Deviation Correction and Assimilation Experiment on L-band Radiosonde Humidity Data
-
摘要: L波段探空仪观测资料是基础资料之一,无论在天气预报还是在数值天气预报中都起着重要作用,其资料质量直接影响数值模式同化分析及降水预报准确性。通过对我国3种常用的L波段探空仪观测湿度的偏差特性比较,研发适合该仪器的偏差订正方案,并在GRAPES同化系统中加以试验应用。结果表明:L波段探空仪湿度观测资料与ECMWF再分析湿度场比较有偏干现象。多种偏差订正方案订正结果显示:湿度偏差值比订正前减小,特别是在500 hPa以上层次减小明显。在GRAPES分析同化系统中使用Vomel偏差订正方案,分析偏差减小5%;预报模式个例和连续试验中湿度观测订正后预报降水更接近实况,预报降水检验评分显著提高,故该订正方案在实际应用中表现出积极的正效果。Abstract: The radiosonde observation of L band is a kind of conventional data, which plays an important role in weather forecast and numerical forecast. In recent years, with the progress of assimilation technology, the requirement of data precision also improves. It is found that more and more researches and operational forecasting centers are doing detailed classification and analysis for each type of instrument, even in each region and each season, according to the development of numerical forecast data assimilation technology. The method of humidity deviation correction takes the influence of observation pressure, temperature, solar altitude angle and other factors on the observation instrument into account and formulates a targeted deviation correction scheme to improve the data.Based on the analysis of humidity deviation and distribution characteristics of three kinds of L-band radiosonde instruments used in China, an effective correction method suitable for L-band radiosonde instruments in China has been developed and applied in GRAPES assimilation analysis. By improving the assimilation analysis and model prediction results, the observed humidity deviation of 3 kinds of instruments and results of continuous tests show as follows.Three main types of radiosonde instruments are used in China, among which Instrument 32 is most widely used, Instrument 31 and 33 are used at a dozen stations. The deviation of Instrument 32 is smaller than that of Instrument 31. The deviation of Instrument 33 is smaller when the humidity is greater than 60%, and greater than the others below the level of 400 hPa and the humidity is less than 60%.Compared with ECMWF reanalysis of humidity field, there is a dry phenomenon in L-band radiosonde humidity observation. Compared with the control test, the humidity deviation value of various deviation correction schemes is obviously reduced above the level of 500 hPa. The Vomel deviation correction scheme is used in GRAPES assimilation system, and the analytical deviation is reduced by 5%. After the humidity observation is revised, the forecast precipitation is closer to the actual situation, and the test score of forecast precipitation is improved significantly.Through the analysis and comparison of humidity observation deviations of several kinds of radiosonde instruments in China, the evaluation and understanding of the performance of these instruments are deepened, and the revised scheme suitable for radiosonde humidity deviation in China has been developed, which has achieved better application effect in the test. It lays the foundation for the better use of these data in practical applications, and makes an active attempt to better classifying sounding instruments.
-
图 8 2013年7月9日00:00 24 h降水实况和预报结果
(a)24 h降水实况,(b)采用方案1预报结果,(c)采用方案2和方案1预报结果之差,(d)采用方案2预报结果,(e)采用方案4和方案1预报结果之差,(f)采用方案4预报结果,(g)采用方案5和方案1预报结果之差,(h)采用方案5预报结果
Fig. 8 24 h rainfall of observation and forecast at 0000 UTC 9 Jul in 2013
(a)observation, (b)forecast of scheme 1, (c)forecast bias between scheme 2and scheme 1, (d)forecast of scheme 2, (e)forecast bias between scheme 4 and scheme 1, (f)forecast of scheme 4, (g)forecast bias between scheme 5 and scheme 1, (h)forecast of scheme 5
表 1 5种偏差订正方案
Table 1 Five bias correction schemes
方案 质量控制方案 内容说明 1 无 未订正 2 对湿度不小于60%的探空资料
采用分段线性函数订正400 hPa及以上层次加以订正 3 对湿度不小于60%的探空资料
采用分段线性函数订正所有层次订正 4 Vomel方案订正 400 hPa及以上层次订正 5 方案3基础上Vomel方案订正 400 hPa及以上层次采用Vomel方案订正 -
[1] 姚雯, 马颖, 徐文静.L波段电子探空仪相对湿度误差研究及其应用.应用气象学报, 2008, 19(3):356-361. doi: 10.3969/j.issn.1001-7313.2008.03.012 [2] Vomel H, Selkirk H.Radiation dry bias of the Vaisala RS92 humidity sensor. J Atmos Technol, 2007, 24(6):953-963. doi: 10.1175/JTECH2019.1 [3] Paul E C, Richard H J.Correction of humidity biases in Vaisala RS80-H sondes during NAME. J Atmos Ocean Technol, 2009, 26(9):1763-1780. doi: 10.1175/2009JTECHA1222.1 [4] Yoneyama K, Fujita M, Sato N, et al.Correction for radiation dry bias found in RS92 radiosonde data during the MISMO field experiment. SOLA, 2008, 4:13-16. doi: 10.2151/sola.2008-004 [5] Anna A P, Drasko V, Anton B, et al.Radiosonde humidity bias correction over the West African region for the special AMMA reanalysis at ECMWF. Q J R Meteor Soc, 2009, 135:595-617. doi: 10.1002/qj.v135:640 [6] Bian J C, Chen H B, Voemel H, et al.Intercomparison of humidity and temperature sensors:GTS1, Vaisala RS80, and CFH. Adv Atmos Sci, 2011, 28(1):139-146. doi: 10.1007/s00376-010-9170-8 [7] Faccani C, Rabier F, Fourrie N, et al.The impacts of AMMA radiosonde data on the French Global Assimilation and Forecast System. Wea Forecasting, 2009, 24(5):1268-1286. doi: 10.1175/2009WAF2222237.1 [8] Reinaldo B da S, Gilbert O F, Luiz A T M, et al. Executive Summary of the WMO Intercomparison of GPS Radiosondes. Instruments and Observing Methods Report No. 76, WMO/TD-No. 1153, Geneva: WMO, 2003: 3-5. [9] 姚爽, 陈敏, 王建捷.L波段分钟数据在WRF模式中的变分同化应用试验.气象, 2015, 41(6):695-706. http://d.old.wanfangdata.com.cn/Periodical/qx201506004 [10] 徐文静, 郭亚田, 黄炳勋, 等.GTS碳湿敏元件性能测试数据分析及相对湿度订正.气象科技, 2007, 35(3):423-428. doi: 10.3969/j.issn.1671-6345.2007.03.025 [11] 庄照荣, 薛纪善, 韩威, 等.探空观测黑名单检查在变分同化系统中的应用.应用气象学报, 2014, 25(3):274-283. doi: 10.3969/j.issn.1001-7313.2014.03.004 [12] 王英, 熊安元.L波段探空仪器换型对高空湿度资料的影响.应用气象学报, 2015, 26(1):76-85. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20150108&flag=1 [13] 马舒庆, 李峰, 邢毅.从毛里求斯国际探空系统对比看全球探空技术的发展.气象科技, 2006, 34(5):606-609. doi: 10.3969/j.issn.1671-6345.2006.05.019 [14] 李伟, 李锋, 赵志强, 等.L波段气象探测系统建设技术评估报告.北京:气象出版社, 2009. [15] 郝民, 龚建东, 王瑞文, 等.中国L波段探空湿度观测资料的质量评估及偏差订正.气象学报, 2015, 73(1):187-199. http://d.old.wanfangdata.com.cn/Periodical/qxxb201501014 [16] 朱丽娟, 龚建东, 黄丽萍, 等.GRAPES三维云初始场形成及在短临预报中的应用.应用气象学报, 2017, 28(1):38-51. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20170104&flag=1 [17] 唐南军, 刘艳, 李刚, 等.中低空探空相对湿度观测数据的新问题——基于中国L波段探空系统湿度观测异常偏干现象的初步分析.热带气象学报, 2014, 30(4):643-653. doi: 10.3969/j.issn.1004-4965.2014.04.005 [18] 刘艳, 薛纪善, 张林, 等.GRAPES全球三维变分同化系统的检验与诊断.应用气象学报, 2016, 27(1):1-15. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20160101&flag=1 [19] 王金成, 陆慧娟, 韩威, 等.GRAPES全球三维变分同化业务系统性能.应用气象学报, 2017, 28(1):11-24. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20170102&flag=1 [20] 郝民, 龚建东, 徐枝芳.地面报中高山站资料的应用分析.气象, 2016, 42(4):424-435. http://d.old.wanfangdata.com.cn/Periodical/qx201604005 [21] 余贞寿, 冀春晓, 杨程, 等.同化风廓线雷达资料对浙江降水预报改进评估.应用气象学报, 2018, 29(1):97-110. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20180109&flag=1 [22] 张林, 刘永柱.GRAPES全球四维变分同化系统极小化算法预调节.应用气象学报, 2017, 28(2):168-176. http://qikan.camscma.cn/jams/ch/reader/view_abstract.aspx?file_no=20170204&flag=1 [23] Pathack B, Nas h J, Smout R, et al. WMO Intercomparison of High Quality Radiosonde Systems. Instruments and Observing Methods Report No. 94, WMO/TD-No. 1354, Geneva: WMO, 2006. [24] 世界气象组织. 气象仪器和观测方法指南(第六版). 2005.