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On the connection between tropical circulation, convective mixing, and climate sensitivity
Author(s) -
Tomassini L.,
Voigt A.,
Stevens B.
Publication year - 2014
Publication title -
quarterly journal of the royal meteorological society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.744
H-Index - 143
eISSN - 1477-870X
pISSN - 0035-9009
DOI - 10.1002/qj.2450
Subject(s) - convection , climatology , convective mixing , environmental science , climate sensitivity , atmospheric sciences , atmospheric circulation , climate model , mixing (physics) , circulation (fluid dynamics) , atmosphere (unit) , walker circulation , free convective layer , climate change , meteorology , geology , geography , mechanics , sea surface temperature , physics , oceanography , quantum mechanics
The connection between the large‐scale tropical circulation of the atmosphere, convective mixing, and climate sensitivity is explored in a wide range of climates through a perturbed‐parameter ensemble of a comprehensive Earth System Model. Four parameters related to the representation of atmospheric moist convection are found to dominate the response of the model. Their values govern the strength of the tropical circulation, the surface temperature, atmospheric humidity, and the strength of the tropical overturning circulation, largely through their influence on the atmospheric stability. The same convective parameters, albeit in different combinations, also have a strong influence on the equilibrium climate sensitivity of the model, which ranges from a little over 3 °C to more than 10 °C. The importance of the most poorly represented processes in determining important aspects of the behaviour of the model argues for the need to move beyond statistical approaches to estimating climate sensitivity and to focus on the development of a better understanding and representation of convective mixing, particularly in the Tropics.