浙江省春季不同类型暖区天气降水特征

doi:10.11755/j.issn.1006-7639(2021)-05-0766

摘要/Abstract

摘要：

利用2007—2016年春季浙江及周边地区气象站观测资料与ECMWF再分析资料,分析总结浙江省春季暖区降水天气过程的环流特征及中尺度概念模型。结果表明:浙江春季暖区天气具有云量多、雨量小、气温高、日温差小的特点,暖区降水的环流形势可分为西南气流型、暖切北抬型、冷切靠近型、东南气流型4类;冷切靠近型降雨最强,其次为暖切北抬型,雨量分布均表现为西南部大、东北部小,而东南气流型降雨最小。中尺度分析发现,浙江春季暖区降雨出现在沿海近地层东南气流与低层西南气流交汇的辐合上升区、850 hPa等θ_se线密集区,雨带走向与等θ_se线平行;近地层残留的冷空气和海陆温差造成的斜压不稳定可导致降水明显增强。

关键词: 春季暖区降水, 天气分型, 环流特征, 中尺度结构

Abstract:

Based on conventional observation data from weather stations of Zhejiang Province and its surrounding and ERA-Interim reanalysis data from March to May during 2007-2016, the circulation characteristics and meso-scale conceptual model of warm sector rainfall processes in spring in Zhejiang Province were analyzed and summarized. The results show that the cloud was more, the precipitation was small, the temperature was high and the daily temperature difference was small during warm sector weathers in spring in Zhejiang Province. The warm sector rainfall processes were divided into four types according to 850 hPa wind field, and they were the southwestern airflow pattern, warm shear northward extending pattern, cold shear approaching pattern and southeastern airflow pattern, respectively. The warm sector rainfall for cold shear approaching pattern was the strongest, and then followed by warm shear northward extending pattern, their precipitation was large in the southwest and was small in the northeast, while that for southeastern airflow pattern was the smallest. Meso-scale analysis found that the warm sector rainfall often appeared in the dense isoline area of θ_se on 850 hPa and the convergence upward area of intersection of southeasterly airflow near surface and low-level southwesterly airflow over the coastal of Zhejiang, and rain belt paralleled to θ_se isolines. The baroclinic instability which caused by residual cold air near surface and temperature difference between land and sea could significantly increase the precipitation of warm sector.

Key words: warm sector rainfall in spring, weather patterns, circulation characteristics, meso-scale structure

中图分类号:

P426.6

翁之梅,周雪君,甘晶晶,王凯. 浙江省春季不同类型暖区天气降水特征[J]. 干旱气象, 2021, 39(5): 766-774.

WENG Zhimei,ZHOU Xuejun,GAN Jingjing,WANG Kai. Rainfall Characteristics of Warm Sector Weathers with Different Patterns in Spring in Zhejiang[J]. Journal of Arid Meteorology, 2021, 39(5): 766-774.

图/表 8

图1 浙江省春季暖区天气形势分型 (a)西南气流型,(b)暖切北抬型,(c)冷切靠近型,(d)东南气流型 (方框为研究区域,粗箭头线为显著流线,细线为切变线)

Fig.1 Patterns of warm sector weather situation in spring in Zhejiang (a) southwestern airflow pattern, (b) warm shear northward extending pattern,(c) cold shear approaching pattern, (d) southeastern airflow pattern (the box for the study area, thick line with arrow for significant streamline, and thin line for shear line)

图2 2007—2016年春季不同类型暖区降水天气下浙江平均雨量空间分布(单位:mm) (a)西南气流型,(b)冷切靠近型,(c)暖切北抬型,(d)东南气流型

Fig.2 The spatial distribution of average precipitation under warm sector rainfall weathers with different patterns in Zhejiang in spring from 2007 to 2016 (Unit: mm) (a) southwestern airflow pattern, (b) cold shear approaching pattern,(c) warm shear northward extending pattern, (d) southeastern airflow pattern

图3 2007—2016年春季不同类型暖区降水天气下浙江最大日雨量空间分布(单位:mm) (a)西南气流型,(b)冷切靠近型,(c)暖切北抬型,(d)东南气流型

Fig.3 The spatial distribution of the maximum daily precipitation under warm sector rainfall weathers with different patterns in Zhejiang in spring from 2007 to 2016 (Unit: mm) (a) southwestern airflow pattern, (b) cold shear approaching pattern,(c) warm shear northward extending pattern, (d) southeastern airflow pattern

图4 浙江省春季各类型暖区天气下平均雨量的月际变化

Fig.4 The monthly change of average precipitation under warm sector rainfall weathers with different patterns in spring in Zhejiang

图5 浙江省春季各类暖区降水过程夜间与白天雨量差(单位:mm) (a)西南气流型,(b)暖切北抬型,(c)冷切靠近型,(d)东南气流型

Fig.5 The difference of precipitation between the daytime and the nighttime for warm sector rainfall weathers with different patterns in spring in Zhejiang (Unit: mm) (a) southwestern airflow pattern, (b) warm shear northward extending pattern, (c) cold shear approaching pattern, (d) southeastern airflow pattern

表1 2007—2016年春季浙江各类暖区降水过程典型个例的时间及雨量

Tab.1 The time and precipitation of the warm sector rainfall weathers with different patterns in spring in Zhejiang from 2007 to 2016

类型	个例时间	最大雨量/mm	最大雨量出现站点
西南气流型	2010年3月13日20:00至14日08:00	68.3	江山仕阳
暖切北抬型	2016年4月26日20:00至27日08:00	158.9	淳安龙姚
冷切靠近型	2014年5月13日20:00至14日08:00	150.9	淳安木瓜
东南气流型	2016年4月11日08:00—20:00	40.3	庆元岭头

图6 浙江春季不同类型暖区降水个例的流场(黑色流线)、垂直速度(蓝色线,单位:Pa·s-1)及θse(阴影,单位:K)的纬向垂直剖面 (a)西南气流型(沿28.875°N),(b)暖切北抬型(沿29.5°N),(c)冷切靠近型(沿30°N),(d)东南气流型(沿27.5°N)

Fig.6 The zonal vertical section of airflow field (black streamlines), vertical velocity (blue lines, Unit: Pa·s-1) and θse (shadows, Unit: K) during the warm sector rainfall processes with different patterns in spring in Zhejiang (a) southwestern airflow pattern (along 28.875°N), (b) warm shear northward extending pattern (along 29.5°N), (c) cold shear approaching pattern (along 30°N), (d) southeastern airflow pattern (along 27.5°N)

图7 浙江省春季不同类型暖区降水概念模型 (a)西南气流型,(b)暖切北抬型,(c)冷切靠近型,(d)东南气流型 (蓝色阴影为雨区)

Fig.7 Conceptual model of rainfall caused by warm sector with different patterns in spring in Zhejiang (a) southwestern airflow pattern, (b) warm shear northward extending pattern, (c) cold shear approaching pattern, (d) southeastern airflow pattern (the blue shadow for rain area)

参考文献 15

[1]	孙明, 王博妮, 艾文文, 等. 江苏南部一次暖区降水诱发的大雾过程分析[J]. 干旱气象, 2020, 38(5):764-770.
[2]	谌芸, 陈涛, 汪玲瑶, 等. 中国暖区暴雨的研究进展[J]. 暴雨灾害, 2019, 38(5):483-493.
[3]	何立富, 陈涛, 孔期. 华南暖区暴雨研究进展[J]. 应用气象学报, 2016, 27(5):559-569.
[4]	黄士松. 华南前汛期暴雨[M]. 广州: 广东科技出版社, 1986:243-245.
[5]	韦统建. 华南前汛期暖区暴雨流场结构的特征[J]. 热带气象学报, 1994, 10(1):37-46.
[6]	丁治英, 刘彩虹, 沈新勇. 2005—2008年5、6月华南暖区暴雨与高、低空急流和南亚高压关系的统计分析[J]. 热带气象学报, 2011, 27(3):307-316.
[7]	张芹, 苏莉莉, 张秀珍, 等. 山东一次暖区暴雨的环境场特征和触发机制[J]. 干旱气象, 2019, 37(6):933-943.
[8]	张萍萍, 董良鹏, 钟敏, 等. 湖北省西南气流型暖区暴雨相关特征分析[J]. 沙漠与绿洲气象, 2019, 13(6):13-19.
[9]	徐珺, 杨舒楠, 孙军, 等. 北方一次暖区大暴雨强降水成因探讨[J]. 气象, 2014, 40(12):1455-1463.
[10]	赵玉春, 李泽椿, 肖子牛. 华南锋面与暖区暴雨个例对比分析[J]. 气象科技, 2008, 36(1):47-54.
[11]	苗春生, 杨艺亚, 王坚红, 等. 两类华南沿海暖区暴雨特征及热力发展机制对比研究[J]. 热带气象学报, 2017, 33(1):53-63.
[12]	ZHANG X M, MENG W G, ZHANG Y X, et al. Analysis of mesoscale convective systems associated with a warm-sector rainstorm event over south China[J]. Journal of Tropical Meteorology, 2011, 17(1):1-10.
[13]	徐燚, 闫敬华, 王谦谦, 等. 华南暖区暴雨的一种低层重力波触发机制[J]. 高原气象, 2013, 32(4):1050-1061.
[14]	王坚红, 杨艺亚, 苗春生, 等. 华南沿海暖区辐合线暴雨地形动力机制数值模拟研究[J]. 大气科学, 2017, 41(4):784-796.
[15]	BROWNING K A. The mesoscale data base and its use in mesoscale forecasting[J]. Quarterly Journal of the Royal Meteorolgical Society, 1989, 115:717-762.