Evaluation of ozone and water vapor fields from the ECMWF reanalysis ERA-40 during 1991–1999 in comparison with UARS satellite and MOZAIC aircraft observations
Evaluation of ozone and water vapor fields from the ECMWF reanalysis ERA-40 during 1991–1999 in comparison with UARS satellite and MOZAIC aircraft observations
复制标题
1991-1999 年期间 ECMWF 再分析 ERA-40 的臭氧和水汽场评估，与 UARS 卫星和 MOZAIC 飞机观测结果的比较
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
A. O'Neill
中科院分区：
文献类型：
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作者：
E. Oikonomou;A. O'Neill
[1] 欧洲中期天气预报中心 (ECMWF) 40 年再分析 (ERA-40) 1990 年代的臭氧和水蒸气再分析场已与来自高层大气研究卫星 (UARS) 上的卤素掩星实验 (HALOE) 和微波临边探测仪 (MLS) 仪器的独立卫星数据进行了比较。此外，ERA-40 还与空中客车在用飞机 (MOZAIC) 计划的臭氧和水蒸气测量数据进行了比较。总体而言，与独立观测得出的值相比，ERA-40 平流层上层的臭氧含量多了约 5-10%，水蒸气含量少了 15-20%。再分析中的这种干偏差似乎是全球性的，并延伸到平流层中层，低至 40 hPa。 ERA-40 和独立观测之间的大部分差异和季节变化发生在热带地区的对流层上层和平流层下层和高纬度地区。 ERA-40 再现了比独立观测更弱的南极臭氧空洞，且垂直范围更小；重新分析时热带平流层臭氧最大值较低。 ERA-40 的水蒸气混合比比 MOZAIC 大得多，在热带对流层上层通常高 20%，在高纬度平流层下层可能超过 60%。结果表明 ECMWF 再分析系统中的布鲁尔-多布森环流太快，ERA-40 在热带平流层再现水蒸气“录音机”信号的方式存在缺陷也证明了这一点。最后，本文通过 ERA-40 与独立观察结果的比较，研究了 20 世纪 90 年代的偏差及其时间变化。我们还讨论了评估结果如何取决于所使用的仪器以及数据的版本。
[1] The European Centre for Medium-Range Weather Forecasts (ECMWF) 40-year Reanalysis (ERA-40) ozone and water vapor reanalysis fields during the 1990s have been compared with independent satellite data from the Halogen Occultation Experiment (HALOE) and Microwave Limb Sounder (MLS) instruments on board the Upper Atmosphere Research Satellite (UARS). In addition, ERA-40 has been compared with aircraft data from the Measurements of Ozone and Water Vapour by Airbus In-Service Aircraft (MOZAIC) program. Overall, in comparison with the values derived from the independent observations, the upper stratosphere in ERA-40 has about 5–10% more ozone and 15–20% less water vapor. This dry bias in the reanalysis appears to be global and extends into the middle stratosphere down to 40 hPa. Most of the discrepancies and seasonal variations between ERA-40 and the independent observations occur within the upper troposphere over the tropics and the lower stratosphere over the high latitudes. ERA-40 reproduces a weaker Antarctic ozone hole, and of less vertical extent, than the independent observations; values in the ozone maximum in the tropical stratosphere are lower for the reanalysis. ERA-40 mixing ratios of water vapor are considerably larger than those for MOZAIC, typically by 20% in the tropical upper troposphere, and they may exceed 60% in the lower stratosphere over high latitudes. The results imply that the Brewer-Dobson circulation in the ECMWF reanalysis system is too fast, as is also evidenced by deficiencies in the way ERA-40 reproduces the water vapor ‘‘tape recorder’’ signal in the tropical stratosphere. Finally, the paper examines the biases and their temporal variation during the 1990s in the way ERA-40 compares to the independent observations. We also discuss how the evaluation results depend on the instrument used, as well as on the version of the data.