气候变化领域集成服务门户(CCPortal): Global tropopause altitudes in radiosondes and reanalyses

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DOI	10.5194/acp-19-5661-2019
	Global tropopause altitudes in radiosondes and reanalyses
	Xian T.; Homeyer C.R.
发表日期	2019
ISSN	16807316
起始页码	5661
结束页码	5678
卷号	19 期号:8
英文摘要	Accurate depictions of the tropopause and its changes are important for studies on stratosphere- troposphere exchange and climate change. Here, the fidelity of primary lapse-rate tropopause altitudes and double tropopause frequencies in four modern reanalyses (ERAInterim, JRA-55, MERRA-2, and CFSR) is examined using global radiosonde observations. In addition, long-term trends (1981-2015) in these tropopause properties are diagnosed in both the reanalyses and radiosondes. It is found that reanalyses reproduce observed tropopause altitudes with little bias (typically less than -150 m) and error comparable to the model vertical resolution. All reanalyses underestimate the double tropopause frequency (up to 30% lower than observed), with the largest biases found in JRA-55 and the smallest in CFSR. The underestimates in double tropopause frequency are primarily attributable to the coarse vertical resolution of the reanalyses. Significant increasing trends in both tropopause altitude (40-120m per decade) and double tropopause frequency (- 3% per decade) were found in both the radiosonde observations and the reanalyses over the 35-year analysis period (1981-2015). ERA-Interim, JRA-55, and MERRA-2 broadly reproduce the patterns and signs of observed significant trends, while CFSR is inconsistent with the remaining datasets. Trends were diagnosed in both the native Eulerian coordinate system of the reanalyses (fixed longitude and latitude) and in a coordinate system where latitude is defined relative to the mean latitude of the tropopause break (the discontinuity in tropopause altitude between the tropics and extratropics) in each hemisphere. The coordinate relative to the tropopause break facilitates the evaluation of tropopause behavior within the tropical and extratropical reservoirs and revealed significant differences in trend estimates compared to the traditional Eulerian analysis. Notably, increasing tropopause altitude trends were found to be of greater magnitude in coordinates relative to the tropopause break, and increasing double tropopause frequency trends were found to occur primarily poleward of the tropopause break in each hemisphere. © Author(s) 2019.
语种	英语
scopus关键词	climate change; radiosonde; stratosphere-troposphere interaction; tropopause
来源期刊	Atmospheric Chemistry and Physics
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/144453
作者单位	School of Meteorology, University of Oklahoma, Norman, OK 73072, United States; School of Earth and Space Sciences, University of Science and Technology of China, Anhui, 230026, China
推荐引用方式 GB/T 7714	Xian T.,Homeyer C.R.. Global tropopause altitudes in radiosondes and reanalyses[J],2019,19(8).
APA	Xian T.,&Homeyer C.R..(2019).Global tropopause altitudes in radiosondes and reanalyses.Atmospheric Chemistry and Physics,19(8).
MLA	Xian T.,et al."Global tropopause altitudes in radiosondes and reanalyses".Atmospheric Chemistry and Physics 19.8(2019).