Atmospheric modelling using high resolution radiative transfer codes and identification of CO2 absorption bands to estimate coalfire related emissions

Recent studies of ice cores from Greenland and Antarctica have proven that both temperature and CO2 content of the earth’s atmosphere followed a regular 100,000 year cycle of change and that they are closely correlated. Moreover, the observed increase of CO2 in the atmosphere exceeds the predicted values extrapolated from historical data. Other than industrialization and rapid urbanization, geo-natural hazards such as spontaneous combustion of coal contribute a considerable amount of CO2 to the atmosphere. To establish a functional environmental model, it is important to quantify the amount of Green House Gas (GHG) emissions on a local scale. Radiative transfer codes, such as FASCOD (Fast Atmospheric Signature Code) with HITRAN2K (High Resolution Transmission) spectral database can simulate atmospheric transmission and path radiance with customized gas composition (CO2, water vapour, CO etc.) and concentration to understand the phenomena in a specific wavelength region. In the present study a number of atmospheric models were simulated with different CO2 concentrations (ppmv) with combination of water vapour and other atmospheric gases such as CO, CH4, N2O, SO2 etc., to find out the interference patterns of these gases over CO2 absorption bands. The transmission features of these gas combinations were analysed by partial least square regression models. These models show that the most suitable CO2 absorption bands are located around 2μm such as 2.0086, 2.0095, 2.0101μm. The spectral information derived from different concentrations of CO2 can be fitted in multivariate models to predict the CO2 concentration from spectral information in a controlled environment.