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A process‐based framework for quantifying the atmospheric preconditioning of surface‐triggered convection
Author(s) -
Tawfik Ahmed B.,
Dirmeyer Paul A.
Publication year - 2014
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1002/2013gl057984
Subject(s) - mesoscale meteorology , condensation , forcing (mathematics) , convection , environmental science , mixing (physics) , atmospheric sciences , humidity , potential temperature , mixing ratio , atmosphere (unit) , meteorology , climatology , mechanics , geology , physics , quantum mechanics
Here we introduce the heated condensation framework, which contains a suite of variables for isolating the atmospheric boundary state from local surface forcing. The buoyant condensation level (BCL) and buoyant mixing temperature ( θ BM ) quantify the degree to which the atmosphere is preconditioned for moist convection and can be calculated for any time of day or year using standard vertical profiles of temperature and humidity. Unlike the lifted condensation level and convective inhibition, the BCL is constructed through incremental mixing from the surface rather than lifting a hypothetical parcel. In this regard, the BCL represents a conserved condensation level diagnostic inherent to a given profile. The BCL and θ BM are shown to be applicable over a range of climate regimes and respond to synoptic and mesoscale forcings, illustrating its broader utility. A suite of variables relating the BCL directly to surface fluxes is also introduced.