Project Summary

Ron Schlitz

Physical and Biological Processes at the Tidally Mixed Front on Southern Georges Bank

Physical and jointly physical/biological measurements are proposed as part of the 1999 GLOBEC intensive period focusing on cross-frontal physical and biological processes over Georges Bank. The emphasis is on issues involving the exchange of water and plankton (zooplankton and ichthyoplankton) across the front that is produced by tidal mixing and located along the southern side of Georges Bank. First, a seven-element moored array on the southern side of the Bank is proposed to investigate the local kinematics and dynamics of circulation within the frontal regime and to observe hydrographic properties. Second, three highly resolved MOCNESS surveys (during setting, servicing, and recovery of the moorings) are proposed to investigate the biological structure near the front and exchange of plankton across the front. The MOCNESS surveys would span normal zooplankton observations including a Video Plankton Recorder (VPR) and include physical variables (temperature, salinity, transmission, and fluorescence). The context for the experimental work will be modeling that will establish the balance of forces maintaining the front and investigate distribution and movement of plankton within the frontal regime.

Note: On each of the three cruises during the experimental phase the biological sampling will include an extensive electronics packege on the MOCNESS samplers. Most noteworthy are two cameras at different focal lengths allowing a wide range of resolution. If details are needed in the discussions, Lew Incze can provide further specifications since he is one of the co-authors on the Lough proposal.