Project 3: Results 9/2000

The Impact of Episodic Events on Nearshore-offshore Transport in the Great Lakes: Physical Oceanography

PIs: Saylor, J. H., Miller, G. S., and M. J. McCormick Canadian Colleagues: Murthy, C. R., Rao, R., Miners, K., Chiocchio, F. and J. Bull

Objectives:

To identify and quantify the physical processes generating nearshore- offshore transport of biogeochemically important materials during winter/spring episodic events;
To establish an observation strategy for generating maximum resolution of all the dominant time and space scales;
To estimate the velocity field along and across the plume as it evolves;
To determine the coastal energetics of the two-gyre vorticity wave under barotropic conditions and its response to increasing baroclinicity;
To determine the climatology of coastal energetics of the episodic nearshore current reversals during winter/spring and summer conditions;
To estimate particle dispersion from Lagrangian statistics and compare with circulation model based estimates to assess model adequacy;
To undertake a comparative study of coastal ocean processes from this program and past programs undertaken in the Great Lakes;
To establish a database of all of our observations and make them easily available to other program participants.

Approach:

Our observation program is concentrated along the southeast coast of Lake Michigan which, based upon satellite AVHRR data, appears to be the best location for observing cross-margin transport. The observation strategy is based upon moored instrument arrays and Lagrangian measurement.

Results:

During the pilot year it was quickly realized that additional data coverage was necessary to augment the observational program. Consequently, GLERL funded scientists from CCIW to participate in EEGLE. In addition to their expertise they brought additional equipment, some of which they deployed in shallow, high risk areas in the primary study region. To date the major focus has been on obtaining and cataloging data from these experiments. Data results are summarized in the following table and some preliminary findings can be found under the products listed on the next page.

Year Days of temp data Days of VACM data Days of ADCP data Days of SACM data Days of drifter data

'97-'98 11,940 4,030 890 - 55

'98-'99 29,785 7,020 2,020 1,540 400

'99-'00 18,515 5,400 1,560 1,450 310

Year	Days of temp data	Days of VACM data	Days of ADCP data	Days of SACM data	Days of drifter data
'97-'98	11,940	4,030	890	-	55
'98-'99	29,785	7,020	2,020	1,540	400
'99-'00	18,515	5,400	1,560	1,450	310