Application of Space-borne Microwave and Optical-I/R Remote Sensing to Characterize Global Soil Moisture Constraints to Soil Respiration
Lucas
A.
Jones, University of Montana, lucas@ntsg.umt.edu
(Presenting)
John
S.
Kimball, University of Montana, johnk@ntsg.umt.edu
Yonhong
Yi, University of Montana, yonghong.yi@ntsg.umt.edu
Rolf
H.
Reichle, NASA GSFC/GMAO, rolf.reichle@nasa.gov
Kyle
C.
McDonald, Jet Propulsion Laboratory, kyle.c.mcdonald@jpl.nasa.gov
Soil respiration is a key component of terrestrial net ecosystem CO2 exchange (NEE) and is difficult to characterize with satellite optical/IR remote sensing. We developed an algorithm for determining daily NEE using synergistic measurements from satellite optical/IR and microwave remote sensing. We applied the algorithm using soil moisture and temperature information from the AMSR-E microwave radiometer, and gross primary productivity (GPP) inputs from MODIS. We verify AMSR-E soil moisture retrievals using antecedent daily precipitation from the Tropical Rainfall Monitoring Mission (TRMM). We then explore functional relations between soil respiration and soil moisture by comparing model results to in situ tower based CO2 flux measurements and soil inventory data using a Bayesian synthesis approach. The soil moisture response is roughly parabolic, whereas the optimum rate can be shifted toward higher levels of moisture for arid ecosystems. We find that the seasonality of soil respiration and the global distribution of soil carbon are reasonably captured by the model. Areas of high disturbance frequency and areas of semi-permanent inundation have lower and higher soil carbon, respectively, relative to steady-state results. This study represents an important step in monitoring terrestrial NEE from space borne observations and is informing the development of future operational carbon products under the Soil Moisture Active Passive (SMAP) decadal survey mission.
Presentation Type: Poster
Poster Session: Carbon Cycle Science
NASA TE Funded Awards Represented:
Kimball, John
Development of a Satellite-based Terrestrial Carbon Flux Model in Support of SMAP Carbon Cycle Science