A climatological comparison of column-integrated water vapor for the third-generation reanalysis datasets
A climatological comparison of column-integrated water vapor for the third-generation reanalysis datasets
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第三代再分析数据集柱积分水汽的气候学比较
DOI：
10.1007/s11430-015-5183-6
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发表时间：
2016
影响因子：
5.7
通讯作者：
Yang YuanJian
中科院分区：
文献类型：
--
作者：
Wang Yu;Zhang Ying;Fu YunFei;Li Rui;Yang YuanJian
大气再分析数据集已被广泛用于了解大气水汽在不同时间和空间尺度上的变化，以进行气候变化研究。然而，各种重分析数据集之间的差异导致了相应结果的不确定性。本研究比较了欧洲中期天气预报中心中期再分析（ERA-Interim）、现代时代研究与应用回顾分析（MERRA）和气候预报系统再分析（CFSR）等三个最新的第三代大气再分析2000年至2012年期间的大气柱积分水汽气候特征，并对它们之间的差异给出了可能的解释。结果表明，三个数据集在多年全球分布、年际循环变化、长期趋势等方面存在显着差异，但描述水汽变化的主模态具有较高的相似性。海洋上空，CWV长期变化特征相似，但3个数据集的主要差异位于热带辐合带、南太平洋辐合带和暖云区的赤道地区，这与对流参数化方案、暖云处理和星基观测同化再分析模型的差异有关。此外，这些 CWV 产品与海洋观测（基于卫星的反演）相当一致。另一方面，与无线电探空仪观测相比，所有三个 CWV 数据集的土地上都有大约 2.5 kg/m2 的系统性低估。由于复杂环境下陆地-大气相互作用模型的差异以及无线电探空仪观测的缺乏，导致南美洲亚马逊盆地、非洲中部和部分山区存在明显的水汽缺口。这些结果将有助于更好地理解各种再分析数据集之间的气候学差异，并针对不同的研究需求更合理地选择水汽数据集。
The atmospheric reanalysis datasets have been widely used to understand the variability of atmospheric water vapor on various temporal and spatial scales for climate change research. The difference among a variety of reanalysis datasets, however, causes the uncertainty of corresponding results. In this study, the climatology of atmospheric column-integrated water vapor for the period from 2000 to 2012 was compared among three latest third-generation atmospheric reanalyses including European Centre for Medium-range Weather Forecasts Interim Re-Analysis (ERA-Interim), Modern-Era Retrospective Analysis for Research and Applications (MERRA), and Climate Forecast System Reanalysis (CFSR), while possible explanation on the difference between them was given. The results show that there are significant differences among three datasets in the multi-year global distribution, variation of interannual cycle, long-term trend and so on, though high similarity for principal mode describing the variability of water vapor. Over oceans, the characteristics of long-term CWV variability are similar, whereas the main discrepancy among three datasets is located around the equatorial regions of the Intertropical Convergence Zone, the South Pacific Convergence Zone and warm cloud area, which is related with the difference between reanalysis models for the scheme of convective parameterization, the treatment of warm clouds, and the assimilation of satellite-based observations. Moreover, these CWV products are fairly consistent with observations (satellite-based retrievals) for oceans. On the other hand, there are systematic underestimations about 2.5 kg/m2over lands for all three CWV datasets, compared with radiosonde observations. The difference between models to solve land-atmosphere interaction in complex environment, as well as the paucity in radiosonde observations, leads to significant water vapor gaps in the Amazon Basin of South America, central parts of Africa and some mountainous regions. These results would help better understand the climatology difference among various reanalysis datasets better, and more properly choose water vapor datasets for different research requirements.