Analysis on the Impacts of Straw Burning on Air Quality in Beijing -Tianjing - Hebei Region

The beginning of October is the high occurrence period of straw burning in North China and Jianghuai region. Heavy pollution weather caused by straw burning often takes place in recent two years,and thus human factor increases the unpredictability of the air quality forecast. In the early autumn of 2015,a continuous fog-haze weather and heavy air pollution event occurred in North China and Jianghuai region due to the straw burning. In this paper,the effect of straw burning on air quality under the same adverse diffusive meteorological conditions has been analyzed by using the ground and upper air meteorological observation data and air quality monitoring data of Environmental Protection Agency in recent two years. The comparison results show that the basic conditions of heavy pollution are weak wind and the unfavorable diffusion situation. In contrast,relative humidity is the key factor,only 40% of relative humidity during the straw burning can reach heavy pollution level during no straw burning.

Analysis on Discipline Construction and Development Strategy of National-level Professional Research Institutes

Discipline construction is development core of a professional research institute. The paper describes function,guiding ideology,and construction of discipline construction,based on giving a national-level professional research institute directly under the Ministry of Science and Technology,as an example. Furthermore,according to current situation of discipline construction in a professional research institute,the paper discusses development ideas of discipline construction. The final goal of the paper is to provide basis and reference for reinforcing discipline construction of professional research institutes.

Analysis of a Heavy Rainfall Event over Beijing During 21-22 July2012 Based on High Resolution Model Analyses and Forecasts

The heaviest rainfall over 61 yr hit Beijing during 21-22 July 2012.Characterized by great rainfall amount and intensity,wide range,and high impact,this record-breaking heavy rainfall caused dozens of deaths and extensive damage.Despite favorable synoptic conditions,operational forecasts underestimated the precipitation amount and were late at predicting the rainfall start time.To gain a better understanding of the performance of mesoscale models,verification of high-resolution forecasts and analyses from the WRFbased BJ-RUCv2.0 model with a horizontal grid spacing of 3 km is carried out.The results show that water vapor is very rich and a quasi-linear precipitation system produces a rather concentrated rain area.Moreover,model forecasts are first verified statistically using equitable threat score and BIAS score.The BJ-RUCv2.0forecasts under-predict the rainfall with southwestward displacement error and time delay of the extreme precipitation.Further quantitative analysis based on the contiguous rain area method indicates that major errors for total precipitation（〉 5 mm h^（-1）） are due to inaccurate precipitation location and pattern,while forecast errors for heavy rainfall（〉 20 mm h^（-1）） mainly come from precipitation intensity.Finally,the possible causes for the poor model performance are discussed through diagnosing large-scale circulation and physical parameters（water vapor flux and instability conditions） of the BJ-RUCv2.0 model output.

Precipitation Forecast Test Based on MODE

Abstract By testing and analyzing BJ-RUC forecast of one precipitation process, MODE was introduced. MODE could give objective comparison from position of precipitation falling zone, shape and direction, and reflect intensity difference between forecast and actual situation, which comprehensively reflected precipitation forecast performance of the model, and was close to subjective judgment thinking of forecaster.