Rick Reynolds and Dariusz Stramski

Measurements of IOPs and

Characterization of Particle Assemblages

for Monterey Bay Experiment

Marine Physical LaboratoryScripps Institution of OceanographyUniversity of California, San Diego

Fourth Coast Meeting; 28-29 June 2006, Monterey, CA

Collection of a bio-optical data set for: 1. Development of ocean color algorithms for Particulate Organic Carbon (POC) and Total Suspended Particle Mass (TSPM) concentrations.

2. Ground-truth validation of ocean color products.

Primary objective for experiment

• Measurement of multi-angle scattering at 532 nm (Dawn-EOS)

• Determination of POC and TSPM concentration

• Particle counting, imaging, and identification on selected samples (FlowCAM)

In situ measurements on the R/V Martin • Vertical profiles of the spectral light scattering and

absorption properties of seawater with a Multisensor Datalogger System (MDS)

• Particle size distribution from inversion of light scattering data

Analysis of discrete water samples

In situ measurements of IOPs and PSDMultisensor Datalogger System (MDS)

• CTD sensors (SeaBird)

• Two beam transmissometers (C-Star, Wetlabs)

488 and 660 nm

• Backscattering sensor (Hydroscat-6, HobiLabs)

6 wavelengths: 442, 470, 555, 589, 620, and 671 nm

• Two absorption/backscattering sensors (aBeta, HobiLabs)420 and 510 nm

• Forward light scattering (32 angles, 0.1–14°) and beam transmission at 532 nm, Particle Size Distribution 1-200 m (LISST-100X, Sequoia)

Footprint: ~1 m2

Wire time: 10-20 min. per profile

Internal power and data logging

Water Sample Analyses(Filtrations onboard or shore lab)

• POC and PON (3x500 ml per depth)

• TSPM (≡ TSS)

(3x500 ml per depth)Inorganic and Organic fractions

3 liters per depthSurface, Chl and cp max

SHORE LABDAWN-EOS Multi-Angle Light Scattering

Volume scattering function at 532 nm18 angles, 22-147°Vertical and horizontal polarizations

Scattering Angle [deg]

0.1 1 10 100

Part

icle

VSF

(532

) [

m-1

sr-

1 ]

10-3

10-2

10-1

100

101

102

103

104

Lisst 100XDawn EOSECO-VSF

Imperial Beach Pier10 May 2006

Footprint: 40x60 cmSample Vol: 20 ml

FlowCAM analysis of particlesCounting, imaging, and sizing of particles 5-100 mLight scattering, Fluorescence of Chl a and PECollect and store preserved samples (100 ml); Analysis of selected samples back at SIO (e.g. HABs)

Algorithm Development for POC and TSPM concentration

We will explore the use of different approaches to algorithm development:

• Empirical (Requires POC, TSPM, bb, Rrs)2-step approach (Stramski et al. 1999) Band ratio correlations (Stramska and Stramski 2005)

• Semianalytical and Radiative Transfer Modeling (Constituents => IOPs => Rrs)

Spectral matching and LUT (Reynolds et al. 2001, Mobley et al. 2005)

Summary of Requirements for Monterey Bay Experiment

• 2 PersonnelR. Reynolds (Ship)V. Wright (Shore)

• R/V MartinA-Frame, 10-20 min. per stationWater samples (3-4 depths, 3 liters per depth)Shuttling of water samples to shore?

• Shore Lab FacilitiesBench space for Dawn-EOS Shared filtration setupDrying oven (60° C)