G. Beig

Satellite derived trends in NO2 over the major global hotspot regions during the past decade and their inter-comparison.

We assessed satellite derived tropospheric NO(2) distribution on a global scale and identified the major NO(2) hotspot regions. Combined GOME and SCIAMACHY measurements for the period 1996-2006 have been used to compute the trends over these regions. Our analysis shows that tropospheric NO(2) column amounts have increased over the newly and rapidly developing regions like China (11+/-2.6%/year), south Asia (1.76+/-1.1%/year), Middle East (2.3+/-1%/year) and South Africa (2.4+/-2.2%/year). Tropospheric NO(2) column amounts show some decrease over the eastern US (-2+/-1.5%/year) and Europe (0.9+/-2.1%/year). We found that although tropospheric NO(2) column amounts decreased over the major developed regions in the past decade, the present tropospheric NO(2) column amounts over these regions are still significantly higher than those observed over newly and rapidly developing regions (except China). Tropospheric NO(2) column amounts show some decrease over South America and Central Africa, which are major biomass burning regions in the Southern Hemisphere.

Premature mortality in India due to PM2.5 and ozone exposure

This bottom-up modeling study, supported by new population census 2011 data, simulates ozone (O3) and fine particulate matter (PM2.5) exposure on local to regional scales. It quantifies, present-day premature mortalities associated with the exposure to near-surface PM2.5 and O3 concentrations in India using a regional chemistry model. We estimate that PM2.5 exposure leads to about 570,000 (CI95: 320,000–730,000) premature mortalities in 2011. On a national scale, our estimate of mortality by chronic obstructive pulmonary disease (COPD) due to O3 exposure is about 12,000 people. The Indo-Gangetic region accounts for a large part (~42%) of the estimated mortalities. The associated lost life expectancy is calculated as 3.4 ± 1.1 years for all of India with highest values found for Delhi (6.3 ± 2.2 years). The economic cost of estimated premature mortalities associated with PM2.5 and O3 exposure is about 640 (350–800) billion USD in 2011, which is a factor of 10 higher than total expenditure on health by public and private expenditure.

Estimation of the lifetime of nitrogen oxides over India using SCIAMACHY observations

The NOx lifetime is needed to determine NOx source strength and allow for source apportionment studies. Satellite observations of tropospheric column NO2 may be used to estimate the NOx lifetime by analysing tropospheric NO2 decay in the outflow region. In this study, we used Scanning Imaging Absorption Spectrometer for Atmospheric Cartography (SCIAMACHY) observations of tropospheric NO2 to quantify the lifetime of NOx, ‘’, over the Indian region. We analysed a tropospheric NO2 plume that originated over the city of Mumbai and its downwind evolution over the Arabian Sea as a function of distance (decay curve). The observed pattern of decay curve is fitted with the exponential decay fit model, which gives an e-folding distance of 107 km. The fit result yields a mean lifetime of NOx of about = 10.2 h based on SCIAMACHY observations. In addition, we quantified using CHIMERE chemical mechanisms and compared the result with the satellite-based estimation. The estimated for India, based on CHIMERE simulation, is about 11.9 h, comparable to the calculated by satellite observations.