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A GREAT LAKES EVAPORATION NETWORK. P.D. Blanken 1 , J.D. Lenters 2 , C. Spence 3 and R. Yerubandi 3 1 University of Colorado 2 University of Nebraska-Lincoln 3 Environment Canada. History.
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A GREAT LAKES EVAPORATION NETWORK P.D. Blanken1, J.D. Lenters2, C. Spence3 and R. Yerubandi3 1University of Colorado 2University of Nebraska-Lincoln 3Environment Canada
History • The International Upper Great Lakes Study provided an important catalyst for the deployment of instrumentation for direct measurements of evaporation from the Laurentian Great Lakes. • At the end of the IUGLS, the Study Board noted the need for support and expansion of evaporation data collection programs (among others). • Such programs that would enhance evaporation estimates are important for building adaptive management capacity.
Objectives and goals • Three major science objectives for the network • estimate evaporation rates; • research evaporation processes; • provide data to evaluate operational hydrometeorological and climate models across all five Laurentian Great Lakes • Three major science goals for the network • development of a database of meteorological and energy budget observations for each of the five Laurentian Great Lakes; • improve understanding of evaporation – ice – albedo – energy budget interactions over time scales from months to years; • a quantified reduction in uncertainty from present predictive tools
Site selection factors • Representativeness • Fetch • Logistics • Synergy • Existing data
Site selection - Lake Erie http://iweb.cmc.ec.gc.ca/~armnvfo/gemlam/uv_2011101312-2011101712/lake_erie/index.html
Current and proposed sites Stannard Rock Granite Island White Shoal Spectacle Reef Wolfe Island NWRI Wave Tower Long Point
Instrumentation wind speed and direction incoming radiation turbulent fluxes thermohygrometer rainfall + surface water temperature
Physical processes From: Blanken et al. (2011) From: Spence et al. (2011)
Observations Adapted from: Spence et al. (2011)
Model evaluation y = 0.86x -0.28 R2 = 0.63
Model evaluation From: Deceau et al. (in press)
Reduction in uncertainty • Cross validation efforts are to be encouraged with the increased availability to data and information. • Coordinate ground based eddy covariance measurement with aircraft based measurements during dedicated field campaigns
Outreach • Information outreach efforts need to include clients and the public in order to help ensure activities remain worthy.
Concluding remarks • How can the needs of the hydrologic and meteorological communities for evaporation data and information be met in a mutually consistent way? • Ensure the construction of an accessible centralized database with robust quality data. • A concerted effort to build feedback loops between monitoring and modelling to reduce uncertainty. Instrumentation should remain in place as long as it is actively used to reduce uncertainty in evaporation estimates to acceptable levels. • Collaboration must be encouraged and outreach efforts must be a priority.