MODIS-derived surface temperature of the Great Salt Lake

Abstract

The surface temperature of Utah's hypersaline Great Salt Lake is examined between 2000 and 2007 using 3345 images from the Moderate Resolution Imaging Spectroradiometer (MODIS) on board the NASA Earth Observing System Terra and Aqua platforms. This study shows the utility of using a multi-year record of the easily accessible and fully processed MODIS thermal imagery to monitor spatial, diurnal, seasonal, and annual variations in the surface water temperature (SWT) of lakes where long-term in situ measurements are rarely available. A cloud-free Terra image is available on average every day during the summer and early fall, every other day during spring and late fall, and every third day during the winter. MODIS-derived lake SWT exhibits a cool bias (~ − 1.5 °C) relative to in situ temperature observations gathered from three buoys and a slowly-moving watercraft. The dominant SWT signal is the annual cycle (with a range of 26 °C and peak temperature in mid-July) while the diurnal range is as large as 4 °C during the spring season. Year-to-year variations in SWT are largest during the fall with over 1 °C anomalously warm (cold) departures from the 8-year monthly medians observed during fall 2001 (2006). The MODIS imagery provides an updated SWT climatology for operational weather forecasting applications (e.g., lake-effect snow storm prediction) as well as for input into operational and research numerical weather prediction models.