A generalized complementary relationship between actual and potential evaporation defined by a reference surface temperature. Issue 1 (22nd January 2016)

• Record Type: Journal Article
• Authors: Aminzadeh, Milad; Roderick, Michael L.; Or, Dani
• Is Part Of: Water resources research. Volume 52:Issue 1(2016:Jan.)
• Page Start: 385
• Page End: 406
• Publication Date: 2016-01-22
• Subjects: complementary relationship -- surface temperature -- potential evaporation -- actual evaporation -- CR asymmetry parameter; Hydrology -- Periodicals; 333.91
• DOI: 10.1002/2015WR017969
• Languages: English
• ISSNs: 0043-1397

Abstract

Abstract: The definition of potential evaporation remains widely debated despite its centrality for hydrologic and climatic models. We employed an analytical pore‐scale representation of evaporation from terrestrial surfaces to define potential evaporation using a hypothetical steady state reference temperature that is common to both air and evaporating surface. The feedback between drying land surfaces and overlaying air properties, central in the Bouchet (1963) complementary relationship, is implicitly incorporated in the hypothetical steady state where the sensible heat flux vanishes and the available energy is consumed by evaporation. Evaporation rates predicted based on the steady state reference temperature hypothesis were in good agreement with class A pan evaporation measurements suggesting that evaporation from pans occurs with negligible sensible heat flux. The model facilitates a new generalization of the asymmetric complementary relationship with the asymmetry parameter b analytically predicted for a wide range of meteorological conditions with initial tests yielding good agreement between measured and predicted actual evaporation. Key Points: Definition of potential evaporation using a steady state reference temperature Generalization of complementary relationship between actual and potential evaporation Physically based estimation of the CR asymmetry parameter (b) and actual evaporation