Temporal coverage: 9 June 2002 - 27 September 2011
The AMSR-E Daily Landscape Freeze/Thaw layer shows the predominant daily frozen or non-frozen (thawed) status of the landscape in vegetated regions where seasonal frozen temperatures are a major constraint to ecosystem processes. It is derived using a temporal change classification of calibrated radiometric brightness temperatures at 36.5 GHz frequency from the AMSR-E instrument. The layer shows 4 states: frozen, non-frozen (thawed), transitional (AM frozen, PM thawed) and inverse transitional (AM thawed, PM frozen) conditions.
The freeze/thaw layer is useful for assessing the impact of freeze/thaw variations on vegetation growing seasons and land-atmosphere carbon exchange; snow cover, permafrost and active layer properties; surface energy and water budgets; distinguishing freeze/thaw dynamics in accordance with regional terrain features, weather events, seasonal and annual climate anomalies, and long-term climate changes.
The Advanced Microwave Scanning Radiometer – Earth Observing System (AMSR-E) is a multi frequency, dual polarized passive microwave instrument. It detects faint microwave emissions from the Earth’s surface and atmosphere.
The MEaSUREs global record of daily landscape freeze/thaw status is available for the AMSR-E instrument. The sensor and imagery resolution is 25 km; temporal resolution was daily, as derived from morning (AM) and afternoon (PM) sensor brightness temperature retrievals.
References: NSIDC - MEaSUREs Global Record of Daily Landscape Freeze/Thaw Status, Version 3; Freeze/Thaw Earth System Data Record