2012 AGU Chapman Conference on Remote Sensing of the ...

Mohr, Karen I.Multi-scale observations and modeling of thehydrological dynamics of Andean peatbogsMohr, Karen I. 1 ; Slayback, Daniel 2, 3 ; Yager, Karina 4, 3 ; Tucker,Compton J. 5 ; Mark, Bryan 6 ; Seimon, Anton 71. Mesoscale Atmospheric Processes Laboratory, NASA-GSFC, Greenbelt, MD, USA2. Science Systems & Applications, Inc., Greenbelt, MD,USA3. Biospheric Sciences Laboratory, NASA-GSFC, Greenbelt,MD, USA4. NASA Post-Doctoral Program, NASA-GSFC, Greenbelt,MD, USA5. Earth Sciences Division, NASA-GSFC, Greenbelt, MD,USA6. Byrd Polar Research Center and Department ofGeography, Ohio State University, Columbus, OH, USA7. Wildlife Conservation Society, New York, NY, USANinety percent of the Earth’s tropical glaciers arelocated in Peru and Bolivia, and these glaciers provide a keyresource to regional pastoral agricultural systems thatsupport large Andean populations. Meltwater from theglaciers and seasonal precipitation sustain numerous alpinepeatbogs that provide critical year-round islands ofnutritious forage for livestock. We have documented a 30%recession in Peruvian and Bolivian glaciers over the past 20years. The potential for significant changes in the glacialcontribution to regional runoff may directly affect thesustainability of these peatbog systems. This is the firstattempt to link observed changes in glacial runoff due toclimate change to future regional pastoral agriculturalproductivity. We have recently begun a NASA-funded projectto document and model the behavior of these peatbogsystems. We seek to learn how the water balances in peatbogsand therefore pastoral agriculture in this region may beaffected by glacier recession due to climate change. We willuse ground observations of precipitation, streamflow, andisotopic analyses of peatbog and stream waters bothhistorical and from our own observing network to documentthe water balances of selected peatbogs. These water balancesand satellite-observed changes in glacial recession will formthe baseline for modeling of the surface hydrology of thisregion. We will impose expected climate change scenarios ona hydrological modeling framework based on the NASA-Goddard Land Information System (LIS), a multi-scale,multi-model hydrologic prediction and data assimilationsystem that runs on NASA’s high performance computers.Predicted interseasonal and interannual changes in peatbogextents will be used to estimate changes in forageproduction. Our presentation shows the evidence forchanges in glacial recession from satellite data and the set-upand initial observations from our hydrological observingsystems in multiple peatbogs in a variety of microclimates inthe region.Moller, DelwynInitial Evaluations of SWOT Water SurfaceElevation Retrievals Using a High-Fidelity DynamicSimulatorMoller, Delwyn 1 ; Rodriguez, Ernesto 2 ; Andreadis,Konstantinos 21. Remote Sensing Solutions, Sierra Madre, CA, USA2. Jet Propulsion Laboratory, California Institute ofTechnology, Pasadena, CA, USAThe Surface Water Ocean Topography (SWOT)mission’s key payload, the Ka-band radar inteferometer(KaRIN), is capable of high-resolution wide-swath altimetryof both the ocean surface and terrestrial surface water. Theability to observe and monitor the volume of water storedand flowing in rivers, lakes and wetlands globally is ofparamount importance yet surface water is poorly observedeven in the industrialized world and observations are almostcompletely lacking elsewhere. For terrestrial hydrology,SWOT will provide the key hydrologic variables needed forcomprehensive river discharge and storage observations;specifically maps of temporal height change, slope and thespatial extent of surface water. To support pre-missionactivities and development, we have developed a SWOTinstrument simulator which mimics the interaction of theKaRIN’s transmitted electromagnetic wave with thetopography below. This simulator allows for the predictionand assessment of layover impact, water temporaldecorrelation performance implications and the impact oftropospheric delay and precipitation. It also provides a toolfor development and test of calibration and classificationalgorithms. In this paper we use a KaRIN instrumentsimulator to provide realistic and dynamic syntheticobservations over a study region of the Ohio river. This isachieved by integrating the simulator with a high spatialresolution hydrodynamic temporal model of the Ohio studyregion. The result is a high fidelity assessment of theperformance of the height (and thus slope) andclassification (and thus river width) reconstruction we canexpect during the SWOT mission. Specifically, the KaRINsimulator is used to generate synthetic observations with atemporal and spatial sampling identical to that whichSWOT would generate. Derivation of height, slope andwidth from the interferograms are demonstrated. Beyondthis we illustrate how the swath measurements frommultiple passes overlay to create a synoptic view of theregion. Included in this assessment is the impact oftopographic layover on the accuracy of the estimatedelevations and rudimentary land/water classification as afirst order measure of performance. The results illustrate thestrengths of the KaRIN data to provide two-dimensionalriver discharge maps at fine (~100m) resolution. In thefuture, we will extend these results to encompass a basinscalestudy over seasonal time-frames. We will also furtherrefine classification algorithms and their sensitivity toeffects of temporal decorrelation in addition to backscattervariability and contrast.102