A satellite based algorithm to estimate global net ecosystem CO2 exchange
Yonghong
Yi, 1 Flathead Lake Biological Station, University of Montana,Polson MT,59860-9659, 2 Numerical Terradynamic Simulation Group, University of Montana, Missoula MT,59812, yonghong.yi@ntsg.umt.edu
(Presenting)
John
S.
Kimball, 1 Flathead Lake Biological Station, University of Montana,Polson MT,59860-9659, 2 Numerical Terradynamic Simulation Group, University of Montana, Missoula MT,59812,, johnk@flbs.umt.edu
Rama
R.
Nemani, 3 NASA Ames Research Center, CA, 94035, rama.nemani@nasa.gov
Kyle
McDonald, 4 Jet Propulsion Laboratory, California Institute of Technology,CA, 91109, kyle.c.mcdonald@jpl.nasa.gov
A purported land carbon sink plays a major role in determining the rate and potential impacts of global warming. The net ecosystem exchange (NEE) of CO2 is a fundamental measure of the balance between carbon uptake by vegetation gross primary production (GPP) and carbon losses through ecosystem respiration (Reco). We applied a simple terrestrial carbon flux (TCF) model driven by satellite optical-IR and microwave remote sensing data to quantify NEE and component carbon fluxes. We conducted a global TCF implementation using the MODerate resolution Imaging Spectroradiometer (MODIS) GPP, Advanced Microwave Scanning Radiometer for EOS (AMSR-E) soil moisture and temperature retrievals, and MERRA reanalysis data. Global soil inventory data were used to optimize model parameters controlling temperature and moisture constraints to Reco, while results were verified using tower CO2 flux measurements from global FLUXNET sites. The TCF results generally reproduce the observed global pattern of surface soil organic carbon (SOC), with large accumulations in northern (>=50°N) forests. The NEE results are within the accuracy range of the tower CO2 flux measurements and reproduce observed seasonality and spatial patterns. The derived global NEE time series (2000 - 2006) show that tropical latitudes contribute most of the inter-annual variation in global NEE, while the northern (>= 40°N) latitudes are a significant carbon sink. This study provides for global mapping and monitoring of NEE from satellite sensors and is informing development of new operational carbon products under the SMAP Decadal Survey mission. This work was conducted at the University of Montana, Ames Research Center and Caltech Jet Propulsion Laboratory under contract to NASA.
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