CAJ | 학술논문

同化地面观测资料能够获得丰富的地面大气信息，这对于大气边界层的准确模拟尤为重要。由于地面观测资料同化一直受到地面观测资料质量较差的影响，因此，地面观测资料的质量控制是提高地面资料同化效果的重要方法之一。为了分析基于经验正交函数分解质量控制方法（Empirical Orthogonal Function quality control，EOF-QC）对地面资料同化效果的影响，并进一步检验该方法在实际同化试验中的应用效果，在 WRF 的三维变分同化系统中引入了经验正交函数分解质量控制法，同时通过一系列同化试验比较了经验正交函数分解质量控制法与原系统自带的基于观测与模拟偏差质量控制法（Ob-servation Minus Background quality control，OMB-QC）的差异。2008年1和7月的多个强降水预报试验结果表明，经验正交函数分解质量控制法能够保留更多天气系统的有效观测信息，更为客观准确地反映大气真实状态；同化经过经验正交函数分解质量控制法后的观测资料，模式预报的温度降低，在北部形成一个气旋性环流，该环流底部的偏西气流带动北部冷空气东移入海，同时冷空气南下也削弱了带有丰富水汽的西南气流，从而使模式预报的降水范围和强度更加合理。降水的空间分布对比结果也表明，经验正交函数质量控制法改善了模式对降水落区和强度的预报能力，各个量级的降水评分有明显提高，模拟结果更接近于实况。各组数值模拟试验结果表明，经验正交函数分解质量控制法在 WRF-3DVAR 中具有较高的应用潜力。
동화지면관측자료능구획득봉부적지면대기신식，저대우대기변계층적준학모의우위중요。유우지면관측자료동화일직수도지면관측자료질량교차적영향，인차，지면관측자료적질량공제시제고지면자료동화효과적중요방법지일。위료분석기우경험정교함수분해질량공제방법（Empirical Orthogonal Function quality control，EOF-QC）대지면자료동화효과적영향，병진일보검험해방법재실제동화시험중적응용효과，재 WRF 적삼유변분동화계통중인입료경험정교함수분해질량공제법，동시통과일계렬동화시험비교료경험정교함수분해질량공제법여원계통자대적기우관측여모의편차질량공제법（Ob-servation Minus Background quality control，OMB-QC）적차이。2008년1화7월적다개강강수예보시험결과표명，경험정교함수분해질량공제법능구보류경다천기계통적유효관측신식，경위객관준학지반영대기진실상태；동화경과경험정교함수분해질량공제법후적관측자료，모식예보적온도강저，재북부형성일개기선성배류，해배류저부적편서기류대동북부랭공기동이입해，동시랭공기남하야삭약료대유봉부수기적서남기류，종이사모식예보적강수범위화강도경가합리。강수적공간분포대비결과야표명，경험정교함수질량공제법개선료모식대강수락구화강도적예보능력，각개량급적강수평분유명현제고，모의결과경접근우실황。각조수치모의시험결과표명，경험정교함수분해질량공제법재 WRF-3DVAR 중구유교고적응용잠력。
Surface data assimilation can provide a wealth of ground information,which is particularly important for the accurate simulation of atmospheric boundary layer.Surface data assimilation has always been impacted by the poor quality of observa-tions,and an improving data quality control (QC)method for surface observations is an essential way to advance the effect of data assimilation.In order to improve the impact of surface data assimilation and discuss the influence of this method for precip-itation forecast,the EOF (Empirical Orthogonal Function)-QC is introduced into the WRF three-dimensional variational assim-ilation system.Two severe precipitation events during the periods of 28-29 January 2008 and 14-15 July 2008 have been used to investigate the difference between the EOF-QC and the OMB (observation minus background)-QC.The results show that the EOF-QC can retain weather oscillations in the observations more effectively and reflect the true state of the atmosphere more objectively and accurately than the OMB-QC.The temperature is cooling when assimilating the data after EOF-QC, which yield to a cyclonic circulation,leading the cold air from the north to moving toward the east and weakening the southwest flow with abundant water vapor.The EOF-QC can make the model forecasts of the range and intensity of precipitation become more reasonable.The spatial distribution of precipitation also shows that EOF-QC can improve the forecasting capability of precipitation area and precipitation intensity,the forecasting skill scores are also significantly enhanced.The spatial distribution of precipitation is more close to the real situation than other experiments.The numerical simulations indicate that the EOF-QC method has good potential application in WRF-3DVAR.