利用常规气象观测资料、加密自动站观测资料、污染物PM2.5质量浓度数据等,对近3年天津秋冬季出现的重度霾天气过程进行分析。主要从重度霾天气发生的天气形势、气象要素特征、减弱消散条件等方面进行分析。结果表明:秋冬季重度霾天气发...利用常规气象观测资料、加密自动站观测资料、污染物PM2.5质量浓度数据等,对近3年天津秋冬季出现的重度霾天气过程进行分析。主要从重度霾天气发生的天气形势、气象要素特征、减弱消散条件等方面进行分析。结果表明:秋冬季重度霾天气发生时500 h Pa环流形势基本为弱西北气流或偏西气流,低层850 h Pa为高压脊前偏北气流或暖高压脊或高压后部西南气流等控制;地面气压场较弱,多为鞍形场、低压或高压后部控制,风力较小。重度霾天气发生时,海平面气压值基本在1 023~1 028.5 h Pa之间,地面多为南到东南风,风速<1.0 m/s,水平能见度较差(基本在2.0 km以下),当空气湿度较大、雾和霾同时存在时能见度会降至1.0 km以下,另外霾天气发生时在850 h Pa以下均存在较强逆温层或双层逆温现象。对于重度霾天气减弱消散条件,除冷空气东移南下能对污染物起到很好消除作用外,当地面西南风明显加大、出现浓雾天气近地层空气达到饱和以及受偏东路径冷空气影响时,也会对重度霾过程减弱消散起到较好的作用。另外受海风环流影响时,天津大气污染扩散条件会好转、污染物浓度降低、重度霾过程会减弱消散;但因存在海风锋锋前累积增长特征,受海风影响地区会出现霾污染加重的现象(一般为3 h左右,与海风强度及移动速度有关)。展开更多
In this work,the results of a coupled experiment and an uncoupled experiment conducted in one of our former works are used to analyze the impact of air-sea interactions on the structure of typhoons.Results reveal that...In this work,the results of a coupled experiment and an uncoupled experiment conducted in one of our former works are used to analyze the impact of air-sea interactions on the structure of typhoons.Results reveal that typhoon-induced SST decreases to reduce the latent heat fluxes transporting from the ocean to the atmosphere and cause the flux of sensible heat to transfer downward from the atmosphere to the ocean.Such SST reduction also has remarkable impacts on the typhoon structure by making the typhoon more axisymmetric,especially in the middle and high levels.This study also analyzes the basic characteristics of symmetric typhoon structure.展开更多
文摘利用常规气象观测资料、加密自动站观测资料、污染物PM2.5质量浓度数据等,对近3年天津秋冬季出现的重度霾天气过程进行分析。主要从重度霾天气发生的天气形势、气象要素特征、减弱消散条件等方面进行分析。结果表明:秋冬季重度霾天气发生时500 h Pa环流形势基本为弱西北气流或偏西气流,低层850 h Pa为高压脊前偏北气流或暖高压脊或高压后部西南气流等控制;地面气压场较弱,多为鞍形场、低压或高压后部控制,风力较小。重度霾天气发生时,海平面气压值基本在1 023~1 028.5 h Pa之间,地面多为南到东南风,风速<1.0 m/s,水平能见度较差(基本在2.0 km以下),当空气湿度较大、雾和霾同时存在时能见度会降至1.0 km以下,另外霾天气发生时在850 h Pa以下均存在较强逆温层或双层逆温现象。对于重度霾天气减弱消散条件,除冷空气东移南下能对污染物起到很好消除作用外,当地面西南风明显加大、出现浓雾天气近地层空气达到饱和以及受偏东路径冷空气影响时,也会对重度霾过程减弱消散起到较好的作用。另外受海风环流影响时,天津大气污染扩散条件会好转、污染物浓度降低、重度霾过程会减弱消散;但因存在海风锋锋前累积增长特征,受海风影响地区会出现霾污染加重的现象(一般为3 h左右,与海风强度及移动速度有关)。
基金Key Project of Natural Science Foundation of China (40730948)Coupling Experiment on Typhoons, Waves and Storm Surges of South China Sea and Assessment of Typhoon Disasters, a project of Tropical Marine Meteorological Science FoundationObservation/Model Experiments of Marine Meteorological Disasters and Construction of Application Platform, a project of Specialized Foundation for Public Welfare Science Research Institutions of Finance Ministry
文摘In this work,the results of a coupled experiment and an uncoupled experiment conducted in one of our former works are used to analyze the impact of air-sea interactions on the structure of typhoons.Results reveal that typhoon-induced SST decreases to reduce the latent heat fluxes transporting from the ocean to the atmosphere and cause the flux of sensible heat to transfer downward from the atmosphere to the ocean.Such SST reduction also has remarkable impacts on the typhoon structure by making the typhoon more axisymmetric,especially in the middle and high levels.This study also analyzes the basic characteristics of symmetric typhoon structure.
