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首页> 外文期刊>Atmospheric environment >Benzene, toluene, ozone, NO_2 and SO_2 measurements in an urban street canyon in Thessaloniki, Greece
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Benzene, toluene, ozone, NO_2 and SO_2 measurements in an urban street canyon in Thessaloniki, Greece

机译：希腊塞萨洛尼基城市街道峡谷中的苯，甲苯，臭氧，NO_2和SO_2测量

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摘要

Benzene, toluene, sulphur dioxide, ozone and nitrogen dioxide were measured at a mean level of 13.5 m above ground in a narrow, four-lane street canyon (height 30 m, width 20 m) in Thessaloniki, Greece during the period January-July 1997 by means of a commercial differential optical absorption spectrometer (OPSIS DOAS). Primary pollutant levels were found to be 2.5-4.4 times higher during the cold part of the year than during the warm part of the year, the winter/ summer ratio increasing with the reaction rate constant with OH for each of the measured species. Ozone, on the other hand, exhibited a winter/summer ratio of 0.36. NO_2 originates from both primary and secondary sources; its winter/ summer concentration ratio of 1.4 lies, therefore, between those of primary pollutants and ozone. Pollution levels were influenced considerably by wind speed, while for the street canyon under study wind direction did not influence pollutant levels considerably. While primary pollution was found to decrease with increasing wind speed, ozone increased. Benzene mean levels during the study period were around 6 ppb and hence much higher than the EU annual limit value of 5 μg m~(-3) (1.44 ppb at STP). Toluene mean levels were around 14 ppb and hence also several times above the WHO recommendation of 2 ppb for 24 h. The apportionment of traffic emissions in four time zones used in most inventories in urban airshed models was tested using benzene and toluene measurements at low (< 1 m s~(-1)) wind speeds. The agreement between model emissions and calculated emissions apportionment into the four time zones was good, except for Zone D (23:00-1:59), where model inventory emissions were somewhat too low.
机译：1月至7月期间，在希腊塞萨洛尼基的一个狭窄的四车道街道峡谷（高30 m，宽20 m）中，苯，甲苯，二氧化硫，臭氧和二氧化氮的平均含量为地上13.5 m。 1997年通过商用差动光吸收光谱仪（OPSIS DOAS）获得。发现在寒冷的一年中，主要污染物的水平是温暖季节中的2.5-4.4倍，每种被测物种的冬/夏比率随与OH的反应速率常数的增加而增加。另一方面，臭氧的冬夏比为0.36。 NO_2来自主要和次要来源；因此，它的冬/夏季浓度比为1.4，介于主要污染物和臭氧浓度之间。风速对污染水平的影响很大，而在研究中的街道峡谷，风向对污染物水平的影响不大。虽然发现主要污染随风速的增加而减少，但臭氧却增加了。研究期间的苯平均水平约为6 ppb，因此远高于欧盟的5μgm〜（-3）的年度限值（STP为1.44 ppb）。甲苯的平均水平约为14 ppb，因此也比WHO提出的24 pp 2 ppb的建议高出数倍。在低风速（<1 m s〜（-1））下，使用苯和甲苯测量数据，对城市清单模型中大多数清单中使用的四个时区的交通排放分配进行了测试。模型区的排放量与计算得出的四个时区的排放量分配之间的一致性很好，但D区（23：00-1：59）除外，该区的模型库存排放量太低。

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