Observations and model predictions of water skin temperatures at MTI core site lakes and reservoirs

摘要

The Savannah River Technology Center (SRTC) measured water skin temperatures at four of the Multi-spectral Thermal Imager (MTI) core sites. The depression of the skin temperature relative to the bulk water temperature (DELTA T) a few centimeters below the surface is a complex function of the weather conditions, turbulent mixing in the water and the bulk water temperature. Observed skin temperature depressions range from near zero to more than 1.0 deg C. Skin temperature depressions tend to be larger when the bulk water temperature is high, but large depressions were also observed in cool bodies of water in calm conditions at night. We compared AT predictions from three models (SRTC, Schlussel and Wick) against measured AT's from 15 data sets taken at the MTI core sites. The SRTC and Wick models performed somewhat better than the Schlussel model, with RMSE and average absolute errors of about 0.2 deg C, relative to 0.4 deg C for the Schlussel model. The average observed DELTA T for all 15 databases was -0.7 deg C.