江苏省空气质量预报准确度及改进方法分析

介绍了江苏省重污染天气监测预报预警系统以及大气重污染预警会商流程,将2015年13个地级市的模式预报、人工预报结果分别与实际观测值进行比较。结果表明:人工预报更准确,PM_(2.5)日均值、臭氧日最大8 h平均值、AQI 3个指标人工预报和实况的相关性分别比模式预报高出12.8%、0.3%、11.4%,平均标准误差(MNE)分别低20.7%、3.1%、23.1%。依据国家空气质量预报技术指南评分办法,对各市2015年全年空气质量级别为"良"时进行评分。通过开展07∶00预报更新,使2015年上半年空气质量预报级别得分平均提高了0.9分,全年级别得分平均提高了2.6分;通过改进模式预报参数,使PM_(2.5)日均预报值、臭氧日最大8 h平均预报值、AQI预报值和实际观测值的相关性比上年同期分别提高26.0%、5.0%、33.9%,MNE分别降低3.6%、31.3%、7.6%。

Analysis on the Accuracy of Air Quality Forecast and Its Improvement Method in Jiangsu Province

This article introduced the general structure of the serious air pollution monitoring forecasting system and the conference discussion procedure of serious air pollution early warning in Jiangsu province. By comparing with the predicted data against observations,the results indicated that the predicted data by engineers were more accurate than air quality forecast model of all 13 prefecture-level cities in 2015. The correlations of daily average PM_2.5, daily maximum 8-hour average ozone and AQI between predicted and observed data by engineers were 12.8%, 0.3% and 11.4% higher than model forecast, respectively. The mean normalized error (MNE) of predicted data against observations by engineers were 20.7%, 3.1% and 23.1% lower than model forecast, respectively. According to the national forecast technical guide scoring method, every cities'' scores are calculated when AQI level is "good". Two measurements could improve prediction accuracy, one of them was to updating forecast data at 07 o''clock in the next day''s morning, as a result, air quality forecast level increased 0.9 point in the first half year of 2015, and increased 2.6 points for the whole year. The second method was to optimizing forecast model''s parameter. The correlations between observed data and predicted data of daily average PM_2.5, daily maximum 8-hour average ozone and AQI increased 26.0%, 5.0% and 33.9% respectively, MNE of three indicators decreased 3.6%, 31.3% and 7.6% respectively.