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

100+ lake temperature records are obtained from satellitebasedmethods. We focus primarily on mean summer watertemperatures for the 25-year period 1985-2009, as thisprovides a common time period with the largest amount ofavailable data. Linear regression analysis reveals that 65% ofthe lakes in the database are experiencing significantsummertime warming (p < 0.1), with another 30% warmingat a rate that is not statistically significant. Only 5% of thelakes in the database show cooling trends (none of which aresignificant). The in situ and satellite-based measurementsshow a very similar distribution of water temperature trendsamong lakes, with a mean value of approximately +0.5°C/decade and standard deviation of +/-0.3 °C/decade(maximum = +1.0 °C/decade). We also examine a variety ofexternal controlling factors (climate, geography, lakemorphometry, etc.) to understand the physical mechanismsassociated with the global and regional patterns of lakewarming.Lenters, John D.Towards a Circum-Arctic Lakes ObservationNetwork (CALON)Jones, Benjamin M. 1 ; Hinkel, Kenneth M. 2 ; Lenters, John D. 3 ;Grosse, Guido 4 ; Arp, Christopher D. 5 ; Beck, Richard A. 2 ;Eisner, Wendy R. 2 ; Frey, Karen E. 6 ; Liu, Hongxing 2 ; Kim,Changjoo 2 ; Townsend-Small, Amy 21. Alaska Science Center, U.S. Geological Survey, Anchorage,AK, USA2. Department of Geography, University of Cincinnati,Cincinnati, OH, USA3. School of Natural Resources, University of Nebraska,Lincoln, NE, USA4. Geophysical Institute, University of Alaska Fairbanks,Fairbanks, AK, USA5. Institute of Northern Engineering, University of AlaskaFairbanks, Fairbanks, AK, USA6. Geography, Clark University, Worcester, MA, USARoughly one-quarter of the lakes on Earth are located inthe Arctic. To date, however, there has been no systematiccollection of key lake parameters or baseline data in theArctic to assess changes in lake water quality and quantity(e.g. due to the impacts of warmer temperatures, changes incloud cover and precipitation patterns, permafrostdegradation, and human water use). With funding from theNational Science Foundation’s Arctic Observing Network(AON) program we are working towards the establishmentof a Circum-Arctic Lakes Observation Network (CALON) byfocusing our initial efforts on a set of lakes located innorthern Alaska. Our team members have been working onlakes in Arctic Alaska for the past decade and are currentlymonitoring lake characteristics at a number of locations.The primary objectives of CALON are to expand andintegrate our existing lake monitoring network across ArcticAlaska as well as to further develop lake monitoringstrategies for Arctic conditions to provide data for keyindices using in situ measurements, field surveys, andremote sensing/GIS technologies. CALON will monitor keyindices such as lake temperature, water level, net radiation,ice cover, and numerous water quality and biophysicalparameters. In <strong>2012</strong>, we will enhance the existing in situnetwork by instrumenting lake monitoring sites to collectyear-round baseline data and assess physical, chemical, andbiological lake characteristics across environmentalgradients. This will be accomplished by implementing amulti-scale (hierarchical) lake instrumentation scheme with16 intensive and 35 basic monitored lakes. Regional scalingand extrapolation of key metrics will be accomplishedthrough calibration and validation of satellite imagery withground measurements. Thus, multi-sensor remote sensingwill be a key component in the development of CALON.Initially, we will focus on bathymetric mapping using highresolutionmultispectral satellite imagery, detection of waterquality parameters using spaceborne platforms, historic lakestage and ice surface elevation measurements using ICESatand comparable future laser altimetry missions, thedetection of surface water temperatures from spacebornethermal imagers, as well as changes in lake ice timing andthickness using SAR image time series. Through thecombination of in situ field sensors and continuous datalogging, field surveys, and spaceborne remote sensing weplan to standardize protocols that will enable inter-sitecomparison and to prepare for expansion towards a pan-Arctic network. All data acquired within CALON will bemade publicly available in a timely manner in accordancewith NSF AON goals of rapid data sharing. Further,measurements collected by the CALON project can be usedas validation sites for future airborne and spacebornemissions in the Arctic.https://sites.google.com/a/giesn.com/nsf-calon/Lettenmaier, Dennis P.Planning for the Next Generation of Water CycleMissions INVITEDLettenmaier, Dennis P. 11. Dept Civil Eng, Univ Washington, Seattle, WA, USARemote sensing has become an increasingly common, ifnot routine, source of observations for the hydrology andwater cycle community. In many parts of the globe where insitu observations are sparse, remote sensing is a criticalsource of information about precipitation, land cover,surface and subsurface storage, and snow, without whichmodern hydrologic predictions would be difficult orimpossible. In 2007, the U.S. National Research Councilissued the Decadal Review of Earth Science and Applicationsfrom Space (ESAS) – the first attempt to prioritize the nextgeneration of earth science missions. Missions were groupedinto three tiers – nominally on the basis of readiness,although the tiers de facto became priority levels. Of threemissions considered by the Decadal Review that wereprimarily related to hydrologic science and applications, onewas assigned to each of the three tiers – SMAP (SoilMoisture Active Passive) to tier 1, SWOT (Surface Water andOcean Topography) to tier 2, and SCLP (Snow and ColdLand Processes) to tier 3. GRACE-2, also of great interest to90