气候变化领域集成服务门户(CCPortal): An assessment of tropopause characteristics of the ERA5 and ERA-Interim meteorological reanalyses

CCPortal

DOI	10.5194/acp-22-4019-2022
	An assessment of tropopause characteristics of the ERA5 and ERA-Interim meteorological reanalyses
	Hoffmann, Lars; Spang, Reinhold
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	4019
结束页码	4046
卷号	22 期号:6 页码:28
英文摘要	The tropopause layer plays a key role in manifold processes in atmospheric chemistry and physics. Here we compare the representation and characteristics of the lapse rate tropopause according to the definition of the World Meteorological Organization (WMO) as estimated from European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis data. Our study is based on 10-year records (2009 to 2018) of ECMWF's state-of-the-art reanalysis ERA5 and its predecessor ERA-Interim. The intercomparison reveals notable differences between ERA5 and ERA-Interim tropopause data, in particular on small spatiotemporal scales. The monthly mean differences of ERA5 minus ERA-Interim tropopause heights vary between -300 m at the transition from the tropics to the extratropics (near 30 degrees S and 30 degrees N) to 150 m around the Equator. Mean tropopause temperatures are mostly lower in ERA5 than in ERA-Interim, with a maximum difference of up to -1.5 K in the tropics. Monthly standard deviations of tropopause heights of ERA5 are up to 350 m or 60 % larger than for ERA-Interim. Monthly standard deviations of tropopause temperatures of ERA5 exceed those of ERA-Interim by up to 1.5 K or 30 %. The occurrence frequencies of double-tropopause events in ERA5 exceed those of ERA-Interim by up to 25 percentage points at middle latitudes. We attribute the differences between the ERA5 and ERA-Interim tropopause data and the larger, more realistic variability of ERA5 to improved spatiotemporal resolution and better representation of geophysical processes in the forecast model as well as improvements in the data assimilation scheme and the utilization of additional observations in ERA5. The improved spatiotemporal resolution of ERA5 allows for a better representation of mesoscale features, in particular of gravity waves, which affect the temperature profiles in the upper troposphere and lower stratosphere (UTLS) and thus the tropopause height estimates. We evaluated the quality of the ERA5 and ERA-Interim reanalysis tropopause data by comparisons with COSMIC and MetOp Global Positioning System (GPS) satellite observations as well as high-resolution radiosonde profiles. The comparison indicates an uncertainty of the first tropopause for ERA5 (ERA-Interim) of about +/- 150 to +/- 200m (+/- 250m) based on radiosonde data and +/- 120 to +/- 150m (+/- 170 to +/- 200 m) based on the coarser-resolution GPS data at different latitudes. Consequently, ERA5 will provide more accurate information than ERA-Interim for future tropopause-related studies.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000776518900001
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/273207
作者单位	Helmholtz Association; Research Center Julich; Helmholtz Association; Research Center Julich; Helmholtz Association; Research Center Julich
推荐引用方式 GB/T 7714	Hoffmann, Lars,Spang, Reinhold. An assessment of tropopause characteristics of the ERA5 and ERA-Interim meteorological reanalyses[J],2022,22(6):28.
APA	Hoffmann, Lars,&Spang, Reinhold.(2022).An assessment of tropopause characteristics of the ERA5 and ERA-Interim meteorological reanalyses.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(6),28.
MLA	Hoffmann, Lars,et al."An assessment of tropopause characteristics of the ERA5 and ERA-Interim meteorological reanalyses".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.6(2022):28.