Climate and climate change in a radiative-convective equilibrium version of ECHAM6
| Autor: | Aiko Voigt, Bjoern Stevens, Dagmar Popke |
|---|---|
| Rok vydání: | 2013 |
| Předmět: |
Runaway climate change
Global and Planetary Change 010504 meteorology & atmospheric sciences Climate commitment Climate change 010502 geochemistry & geophysics Atmospheric sciences 01 natural sciences Cloud feedback Physics::Geophysics 13. Climate action Climatology Tropical climate Polar amplification General Earth and Planetary Sciences Environmental Chemistry Climate sensitivity Environmental science Climate model Astrophysics::Earth and Planetary Astrophysics Physics::Atmospheric and Oceanic Physics 0105 earth and related environmental sciences |
| Zdroj: | Journal of Advances in Modeling Earth Systems. 5:1-14 |
| ISSN: | 1942-2466 |
| DOI: | 10.1029/2012ms000191 |
| Popis: | [1] A radiative-convective equilibrium (RCE) configuration of a comprehensive atmospheric general circulation model, ECHAM6, is coupled to a mixed-layer ocean for the purpose of advancing understanding of climate and climate change. This configuration differs from a standard configuration only through the removal of land-surface processes, spatial gradients in solar insolation, and the effects of rotation. Nonetheless, the model produces a climate that resembles the tropical climate in a control simulation of Earth's atmosphere. In the RCE configuration, regional inhomogeneities in surface temperature develop. These inhomogeneities are transient in time but sufficiently long-lived to establish large-scale overturning circulations with a distribution similar to the preindustrial tropics in the standard configuration. The vertical structure of the atmosphere, including profiles of clouds and condensate conditioned on the strength of overturning, also resembles those produced by a control simulation of Earth's tropical atmosphere. The equilibrium climate sensitivity of the RCE atmosphere can explain 50% of the global climate sensitivity of a realistic configuration of ECHAM6. Part of the difference is attributed to the lack of polar amplification in RCE. The remainder appears to be related to a less positive cloud shortwave feedback, which results from an increase in low cloudiness with increasing surface temperatures in the RCE configuration. The RCE configuration shows an increase of climate sensitivity in a warmer climate. The increase in climate sensitivity scales with the degree to which the upper-troposphere temperature departs from a moist adiabat. |
| Databáze: | OpenAIRE |
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