is ongoing. For global remote sensing of ET and monitoring of drought based on ET estimates, the ALEXI model using the thermal observations from NOAA operational observations of VIIRS onboard the Suomi National Polar‐orbiting Partnership and Joint Polar Satellite System satellites has been demonstrated to be promising (Hain et al., 2017). More intercomparison and validation studies using approaches based on the ALEXI model, the PM equation, the PT equation, and other methods for globally estimating and monitoring drought are needed.
ACKNOWLEDGMENTS
This study has been supported by NOAA and NASA programs including NOAA GOES‐R Risk Reduction program, NOAA NESDIS PSDI program, NOAA JPSS Proving Ground and Risk Reduction Program, and NASA Applied Science Program. Contents of this chapter are solely the opinions of the author(s) and do not constitute a statement of policy, decision, or position on behalf of NOAA or the US Government.
Figure 2.7 Monthly BDI_b for the southern United States (from 25°N, −115°W to 40°N, −90°W) domain in 2011.
(Source: From Yin, J., Zhan, X., Hain, C. R., Liu, J., & Anderson, M. C. (2018). A Method for Objectively Integrating Soil Moisture Satellite Observations and Model Simulations Toward a Blended Drought Index. Water Resources Research, 54(9), 6772–6791. © 2018, John Wiley & Sons.)
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