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Falling Snow Radiative Effects Enhance the Global Warming Response of the Tropical Pacific Atmosphere
Author(s) -
Chen ChaoAn,
Li J.L. F.,
Richardson Mark,
Lee WeiLiang,
Fetzer Eric,
Stephens G.,
Hsu HuangHsiung,
Wang YiHui,
Yu JiaYuh
Publication year - 2018
Publication title -
journal of geophysical research: atmospheres
Language(s) - English
Resource type - Journals
eISSN - 2169-8996
pISSN - 2169-897X
DOI - 10.1029/2018jd028655
Subject(s) - coupled model intercomparison project , climatology , environmental science , precipitation , radiative transfer , snow , climate model , atmospheric sciences , atmosphere (unit) , climate change , global warming , walker circulation , sea surface temperature , geology , meteorology , geography , oceanography , physics , quantum mechanics
Most models from the Coupled Model Intercomparison Project phase 5 (CMIP5) do not include the radiative effects of falling snow. This has been shown to bias simulations of radiation and circulation in the Pacific present‐day mean state. Here we explore how precipitating ice radiative effects contribute to simulated Pacific climate change via a pair of sensitivity experiments with and without snow radiative effects (SnowOn/SnowOff) using 1pctCO 2 simulations of the Community Earth System Model version 1 (CESM1) climate model, in which atmospheric CO 2 increases at 1% per year for 140 years. In addition, we compare our results with the CMIP5 ensemble mean. The initial climate state of each 1pctCO 2 run shows similar patterns to present‐day simulations. Under global warming, the regions of convective activity tend to intensify and shift eastward. These changes are stronger in the SnowOn simulation, which also displays a stronger zonal gradient of sea surface temperature warming relative to SnowOff. The changes in convective activity and the associated precipitation are particularly notable: with reduced precipitation around the maritime continent, and an approximate doubling of the precipitation increase over parts of the western Pacific in SnowOn. CESM1 SnowOff patterns of change are similar to those in CMIP5 models that exclude snow radiative effects, hinting that future warming‐driven changes in precipitation and circulation over the Pacific might be stronger than those simulated by most CMIP5 models.