DOI: 10.1007/s00382-016-3352-8
Scopus记录号: 2-s2.0-84988349812
论文题名: The response of future projections of the North American monsoon when combining dynamical downscaling and bias correction of CCSM4 output
作者: Meyer J.D.D. ; Jin J.
刊名: Climate Dynamics
ISSN: 9307575
出版年: 2017
卷: 49, 期: 2017-01-02 起始页码: 433
结束页码: 447
语种: 英语
英文关键词: Community Climate Model System version 4
; GCM bias correction
; North American monsoon
; Regional climate modeling
英文摘要: A 20-km regional climate model (RCM) dynamically downscaled the Community Climate System Model version 4 (CCSM4) to compare 32-year historical and future “end-of-the-century” climatologies of the North American Monsoon (NAM). CCSM4 and other phase 5 Coupled Model Intercomparison Project models have indicated a delayed NAM and overall general drying trend. Here, we test the suggested mechanism for this drier NAM where increasing atmospheric static stability and reduced early-season evapotranspiration under global warming will limit early-season convection and compress the mature-season of the NAM. Through our higher resolution RCM, we found the role of accelerated evaporation under a warmer climate is likely understated in coarse resolution models such as CCSM4. Improving the representation of mesoscale interactions associated with the Gulf of California and surrounding topography produced additional surface evaporation, which overwhelmed the convection-suppressing effects of a warmer troposphere. Furthermore, the improved land–sea temperature gradient helped drive stronger southerly winds and greater moisture transport. Finally, we addressed limitations from inherent CCSM4 biases through a form of mean bias correction, which resulted in a more accurate seasonality of the atmospheric thermodynamic profile. After bias correction, greater surface evaporation from average peak GoC SSTs of 32 °C compared to 29 °C from the original CCSM4 led to roughly 50 % larger changes to low-level moist static energy compared to that produced by the downscaled original CCSM4. The increasing destabilization of the NAM environment produced onset dates that were one to 2 weeks earlier in the core of the NAM and northern extent, respectively. Furthermore, a significantly more vigorous NAM signal was produced after bias correction, with >50 mm month−1 increases to the June–September precipitation found along east and west coasts of Mexico and into parts of Texas. A shift towards more extreme daily precipitation was found in both downscaled climatologies, with the bias-corrected climatology containing a much more apparent and extreme shift. © 2016, Springer-Verlag Berlin Heidelberg. 资助项目: NSF, National Science Foundation
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/53168
Appears in Collections: 过去全球变化的重建
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作者单位: Department of Plants Soils and Climate, Utah State University, Logan, UT, United States; Department of Watershed Science, Utah State University, Logan, UT, United States
Recommended Citation:
Meyer J.D.D.,Jin J.. The response of future projections of the North American monsoon when combining dynamical downscaling and bias correction of CCSM4 output[J]. Climate Dynamics,2017-01-01,49(2017-01-02)