Institute of Environmental Sciences and Engineering (IESE), National University of Sciences and Technology (NUST), Islamabad, Pakistan.
Satellite Remote Sensing Group, Max-Planck-Institute for Chemistry, Mainz, Germany.
J Environ Sci (China). 2016 May;43:4-14. doi: 10.1016/j.jes.2015.04.038. Epub 2015 Dec 28.
This paper discusses the findings of the first car MAX-DOAS (multi-axis differential optical absorption spectroscopy) field campaign (300km long) along the National Highway-05 (N5-Highway) of Pakistan conducted on 13 and 14 November, 2012. The main objective of the field campaign was to assess the spatial distribution of tropospheric nitrogen dioxide (NO2) columns and corresponding concentrations along the N5-Highway from Islamabad to Lahore. Source identification of NO2 revealed that the concentrations were higher within major cities along the highway. The highest NO2 vertical column densities (NO2 VCDs) were found around two major cities of Rawalpindi and Lahore. This study also presents a comparison of NO2 VCDs measured by the ozone monitoring instrument (OMI) and car MAX-DOAS observations. The comparison revealed similar spatial distribution of the NO2 columns with both car MAX-DOAS and satellite observations, but the car MAX-DOAS observations show much more spatial details. Maximum NO2 VCD retrieved from car MAX-DOAS observations was up to an order of magnitude larger than the OMI observations in urban areas.
本文讨论了 2012 年 11 月 13 日和 14 日在巴基斯坦国家 05 号高速公路（N5 高速公路）沿线进行的首次汽车 MAX-DOAS（多轴差分光学吸收光谱）现场考察的结果（长达 300 公里）。该现场考察的主要目的是评估从伊斯兰堡到拉合尔的 N5 高速公路沿线对流层二氧化氮（NO2）柱的空间分布和相应浓度。NO2 的源识别表明，公路沿线主要城市的浓度较高。在拉瓦尔品第和拉合尔这两个主要城市周围发现了最高的 NO2 垂直柱密度（NO2 VCD）。本研究还比较了臭氧监测仪（OMI）和汽车 MAX-DOAS 观测测量的 NO2 VCD。比较表明，NO2 柱的空间分布与汽车 MAX-DOAS 和卫星观测相似，但汽车 MAX-DOAS 观测显示出更多的空间细节。从汽车 MAX-DOAS 观测中检索到的最大 NO2 VCD 在城市地区比 OMI 观测高一个数量级。
