Analysis of tropospheric NO2 over Iraq using OMI satellite measurements

Abstract

Tropospheric nitrogen dioxide (NO2) is a trace gas with important impact on atmospheric chemistry, human health and a key pollutant in particular cities, measured from space since the mid-1990s by the GOME, SCIAMACHY, OMI, and GOME-2 instruments. This study present ten years (monthly and yearly averaged) dataset from Ozone Monitoring Instrument (OMI) used to investigate tropospheric NO2 characteristics and variations over Iraq during 2005–2014. Annual NO2 shows an elevation from the northern to the southern and highest values was at central parts of Iraq. Monthly distributions revels higher values NO2 in winter and summer than spring and autumn seasons, and rising NO2 throughout study period over industrial and crowded urban zones. The trend analysis over Baghdad shows a linear growth rate 9.8% per year with an annual average (5.6·1015 molecules per 1 cm2). The air mass trajectory analysis as hotspot regions shows seasonal fluctuations between winter and summer seasons depend on weather conditions and topography. The increased NO2 values in winter are due to anthropogenic emissions and subsequent plumes from Europe. In addition, in summer because of hot weather and large paddy fields emissions. The lowest NO2 value was at monsoon period mostly linked to the rains. The OMI data and satellite information are able to observe the troposphere NO2 elevation at different regions.