The Evolution of AVHRR-Derived Water Temperatures over Lakes in the Mackenzie Basin and Hydrometeorological Applications

Abstract

Abstract The temperature evolution of water bodies is determined and compared over the Mackenzie River hydrological basin. The thermal IR observations used to determine the water temperatures were extracted from NOAA's Advanced Very High Resolution Radiometer (AVHRR) satellite data over the period from April 1999 to September 1999. The IR temperatures were calibrated and adjusted to account for the intervening atmosphere. For each day, 1-km-resolution temperature scenes were generated. From the temperature scenes, clear-sky temperature values were extracted for water bodies with areas larger than 100 km2. The temperature cycle over water bodies can be decomposed into a small positive slope from near 0°C until the water temperature reaches 4°C, followed by a quadratic trend that can be easily fitted. The quadratic curve fit parameters give information for cataloging and comparing each water body's seasonal temperature cycle. Data stratification confirms a strong latitudinal influence on the shape of the cu...