1 / 10

Great Lakes In-Lake Hydrology

Great Lakes In-Lake Hydrology. Carlo DeMarchi Dept. of Geological Sciences Case Western Reserve University. Great Lakes In-Lake Hydrology. Over-Lake Precipitation Lake Evaporation Wind Water Surface Temperature Air Temperature Humidity Ice Cover Water Levels.

yosefu
Download Presentation

Great Lakes In-Lake Hydrology

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Great Lakes In-Lake Hydrology Carlo DeMarchi Dept. of Geological Sciences Case Western Reserve University

  2. Great Lakes In-Lake Hydrology • Over-Lake Precipitation • Lake Evaporation • Wind • Water Surface Temperature • Air Temperature • Humidity • Ice Cover • Water Levels

  3. Over-Lake Precipitation • Interpolation of Rain Gages • Integration of Rain Gages and Radar • Satellite-Based Remote Sensing • Integration of Radar, Gages, and Satellites

  4. Distance (> 100 km) • Difference in over-lake and over-land precipitation (lake-effect snow)

  5. Estimating Uncertainty in GLERL’s Monthly Overlake Precipitation • Merging NCEP Multisensor Precipitation Estimates and rain gage data • Radar Coverage is spatially and temporally irregular • Rain gage correction is less effective over lake (no gages) • Bias (0.5%-7.5%) • Uncertainty 20-45%.

  6. Satellite Remote Sensing • For the Great Lakes • Correlation of Daily TMPA and CMORPH with MPE is 0.5-0.8 during summer and 0.2-0.7 during winter. • Low Bias • Edge of GOES’ useful area for quantitative analysis • Integration of Radar, Satellite, and rain gages Tian et al 2007

  7. Great Lakes Lake Evaporation • Given the size of the Great Lakes, measurement of evaporation was impossible up to now • Estimation could be done by water balance or energy balance • Calibration of thermodynamic models can be done only indirectly (ice cover and lake surface temperature) • Eddy covariance system

  8. GLERL Large Lake Thermodynamic Model • 1-D Model • Lumped-parameter Model • Uses Daily Lake-wide Meteorology Input • Mean Air Temperature • Mean Dew Point Temperature • Mean Wind Speed • Mean Cloud Cover • Empirically Calibrated to Water Surface Temperature for 1948-1988 • Buoy data available only during Summer,

  9. Eddy Covariance Method • Spence and Blanken • June 2008, Sept. 2009 • Large footprint • Extension of “point” data to entire lake depends on wind, water temperature, etc. • Data in reasonable agreement with GLERL

  10. How to Improve Evaporation Estimates • For both the thermodynamic and Eddy Covariance approach: • Presently Off line; Assimilation of SST from satellite • Estimating 2m wind? (ERS-1, ERS-2, QuikSCAT, MetOp-A, ASCAT; SSM/I) • Estimating 2m Air Temperature • Estimating air humidity (ERS-1, ERS-2, MODIS) • Use alternative evapotranspiration models like SEBAL, S-SEBI?

More Related