江淮地区两次持续性强降雪过程大气环流及低频特征
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摘要
利用NCEP/NCAR逐日再分析资料和地面观测资料,对比分析了2018年1月江淮地区两次持续性强降雪过程的大气环流,研究了中高、低纬度系统(阻塞高压和南支槽)在持续性强降雪过程中的协同作用,探讨了阻高指数和南支槽指数正负位相的低频波动对中长期预报的可参考性。结果表明:(1)两次强降雪过程发生时大气环流持续异常,极涡呈"偶极型",中高纬度阻塞形势明显,地面冷高压强大,有利于强冷空气南下;低纬度副高、南支槽维持,有利于暖湿气流向江淮地区输送;冷暖空气交汇,出现明显的中高、低纬度系统协同作用;(2)强降雪过程主要是由中高纬度系统尤其是阻塞高压稳定维持和低纬度的南支槽相互配合造成的,两次过程均发生在阻高偏强、南支槽偏强且位势高度峰区和谷区相叠加的时间段;(3)两次持续性强降雪过程中,极涡位置、阻高和南支槽强度以及低层水汽条件、垂直环流等方面存在一定的差异,使得两次过程的降雪范围、强度和类型具有不同特点;(4)阻高异常偏强(弱)或南支槽异常偏强(弱)有(不)利于持续性降雪过程发生;持续性强降雪发生时阻高和南支槽的差值指数(UI-STI)具有明显异常偏高的特征,对强降雪过程预报具有一定的指示意义;(5)阻高和南支槽指数具有显著的10～30天低频变化特征,其正负位相的低频波动可提前两周以上,为强降雪过程预报提供参考。
Based on the surface observation data and NCEP/NCAR daily reanalysis data,the atmospheric circulation of the two persistent heavy snow processes over Yangtze and Huaihe River Valleys in January 2018 were analyzed,and the impact of synoptic system and low-frequency variation in high and low latitudes( Ural block high and southern branch trough) on persistent heavy snow processes were discussed. Results are shown as follows:( 1) The two processes happened with persistent atmospheric circulation anomalies,for example,the polar vortex had a dipole-type distribution,and the blocking high pressure was steady and strong in middle-high latitudes,with cold high pressure over the plain,thus in favor of the southward advance of cold air. In lower latitude,the west Pacific subtropical high and southern branch trough were stable,which is very favorite to transportation of heat and moisture to Yangtze and Huaihe River valleys. Cold air from north and warm-mosit air from south converged to each other and then the favorite environment of heavy snow could appear.( 2) The stable and strong Ural block high and the southern branch trough and their interaction played an important role in the two processes.( 3) There were differences of the polar vortex、blocking high、southern branch trough、low-level moisture and vertical circulation between the two processes,leading to different features on snow area、intensity and type.( 4) Stronger blocking high and deeper southern branch trough benefit the occurrence of persistent heavy snow. The variation between the index of blocking high and southern branch trough was high in those strong snow days,which had important implications for middle and long term forecast on persistent heavy snow.( 5) The low-frequency oscillation period of 10 ～ 30 days was the most remarkable component of blocking high and southern branch trough and gave a good reference on weather forecast over two weeks.
Based on the surface observation data and NCEP/NCAR daily reanalysis data,the atmospheric circulation of the two persistent heavy snow processes over Yangtze and Huaihe River Valleys in January 2018 were analyzed,and the impact of synoptic system and low-frequency variation in high and low latitudes( Ural block high and southern branch trough) on persistent heavy snow processes were discussed. Results are shown as follows:( 1) The two processes happened with persistent atmospheric circulation anomalies,for example,the polar vortex had a dipole-type distribution,and the blocking high pressure was steady and strong in middle-high latitudes,with cold high pressure over the plain,thus in favor of the southward advance of cold air. In lower latitude,the west Pacific subtropical high and southern branch trough were stable,which is very favorite to transportation of heat and moisture to Yangtze and Huaihe River valleys. Cold air from north and warm-mosit air from south converged to each other and then the favorite environment of heavy snow could appear.( 2) The stable and strong Ural block high and the southern branch trough and their interaction played an important role in the two processes.( 3) There were differences of the polar vortex、blocking high、southern branch trough、low-level moisture and vertical circulation between the two processes,leading to different features on snow area、intensity and type.( 4) Stronger blocking high and deeper southern branch trough benefit the occurrence of persistent heavy snow. The variation between the index of blocking high and southern branch trough was high in those strong snow days,which had important implications for middle and long term forecast on persistent heavy snow.( 5) The low-frequency oscillation period of 10 ～ 30 days was the most remarkable component of blocking high and southern branch trough and gave a good reference on weather forecast over two weeks.
引文
布和朝鲁,纪立人,施宁,2008.2008年初我国南方雨雪低温天气的中期过程分析Ⅰ:亚非副热带急流低频波[J].气候与环境研究,13(4):419-433.
陈官军,魏凤英,2012.基于低频振荡特征的夏季江淮持续性降水延伸期预报方法[J].大气科学,36(3):633-644.
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丑纪范,2011.天气和气候的可预报性[J].气象科技进展,1(2):12-14.
丑纪范,郑志海,孙树鹏,2010.10~30天延伸期数值天气预报的策略思考-直面混沌[J].气象科学,30(5):569-573.
丁一汇,梁萍,2010.基于MJO的延伸期预报[J].气象,36(7):111-122.
杜小玲,高守亭,彭芳,2014.2011年初贵州持续低温雨雪冰冻天气成因研究[J].大气科学,38(1):61-72.
辜旭赞,2011.2008年1月我国南方持续性雨雪过程的诊断分析[J].高原气象,27(1):150-157.
郭荣芬,高安生,杨素雨,2010.低纬高原两次冬季南支槽强降水的对比分析[J].大气科学学报,33(1):82-88.
胡顺起,曹张弛,陈滔,2017.山东省南部一次极端大暴雪过程诊断分析[J].高原气象,36(4):984-992.DOI:10.7522/j.issn.1000-0534.2016.00134.
金荣花,马杰,毕宝贵,2010.10~30 d延伸期预报研究进展和业务现状[J].沙漠与绿洲气象,4(2):1-5.
金祖辉,孙淑清,1996.东亚大陆冬季风的低频振荡特征[J].大气科学,20(1):101-111.
李登文,乔琪,魏涛,2009.2008年初我国南方冻雨雪天气环流及垂直结构分析[J].高原气象,28(5):1140-1148.
刘晶,李娜,陈春艳,2018.新疆北部一次暖区暴雪过程锋面结构及中尺度云团分析[J].高原气象,37(1):158-166.DOI:10.7522/j.issn.1000-0534.2017.00008.
马宁,李跃凤,琚建华,2011.2008年初中国南方低温雨雪冰冻天气的季节内振荡特征[J].高原气象,30(2):318-327.
秦剑,潘里娜,石鲁平,1991.南支槽与强冷空气结合对云南冬季天气的影响[J].气象,17(3):39-43.
孙国武,李震坤,信飞,等,2013.延伸期天气过程预报的一种新方法-低频天气图[J].大气科学,37(4):945-954.
孙艳辉,李泽椿,寿绍文,2017.东北地区两次历史罕见暴风雪天气过程的分析[J].高原气象,36(2):549-561.DOI:10.7522/j.issn.1000-0534.2017.00012.
索渺清,丁一汇,2009.冬半年副热带南支西风槽结构和演变特征研究[J].大气科学,33(3):425-442.
陶诗言,卫捷,2008.2008年1月我国南方严重冰雪灾害过程分析[J].气候与环境研究,13(4):337-350.
王允,张庆云,彭京备,2008.东亚冬季环流季节内振荡与2008年初南方大雪关系[J].气候与环境研究,13(4):459-467.
杨成芳,李泽椿,李静,等,2008.山东半岛一次持续性强冷流降雪过程的成因分析[J].高原气象,27(2):442-451.
张永莉,范广洲,周定文,等,2012.冬半年南支槽的气候特征分析[J].成都信息工程学院学报,27(2):196-201.
张娇,王东勇,朱佳宁,等,2011.淮河流域持续性强降水的重要前期信号[J].气象,37(11):1329-1335.
赵思雄,孙建华,2008.2008年初南方雨雪冰冻天气的环流场与多尺度特征[J].气候与环境研究,13(4):351-367.
赵俊虎,杨柳,曾宇星,等,2016.夏季长江中下游和华南两类雨型的环流特征及预测信号[J].大气科学,40(6):1182-1198.
周雪松,杨成芳,孙兴池,2013.两次早春暴雪过程的对比分析[J].高原气象,32(2):446-455.DOI:10.7522/j.issn.1000-0534.2012.00043.
陈官军,魏凤英,2012.基于低频振荡特征的夏季江淮持续性降水延伸期预报方法[J].大气科学,36(3):633-644.
丑纪范,2002.大气科学中的非线性与复杂性[M].北京:气象出版社,1-204.
丑纪范,2011.天气和气候的可预报性[J].气象科技进展,1(2):12-14.
丑纪范,郑志海,孙树鹏,2010.10~30天延伸期数值天气预报的策略思考-直面混沌[J].气象科学,30(5):569-573.
丁一汇,梁萍,2010.基于MJO的延伸期预报[J].气象,36(7):111-122.
杜小玲,高守亭,彭芳,2014.2011年初贵州持续低温雨雪冰冻天气成因研究[J].大气科学,38(1):61-72.
辜旭赞,2011.2008年1月我国南方持续性雨雪过程的诊断分析[J].高原气象,27(1):150-157.
郭荣芬,高安生,杨素雨,2010.低纬高原两次冬季南支槽强降水的对比分析[J].大气科学学报,33(1):82-88.
胡顺起,曹张弛,陈滔,2017.山东省南部一次极端大暴雪过程诊断分析[J].高原气象,36(4):984-992.DOI:10.7522/j.issn.1000-0534.2016.00134.
金荣花,马杰,毕宝贵,2010.10~30 d延伸期预报研究进展和业务现状[J].沙漠与绿洲气象,4(2):1-5.
金祖辉,孙淑清,1996.东亚大陆冬季风的低频振荡特征[J].大气科学,20(1):101-111.
李登文,乔琪,魏涛,2009.2008年初我国南方冻雨雪天气环流及垂直结构分析[J].高原气象,28(5):1140-1148.
刘晶,李娜,陈春艳,2018.新疆北部一次暖区暴雪过程锋面结构及中尺度云团分析[J].高原气象,37(1):158-166.DOI:10.7522/j.issn.1000-0534.2017.00008.
马宁,李跃凤,琚建华,2011.2008年初中国南方低温雨雪冰冻天气的季节内振荡特征[J].高原气象,30(2):318-327.
秦剑,潘里娜,石鲁平,1991.南支槽与强冷空气结合对云南冬季天气的影响[J].气象,17(3):39-43.
孙国武,李震坤,信飞,等,2013.延伸期天气过程预报的一种新方法-低频天气图[J].大气科学,37(4):945-954.
孙艳辉,李泽椿,寿绍文,2017.东北地区两次历史罕见暴风雪天气过程的分析[J].高原气象,36(2):549-561.DOI:10.7522/j.issn.1000-0534.2017.00012.
索渺清,丁一汇,2009.冬半年副热带南支西风槽结构和演变特征研究[J].大气科学,33(3):425-442.
陶诗言,卫捷,2008.2008年1月我国南方严重冰雪灾害过程分析[J].气候与环境研究,13(4):337-350.
王允,张庆云,彭京备,2008.东亚冬季环流季节内振荡与2008年初南方大雪关系[J].气候与环境研究,13(4):459-467.
杨成芳,李泽椿,李静,等,2008.山东半岛一次持续性强冷流降雪过程的成因分析[J].高原气象,27(2):442-451.
张永莉,范广洲,周定文,等,2012.冬半年南支槽的气候特征分析[J].成都信息工程学院学报,27(2):196-201.
张娇,王东勇,朱佳宁,等,2011.淮河流域持续性强降水的重要前期信号[J].气象,37(11):1329-1335.
赵思雄,孙建华,2008.2008年初南方雨雪冰冻天气的环流场与多尺度特征[J].气候与环境研究,13(4):351-367.
赵俊虎,杨柳,曾宇星,等,2016.夏季长江中下游和华南两类雨型的环流特征及预测信号[J].大气科学,40(6):1182-1198.
周雪松,杨成芳,孙兴池,2013.两次早春暴雪过程的对比分析[J].高原气象,32(2):446-455.DOI:10.7522/j.issn.1000-0534.2012.00043.