气候变化领域集成服务门户(CCPortal): Consistency and representativeness of integrated water vapour from ground-based GPS observations and ERA-Interim reanalysis

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DOI	10.5194/acp-19-9453-2019
	Consistency and representativeness of integrated water vapour from ground-based GPS observations and ERA-Interim reanalysis
	Bock O.; Parracho A.C.
发表日期	2019
ISSN	16807316
起始页码	9453
结束页码	9468
卷号	19 期号:14
英文摘要	This study examines the consistency and representativeness differences of daily integrated water vapour (IWV) data from ERA-Interim reanalysis and GPS observations at 120 global sites over a 16-year period (1995-2010). Various comparison statistics are analysed as a function of geographic, topographic, and climatic features. A small (±1 kgm-2) bias is found in the reanalysis across latitudes (moist in northern and southern midlatitudes and dry in the tropics). The standard deviation of daily IWV differences is generally below 2 kgm-2 but peaks in the northern and southern storm-track regions. In general, the larger IWV differences are explained by increased representativeness errors, when GPS observations capture some small-scale variability that is not resolved by the reanalysis. A representativeness error statistic is proposed which measures the spatiotemporal variability in the vicinity of the GPS sites, based on reanalysis data at the four surrounding grid points. It allows to predict the standard deviation of daily IWV differences with a correlation of 0.73. In general, representativeness differences can be reduced by temporal averaging and spatial interpolation from the four surrounding grid points. A small number of outlying cases (15 sites) which do not follow the general tendencies are further examined. It is found that their special topographic and climatic features strongly enhance the representativeness errors (e.g. steep topography, coastlines, and strong seasonal cycle in monsoon regions). Discarding these sites significantly improves the global ERA-Interim and GPS comparison results. The selection of sites a priori, based on the representativeness error statistic, is able to detect 11 out of the 15 sites and improve the comparison results by 20% to 30 %. © Author(s) 2019.
语种	英语
scopus关键词	data assimilation; diurnal variation; error analysis; GPS; ground-based measurement; interpolation; spatial variation; water vapor
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/144257
作者单位	Université de Paris, Institut de Physique du Globe de Paris, CNRS, IGN, Paris, France; ENSG-Géomatique, IGN, Marne-la-Vallée, France; LATMOS-IPSL, CNRS UMR8190, Sorbonne Université, Paris, France
推荐引用方式 GB/T 7714	Bock O.,Parracho A.C.. Consistency and representativeness of integrated water vapour from ground-based GPS observations and ERA-Interim reanalysis[J],2019,19(14).
APA	Bock O.,&Parracho A.C..(2019).Consistency and representativeness of integrated water vapour from ground-based GPS observations and ERA-Interim reanalysis.Atmospheric Chemistry and Physics,19(14).
MLA	Bock O.,et al."Consistency and representativeness of integrated water vapour from ground-based GPS observations and ERA-Interim reanalysis".Atmospheric Chemistry and Physics 19.14(2019).