Final Report for "Interdecadal climate regime transition and its interaction with climate change in CMIP5 simulations" (DOE Grant DE-SC0005344)

doi:10.2172/1109482

GSTDTAP > 地球科学

DOI	10.2172/1109482
报告编号	DOE-ASU-05344
来源ID	OSTI ID: 1109482
	Final Report for "Interdecadal climate regime transition and its interaction with climate change in CMIP5 simulations" (DOE Grant DE-SC0005344)
	Huang, Huei-Ping [Arizona State University]
	2013-12-10
出版年	2013
语种	英语
国家	美国
领域	地球科学
英文摘要	Large-amplitude interdecadal shifts of atmospheric and ocean states from one climate regime to another have been observed several times in the 20th century. They include the 1976 transition from cool tropical Pacific SST to warm tropical SST and the post-1998 reversal back to a cooler state. The transition events affect both atmospheric circulation and global water cycle. Because on decadal-to-interdecadal time scale the amplitude of the climate shift is comparable to the trend induced by anthropogenic greenhouse gas forcing, understanding the structure, statistics, and predictability of those events is critical for near-term climate projection. This study analyzed the statistics and predictability of the transition events in the CMIP5 climate model simulations by using a set of climate indices, including atmospheric angular momentum (AAM) and regionally integrated hydrological variables. A significant improvement in the simulated 20th century climatology of AAM is found in CMIP5, compared to earlier simulations in CMIP3. Nevertheless, the improvement in the simulated decadal-to-interdecadal variability in AAM is relatively minor. Systematic biases in the regional water cycle that exist in CMIP3 are found to also exist in CMIP5, although with slight improvements in the latter. Climate shift events with an amplitude comparable to the observed 1976 or 1998 event are found to rarely occur in the CMIP5 20th century simulations. In the 21st century simulations with increasing GHG concentration, the upward trend superimposed to natural variability slightly increases the frequency of occurrences of the large-amplitude events. Even so, 1976-like events remain rare in those runs. In an additional analysis of the CMIP5 Decadal Runs for the 20th century, it is found that the decadal predictability in terms of AAM is generally weak, with useful predictability mainly restricted to within ENSO time scale. Overall, this study showed promises in the improved performance of CMIP5 in some aspects but also revealed the relatively limited ability for the models to capture sharp climate shift events.
英文关键词	Climate change Climate modeling Atmospheric angular momentum
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来源平台	US Department of Energy (DOE)
引用统计
文献类型	科技报告
条目标识符	http://119.78.100.173/C666/handle/2XK7JSWQ/6138
专题	地球科学
推荐引用方式 GB/T 7714	Huang, Huei-Ping [Arizona State University]. Final Report for "Interdecadal climate regime transition and its interaction with climate change in CMIP5 simulations" (DOE Grant DE-SC0005344),2013.