宁波市近地层臭氧浓度变化及预测

Variation of ozone concentration and prediction in surface layer in Ningbo

利用2010—2013年宁波市近地层臭氧浓度等环境监测资料、地面气象观测资料和NCEP再分析资料,分析了宁波市臭氧浓度的分布规律及其与环境条件的相关性,并建立了臭氧浓度预测方程。结果表明:2010—2013年宁波市近地层臭氧浓度日变化呈"单峰型",峰值一般出现在午后;臭氧月浓度变化呈"双峰型",两个峰值分别出现在5月和10月。选取与宁波近地层臭氧浓度相关性较好的日平均气压、水汽压、气温、NO2浓度和SO2浓度等作为预报因子建立回归模型预测臭氧浓度,模型通过了显著性检验,预报效果较好。统计分析了宁波市臭氧浓度超标日的常见天气型,表明变性冷高压、均压场、高空脊、副热带高压及热带气旋外围影响型为易导致宁波市臭氧污染的天气型,5种天气型所占比例分别为22.1%、9.5%、24.4%、31.4%和8.7%,其他天气型占3.9%;并通过合成分析法,说明了5种天气型相关的天气形势。

Using environmental observation data of ozone in the surface layer,the meteorological observation data and NCEP reanalysis data form 2010 to 2013,the ozone distribution and its relevance with various environmental elements were analyzed,and a forecast model of ozone concentration was established.The results showthat daily ozone concentration curve is unimodal and the peak generally appears in the afternoon in Ningbo.Meanwhile,annual variation of ozone concentration curve is bimodal and the two peaks occur in May and October,respectively.The forecast model is established by choosing daily mean pressure,vapor pressure,temperature,NO2 concentration and SO2 concentration which has good correlations with ozone concentration as predictors.After the evaluation,the model prediction effect is relatively good.Statistics of weather types leading to excessive ozone levels suggest that ozone pollution easily happens in several weather types such as transformed cold high pressure,uniform pressure field,upper ridge,subtropical high and peripheral tropical cyclone,and their proportions are 22.1%,9.5%,24.4%,31.4% and 8.7%,while other weather types only account for 3.9%.Weather situation of each type is showed by a synthetic analysis method.