A global satellite environmental data record derived from AMSR-E
and AMSR2 microwave earth observations
Jinyang Du1, John S. Kimball2, Lucas A. Jones1, Youngwook Kim1, Joseph Glassy2, and Jennifer D. Watts11Numerical Terradynamic Simulation Group, College of Forestry & Conservation, The University of Montana, Missoula, MT 59812, United States 2Lupine Logic, Inc., Missoula, MT 59802, United States
Abstract. Space-borne microwave remote sensing is widely used to monitor global environmental changes for understanding hydrological, ecological and climate processes. A new global land parameter data record (LPDR) was generated using similar calibrated, multi-frequency brightness temperature (Tb) retrievals from the Advanced Microwave Scanning Radiometer for EOS (AMSR-E) and the Advanced Microwave Scanning Radiometer 2 (AMSR2). The resulting LPDR provides a long-term (Jun. 2002 – Dec. 2015) global record of key environmental observations at 25-km grid cell resolution, including surface fractional open water (fw) cover, atmosphere precipitable water vapor (PWV), daily maximum and minimum surface air temperatures (Tmx and Tmn), vegetation optical depth (VOD) and surface volumetric soil moisture (vsm). Global mapping of the land parameter climatology means and seasonal variability over the full-year records from AMSR-E (2003–2010) and AMSR2 (2013–2015) observation periods is consistent with characteristic global climate and vegetation patterns. Quantitative comparisons with independent observations indicated favorable LPDR performance for fw (R ≥ 0.75; RMSE ≤ 0.06), PWV (R ≥ 0.91; RMSE ≤ 4.99 mm), Tmx and Tmn (R ≥ 0.90; RMSE ≤ 3.48 ºC), and vsm (0.63 ≤ R ≤ 0.84; bias corrected RMSE ≤ 0.06 cm3/cm3). The LPDR derived global VOD record is also proportional to satellite observed NDVI (GIMMS3g) seasonality (R ≥ 0.88) due to synergy between canopy biomass structure and photosynthetic greenness. Statistical analysis shows overall LPDR consistency, but with small biases between AMSR-E and AMSR2 retrievals that should be considered when evaluating long-term environmental trends. The resulting LPDR and potential updates from continuing AMSR2 operations provide for effective global monitoring of environmental parameters related to vegetation activity, terrestrial water storage and mobility; and are suitable for climate and ecosystem studies. The LPDR data set is publicly available at http://files.ntsg.umt.edu/data/LPDR_v2.
Du, J., Kimball, J. S., Jones, L. A., Kim, Y., Glassy, J., and Watts, J. D.: A global satellite environmental data record derived from AMSR-E
and AMSR2 microwave earth observations, Earth Syst. Sci. Data Discuss., doi:10.5194/essd-2017-27, in review, 2017.