Marine Ecosystem Dynamics Modeling Laboratory

LAKE SUPERIOR-MM5

The MM5 Flow Chart

Our previous modeling experiments clearly show that the circulation in Lake Superior is domaintly driven by the wind plus seasonal variation of surface heat flux/short-wave penetration. Uncertainty in the wind data is one of major factors that directly affect the simulation accuracy.

Efforts was made to build a forecast model system for Lake Superior: 1) using meso-scale meteorological model (called MM5) or Weather Research Forcaster (WRF) to provide the 5 days of the wind forecast and 2) using the forecasted wind and heat flux to drive FVCOM to provide 5 days of the 3-D current and water temperature fields. In this system the MM5 was operated using two-way nesting from 3 domain. Horizontal resolutions of these domains are 45, 15, and 5 km, with an output of the wind in a 5 km resolution. All buoys and coastal weather station measurement data are assimilated into MM5 to provide a reasonable wind and heat flux flieds.

An effort has been made to upgrade the MM5 system to WRF. With WRF, we can provide the 1-km resolution wind field with better resolution of meso-scale wind variability.

Nested domains

3 nested computational domain of MM5. This is the original MM5 system we built for KITES. This setup was used to re-build the meso-scale fields of surface wind and heat flux for 1999 based on NCEP output. The updated version of MM5 that has been upgraded to 3 domains with horizontal resolutions of 27, 9 and 3 km.

All NOAA buoys and coastal weather stations are included in the nudging data assimilation. The SST was also nudged into the model for the surface heat flux estimation. The heat flux calculation used in this system was the one modified by Chen et al. (2005).

Click the image on the right to see the full-size image.

An example of MM5 wind animation

The Lake Superior MM5 was set up at UMASS-D and run to provide the 1999 wind field for KITES project. With assimilated buoy winds, MM5 provided a much better wind field than the interpolated wind fields from the coastal weather stations. The animation shown here is just an example.

Click the image on the right to view the animation.

 

An example of MM5 surface heat flux animation

This animation is just an example showing the ability of MM5 in resolving the meso-scale varability of the surface heat flux in Lake Superior. The updated Lake Superior MM5 has included the satellite-derived SST for the heat budget estimation.

Click the image on the right to view the animation.

Wind field interpolated from all surrounding weather stations plus NOAA buoys

This is an animation showing the daily distribution of the surface wind interpolated from weather stations around the coast and NOAA buoys in the lake. An empirical relationship between the land and water wind was used to convert the land wind to the water wind.

Click the image on the right to view the animation

«PreviousNext» Posted on January 15, 2014