Open AccessLand‐Surface‐Atmosphere Coupling in Observations and Models
Author(s) -
Betts Alan K.
Publication year - 2009
Publication title -
journal of advances in modeling earth systems
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.03
H-Index - 58
ISSN - 1942-2466
DOI - 10.3894/james.2009.1.4
Subject(s) - longwave , atmospheric sciences , environmental science , shortwave , diabatic , forcing (mathematics) , atmosphere (unit) , planetary boundary layer , diurnal cycle , precipitation , climatology , radiative forcing , condensation , sensible heat , climate model , boundary layer , radiative transfer , meteorology , geology , climate change , physics , mechanics , aerosol , thermodynamics , quantum mechanics , adiabatic process , oceanography
The diurnal cycle and the daily mean at the land‐surface result from the coupling of many physical processes. The framework of this review is largely conceptual; looking for relationships and information in the coupling of processes in models and observations. Starting from the surface energy balance, the role of the surface and cloud albedos in the shortwave and longwave fluxes is discussed. A long‐wave radiative scaling of the diurnal temperature range and the night‐time boundary layer is summarized. Several aspects of the local surface energy partition are presented: the role of soilwater availability and clouds; vector methods for understanding mixed layer evolution, and the coupling between surface and boundary layer that determines the lifting condensation level. Moving to larger scales, evaporation‐precipitation feedback in models is discussed; and the coupling of column water vapor, clouds and precipitation to vertical motion and moisture convergence over the Amazon. The final topic is a comparison of the ratio of surface shortwave cloud forcing to the diabatic precipitation forcing of the atmosphere in ERA‐40 with observations.