Atmospheric CO₂ Variations in Two Contrasting Environmental Sites Over India

Abstract

We analyzed the influence of environmental parameters on the temporal variation of atmospheric carbon dioxide (CO 2) mixing ratios in two environmentally contrasting Indian sites, Dehradun (30.1°N, 77.4°E, humid subtropical station) and Gadanki (13.5°N, 79.18°E, dry tropical station), from October 2010 to September 2011. The annual range of mixing ratios is low in Gadanki as compared to those of Dehradun because of relatively less monthly variation in temperature and relative humidity (RH) at Gadanki. At both the stations, the minimum mixing ratios are present during the high ecosystem productivity seasons in the afternoon hours. The maximum values are in the early morning hours. However, low wind speed conditions control the unexpected afternoon high mixing ratios in Gadanki during the pre-monsoon season. The early morning maximum is high during monsoon and postmonsoon seasons in Dehradun and Gadanki, respectively, whereas morning inflexion occurred earlier in Gadanki compared with Dehradun. The effect of cloudiness on the CO 2 uptake depends on the canopy cover.

Influence of Meteorology and interrelationship with greenhouse gases (CO<sub>2</sub> and CH<sub>4</sub>) at a suburban site of India

“…In the evening hours, surface inversion begins and form a shallow stable boundary layer, causing the enhancement in GHG concentration near the surface. A similar trend in diurnal variation of GHGs is reported from other parts of the country (Patil et al, 2013;Mahesh et al, 2013;Sharma et al, 2014;Nishanth et al, 2014).…”

Temporal variations of atmospheric CO<sub>2</sub> and CO at Ahmedabad in western India

“…Further, the CO / CO 2 ratio is also observed at about 13 ppb ppm −1 in the south-eastern Asian outflow during February-April 2001 during the TRACE-P cam- paign and it suggests the combined influence of fossil fuel and biofuel burning (Russo et al, 2003). The overall ratios (using all data) from autumn to spring (8.4-12.7 ppb ppm −1 ) suggest the dominance of local emission sources during these seasons, and this range corresponds to the range of anthropogenic combustion sources (10-15 ppb ppm −1 ) in developed countries (Suntharalingam et al, 2004;Takegawa et al, 2004;Wada et al, 2011). This suggests that the overall emissions of CO over Ahmedabad are mostly dominated by the anthropogenic combustion during these seasons.…”

“…The first observations of CO 2 , CO and other greenhouse gases started in February 1993 from Cape Rama (CRI: a clean site) on the south-west coast of India using flask samples (Bhattacharya et al, 2009). Since then, several other groups have initiated the measurements of surface-level greenhouse gases Sharma et al, 2014;Tiwari et al, 2014;Lin et al, 2015). Most of these measurements are made at weekly or fortnightly time intervals.…”

Observations and Modeling of GHG Concentrations and Fluxes Over India

“…In the next phase of the carbon cycle study in India, the Indian Space Research Organisation (ISRO) started the National Carbon Project (NCP) under the auspices of the ISRO Geosphere-Biosphere Program (IGBP) in the early phase of the 2010s. The NCP endeavors to understand the GHGs dynamics and estimate their budget by means of a robust observational network across the country (Chanda et al 2013(Chanda et al , 2014Sharma et al 2013Sharma et al , 2014Patel et al 2011;Mahesh et al 2014Mahesh et al , 2016Mahesh et al , 2019Sreenivas et al 2016Sreenivas et al , 2019Jha et al 2013Jha et al , 2014Rodda et al 2016). At about the same time, another GHGs observational program (CO 2 and CH 4 ) at a semi-urban hilly site near Pune, called Sinhagad (SNG), was initiated by the Indian Institute of Tropical Meteorology, Pune, under the patronage of the Ministry of Earth Sciences (MoES), Government of India.…”