Analysis of Meteorological Characteristics of Heavy Haze Process in Tianjin in Autumn and Winter and the Role of Sea Breeze
DONG Gaohong
YU Lili
HAO Tianyi
Abstract：Using conventional meteorological observation data,encrypt automatic station data and PM2.5 pollutant concentration data,the heavy haze process that has happened during autumn and winter of last three years in Tianjin was studied,with analysis of weather situations,meteorological element characteristic and the weakening dissipation conditions of heavy haze process.The results show that when the heavy haze occured in autumn and winter,the 500 hPa circulation situation is basically weak northwest airflow or western airflow and the 850 hPa circulation situation is substantially controlled by northerly flow before high pressure ridge or warm ridge of high pressure or high rear southwest flow.And at this time,sea level pressure field are weak and mostly controlled by the saddle-shaped field or low pressure or rear of high pressure,and wind is weak.When the heavy haze occurred,the sea level pressure was between 1 023～1 028.5 hPa,the ground is south wind(or southeast wind)and the wind speed is less than 1.0 m/s,and the horizontal visibility is poor (basically below 2.0 km).When the air humidity is high and fog-haze exist simultaneously,the visibihty will be reduced to below 1.0 km.In addition,there are strong inversion layer or double inversion layer phenomenon below 850 hPa when haze weather occurred.For the severe haze appearing in autumn and winter,besides the cold air from northwest can clear the pollutants,when the southwest wind significantly increased and fog appeares and near surface air saturated and the weak cold air from east,these features all played a valuable role for pollutant dispersion.In addition,when affected by sea breeze,atmospheric pollution diffusion conditions will be significantly better,pollutants concentration will be reduced and air quality will be significantly better.However,due to the cumulative growth before the sea breeze front and fine particulate matter when wet growth,concentration of pollutants will be increased near the sea breeze front frontal zone at a short period of time(usually about 3 hours,and related with sea breeze intensity and speed of movement).
Keywords：autumn and winterheavy haze weathermeteorological conditionsthe role of sea breeze
Publication Date：2017-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：8( 117-123,184 )