Six research groups participated in the cruise. A description of the measurements made by each group follows.
 

Also find:

• General Chronology
• Events Log
• Scientific Personnel

University of Connecticut - Dr. C. Roesler

The University of Connecticut's contribution to the Summer 1996 CM&O cruise consisted of in-water inherent optical property (IOP) measurements and sample a nalyses. Ninety profiles of size fractionated spectral absorption and attenuation coeffic ients were made in concert with water collection. The optical package consisting of three WET Labs ac-9's (nine wavelength absorption and attenuation meter), SAFire (spectral fluorescence and absorption meter) ( P.Coble ), a Super MODAPS (Modular Data and Power System), and an FSI micro-CTD, was deployed on the ship's CTD/rosette syst em. Multiple casts allowed replicate profiles of the total and <0.2mm fraction IOP's to be obtained while the filter cartridge of the third ac-9 was changed between casts to obtain single profiles of the < 1, < 5, or < 10 mm fraction IOP's. A Sequoia Scientif ic LISST100 simultaneously recorded the forward volume scattering function (0.5 to 5 degrees), although the data stream was not integrated through the MODAPS system. Profiles of particle size distributions (5 to 500 mm diameters) were derived fro m the volume scattering function measurements. Water samples were analyzed fluorometrically for pigment concentration and spectrophotometrically for dissol ved and particulate absorption spectra (the latter were separated into phytoplankton and non- phytoplankton components). All analyses were performed on size fractionated wat er samples in accordance with the in situ fractionation. A Galai CIS 100 was used t o determine the particle size distributions (0.5 to 150 mm diameters) of the water samples.
 

Texas A&M University - Dr. W. Gardner and Dr. I. Walsh

The TAMU group made 53 profiles with the LAPS system, which includes two video cameras, CTD, Sea Tech chlorophyll fluorometer, transmissometer, and light scatt ering sensor, and a Sequoia LISST. The video cameras photograph different volumes of water to image particles; >~200mm in the small volume and > 500mm in the large volume camera system. LISST is designed to measure the in-situ particle size distribut ion between 5 and 500 mm . Most of the signal from the LSS and transmissometer come from particles <20mm . The abundance and size distribution of particles <20mm were analyzed in water samples from 50 CTD hydrocasts with a Coulter Multisizer. Sam ples from the water bottles on the CTD casts were filtered to measure the concentrati on of particulate organic carbon and total particulate matter. These data provide one method for calibrating the transmissometer profiles made on the 90 CTD casts. Core samp les of surface sediment were obtained. A sediment trap was deployed and samples from f ive depths were obtained from a two week deployment prior to the passage of Hurrican e Edouard.
 

Oregon State University - Dr. R. Zaneveld and Dr. S. Pegau

The Slow Descent Rate Optical Platform (SlowDROP) was used to obtain high vertic al resolution (~ 4cm) measurements of optical and physical parameters. Mounted on the platform were a SBE 911 plus CTD, an unfiltered WET Labs ac-9, an ac-9 with a 0 .2 mm pore size filter on the intake of the absorption tube, a SAFire, an SRI bb-4 bac kscattering sensor and a WET Labs prototype backscattering instrument. A WET Labs MODAPS unit was used to power the instruments and to collect the data from all the inst ruments in a format that allows the separate data streams to be merged. For the last four days of the cruise an ac-9 with a 5mm pore size filter and a LISST-100 supplied by Dr. Roesl er were added to the package. Additionally, the O.S.U. SAFire was exchanged with the SA Fire belonging to Dr. Coble. A common filter set was used in all ac-9's with wavelen gths of 412, 440, 488, 510, 532, 555, 650, 676, and 715 nm. Backscattering measurements were made on the bb-4 at wavelengths of 440 and 675 nm. The SAFire contains 6 excita tion wavelengths (5 in the visible and 1 in the ultraviolet) and 16 emission waveleng ths. From the ac-9 with the 0.2mm filter, the spectral absorption coefficients of d issolved materials were determined. The unfiltered ac-9 was used to determine the spectr al absorption, attenuation and scattering coefficients of all components. The diff erence of these two absorption measurements provides the spectral absorption coefficients of the suspended particles. Addition of the third ac-9 allowed the particulate absorpt ion spectrum to be broken into contributions by particles less than and greater than 5 mm. The SAFire provides excitation and emission spectra of dissolved and suspended materials, and a measure of the scattering function at 90 degrees. The CTD was used to measure temperature and salinity along with chlorophyll fluorescence using a WET Labs Wetstar fluorometer, a transmissometer, and oxygen concentration. On most days the SlowDROP package was deployed repeatedly during three 1.5 hour long sessions. During each session 4 to 10 profiles were made from the surface to within a few meters of the bottom. During the transects two or three profiles were mad e at each location.
 

University of South Florida - Dr. P.Coble

Gelbstoff concentrations and spectral properties were measured as a function of hydrography and turbulent mixing using three different in situ instruments. A S ea Tech DOM fluorometer (Ex/Em at 320/420 nm, 40 nm b.p.) was used to collect profiles o n the CTD package. A WET Labs SAFire was deployed on the CTD rosette frame integrated with 3 WET Labs ac-9's and an FSI CTD via a WET Labs superMODAPS (Roesler). A WET Labs GPF (General purpose fluorometer) configured to measure gelbstoff (Ex/E m at 265/420 nm) was used in the ship's underway sea water system. Discrete sampl es were collected using the rosette and excitation-emission matrix (EEM) spectroscopy wa s performed using a SPEX Fluorolog II. Absorption scans were made on discrete sam ples using a Hitachi U 3300 spectrophotometer with 10 cm cells.
 

Woods Hole Oceanographic Institution - Dr. H. Sosik and Dr. R. Olson

Measurements were carried out to characterize the relationship between in situ l ight fields and the abundance and optical properties of suspended particulates. 51 deployme nts of the Satlantic SPMR/SMSR underwater radiometer were completed. This device measures downwelling irradiance, upwelling radiance, and surface downwelling irradiance at 7 wavelengths ( 412, 443, 490, 510, 555, 665, and 683 nm), as well as depth, temperature, and conductivity. A WET Labs ac-9 was contributed to the instrumen t package on the CTD frame. This ac-9 was interfaced with the super MODAPS data acquisition system (Roesler) to measure the optical properties of the components smaller than 0.2 mm.

Sip-board flow cytometry was used to analyze fluorescence and light scattering p roperties of individual particles. This information will be used to determine the size di stributions of phytoplankton and other particles, to estimate their contributions to total s cattering, and to help explain variability in particle absorption. Ten ml water samples, c ollected 3 to 4 times per day from 6 depths throughout the water column were processed to enumerate and characterize particles in the size range of 1 to 50 mm in diameter. Properties measured were fluorescence, forward angle light scattering (2- 19 deg rees), and side angle light scattering (73- 107 degrees) in red (660- 700 nm), orange ( 560- 630 nm), and green (530- 560 nm) portions of the spectrum.

To obtain information about the local productivity of biological particles, incu bations were carried out to measure photosynthetic rates based on C-14 uptake. Three in situ experiments and 80 laboratory experiments were conducted. In situ incubations w ere conducted at 6 depths from local sunrise to sunset. Photosynthesis was measure d in 1 h laboratory experiments over a wide range of light intensities in water collected from 4 depths. These results will be used for modeling of primary production.

Supplementary sampling included freezing of water for nutrient and total inorgan ic carbon analysis, and preservation of water samples for backup flow cytometry and microscopy. Some of the preserved water may be used to identify and enumerate phytoplankton too large or rare for standard flow cytometry.
 

University of Washington - Dr. M. Gregg

Microstructure and CTD measurements were carried out using free fall MMP's (Mari ne Microstructure Profiler). Measurements were carried out from August 19 to Sept. 1 and from Sept. 4 to 7 during 12 hr periods near the central CMO site.

GENERAL CHRONOLOGY

August 17 and 18	Transect along 70 ° 30' W from 41 ° 10' N to 40 ° 00' N, station s every 10 NMi.
August 18	Deploy A.Williams' tripod at 40 ° 29.359' N 70 ° 30.281' W.
August 18- 31	Optical and microstructure profiling near the central site ( 40 ° 30' N 70 ° 30' W).
Sept. 1-3	Wait out Hurricane Edouard in Newport RI.
Sept . 4, 5.	Optical and microstructure profiling near the central site ( 40 ° 30' N 70 ° 30' W).
Sept. 5, 6.	Transect from the central site to 39 ° 50' N along 70 ° 30' W, profiling every 10 NMi.
Sept. 6.	Optical and microstructure profiling near the central site ( 40 ° 30' N 70 ° 30' W).
Sept. 7.	Transect from the central site to 41 ° 00' N along 70 ° 30 ' W, profiling every 10 NMi.

EVENTS LOG

The events log describes time and location of each profiling or mooring activity using the instrumentation described above.
 

SCIENTIFIC PERSONNEL

* * e-mail addresses of CMO Participants * *

University of Connecticut: Dr. Collin Roesler (PI), Jennifer Simeon, Mary Kay Talbot

University of Washington: Dr. Michael Gregg (PI), Jack Miller, Earl Krause, Gordy Welsh, Jody Klymak, Jen Mackinnon

Texas A&M University: Dr. Wilf Gardner (PI), Dr. Ian Walsh (PI), Jan Gundersen, Josh Blakey

Woods Hole Oceanographic Institution: Dr. Heidi Sosik (PI), Dr. Rob Olson (PI), Rebecca Green, Ludmilla Shalapgonok

University of South Florida: Dr. Paula Coble (PI), Dr. Bernard Avril

Oregon State University: Dr. Ron Zaneveld (PI, Chief Scientist), Dr. Scott Pegau, Andrew Barnard
 

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* With comments on content refer to Ronald Zaneveld

* This page maintained by J.J.Fredericks

Last Modified: 26 September, 1996