2018年12月大气环流和天气分析
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摘要
2018年12月大气环流主要特征为:北半球极涡为单极型分布,欧亚中高纬呈两槽一脊型,环流经向度大,有利于引导冷空气南下;南支槽偏强,且副热带高压位置偏西,有利于水汽向我国南方地区输送。12月,全国平均降水量为18. 7 mm,较常年同期偏多73.1%;全国平均气温为-3. 8℃,较常年同期(-3. 2℃)偏低0.6℃。月内共出现2次大范围降水过程、3次冷空气过程和2次雾-霾天气过程。其中,12月5-11日及12月27日至2019年1月1日,我国中东部地区出现两次大范围持续性低温雨雪天气,多地最低气温突破历史极值。
The main characteristics of the general atmospheric circulation in December 2018 are as follow.There was one polar vortex center in the Northern Hemisphere, located in the north of Greenland. The Eurasia mid-high latitude circulation presented a trough-ridge-trough pattern and a great meridionality.The south branch trough was strong, lying around 90°E averagely. The subtropical high stayed more westward than in normal years. The monthly mean precipitation over China was 18. 7 mm, which is73. 1% higher than normal. The monthly mean temperature over China was-3. 8℃, 0. 6℃ lower than normal(-3. 2℃). Two large-scale rainfall, three cold air, and two fog-haze processes occurred in December. From 5 to 11 December and from 27 December 2018 to 1 January 2019, due to the influence of cold wave, two large-scale low-temperature rain and snow processes hit most areas of central and eastern China with lowest temperature breaking historical extremes in many places.
The main characteristics of the general atmospheric circulation in December 2018 are as follow.There was one polar vortex center in the Northern Hemisphere, located in the north of Greenland. The Eurasia mid-high latitude circulation presented a trough-ridge-trough pattern and a great meridionality.The south branch trough was strong, lying around 90°E averagely. The subtropical high stayed more westward than in normal years. The monthly mean precipitation over China was 18. 7 mm, which is73. 1% higher than normal. The monthly mean temperature over China was-3. 8℃, 0. 6℃ lower than normal(-3. 2℃). Two large-scale rainfall, three cold air, and two fog-haze processes occurred in December. From 5 to 11 December and from 27 December 2018 to 1 January 2019, due to the influence of cold wave, two large-scale low-temperature rain and snow processes hit most areas of central and eastern China with lowest temperature breaking historical extremes in many places.
引文
国家气候中心,2018. 2018年12月中国气候影响评价[EB/OL].https://cmdp. ncc-cma. net/influ/moni_china. php. National Climate Center, 2018. Assessment of climate impact over China in December 2018[EB/OL]. https://cmdp. ncc-cma. net/influ/moni_china. php.
刘超,马学款,2017. 2016年12月大气环流和天气分析[J].气象,43(3):378-384. Liu C, Ma X K,2017. Analysis of the December2016 atmospheric circulation and weather[J]. Meteor Mon,43(3):378-384(in Chinese).
王继康,桂海林,马学款,2018. 2017年12月大气环流和天气分析[J].气象,44(3):463-468.Wang J K,Gui H L,Ma X K,2018.Analysis of the December 2017 atmospheric circulation and weather[J]. Meteor Mon,44(3):463-468(in Chinese).
刘超,马学款,2017. 2016年12月大气环流和天气分析[J].气象,43(3):378-384. Liu C, Ma X K,2017. Analysis of the December2016 atmospheric circulation and weather[J]. Meteor Mon,43(3):378-384(in Chinese).
王继康,桂海林,马学款,2018. 2017年12月大气环流和天气分析[J].气象,44(3):463-468.Wang J K,Gui H L,Ma X K,2018.Analysis of the December 2017 atmospheric circulation and weather[J]. Meteor Mon,44(3):463-468(in Chinese).