Stramski, D. Marine Physical Laboratory, Scripps Institution of Oceanography, stramski@mpl.ucsd.edu
Stramska, M. Hancock Institute for Marine Studies, University of Southern California, stramska@usc.edu
Tegowski, J. Institute of Oceanology, Polish Academy of Sciences, tegowski@iopan.gda.pl
Szczucka, J. Institute of Oceanology, Polish Academy of Sciences, szczucka@iopan.gda.pl
Klusek, Z. Institute of Oceanology, Polish Academy of Sciences, klusek@iopan.gda.pl

 
CONCURRENT MEASUREMENTS OF TIME FLUCTUATIONS IN THE INHERENT OPTICAL PROPERTIES AND GAS BUBBLE CONCENTRATION IN THE NEAR-SURFACE OCEANIC LAYER
 
We will present results from optical measurements of the beam attenuation and backscattering coefficients that were carried out concurrently with acoustic measurements of gas bubble concentration in the near-surface layer of the ocean. Our experiment was focused on measuring short-term fluctuations on scales from seconds to minutes. The underlying hypothesis was that occasional events of bubble entrainment by breaking waves may cause significant increases in light scattering in the uppermost few meters of the ocean. We will show examples of time series of optical beam attenuation and backscattering under sea state conditions characterized by moderate development of breaking waves (wind speed ~10 m/s). These data will be compared with time series of bubble concentration measured acoustically at a frequency of 30 kHz, which corresponds to bubble radius of about 100 micrometers. Measurements at two other acoustic frequencies (63 and 115 kHZ) were also made to provide rough estimate of bubble size distribution. The statistical properties of time series obtained from these concurrent optical and acoustic measurements provide the first direct evidence that light scattering by seawater may exhibit measurable fluctuations associated with dynamics of submerged gas bubbles under a wind-disturbed sea surface.
 
Day: Thursday, Feb. 4
Time: 02:00 - 02:15pm
Location: Eldorado Hotel
 
Code: CS61TH0200E