissometer profiles. Presented at the <em>JOA Special Symposium on New Observation Methods, Acapulco, Mexico (1988).</em></p>
<p>Honjo, S., K.W. Doherty, Y.C. Agrawal, and V.L. Asper (1984).</p>
<p>Direct optical assessment of large amorphous aggregates (marine snow) in the deep ocean. <em>Deep-Sea Research</em>, <strong>31</strong>: 67-76.</p>
<p>Walsh, I.D. (1990).</p>
<p><em>Project CATSTIX: Camera, transmissometer, and sediment integration experiment.</em> Ph.D. Dissertation, Texas A &amp; M University, 96pp.</p>
<p>Walsh, I.D. and W.D. Gardner (1992).</p>
<p>Comparison of large particle camera profiles with sediment trap fluxes. <em>Deep-Sea Research</em>, <strong>39</strong>: 1817-1834.</p>
<p>Walsh, I.D., J. Dymond and R. Collier (1988).</p>
<p>Rates of recycling of biogenic components of fast settling particles derived from sediment trap experiments. <em>Deep-Sea Research</em>, <strong>35</strong>: 43-58.</p>
completed
Wilford D. Gardner
Texas A&M University
Dept. of Oceanography
College Station
TX
77843-3146
USA
wgardner@ocean.tamu.edu
pointOfContact
Ian Walsh
Texas A&M University
USA
walsh@oce.orst.edu
pointOfContact
asNeeded
Dataset Version: 26 January 1999
Unknown
event
sta
sta_std
cast
depth_n
agg_num
Sea-Bird Seacat CTD
Large Aggregate Profiling System
SNOY CCD V801
theme
None, User defined
event
No BCO-DMO term
cast
featureType
BCO-DMO Standard Parameters
CTD Sea-Bird SEACAT
Large Aggregate Profiling System
Underwater Camera
instrument
BCO-DMO Standard Instruments
TT050
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
1999-01-26
Arabian Sea
0
BCO-DMO catalogue of parameters from Aggregates from R/V Thomas G. Thompson TT050, 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/10213.rdf
Name: event
Units: dimensionless
Description: <p>event number from event log</p>
http://lod.bco-dmo.org/id/dataset-parameter/10214.rdf
Name: sta
Units: unknown
Description: <p>station number from event log</p>
http://lod.bco-dmo.org/id/dataset-parameter/10215.rdf
Name: sta_std
Units: unknown
Description: <p>Arabian Sea standard station identifier</p>
http://lod.bco-dmo.org/id/dataset-parameter/10216.rdf
Name: cast
Units: dimensionless
Description: <p>LAPS (Large Aggregate Profiling System) cast number</p>
http://lod.bco-dmo.org/id/dataset-parameter/10217.rdf
Name: depth_n
Units: meters
Description: <p>nominal sample depth</p>
http://lod.bco-dmo.org/id/dataset-parameter/10218.rdf
Name: agg_num
Units: number/liter
Description: <p>number of aggregates</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
41787
https://datadocs.bco-dmo.org/file/1VVMol0cOnvG2X/aggregates.csv
aggregates.csv
Primary data file for dataset ID 2562
download
https://osprey.bco-dmo.org/dataset/2562/data/download
download
onLine
dataset
<p>See Platform deployments for cruise specific documentation</p>
<!-- data_object info file from
http://synthesis.whoi.edu/jg/info/jgofs/arabian/ttn-043/data_object -->
<h2>Large Aggregate Profiling System Protocol</h2>
<p>&nbsp;</p>
<p><strong>Ian D. Walsh, Wilford B. Gardner and Mary Jo Richardson</strong></p>
<p>Camera systems have been developed to characterize millimeter size particle distributions in the water column (Honjo etal, 1984; Asper, 1987; Gardner etal, 1988). It is conjectured that the millimeter size class range of particles, thought to be primarily composed of aggregates (``marine snow'') may dominate the total mass flux because of their abundance and high settling rates (Asper, 1987). Camera systems integrated with a CTD and transmissometer (such as the Walsh/Gardner Large Aggregate Profiling System (LAPS)) have the advantage of simultaneously collecting data on the distribution of suspended particles and aggregates along with the physical structure of the water column. This is important as previous work has shown that the distribution of aggregates at depth does not reflect the Suspended Particulate Matter (SPM) distribution, particularly in the case of intermediate depth layers of high aggregate abundance (Gardner and Walsh, 1990; Walsh 1990; Walsh and Gardner, in press). The continuous nature of the LAPS profile allows for the identification of mid-water aggregate nepheloid layers which might be missed by sediment traps or pumping because of low sampling density. This is particularly important to the success of the EQPAC program as the previous sediment trap moorings deployed in the area have shown mid-water column flux maximums (~1000--2000 m) on a yearly and seasonal basis except for a three month period at 11� N, 140� W during which the flux was dominated by a diatom bloom (Walsh <em> et al.</em>, 1988; Dymond and Collier, 1988).</p>
<p>The LAPS system as configured for the EQPAC program consists of a Deep-Sea Power and Light AVCS-101 Autonomous Video Camera (Sony CCD V801) synchronized with a high power strobe, and a Sea-Bird Seacat CTD coupled with a Sea Tech 25 cm pathlength deep transmissometer and a Sea Tech deep fluorometer. The strobe flash is contained and collimated using a stainless steel tube and a triple-lense Fresnel stack. PVC baffles on the lense stack can be set to produce a slab of light 5 to 10 cm thick, perpendicular to the camera. The illuminated imaging area can be varied using the zoom capability of the camera. For imaging the particle size range down to 0.5 mm, a 23 cm wide by 17.25 cm high image is acquired with a slab thickness of 10 cm. Calibration of the images is made by placing a target in the image volume during a preliminary cast and subsequent to all changes of the system parameters (e.g., image volume). Images from the camera are captured using a Data Translation frame capture board and NIH Image software on an Apple Macintosh IIci computer. Images are thresholded and particle counts made using the capabilities of the NIH Image program. Obvious zooplankton and nekton are excluded from the particle counts. Frames in the upper water column where sunlight is visible are excluded from the analysis because of potential ambiguity as to the water volume sampled (i.e., particles outside of the strobe illuminated volume may have been illuminated by sunlight). The strobe flash rate and lowering rate of the LAPS can be varied depending on the desired image density and the length of the cast. Generally the strobe interval is set for 6 seconds and the LAPS is lowered at 20 m/min yielding an image every 2 meters.</p>
<p>Each image is analyzed for the total number of particles and their maximum, minimum and equivalent circular diameters. The particles are binned into 0.5 mm size ranges based on the equivalent circular diameter starting at 0.5 mm. Particle volume is calculated assuming sphericity and diameters equal the means of the ranges.</p>
<p>The Seacat CTD will be factory calibrated prior to the EQPAC cruises. Transmissometer data reduction will be accomplished as outlined in the optics protocols.</p>
<h2>Literature Cited</h2>
<p>Asper, V.L. (1987).</p>
<p>Measuring the flux and sinking speed of marine snow aggregates. <em>Deep-Sea Research</em>, <strong>34</strong>(1A):1-17.</p>
<p>Dymond, J. and R. Collier (1988).</p>
<p>Biogenic particle fluxes in the equatorial Pacific: Evidence for both high and low productivity during the 1982-1983 El-Ni�o. <em>Global Bioceochemical Cycles</em>, <strong>2</strong>: 129-137.</p>
<p>Gardner, W.D. and I.D. Walsh (1990).</p>
<p>Distribution of macroaggregates and fine-grained particles across a continental margin and their potential role in fluxes. <em>Deep-Sea Research</em>, <strong>37</strong>: 401-412.</p>
<p>Gardner, W.D., I.D. Walsh, and V.L. Asper (1988).</p>
<p>Comparison of large-particle camera and transmissometer profiles. Presented at the <em>JOA Special Symposium on New Observation Methods, Acapulco, Mexico (1988).</em></p>
<p>Honjo, S., K.W. Doherty, Y.C. Agrawal, and V.L. Asper (1984).</p>
<p>Direct optical assessment of large amorphous aggregates (marine snow) in the deep ocean. <em>Deep-Sea Research</em>, <strong>31</strong>: 67-76.</p>
<p>Walsh, I.D. (1990).</p>
<p><em>Project CATSTIX: Camera, transmissometer, and sediment integration experiment.</em> Ph.D. Dissertation, Texas A &amp; M University, 96pp.</p>
<p>Walsh, I.D. and W.D. Gardner (1992).</p>
<p>Comparison of large particle camera profiles with sediment trap fluxes. <em>Deep-Sea Research</em>, <strong>39</strong>: 1817-1834.</p>
<p>Walsh, I.D., J. Dymond and R. Collier (1988).</p>
<p>Rates of recycling of biogenic components of fast settling particles derived from sediment trap experiments. <em>Deep-Sea Research</em>, <strong>35</strong>: 43-58.</p>
from Cruise: TT050 <pre>
PI: Ian Walsh and Wilf Gardner
of: Texas A&M University
dataset: Aggregates greater than .5 mm in diameter
dates: August 22, 1995 to September 13, 1995
location: N: 20.3742 S: 9.9375 W: 57.1678 E: 68.7494
project/cruise: Arabian Sea/TTN-050 - Process Cruise 5 (Late SW Monsoon)
ship: Thomas Thompson
</pre>
<h2>Large Aggregate Profiling System Protocol</h2>
<p> </p>
<p><strong>Ian D. Walsh, Wilford B. Gardner and Mary Jo Richardson</strong></p>
<p>Camera systems have been developed to characterize millimeter size particle distributions in the water column (Honjo etal, 1984; Asper, 1987; Gardner etal, 1988). It is conjectured that the millimeter size class range of particles, thought to be primarily composed of aggregates (``marine snow'') may dominate the total mass flux because of their abundance and high settling rates (Asper, 1987). Camera systems integrated with a CTD and transmissometer (such as the Walsh/Gardner Large Aggregate Profiling System (LAPS)) have the advantage of simultaneously collecting data on the distribution of suspended particles and aggregates along with the physical structure of the water column. This is important as previous work has shown that the distribution of aggregates at depth does not reflect the Suspended Particulate Matter (SPM) distribution, particularly in the case of intermediate depth layers of high aggregate abundance (Gardner and Walsh, 1990; Walsh 1990; Walsh and Gardner, in press). The continuous nature of the LAPS profile allows for the identification of mid-water aggregate nepheloid layers which might be missed by sediment traps or pumping because of low sampling density. This is particularly important to the success of the EQPAC program as the previous sediment trap moorings deployed in the area have shown mid-water column flux maximums (~1000--2000 m) on a yearly and seasonal basis except for a three month period at 11� N, 140� W during which the flux was dominated by a diatom bloom (Walsh <em> et al.</em>, 1988; Dymond and Collier, 1988).</p>
<p>The LAPS system as configured for the EQPAC program consists of a Deep-Sea Power and Light AVCS-101 Autonomous Video Camera (Sony CCD V801) synchronized with a high power strobe, and a Sea-Bird Seacat CTD coupled with a Sea Tech 25 cm pathlength deep transmissometer and a Sea Tech deep fluorometer. The strobe flash is contained and collimated using a stainless steel tube and a triple-lense Fresnel stack. PVC baffles on the lense stack can be set to produce a slab of light 5 to 10 cm thick, perpendicular to the camera. The illuminated imaging area can be varied using the zoom capability of the camera. For imaging the particle size range down to 0.5 mm, a 23 cm wide by 17.25 cm high image is acquired with a slab thickness of 10 cm. Calibration of the images is made by placing a target in the image volume during a preliminary cast and subsequent to all changes of the system parameters (e.g., image volume). Images from the camera are captured using a Data Translation frame capture board and NIH Image software on an Apple Macintosh IIci computer. Images are thresholded and particle counts made using the capabilities of the NIH Image program. Obvious zooplankton and nekton are excluded from the particle counts. Frames in the upper water column where sunlight is visible are excluded from the analysis because of potential ambiguity as to the water volume sampled (i.e., particles outside of the strobe illuminated volume may have been illuminated by sunlight). The strobe flash rate and lowering rate of the LAPS can be varied depending on the desired image density and the length of the cast. Generally the strobe interval is set for 6 seconds and the LAPS is lowered at 20 m/min yielding an image every 2 meters.</p>
<p>Each image is analyzed for the total number of particles and their maximum, minimum and equivalent circular diameters. The particles are binned into 0.5 mm size ranges based on the equivalent circular diameter starting at 0.5 mm. Particle volume is calculated assuming sphericity and diameters equal the means of the ranges.</p>
<p>The Seacat CTD will be factory calibrated prior to the EQPAC cruises. Transmissometer data reduction will be accomplished as outlined in the optics protocols.</p>
<h2>Literature Cited</h2>
<p>Asper, V.L. (1987).</p>
<p>Measuring the flux and sinking speed of marine snow aggregates. <em>Deep-Sea Research</em>, <strong>34</strong>(1A):1-17.</p>
<p>Dymond, J. and R. Collier (1988).</p>
<p>Biogenic particle fluxes in the equatorial Pacific: Evidence for both high and low productivity during the 1982-1983 El-Ni�o. <em>Global Bioceochemical Cycles</em>, <strong>2</strong>: 129-137.</p>
<p>Gardner, W.D. and I.D. Walsh (1990).</p>
<p>Distribution of macroaggregates and fine-grained particles across a continental margin and their potential role in fluxes. <em>Deep-Sea Research</em>, <strong>37</strong>: 401-412.</p>
<p>Gardner, W.D., I.D. Walsh, and V.L. Asper (1988).</p>
<p>Comparison of large-particle camera and transmissometer profiles. Presented at the <em>JOA Special Symposium on New Observation Methods, Acapulco, Mexico (1988).</em></p>
<p>Honjo, S., K.W. Doherty, Y.C. Agrawal, and V.L. Asper (1984).</p>
<p>Direct optical assessment of large amorphous aggregates (marine snow) in the deep ocean. <em>Deep-Sea Research</em>, <strong>31</strong>: 67-76.</p>
<p>Walsh, I.D. (1990).</p>
<p><em>Project CATSTIX: Camera, transmissometer, and sediment integration experiment.</em> Ph.D. Dissertation, Texas A & M University, 96pp.</p>
<p>Walsh, I.D. and W.D. Gardner (1992).</p>
<p>Comparison of large particle camera profiles with sediment trap fluxes. <em>Deep-Sea Research</em>, <strong>39</strong>: 1817-1834.</p>
<p>Walsh, I.D., J. Dymond and R. Collier (1988).</p>
<p>Rates of recycling of biogenic components of fast settling particles derived from sediment trap experiments. <em>Deep-Sea Research</em>, <strong>35</strong>: 43-58.</p>
<!-- #EndEditable -->
from Cruise: TT054 <pre>
<strong>PI:</strong> Ian Walsh and Wilf Gardner
<strong>of:</strong> Texas A&M University
<strong>dataset:</strong> Aggregates greater than .5 mm in diameter
<strong>dates:</strong> December 03, 1995 to December 26, 1995
<strong>location:</strong> N: 19.8836 S: 9.9736 W: 57.3035 E: 68.7809
<strong>project/cruise:</strong> Arabian Sea/TTN-054 - Process Cruise 7 (Early NE Monsoon)
<strong>ship:</strong> Thomas Thompson
</pre>
<table border="0" cellpadding="2" style="height:350px; width:725px">
<tbody>
<tr>
<td><!-- #BeginEditable "main%20content" --><!-- data_object info file from
http://synthesis.whoi.edu/jg/info/jgofs/arabian/ttn-043/data_object -->
<h2>Large Aggregate Profiling System Protocol</h2>
<p><strong>Ian D. Walsh, Wilford B. Gardner and Mary Jo Richardson</strong></p>
<p>Camera systems have been developed to characterize millimeter size particle distributions in the water column (Honjo etal, 1984; Asper, 1987; Gardner etal, 1988). It is conjectured that the millimeter size class range of particles, thought to be primarily composed of aggregates (``marine snow'') may dominate the total mass flux because of their abundance and high settling rates (Asper, 1987). Camera systems integrated with a CTD and transmissometer (such as the Walsh/Gardner Large Aggregate Profiling System (LAPS)) have the advantage of simultaneously collecting data on the distribution of suspended particles and aggregates along with the physical structure of the water column. This is important as previous work has shown that the distribution of aggregates at depth does not reflect the Suspended Particulate Matter (SPM) distribution, particularly in the case of intermediate depth layers of high aggregate abundance (Gardner and Walsh, 1990; Walsh 1990; Walsh and Gardner, in press). The continuous nature of the LAPS profile allows for the identification of mid-water aggregate nepheloid layers which might be missed by sediment traps or pumping because of low sampling density. This is particularly important to the success of the EQPAC program as the previous sediment trap moorings deployed in the area have shown mid-water column flux maximums (~1000--2000 m) on a yearly and seasonal basis except for a three month period at 11� N, 140� W during which the flux was dominated by a diatom bloom (Walsh <em> et al.</em>, 1988; Dymond and Collier, 1988).</p>
<p>The LAPS system as configured for the EQPAC program consists of a Deep-Sea Power and Light AVCS-101 Autonomous Video Camera (Sony CCD V801) synchronized with a high power strobe, and a Sea-Bird Seacat CTD coupled with a Sea Tech 25 cm pathlength deep transmissometer and a Sea Tech deep fluorometer. The strobe flash is contained and collimated using a stainless steel tube and a triple-lense Fresnel stack. PVC baffles on the lense stack can be set to produce a slab of light 5 to 10 cm thick, perpendicular to the camera. The illuminated imaging area can be varied using the zoom capability of the camera. For imaging the particle size range down to 0.5 mm, a 23 cm wide by 17.25 cm high image is acquired with a slab thickness of 10 cm. Calibration of the images is made by placing a target in the image volume during a preliminary cast and subsequent to all changes of the system parameters (e.g., image volume). Images from the camera are captured using a Data Translation frame capture board and NIH Image software on an Apple Macintosh IIci computer. Images are thresholded and particle counts made using the capabilities of the NIH Image program. Obvious zooplankton and nekton are excluded from the particle counts. Frames in the upper water column where sunlight is visible are excluded from the analysis because of potential ambiguity as to the water volume sampled (i.e., particles outside of the strobe illuminated volume may have been illuminated by sunlight). The strobe flash rate and lowering rate of the LAPS can be varied depending on the desired image density and the length of the cast. Generally the strobe interval is set for 6 seconds and the LAPS is lowered at 20 m/min yielding an image every 2 meters.</p>
<p>Each image is analyzed for the total number of particles and their maximum, minimum and equivalent circular diameters. The particles are binned into 0.5 mm size ranges based on the equivalent circular diameter starting at 0.5 mm. Particle volume is calculated assuming sphericity and diameters equal the means of the ranges.</p>
<p>The Seacat CTD will be factory calibrated prior to the EQPAC cruises. Transmissometer data reduction will be accomplished as outlined in the optics protocols.</p>
<h2>Literature Cited</h2>
<p>Asper, V.L. (1987).</p>
<p>Measuring the flux and sinking speed of marine snow aggregates. <em>Deep-Sea Research</em>, <strong>34</strong>(1A):1-17.</p>
<p>Dymond, J. and R. Collier (1988).</p>
<p>Biogenic particle fluxes in the equatorial Pacific: Evidence for both high and low productivity during the 1982-1983 El-Ni�o. <em>Global Bioceochemical Cycles</em>, <strong>2</strong>: 129-137.</p>
<p>Gardner, W.D. and I.D. Walsh (1990).</p>
<p>Distribution of macroaggregates and fine-grained particles across a continental margin and their potential role in fluxes. <em>Deep-Sea Research</em>, <strong>37</strong>: 401-412.</p>
<p>Gardner, W.D., I.D. Walsh, and V.L. Asper (1988).</p>
<p>Comparison of large-particle camera and transmissometer profiles. Presented at the <em>JOA Special Symposium on New Observation Methods, Acapulco, Mexico (1988).</em></p>
<p>Honjo, S., K.W. Doherty, Y.C. Agrawal, and V.L. Asper (1984).</p>
<p>Direct optical assessment of large amorphous aggregates (marine snow) in the deep ocean. <em>Deep-Sea Research</em>, <strong>31</strong>: 67-76.</p>
<p>Walsh, I.D. (1990).</p>
<p><em>Project CATSTIX: Camera, transmissometer, and sediment integration experiment.</em> Ph.D. Dissertation, Texas A & M University, 96pp.</p>
<p>Walsh, I.D. and W.D. Gardner (1992).</p>
<p>Comparison of large particle camera profiles with sediment trap fluxes. <em>Deep-Sea Research</em>, <strong>39</strong>: 1817-1834.</p>
<p>Walsh, I.D., J. Dymond and R. Collier (1988).</p>
<p>Rates of recycling of biogenic components of fast settling particles derived from sediment trap experiments. <em>Deep-Sea Research</em>, <strong>35</strong>: 43-58.</p>
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</table>
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
Sea-Bird Seacat CTD
Sea-Bird Seacat CTD
PI Supplied Instrument Name: Sea-Bird Seacat CTD PI Supplied Instrument Description:Sea-Bird Seacat CTD coupled with a Sea Tech 25 cm pathlength deep transmissometer and a Sea Tech deep fluorometer. Instrument Name: CTD Sea-Bird SEACAT Instrument Short Name:CTD SEACAT Instrument 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)). More information from Sea-Bird Electronics. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/350/
Large Aggregate Profiling System
Large Aggregate Profiling System
PI Supplied Instrument Name: Large Aggregate Profiling System PI Supplied Instrument Description:The LAPS system as configured for the EQPAC program consists of a Deep-Sea Power and Light AVCS-101 Autonomous Video Camera (Sony CCD V801) synchronized with a high power strobe, and a Sea-Bird Seacat CTD coupled with a Sea Tech 25 cm pathlength deep transmissometer and a Sea Tech deep fluorometer. Instrument Name: Large Aggregate Profiling System Instrument Short Name:LAPS Instrument Description: The Large Aggregate Profiling System (LAPS) is a camera system developed to characterize millimeter size particle distributions in the water column. Camera systems are integrated with a CTD and transmissometer and therefore have the advantage of simultaneously collecting data on the distribution of suspended particles and aggregates along with the physical structure of the water column (Honjo et al., 1984; Asper, 1987; Gardner et al., 1988).
SNOY CCD V801
SNOY CCD V801
PI Supplied Instrument Name: SNOY CCD V801 PI Supplied Instrument Description:Deep-Sea Power and Light AVCS-101 Autonomous Video Camera synchronized with a high power strobe Instrument Name: Underwater Camera Instrument Short Name: Instrument Description: All types of photographic equipment that may be deployed underwater including stills, video, film and digital systems. Community Standard Description: http://vocab.nerc.ac.uk/collection/L05/current/180/
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: 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