The photochemical oxidization of hydrocarbon and CO in the presence of NOxis
a major source of tropospheric ozone on both regional and global scale (Crutzen
1988, 1995, Jacob 1999, Varotsos et al. 2005). The two largest sources of CO are
the combustion of fossil fuel and biomass burning. Incomplete oxidation of
methane and other hydrocarbon also produce substantial amount of CO in the
atmosphere. CO is highly variable in space and time and accurate measurement of
its spatial pattern and time evolution is required (i.e. for air quality monitoring
and forecasting applications). The chemical budget of ozone in the troposphere is
largely determined by the NOxconcentration and the solar ultraviolet radiation
reaching the tropopause (Efstathiou et al. 1998, Varotsos et al. 2003). The latter
strongly depends on the stratospheric ozone content, which varies from both the
anthropogenic activities (despite the measures taken in the frame of the Montreal
*Corresponding author. Email: sachinghude@tropmet.res.in
International Journal of Remote Sensing
ISSN 0143-1161 print/ISSN 1366-5901 online # 2010 Taylor & Francis
http://www.tandf.co.uk/journals
DOI: 10.1080/01431160902893519Protocol) and the atmospheric dynamics (Kondratyev et al. 1994, Varotsos and
Cracknell 1994, Chandra and Varotsos 1995, Gernandt et al. 1995, Reid et al.
1998, Varotsos 2002, Efstathiou et al. 2003, Ghude et al., 2008). NOxhas both
substantial anthropogenic sources (e.g. fossil fuel and bio-fuel combustion and
human-induced biomass burning) (Van der A et al. 2006, Ghude et al. 2008) and
natural sources (e.g. soil emissions, wildfires and lightning) (Van der A et al.
2008). NOxalso chemically reacts to form nitric acid (HNO3) (Jacob et al. 2003),
a major component of acid rain, and nitrate aerosols (acid particles) (Ferm et al.
2005, 2006). Through these processes NOxhas a negative effect on the crop
growth and on health by causing respiratory problems, especially in and around
densely populated regions.