SMOS optical thickness changes in response to the growth and development of crops, crop management, and weather

Brian K. Hornbuckle, Jason C. Patton, Andy VanLoocke, Andrew E. Suyker, Matthew C. Roby, Victoria A. Walker, Eswar R. Iyer, Daryl E. Herzmann, Erik A. Endacott
2016 Remote Sensing of Environment  
7 The Soil Moisture and Ocean Salinity (SMOS) remote sensing satellite was launched by the European Space Agency in 2009. The L-band brightness temperature observed by SMOS has been used to produce estimates of both soil moisture and τ , the optical thickness of the land surface. Although τ should theoretically be proportional to the amount of vegetation present within a SMOS pixel, several initial investigations have not been able to confirm this expected behavior. However, when the noise in
more » ... e SMOS τ product is removed, τ in the U.S. Corn Belt, a region of extensive row-crop agriculture, has a distinct shape that mirrors the growth and development of crops. We find that the peak value of SMOS τ occurs at approximately 1000 • C day (base 10 • C) growing degree days after the mean planting date of maize (corn). We can explain this finding in the following way:
doi:10.1016/j.rse.2016.02.043 fatcat:jwx2gnsutbcyhbueliwa7gqlgi