Evaluation and assimilation of ATMS data in the ECMWF system
Evaluation and assimilation of ATMS data in the ECMWF system
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DOI：
10.1002/2013jd020325
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发表时间：
2013-12
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通讯作者：
N. Bormann;A. Fouilloux;W. Bell
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文献类型：
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作者：
N. Bormann;A. Fouilloux;W. Bell
本文报告了欧洲中期天气预报中心（ECMWF）先进技术微波探测器（ATMS）数据的初步经验，包括对校准/验证工作的贡献和初始同化试验。天线温度空间与短期预测的比较用于确定数据的保真度。根据短期预报对ATMS数据进行的监测表明，数据总体质量良好，噪声性能在规范范围内，经过适当的平均，与高级微波探测单元A（AMSU-A）相当或更好。即使在建立适当的天线方向图校正之前，偏差也会随着扫描位置而平滑变化，ATMS在这方面看起来比AMSU-A更好。外部扫描位置可以被同化，而不受偏差的限制，并且与更宽的扫描带一起，这导致与AMSU-A相比，一个ATMS的覆盖范围更好。有迹象表明，ATMS数据中的通道间和空间误差相关性大于AMSU-A，这可能与弱条带效应有关。在两个季节的初始同化试验中，分析和预报的影响在南半球的短期和在北方半球的长期是显著的正的，在其他方面总体上是中性的影响。在一个耗尽的观测系统的背景下的实验表明，ATMS提供了一个可比的预测影响，从一个单一的AMSU-A/微波湿度探测器组合。
This paper reports on the first experiences with Advanced Technology Microwave Sounder (ATMS) data at the European Centre for Medium‐Range Weather Forecasts (ECMWF), both in terms of the contribution to the calibration/validation exercise and in terms of initial assimilation trials. Comparisons in antenna temperature space against short‐term forecasts are used to establish the fidelity of the data. Monitoring of ATMS data against short‐term forecasts shows that the data are generally of good quality, with a noise performance that is well within specification and after appropriate averaging, comparable to or better than that of the Advanced Microwave Sounding Unit‐A (AMSU‐A). Biases vary smoothly with scan positions, even before an appropriate antenna pattern correction has been established, and ATMS looks better than AMSU‐A in this regard. Outer scan positions can be assimilated without restrictions due to biases, and together with the wider swath, this leads to a better coverage from one ATMS compared to one AMSU‐A. There are indications of larger interchannel and spatial error correlations in ATMS data than for AMSU‐A, possibly linked to a weak striping effect. The analysis and forecast impact in initial assimilation trials over two seasons are significantly positive in the short range over the Southern Hemisphere and in the long range over the Northern Hemisphere, with an otherwise overall neutral impact. Experiments in the context of a depleted observing system suggest that ATMS gives a comparable forecast impact to that from a single AMSU‐A/Microwave Humidity Sounder combination.