Global Landscape Freeze-Thaw classification using Satellite Microwave Remote Sensing
Youngwook
Kim, University of Montana, youngwook.kim@ntsg.umt.edu
(Presenting)
John
S
Kimball, University of Montana, johnk@flbs.umt.edu
(Presenting)
Kyle
C
McDonald, Jet Propulsion Laboratory, kyle.mcdonald@jpl.nasa.gov
(Presenting)
Joe
Glassy, Lupine Logic, Inc., joe.glassy@ntsg.umt.edu
The freeze-thaw (F/T) status of the landscape is closely linked to surface energy budget and hydrological activity, vegetation phenology, terrestrial carbon budgets and land-atmosphere trace gas exchange. Satellite microwave radars and radiometers are ideally suited for global F/T monitoring due to insensitivity to signal degradation by atmospheric contamination and solar illumination effects, are uniquely capable of detecting the distinct change in landscape dielectric properties between predominantly frozen and thawed states, and provide a surrogate measure of a range of biophysical processes associated with the F/T signal, especially at high latitudes. In this study, we utilized multi-frequency satellite microwave radiometry from the Special Sensor Microwave Imager (SSM/I) and Advanced Microwave Scanning Radiometer for EOS (AMSR-E), and SeaWinds Ku-band scatterometry to classify global and daily patterns in terrestrial F/T cycles. We defined a global domain for the freeze/thaw data record encompassing all vegetated regions where low temperatures are a major constraint to ecosystem processes. We evaluated daily F/T patterns from the individual sensors, band frequencies, polarizations and AM/PM overpass data. The F/T classification accuracy was assessed relative to in situ WMO surface air temperatures. The microwave sensors produced similar F/T spatial and temporal patterns, with mean annual classification accuracy of 85 (+/-5) %, while annual frozen/unfrozen periods were quantified over the global domain and 20-year record. These results represent a new global Earth System Data Record for the F/T state variable. This work was conducted at the University of Montana and Jet Propulsion Laboratory, California Institute of Technology under contract to NASA.
Presentation Type: Poster
Poster Session: Carbon Cycle Science
NASA TE Funded Awards Represented:
McDonald, Kyle
Satellite Monitoring of Landscape Freeze-Thaw State and Associated Constraints to the North American Carbon Budget