Volume 14, No. 7, December 2014, Pages 1883-1896 PDF(3.54 MB)
Spatio-Temporal Analyses of Atmospheric Sulfur Dioxide Column Densities over Pakistan by Using SCIAMACHY Data
Palwasha Khattak1, Muhammad Fahim Khokhar1,2, Naila Yasmin1,3
1 Institute of environmental sciences and engineering, National University of Sciences and Technology Islamabad, Pakistan
2 Visiting scientist, Satellite Group Max-Planck Institute for Chemistry Mainz, Germany
3 R2V GIS consultancy Rawalpindi, Pakistan
- First database of SO2 column densities present in the atmosphere of Pakistan.
- A statistically significant temporal increase of 70 % is observed for 2004 to 2012.
- Increase is attributed to poor quality fuel, power generation and open solid waste burning.
- Seasonality in SO2 columns over Pakistan is mainly driven by OH concentration and monsoon season.
This paper presents the results of atmospheric Sulfur dioxide (SO2) column densities obtained from satellite observation over Pakistan during the time period of 2004–2012. The level-2 data product of the Scanning Imaging Absorption Spectrometer for Atmospheric Chartography (SCIAMACHY) instrument on-board ENVISAT-1 is used. SO2 column densities are retrieved by applying differential optical absorption spectroscopy (DOAS) technique. The spatio-temporal distribution of SO2 column densities along with the seasonal variation over main cities and regions of Pakistan are discussed. The Nabro volcano eruption in the year 2011 caused high SO2 levels over East Africa, the Middle East and South and Southeast Asia. Satellite images exhibited several episodes of volcanic SO2 column densities transported to Pakistan. The temporal trend in SO2 column densities was calculated, and the significance of the data set was tested with statistical analysis. An overall increase of about 70% (8.7% per year) in SO2 column densities over Pakistan during the time period of 2004–2012 has been calculated. This study presents the first spatial and temporal analyses of SO2 column densities over Pakistan by using satellite observation.
Satellite data; DOAS; Column densities; SO2; Pakistan; ArcGIS.