The Moderate Resolution Imaging Spectroradiometer aboard NASA's Terra and Aqua satellites, providing daily global observations in 36 spectral bands. MODIS is widely used for large-scale water cycle monitoring including snow cover, vegetation health, and evapotranspiration.
MODIS (Moderate Resolution Imaging Spectroradiometer) is a key instrument aboard NASA's Terra (launched 1999) and Aqua (launched 2002) satellites, providing near-daily global coverage in 36 spectral bands at spatial resolutions of 250 m, 500 m, and 1 km. For water resources, MODIS produces operational data products including snow cover extent (MOD10), land surface temperature (MOD11), vegetation indices (MOD13), evapotranspiration (MOD16), and gross primary productivity (MOD17). The daily revisit capability makes MODIS invaluable for monitoring rapidly changing conditions such as flood extent, drought progression, snow melt dynamics, and wildfire impacts on watersheds. MODIS data have been critical for developing the Global Flood Monitoring System and validating continental-scale hydrological models. While the spatial resolution is coarser than Landsat, the high temporal frequency and free data access have made MODIS one of the most widely used satellite sensors in hydrology and water resource management. The MODIS data record spanning over 20 years enables trend analysis of land surface conditions and water cycle components at regional to global scales.