Diurnal variability of surface temperature over lakes: Case study for Lake Huron

The significance of the diurnal variability of Lake Surface Temperature (LST) has been recog-nized, yet, its magnitude in terms of spatial and temporal variability is not well known. Attempts have been made to derive such information from satellites at high spatial resolution, however most have been made from polar orbiters that sample only twice per day. We describe an effort to derive such information from geostationary satellites at hourly time scale and at about 5-km spa-tial resolution. The approach to derive LST uses the Radiative Transfer for TIROS Operational Vertical Sounder (TOVS) (RTTOV) model driven with the Modern-Era Retrospective analysis for Research and Applications (MERRA)-2 information. The methodology has been implemented over Lake Huron for about six years. We present results of evaluation against various independ-ent satellite products and demonstrate that there is a strong diurnal variability in the skin tem-perature over the lake and that the lowest and highest values as derived twice per day from polar orbiting satellites do not represent appropriately the magnitude of the Diurnal Temperature Range (DTR).