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Daily evaporation over a region from lower boundary layer profiles measured with radiosondes
Author(s) -
Sugita Michiaki,
Brutsaert Wilfried
Publication year - 1991
Publication title -
water resources research
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.863
H-Index - 217
eISSN - 1944-7973
pISSN - 0043-1397
DOI - 10.1029/90wr02706
Subject(s) - radiosonde , evaporation , flux (metallurgy) , latent heat , eddy covariance , environmental science , sensible heat , bowen ratio , atmospheric sciences , surface layer , boundary layer , planetary boundary layer , heat flux , daytime , meteorology , materials science , layer (electronics) , thermodynamics , heat transfer , geology , physics , ecology , ecosystem , metallurgy , composite material , biology
Regional daily evaporation was estimated by means of continuous measurements of the available energy flux at the surface and one or more instantaneous determinations of the evaporative fraction (EF). The data were obtained during the First ISLSCP Field Experiment (FIFE) in northeastern Kansas. EF, which is the ratio of the latent heat flux and the available energy flux, was assumed to be constant during the daylight hours; thus it was determined from only a few instantaneous surface flux values calculated on the basis of radiosonde profiles in the surface layer, together with remotely sensed surface temperature. Comparison of 23 estimated and measured daytime evaporation values showed good correlation ( r = 0.97), although the evaporation was underestimated by about 5% on average. In the estimation of daily evaporation, nighttime evaporation must also be considered; measurements by means of the eddy correlation method showed that on average it accounted for some 8% of the total daily evaporation.