CFSv2对浙江省延伸期逐日降水预报性能评估及解释应用初探  

Evaluation of daily precipitation forecast ability over Zhejiang Province within the extended-range and preliminary statistical interpretation-application for CFSv2

作　　者：葛敬文 马浩[1] 刁逸菲 樊高峰[1] 李正泉[1] 刘长征[2] GE Jingwen;MA Hao;DIAO Yifei;FAN Gaofeng;LI Zhengquan;LIU Changzheng(Zhejiang Climate Center,Hangzhou 310000,China;National Climate Center,Beijing 100081,China)

机构地区：[1]浙江省气候中心,杭州310000 [2]国家气候中心,北京100081

出　　处：《气象科学》2024年第4期735-749,共15页Journal of the Meteorological Sciences

基　　金：浙江省自然科学基金联合基金资助项目(LZJMD24D050002);浙江省基础公益研究计划资助项目(LGF19D050001,LGF22D050007);浙江省重点研发计划资助项目(2021C02036);浙江省气象局重点资助项目(2022ZD09,2020ZD14);中国气象局复盘总结专项项目(FPZJ2023-052)。

摘　　要：利用CFSv2长序列回报资料和近6 a实时预报数据,系统分析了模式对浙江短中期(Short-medium Range,SMR,1~10 d)和延伸期(Extended Range,ER,11~30 d)逐日降水的预测性能,并基于系统误差订正(Systematic Bias Correction,SBC)技术开展了解释应用。结果表明:(1)模式回报技巧在SMR时段快速衰减,而在ER时段的衰减明显趋缓;SMR时段的相关系数远高于ER时段,但这两个时段的均方根误差较为接近;(2)从季节演变来看,模式技巧在秋冬季较高而在春夏季相对较低;(3)模式回报结果表现出显著的系统性偏差,这一偏差在各个起报日(提前1~30 d起报)中稳定存在,采用SBC技术开展解释应用,发现订正后模式的回报技巧在ER时段显著提升;(4)进一步将SBC技术应用于实时预报,发现实时预报的技巧也得到了一定的改善,且ER时段的改进效果更为显著。With long-term hindcast and 6-year real-time forecast data of CFSv2,prediction ability on daily precipitation over Zhejiang Province at Short-medium Range(SMR,1-10 d)and Extended Range(ER,11-30 d)by model were comprehensively analyzed.The Systematic Bias Correction(SBC)technology was proposed and conducted for interpretation-application to enhance the forecast capability.Results show that the reforecast skill decreases rapidly in the SMR;while in the ER,the skill declines much more slowly.Generally speaking,the correlation coefficient in the SMR is far higher than that in the ER,however,the root-mean-squared error in both spans can be comparable.As for the seasonal variation,the hindcast skill is relatively high in autumn and winter while relatively low in spring and summer.The reforecast results display remarkable systematic biases,which keep stable in all of the forecast dates(leading 1-30 d).After employing the SBC technology to carry out interpretation-application,the hindcast skill gets an obvious improvement in ER.When the SBC strategy is applied on the CFSv2 real-time forecast,the real-time forecast skill has been increased to a certain extent,especially for the ER.

关 键 词：预报技巧评估 延伸期时段 相关系数 均方根误差 季节变化 系统误差订正 

分 类 号：P457.6[天文地球—大气科学及气象学]