An Earth System Data Record for Land Surface Freeze/Thaw State:
Quantifying Terrestrial Water Mobility Constraints to Global Ecosystem Processes
The FT-ESDR is a NASA MEaSUREs (Making Earth System Data Records for Use in Research Environments) funded effort to provide a consistent long-term global data record of land surface freeze/thaw (FT) state dynamics for all vegetated regions where low temperatures are a major constraint to ecosystem processes. The FT measurement is derived from temporal change classification of global satellite microwave remote sensing time series, including passive microwave radiometry from the Special Sensor Microwave Imager (SSM/I) and Advanced Microwave Scanning Radiometer for EOS (AMSR-E), and radar scatterometry from SeaWinds-on-QuikSCAT. The ecological significance and basis of the FT measurement from satellite microwave remote sensing is summarized in the literature (e.g., see "Publications" section). The FT-ESDR is designed to:
1) distinguish FT heterogeneity in accordance with mesoscale climate and landscape topographic features;
2) establish biophysical linkages between FT processes and vegetation productivity, respiration and associated land-atmosphere carbon exchange;
3) distinguish FT dynamics in accordance with episodic weather events, annual anomalies, periodic climate cycles and long-term climate change trajectories.