Turbulent Exchange Coefficients for Sensible Heat and Water Vapor under Advective Conditions

Authors

Shashi Verma, University of Nebraska - LincolnFollow
Norman J. Rosenberg, University of Nebraska - Lincoln
Blaine L. Blad, University of Nebraska - Lincoln

Date of this Version

1978

Citation

1978 American Meteorological Society

Comments

March 1978 S.B. Verma, N.J. Rosenberg and B.L. Blad Volume 17 330-338

Abstract

Results are presented of micrometeorological measurements made over alfalfa and soybeans under conditions of sensible heat advection at Mead, Neb. The sensible heat advection phenomenon reported here is of a regional rather than a local nature. The exchange coefficient for sensible heat (Kh) is found to be generally greater than the exchange coefficient for water vapor (Kw). This result contradicts the usaul assumption of equality of Kh and Kw under nonadvection (lapse or unstable) conditions when the net transfer of both sensible heat and water vapor are away from the earth's surface. Under advective conditions, however, heat and water vapor are transferred in opposite directions. Our results are supported by Warkaft's (1976) recently published theoretical analysis in which he concludes that the greatest departure of Kh/Kw from unity will occur when temperature an humidity gradients are of opposite sign.