MODELING WORKGROUP MEETING-3

Meeting held at NOAA/GLERL, June 6, 2000

Participants: P.Roebber (UWM), P.Chu, V.Velissariou, Y.Guo (OSU), L.Meadows (UM), J.Budd (MTU), R.Murthy, R.Yerubandi (CCIW), D.Schwab, D.Beletsky, J.Saylor, P.Liu, N.Hawley, J.As-Salek, T.Ali, M.McCracken, G.Lang (GLERL). Chair: D.Schwab. Reported by D.Beletsky.

Contact for this report: Dima Beletsky, dima.beletsky@noaa.gov


Paul Roebber reported on results of meteorological modeling of 7-13 March 1998 event. The model was calibrated with wind data at NDBC buoy 45002. He also discussed modifications to MM5 including adjustment of Charnock constant and lowering of bottom sigma level to better simulate overlake physics. Plans include assimilation of radar data in order to better model mesoscale atmospheric vortex on March 11. Additional plans are to examine meteorological conditions prior to previous resuspension events in order to establish a resuspension event climatology.

Dave Schwab presented results of modeling of idealized mesoscale atmospheric vortex, which can generate strong cyclonic vortex in southern Lake Michigan. Another ongoing project at GLERL is a study of wave data off Chicago for climatological analysis of resuspension events. New aerial photography and ship cruise data obtained during the April 2000 resuspension event were presented. Future plans include development of a simplified (2D) sediment dynamics model and utilization of satellite imagery for model validation.

Dima Beletsky presented results of March-April 1998 and 1999 hydrodynamic modeling. Model results were compared with observations in 1998; model sensitivity to forcing functions was studied using MM5 winds provided by Paul Roebber. Excessive vertical shear in model currents during wind events and overall underestimation of current speeds during reversals were noted. Biological model results for 1998 provided by Changsheng Chen and Rubao Ji were also presented. Future plans include multi-year hydrodynamic model runs (1996-2000).

Ram Yerubandi and Raj Murthy presented analysis of longshore/onshore CCIW current data using 3 models: linear regression, momentum balance and impulse-response function. Empirical models performed quite well for alongshore flow and not as well for cross-shore flow. It was suggested that similar type of analysis can be performed with model data.

Philip Chu, Vasilia Velissariou and Yong Guo reported on the progress with OSU modeling system which includes a hydrodynamic model CH3D, sediment transport model CH3D-SED, wave model WAM and wave-current boundary layer model WCBL. The fully coupled model system is extremely computer intensive and is programmed for use on parallel architecture computers (Cray T3D, Origin 2000). OSU plans to develop a bottom sediment characterization map for initialization of sediment models on the 2-km hydrodynamic grid. There is also a plan to implement a radioactive model coupled with sediment and circulation models.

Lorelle Meadows reported on the availability of current data measured with HF radar in St. Joseph area. Experiments included 2-week radar deployment in 1998, and 7-week deployments in 1999 and 2000 with addition of meteorological buoy also measuring surface currents. The HF radar requires wave heights over 1 foot to create large enough return signal for Doppler processing. Available HF radar-derived current fields will be interpolated to the 2-km hydrodynamic grid in the vicinity of the HF radar sites.

Judy Budd described availability of remote sensing data for analysis of resuspension events. Particular attention was paid to the new data from SeaWIFS system including surface reflectance and chlorophyll data. The problem of time interpolation of satellite data was also discussed.

Junaid As-Salek presented his plans to simulate high-frequency water level fluctuations and storm surges during strong wind events in Lake Michigan.

Discussion topics included review of overall modeling strategy and schedule, selection of priority events for modeling, review of data sources for model calibration and validation, data assimilation of current meter, drifter and HF radar data, use of remote sensing data in hydrodynamic, sediment dynamics, and biological models, simplified hydrodynamic/sediment transport models. It appears that OSU and GLERL will develop complementary circulation/wave/sediment modeling systems with the OSU system being more process- oriented and applicable to episodic events, and the GLERL system more empirically oriented and applicable to long-term simulations.


June 13, 2000