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

to determine the source of the water. We find that theamount of water annually filling and draining the Congowetlands is 111 km^3, which is about one-third the size ofthe water volumes found on the mainstem Amazonfloodplain. Based on amplitude comparisons among thewater volume changes and timing comparisons among theirfluxes, we conclude that the local upland runoff is the mainsource of the Congo wetland water, not the fluvial process ofriver-floodplain water exchange as in the Amazon. Ourhydraulic analysis using altimeter measurements alsosupports our conclusion by demonstrating that watersurface elevations in the wetlands are consistently higherthan the adjacent river water levels. Our research alsohighlights differences in the hydrology and hydrodynamicsbetween the Congo wetland and the mainstem AmazonfloodplainLemoine, Frank G.Monitoring Mass Change Using Global HighResolution GRACE Mascon SolutionsLemoine, Frank G. 1 ; Sabaka, Terence J. 1 ; Boy, Jean-Paul 2 ;Luthcke, Scott B. 1 ; Carabajal, Claudia C. 3, 1 ; Rowlands, DavidD. 11. Planetary Geodynamics Lab., NASA GSFC, Greenbelt,MD, USA2. EOST/IPGS, (UMR 7516 CNRS-UdS), Strasbourg, France3. Sigma Space Corp., Lanham, MD, USAThe Gravity Recovery And Climate Experiment(GRACE) mission has been launched in March 2002, and hasmeasured since the Earth’s time-variable gravity field at highspatial and temporal resolution. Among the applications hasbeen the monitoring of the changes in terrestrial waterstorage (TWS). The standard product developed by theGRACE project and various analysis centers has beenmonthly unconstrained spherical harmonic solutions, whichcan be converted to grids of surface water changes. Thesolutions are affected by strong correlated noise (striping),which can be removed by various filtering techniques. Thisfiltering reduces the amplitude of the retrieved TWS, whichis can be corrected by “re-scaling” the signal using hydrologymodels. At GSFC we have developed global solutions using alocalized mascon (mass concentrations) approach. Usingappropriate constraints, these global solutions allow bettertemporal (10 days) and spatial (2 degree) resolutions, thanthe classical spherical harmonic solutions and do not requireany post-processing. We have developed global solutionswith and without a priori forward-modeling of hydrology.We inter-compare these solutions on a continent and riverbasin basis to global hydrology models, as well as othergridded products derived from the GRACE mission.Lenters, JohnAn international collaboration to examine globallake temperature trends from in situ and remotesensing data: Project objectives and preliminaryresultsLenters, John 1 ; Adrian, Rita 2 ; Allan, Mathew 3 ; de Eyto,Elvira 4 ; Dong, Bo 1 ; Hamilton, David 3 ; Hook, Simon 12 ;Izmestyeva, Lyubov 5 ; Kraemer, Benjamin 6 ; Kratz, Tim 6 ;Livingstone, David 7 ; Mcintyre, Peter 6 ; Montz, Pam 6 ; Noges,Peeter 8 ; Noges, Tiina 8 ; O’Reilly, Catherine 14 ; Read, Jordan 6 ;Sandilands, Ken 9 ; Schindler, Daniel 10 ; Schneider, Philipp 11 ;Silow, Eugene 5 ; Straile, Dietmar 13 ; Van Cleave, Katherine 1 ;Zhdanov, Fedor 51. School of Natural Resources, Univ. of Nebraska-Lincoln,Lincoln, NE, USA2. Leibniz-Institute of Freshwater Ecology and InlandFisheries, Berlin, Germany3. The Univ. of Waikato, Hamilton, New Zealand4. Marine Institute, Newport, Ireland5. Irkutsk State Univ., Irkutsk, Russian Federation6. Univ. of Wisconsin-Madison, Madison, WI, USA7. Eawag, Dubendorf, Switzerland8. Estonian Univ. of Life Sciences, Tartu, Estonia9. Fisheries and Oceans Canada, Winnipeg, MB, Canada10. Univ. of Washington, Seattle, WA, USA11. Norwegian Institute for Air Research, Kjeller, Norway12.JPL, California Institute of Technology, Pasadena, CA,USA13.Univ. of Konstanz, Konstanz, Germany14. Illinois State Univ., Normal, IL, USARecent studies have revealed significant warming oflakes throughout the world, and the observed rate of lakewarming is – in many cases – more rapid than that of theambient air temperature. These large changes in laketemperature have profound implications for lakehydrodynamics, productivity, and biotic communities. Thescientific community is just beginning to understand theglobal extent, regional patterns, physical mechanisms, andecological consequences of lake warming. Although many insitu lake temperature records are available, only a fewencompass long time periods. Most datasets are collected byindividual investigators, have varying sampling protocols,and do not have extensive geographic or temporal coverage.Remote sensing methods, on the other hand, have beenincreasingly used to characterize global trends in lake surfacetemperature, and they provide an invaluable counterpart toin situ measurements. However, the existing satellite recordsdo not extend as far back in time as some of the longer insitu datasets, and remotely sensed measurements captureonly surface temperature, rather than vertical profiles. Inthis study, we present project objectives and preliminaryresults from an international collaborative effort tosynthesize global records of lake temperature from in situand satellite-based measurements. Surface watertemperature data are analyzed from over 120 lakesdistributed across 40 countries. Data from 20 of the lakesare based on in situ measurements, while the remaining89