Analysis of water relations in the soil-plant-atmosphere continuum using a multi-satellite approach

#soil-plant-atmosphere #multi-satellite #approach #soil #moisture #(SM) #canopy #height #measurements #GEDI #vapor #pressure #deficit #(VPD) #Soil #Plant #Atmosphere #Continuum #(SPAC)

Passive microwave satellite missions inform on the available soil moisture (SM) for plant water uptake, as well as on the attenuation that the vegetation exerts over the land microwave emissions. The latter is measured by the parameter vegetation optical depth (VOD), which is a function of the vegetation moisture, canopy structure, and biomass. During my 2-year postdoctoral research with DLR I have addressed two main research topics using these and other complementary variables. First, I have developed a new retrieval algorithm which estimates the vegetation moisture content in gravimetric units (kg water / kg fresh biomass). This is done by isolating the water component from the VOD signal. To do so, complementary information is needed to account for the biomass and structure components. This information is based on canopy height measurements from GEDI and on normalized radar backscatter measurements from Sentinel-1. Second, I am studying the time-lagged correlations between microwave-derived SM, VOD, and atmospheric vapor pressure deficit (VPD) to perform a detailed global-scale analysis of the Soil Plant Atmosphere Continuum (SPAC). Both research lines together open a new path towards Earth Observation-based enhanced assessment of soil and plant conditions, drought impacts, and SPAC water pools and fluxes and their influence on climate extremes.