Seasonal dynamics and impact factors of atmospheric CO2 concentration over subtropical forest canopies: observation from eddy covariance tower and OCO-2 satellite in Northwest Himalaya, India.

摘要: Carbon dioxide (CO2) is the key atmospheric gas that controls earth's greenhouse effect, and forests play a major role in abating CO2 by storing carbon as biomass. Therefore, it vital to understand of different regulating spatiotemporal dynamics concentration. In this study, we have used eddy covariance (EC) tower-based concentration measurements satellite-retrieved column average 2018 diurnal seasonal over sub-tropical forest foothills northwest Himalaya, Uttarakhand, India. EC study revealed canopy peaks during mid-night early morning drop minimum afternoon. On monthly scale, peak was observed July both sites, which result more release ecosystem through respiration microbial decomposition. Enhanced photosynthetic activities late monsoon post-monsoon resulted decrease ecosystem. Among meteorological variables, rainfall found highest control variability Orbiting Observatory-2 (OCO-2) (XCO2) also examined comprehend its reliability on an scale. The OCO-2 retrieved XCO2 value higher than flux tower-measured concentration, might be due differences vertical resolution scale difference. However, from strongly adheres with ground-measured pattern. Our highlights varying functional traits within same climatic conditions show regulation