Measurements of carbon dioxide and heat fluxes during monsoon-2011 season over rural site of India by eddy covariance technique

An increase in carbon dioxide (CO₂) concentrations in the atmosphere due to anthropogenic activities is responsible for global warming and hence in recent years, CO₂ measurement network has expanded globally. In the monsoon season (July–September) of year 2011, we carried out measurements of CO₂ and water vapour (H₂O) concentrations along with wind and air temperature over a tropical site in south-east India having rural topography. To collect these observations, the instrumentations used were the sonic anemometer for wind and temperature, and the open path H₂O/CO₂ infrared gas analyzer for CO₂ and H₂O concentrations. Using these observations, we explored the diurnal variability of CO₂ flux along with sensible and latent heat. The CO₂ flux was positive during night-time and negative during daytime and in phase with convective instability. The CO₂ flux relationships with the meteorological parameters such as wind speed, temperature and heat fluxes have been analysed. The seasonal (monsoon) half hour mean of CO₂ flux which was ?3.55 μmol m^???2 s^???1 indicated the experimental site as a CO₂ sink region (net seasonal uptake). An increase in CO₂ concentrations during weekends was not observed due to unavailability of heavy vehicular traffic.