Space-borne observation of methane from atmospheric infrared sounder: data analysis and distribution over Iraq
Methane (CH4) Volume Mixing Ratio (VMR) at pressure level 925hPa data extracted from Atmospheric Infrared Sounder (AIRS) with spatial resolution of 1°× 1° covering whole of Iraq and surrounding regions (28.5°–38.5°N, 37.5°–49.5°E) have been examined for the period from January 2003 to December 2013. The results show a considerable increasing of CH4 with maximum values at north and north eastern regions during autumn and the early winter, whereas the minimum values appeared at the pristine desert environment at the west and the south-west region during spring months. For more accuracy validation the trend analysis was applied on the retrieved AIRS data at three different stations are Mosul, Baghdad and Basrah. The mean and standard deviation in Mosul, Baghdad and Basrah was (1.8657 ± 0.0198, 1.8536 ± 0.0196, 1.8448 ± 0.0212) ppmv respectively for monthly long term trend analysis. Monthly trend analyses have positive trends (0.0040, 0.0039 and 0.0042) ppmv.y-1 for Mosul, Baghdad and Basrah Consecutively. These results indicate that Satellite observations efficiently present the temporal and spatial variations of the CH4 for the considered study Area.