Study On The Spatial And Temporal Distribution Of PM2.5 In Liaoning Province And Its Relationship With Meteorological Elements

To do a better job of forecasting and warning of haze caused by standard-exceeding PM2.5,based on the monitoring data of PM2.5 concentration in Liaoning province from 2014 to 2016 and the observation data of the same period,Spatial and temporal distribution of PM2.5 mass concentration in Liaoning province was analyzed,while Taking Shenyang as a representative,the influence of meteorological factors on PM2.5 mass concentration and the influence of PM2.5 mass concentration and relative humidity on visibility were studied.The main conclusions are as follows:1.According to the order of PM2.5 mass concentrationin Liaoning province from high to low,the province can be divided into three areas which are central and northern,western,southeastern coastal areas,while highest in Shenyang city and lowest in Chaoyang city.The seasonal distribution was higher in winter and lower in summer,and in spring and Autumn were placed in the middle.The diurnal variation pattern of PM2.5 mass concentration was basically in accordance with the distribution of the double-peak-type with the first peak in the morning and the second at night,and the value and of the two peaks and their time of appearance would change seasonally.Among other meteorological elements,the relative humidity had a great influence,while the wind speed was less effective.2.From a large scale,the wind direction,whichwas one of the main factors determining air flow,had a great influence on the PM2.5 mass concentration in winter of Shenyang city,but because the wind speed in Shenyang in winter was always too slow.by establishing the regressive equation of meteorological factors affecting PM2.5 mass concentration in 4 elements of temperature,relative humidity,air pressure and wind speed which is tested and verified by a process of heavy haze in Liaoning in winter,it is found that the error of PM2.5 mass concentration depends on the too simple analytical method,but the overall relationship(positive or negative)is reliable,for the reason that the variation of PM2.5 mass concentration is actually very complex,and it is not feasible to consider only the conventional ground meteorological observation elements.3.Above all,relative humidity and PM2.5 concentrations have a negative impact on the visibility,correlation between relative humidity and visibility is best,followed by PM2.5,PM10 for visibility is also negative correlation,but its influence is the weakest;when the relative humidity is greater than 80%,The average atmospheric visibility with the relative humidity is increased in rapid decline,indicating that the relative humidity impact the atmospheric visibility predominately;when the relative humidity<80%,the correlation between PM2.5 mass concentration and atmospheric is higher than the correlation when relative humidity?80%.And both showed a high degree of correspondence between the power exponent.Especially in the relative humidity of 70%to 80%of the section,the correlation is stronger than the other two segments relative humidity;Finally when the PM2.5 concentration less than 60?g/m~3,with visibility reduced PM2.5 mass concentration rapid increase.But when PM2.5 mass concentration is greater than 60?g./m~3,the visibility with the change in particle concentration is not very obvious.