Open AccessConvective quasi‐equilibrium in the tropical western Pacific: Comparison with midlatitude continental environment
Author(s) -
Zhang Guang J.
Publication year - 2003
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.67
H-Index - 298
eISSN - 2156-2202
pISSN - 0148-0227
DOI - 10.1029/2003jd003520
Subject(s) - middle latitudes , climatology , forcing (mathematics) , troposphere , convection , atmospheric sciences , environmental science , tropics , precipitation , tropical atlantic , depth sounding , atmosphere (unit) , geology , sea surface temperature , meteorology , oceanography , physics , fishery , biology
This study examines the nature of convective quasi‐equilibrium in the tropical western Pacific using the Tropical Ocean and Global Atmosphere/Coupled Ocean Atmosphere Response Experiment (TOGA COARE) sounding data. Results are compared with those in midlatitudes using data from the southern Great Plains in the United States. It is shown that precipitation is highly correlated to the free tropospheric large‐scale forcing in both the tropics and midlatitudes. In the tropics, but not in the midlatitudes, precipitation is also highly correlated to the total large‐scale forcing that includes surface fluxes. This is because the surface sensible and latent heat fluxes are small over the tropical ocean; thus their contribution to the total large‐scale forcing is relatively small compared to the free tropospheric forcing. The opposite is true for midlatitude continental convection. It is also shown that the free tropospheric quasi‐equilibrium between convection and large‐scale forcing recently proposed by the author for midlatitude continental convection is equally accurate for tropical oceanic convection. The quasi‐equilibrium proposed by Arakawa and Schubert is less accurate in depicting convective stabilization for data averaged from 3 to 24 hours. On timescales longer than 24 hours the two are comparable. Comparisons are made with other studies that use the Arakawa‐Schubert quasi‐equilibrium concept, and seemingly contradictory results are reconciled.