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| Titel |
Study of CO2, CO, CH4variabilities at an urban site of western India using cavity ring down spectroscopy (CRDS) technique. |
| VerfasserIn |
Naveen Chandra, Sethuraman Venkataramani, Shyam Lal |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250101623
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| Publikation (Nr.) |
 EGU/EGU2015-803.pdf |
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| Zusammenfassung |
| Atmospheric abundances of the two important greenhouse gases namely CO2 and CH4are
being affected mainly by emissions from various anthropogenic sources. However, budgets of
these emissions are poorly estimated for the developing Indian region. An attempt
has been made to study the variability of the levels of these gases at an urban site
Ahmedabad (23.03oN, 72.58oE, 55m AMSL), in the western India using a highly sensitive
cavity ring down spectroscopy technique. The average levels of CO2 and CH4 at this
site are 399 – 425 ppmv and 1.8 – 2.6 ppmv respectively. However the diurnal
amplitude of CO2and CH4falls in the range of 6 – 50 ppmv and 0.05 – 1 ppmv
respectively, depending on the seasons. The co-relations of CO2, CH4 with co-emitted CO
gas are used to identify the dominant source types. The measurements show that
atmospheric CO correlates well with CO2 during the autumn and winter. The slope of CO
and CO2 (δCO/δCO2) is found to be in the range of 0.02 and 0.03 which agrees
well with the emission ratio for India as per Asian inventory proposed by Street
et al., (2003) and connote the influence of mixed sources (fossil fuel as well as
biomass burning) during this period. In July, CO doesn’t correlate well with CO2 (r2
=0.14), but the slope is around 0.005. This indicates the dominance of fossil fuel
during this time. The correlation and slope (slope ~ 0.02 and r2 ~ 0.55) of CH4
with CO2 remain fairly constant which demonstrate that the study area does not
have significant changes in the common source of these gases throughout the study
period. More details of the levels, amplitude of diurnal variations of CO2, CO,
CH4in different seasons as well as their mutual interrelationship will be presented. |
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