生物质燃烧对清洁地区地面O3含量的影响

Influence of Biomass Burning on Surface Ozone in Clean Area

使用美国热电子公司的TEMode149C型O3监测仪、TEModel48C型CO监测仪和TEModel42C型NOx监测仪,对上甸子区域大气本底站2005年9月地面O3、CO和NOx的浓度进行了连续监测,获得了同步的气象数据,并详细记录了测站附近生物质燃烧的现象。结果表明,生物质燃烧影响了O3浓度日变化规律,最大小时平均浓度出现在18时(北京时间,下同),峰值过后的5～6h内O3的浓度仍明显高于无燃烧现象的情况,且从燃烧集中时段(15时左右)至傍晚(19时),O3浓度逐时上升;NOx和CO浓度日变化规律和城市地区的观测结果也有不同,浓度高值时段和燃烧时间吻合,其中CO浓度在燃烧集中时段上升明显;生物质燃烧情况下,Δφ(O3)/Δφ(CO)高于无燃烧情况,在午后至傍晚燃烧集中且太阳辐射条件较好的时段内,NOx、CO浓度与O3浓度呈现正相关关系。相同天气条件下的个例对比结果显示:测站受生物质燃烧排放输送的影响,主导风向下燃烧个例中O3浓度明显高出无燃烧个例约0.02mg.m-3。

In order to research the effects to surface O3 in clean area by biomass burning, the concentration of O3, CO, and NOx were monitored at Shangdianzi regional atmospheric background station in September 2005, with TE model 49C type ozone analyzer, TE model 48C type carbon monoxide analyzer and TE model 42C type nitric oxide and nitrogen dioxide analyzer manufactured by US Thermo Electron Corporation, respectively. Meteorological data was obtained and biomass burning cases were recorded in detail synchronously. Results show that diurnal variation of surface O3 was affected by the biomass burning. In biomass burning cases, maximum hourly average O3 concentration displayed at 1800 LST. Besides the O3 concentration was higher than non biomass burning cases in the following 5 to 6 hours, NOx and CO diurnal variation character was different from that observed in urban area. High concentration of NOx and CO correlated with concentrated biomass burning closely. The concentration of CO went up greatly during concentrated burning time. In biomass burning cases, NOx and CO concentration recorded during concentrated biomass burning time showed a good linear correlation with O3 concentration. The rate of photochemical O3 production in the boundary layer O3 by biomass burning calculated from the production ratio △φ（O3）/△φ（CO） was 0.04 much higher than by non-biomass burning, which was 0.02. Studying of the biomass and non-biomass burning cases under the same weather condition showed that effected by the transportation of biomass burning emission, surface O3 concentration was about 0.02 mg·m^-3 higher than that of non-biomass burning cases obtained in the leading wind direction. Hourly variation of surface O3 concentration during noon and afternoon displays that O3 concentration goes up hourly from 1500 LST to 1900 LST in biomass burning cases. It agrees well with the biomass burning time recorded.