摘要
为了解国家气候中心第二代季节预测模式系统(BCCv2)预测产品在重庆地区的动力降尺度效果,利用WRF模式对BCCv2的2016年汛期预测数据进行动力降尺度试验,对比了动力降尺度前后预测的重庆地区汛期平均降水的差异及采用不同边界层参数化方案对降水预测的影响。试验结果表明,动力降尺度能较好地改善BCCv2对重庆地区汛期降水预测整体偏少的情况,且在降水空间分布特征上与观测更加接近。对比采用不同边界层参数化方案(MYJ、MYNN2、YSU和ACM2)后的降水预测结果可知,YSU方案偏差较小;但从整体看,各方案间差异并不明显。对环流场的偏差分析以及进一步利用松弛逼近法进行的试验表明,动力降尺度能较好地改善BCCv2对青藏高原以南和中国南部地区位势高度预测的正偏差,并能改善降尺度前其对高原南部偏西风水汽输送预测的偏弱,但对两广一带向北水汽输送预测依然较弱;边界场在环流形势预测中的偏差可能与动力降尺度预测的重庆地区汛期降水整体偏少存在联系。
To evaluate the dynamical downscaling prediction skill on the averaged precipitation in flood season over Chongqing, using WRF model based on Beijing Climate Center(BCC) second-generation seasonal prediction model system(BCCv2) product, we have conducted a dynamical downscaling prediction test based on the hindcast data over Chongqing during the flood season of 2016 from BCCv2, and compared the effect of different PBL parameterization schemes on the precipitation prediction before and after the dynamical downscaling. The results show that the dynamical downscaling can improve the original prediction in which BCCv2 predicts less precipitation than observation, and the spatial distribution of BCCv2 hindcast data has also been improved by the downscaling. Comparison of precipitation prediction results after using the four PBL parameterization schemes, i.e. MYJ, MYNN2, YSU and ACM2, indicates the YSU has a relative less prediction bias against observations compared to other schemes, although the difference among the four schemes is not very significant. Analysis on the bias of atmosphere circulation between prediction and observation and the nudging test results show that dynamical downscaling can improve the prediction of geopotential height over southern Tibet Plateau and southern China and then weaker moisture transfer by westward wind over southern Tibet Plateau, although the northward moisture transfer over Guangdong and Guangxi is still weak. The bias between boundary field and observation may be connected with the less predicted precipitation than observation over Chongqing during the flood season of 2016 in the dynamical downscaling prediction.
引文
[1] Meehl G A, Covey C, Delworth T, et al. The WCRP CMIP3 multimodel dataset:A new era in climate change research[J]. Bulletin of the American Meteorological Society, 2007, 88(9):1 383-1 394
[2]胡海洋,胡轶佳,钟中,等.WRF模式对中国夏季降水的动力降尺度模拟研究[J].气象科学, 2015, 35(4):413-421
[3]王亚男,智协飞.多模式降水集合预报的统计降尺度研究[J].暴雨灾害, 2012, 31(1):1-7
[4]鞠丽霞,王会军.用全球大气环流模式嵌套区域气候模式模拟东亚现代气候[J].地球物理学报, 2006, 49(1):52-60
[5]张冬峰,徐影,刘向文. RegCM4.4对中国夏季气候的回报和2014年预测[J].气象与环境科学, 2016, 39(2):104-112
[6] Guo D, Wang H. Comparison of a very-fine-resolution GCM with RCM dynamical downscaling in simulating climate in China[J]. Advances in Atmospheric Sciences, 2016, 33(5):559-570
[7] Yu R, Zhou T, Wu T, et al. Development and Evaluation of High Resolution Climate System Models[M]. Springer, 2016
[8]吴统文,宋连春,刘向文,等.国家气候中心短期气候预测模式系统业务化进展[J].应用气象学报, 2013, 24(5):533-543
[9]吴捷,任宏利,张帅,等.BCC二代气候系统模式的季节预测评估和可预报性分析[J].大气科学, 2017, 41(6):1 300-1 315
[10]吴昊旻,黄安宁,姜燕敏,等.不同水平分辨率BCC_CSM模式对中亚夏季降水模拟能力评估[J].干旱区地理, 2016, 39(6):1 305-1 318
[11]何慧根,李巧萍,吴统文,等.月动力延伸预测模式业务系统DERF2.0对中国气温和降水的预测性能评估[J].大气科学, 2014, 38(5):950-964
[12]汪栩加,郑志海,顾伯辉,等. BCC_CSM模式夏季长江中下游水汽输送评估[J].高原气象, 2016, 35(5):1 270-1 279
[13] Skamarock W C, Klemp J B, Dudhia J, et al. A description of the advanced research WRF version 3[G]\\NCAR Technical Note. National Center for Atmospheric Research, Boulder, Colorado, USA, 2008
[14]王子谦,段安民,吴国雄.边界层参数化方案及海气耦合对WRF模拟东亚夏季风的影响[J].中国科学:地球科学, 2014, 44(3):548-562
[15]吴遥,李跃清,蒋兴文,等.两种边界层参数化方案对WRF模拟青藏高原2013年夏季降水的影响[J].高原山地气象研究, 2015, 35(2):7-16
[16]吴遥,李跃清,蒋兴文,等.WRF模拟青藏高原东南部极端旱涝年降水的参数敏感性研究[J].高原气象, 2017, 36(3):619-631
[17]杨文月,马金辉,杨文凯.基于TRMM卫星的近10 a甘肃临夏降水变化特征[J].干旱气象, 2014, 32(6):934-939
[18]白爱娟,刘长海,刘晓东.TRMM多卫星降水分析资料揭示的青藏高原及其周边地区夏季降水日变化[J].地球物理学报, 2008, 51(3):704-714
[19] Taylor K E. Summarizing multiple aspects of model performance in a single diagram[J]. Journal of Geophysical Research:Atmospheres,2001, 106(D7):7 183-7 192
[20]周长艳,李跃清,李薇,等.青藏高原东部及邻近地区水汽输送的气候特征[J].高原气象, 2005, 24(6):880-888
[21]张洁,周天军,宇如聪,等.中国春季典型降水异常及相联系的大气水汽输送[J].大气科学, 2009, 33(1):121-134
[22]王佳津,肖递祥,王春学.四川盆地极端暴雨水汽输送特征分析[J].自然资源学报,2017, 32(10):1 768-1 783
[23]李永华,徐海明,高阳华,等.西南地区东部夏季旱涝的水汽输送特征[J].气象学报,2010, 68(6):932-943
[24]刘晓冉,程炳岩,杨茜,等.川渝地区夏季高温干旱变化特征及其异常年环流形势分析[J].高原气象, 2009, 28(2):306-313
[25]王雅萍,张武,黄晨然.气候动力降尺度方法在复杂下垫面的应用研究[J].兰州大学学报(自然科学版), 2015, 51(4):517-525