Analysis of carbon monoxide levels over Nile Delta, Egypt, using MOPITT satellite data

We present for the first time a detailed climatological analysis of weekly mean carbon monoxide (CO) over the Nile Delta region using data from the Measurements of Pollution in the Troposphere (MOPITT) satellite instrument, from 2001 to 2010. As CO is a trace gas of biomass burning, it was expecting that MOPITT would detect large CO emissions in fall, duing the season of rice straw burning. However the distinct CO peak is recorded at 900 and 800 hPa in the spring rather than the fall. The maximum CO concentrations recorded in October are in the range of 120-134 ppb, whereas those recorded in March at the same levels are more than 160 ppb. The monthly averaging kernels for March and October confirm that the spring CO peak is not due to different sensitivity, but represents a real feature. Accordingly, back trajectory analysis is applied to identify the possible emission sources that substantially affect CO concentrations over the study area in the spring season. The results indicate that the long-range transport of pollution from Europe elevates the CO levels in the lower troposphere over the study area.