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Integration of Daily Inundation Extent Estimates into an Ecosystem-Atmosphere Gas Exchange Model
John
Galantowicz, AER, johng@aer.com
(Presenter)
Lisa
Wei, AER, lwei@aer.com
Arindam
Samanta, AER, asamanta@aer.com
Jeff
Picton, AER, jpicton@aer.com
Bowen
Zhang, Auburn University, bzz0003@tigermail.auburn.edu
Chaoqun
Lu, Auburn University, czl0003@auburn.edu
Jia
Yang, Auburn University, jzy0010@tigermail.auburn.edu
Hanqin
Tian, Auburn University, tianhan@auburn.edu
We are investigating how near-daily surface water and soil moisture observations from NASA's Soil Moisture Active-Passive (SMAP) mission can be integrated into an ecosystem-atmosphere gas exchange model to improve its estimates of greenhouse gas fluxes. Soil moisture and the spatial extent of soil saturation, transient inundation, and wetland ecosystems are key determinants of emissions from the land surface to the atmosphere. SMAP, to be launched in 2014, will combine 1- to 3-km resolution synthetic aperture radar (SAR), 40-km-resolution L-band radiometry, and 3-day revisit period to make a novel dataset expected to provide inundation and soil moisture estimates superior to alternative methods at that temporal-spatial scale. We are testing the potential impact of this new data source using the Dynamic Land Surface Ecosystem Model (DLEM). DLEM quantifies regional fluxes of methane (CH4) and other gases given atmospheric forcing data, with soil saturation as a prognostic variable.
In this poster, we present DLEM results integrated with time-varying subgrid inundation extent inputs from remote sensing observations of North America. To emulate SMAP observations, we have derived a new daily inundation fraction dataset for 2008-2010 using data from NASA’s Advanced Microwave Scanning Radiometer-EOS (AMSR-E). To test data-model integration, we created a testbed composed of DLEM runs in which subgrid land cover conditions were prescribed (e.g., 100% wetlands, land cover without wetlands) and wetland soil moisture was artificially varied (50-100% saturation). The testbed allows us to simulate a larger array of cases than would be possible with individual model runs. Here, we compare CH4 flux results representing two model realizations: one in which the saturated wetlands coverage is held constant and one in which it is allowed to vary with daily inundation estimates. We also discuss CH4 flux sensitivity to soil moisture to demonstrate the potential additional impact of SMAP soil moisture data.
Presentation:
2013_Poster_Galantowicz_36_87.pdf (1613k)
Presentation Type: Poster
Session: Poster Session 1-A
(Tue 11:00 AM)
Associated Project(s):
Poster Location ID: 36
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