Skip to main content


eCommons@Cornell >
Internet-First University Press >
Symposia, Workshops, Conferences >
Hydrologic Discovery Through Physical Analysis Honoring the Scientific Legacies of Wilfried H. Brutsaert and Jean-Yves Parlange >
Hydrologic Discovery - Oral Presentations (Videos) >

Please use this identifier to cite or link to this item:
Title: F2. Evaporation from Lake Kasumigaura: Bulk Coefficients and Spatial Distribution of Latent Heat Flux
Authors: Michiaki, Sugita
Zhongwang, Wei
Aiko, Miyano
Hiroya, Ikura
Issue Date: May-2012
Publisher: Internet-First University Press
Abstract: Study of lake evaporation includes various aspects of Dr Brutsaert’s interests such as the exchange processes on water surface, the development of internal boundary layer, estimation of evaporation rate, among others. In the present study, issues on air-water interaction were first revisited. Secondly, horizontal distribution of latent heat fluxes over the lake surface was estimated to study its variability. For these purposes, 10 Hz water vapor, temperature, and wind velocity data have been obtained at the Koshin Observatory located near the center of Lake Kasumigaura, the second largest lake in Japan (220 km2 with mean depth of 4 m) since June of 2007. The corresponding fluxes were determined by applying the eddy correlation method to estimate the bulk coefficients. Agreement and disagreement with previous studies on the bulk transfer coefficients were identified. Also, the influence of lake current, wave, gustiness was investigated. Based on the derived functional form for the bulk coefficient, horizontal distribution of latent heat flux was estimated by first deriving a 100-m grid map of air temperature, wind speed and humidity over the lake area from interpolation of the observed data at meteorological stations in and around Lake Kasumigaura. The bulk method was then applied to each grid to derive latent heat flux every six hours over a year, by assuming the same surface temperature as that at the Koshin Observatory. This was acceptable as the satellite infrared images indicated the presence of quasi-uniform surface water temperature, presumably to reflect well-mixed water body of the shallow lake. The results indicate larger fluxes at the lake center with smaller values near lake shores, mainly to reflect wind speed differences. In comparison, humidity and air temperature is of lessor importance to cause latent heat variability. The mean evaporation over the entire lake surface was found to be 976 (±56) mm/y, while that at the Koshin observatory was 878 mm/y.
Description: Once downloaded, these high definition QuickTime videos may be played using a computer video player with H.264 codec, 1280x720 pixels, millions of colors, AAC audio at 44100Hz and 29.97 frames per second. The data rate is 5Mbps. File sizes are on the order of 600-900 MB. (Other formats may be added later.) Free QuickTime players for Macintosh and Window computers may be located using a Google search on QuickTime. The DVD was produced by J. Robert Cooke.
Appears in Collections:Hydrologic Discovery - Oral Presentations (Videos)

Files in This Item:

File Description SizeFormat
streaming_29567.htmlView Streaming Video8.25 kBHTMLView/Open
F2_Sugita_SLIDES.pdfPDF of slides used in the lecture7.38 MBAdobe PDFView/Open
F2_Sugita_Evaporation_SD_for_Apple_Devices.m4vDownload small version of Video171.91 MBM4v VideoView/Open
F2_Sugita_Evaporation-HD_for_Apple_Devices_5Mbps.m4vDownload HD Video for Apple Devices540.38 MBM4v VideoView/Open

Refworks Export

Items in eCommons are protected by copyright, with all rights reserved, unless otherwise indicated.


© 2014 Cornell University Library Contact Us