Seasonal and diurnal variations of carbon dioxide and energy fluxes over three land cover types of Nepal

Abstract

This study examines the seasonal and diurnal variations of carbon dioxide and energy fluxes over three land cover types of Nepal by using the eddy covariance method from March to November 2016. The surface energy balance closures were moderate with the values of about 56%, 61%, and 64% closure at Kirtipur, Simara, and Tarahara sites respectively. The monthly average values of net radiation flux and latent heat flux peaked in August at Kirtipur and Tarahara sites whereas in June at the Simara site respectively. The maximum monthly average measured sensible heat flux was 37 W m −2 , 43.6 W m −2 , and 36.3 W m −2 in April for all the sites whereas soil heat flux was 5.1 W m −2 and 2.9 W m −2 in April for Kirtipur and Simara sites and 6.2 W m −2 in June for the Tarahara site. The magnitude of diurnal peak of net ecosystem CO 2 exchange (NEE) reached up to 11.04 μmol m −2 s −1 at Kirtipur, 15.04 μmol m −2 s −1 at Simara, and 10.44 μmol m −2 s −1 at Tarahara sites respectively. Among the three study sites, the ecosystem at the Kirtipur site was a good carbon source; the ecosystems at Simara and Tarahara sites were low and good carbon sink in the growing season. In addition, all three different land cover ecosystem were carbon source when accounted for the measurement period.

Estimation of land surface evapotranspiration using the METRIC model in Nepal

“…For obtaining relevant information for a study area, e.g., identifying the estimated ET for the station area, an average of the estimations available within and surrounding an area (if no estimations are available in the region, e.g., due to cloud) can be used. Details about the station data measurements and processing to derive different heat fluxes and ET can be found in the work of Joshi et al (2020).…”

Tax and Pandemic; Curbing Carbon Burden of India’s Blue Sky

“…1750 but for the last 250 years anthropogenic activities have raised the level to 399ppm by 1999 and rose to 408 ppm in average by 2020.CO 2 release have surged by ≈90% due to use of fossil fuel and ≈78% rise in GHG due to industrialization between year1970 to 2011, ≈25% due to heat and electricity generation, ≈21% Industry, ≈24% through agriculture, ≈14% by transportation and ≈6% rise by civil construction (till 2010) and during 1750 it was 278 ppm, IPCC report, 2018 [7], Kishwan et al 2012 [8], Sharma et al 2013 [9], Patra et al, 2014 [10], Boden et al 2017 [11], Singh , 2018 [12], Roy et al, 2020 [13]. The carbon level increases in India by local emissions, terrestrial biota and environment, Cyclonic disturbances in North Indian Ocean including Bay of Bengal & Arabian Sea, shift of ITCZ, MJO and Nino conditions Saito et al [14], Sheel et al [15] Chhabra A et al [16] and Joshi et al [17]. The seasonal CO 2 concentrations in air exhibit high as one move from equator to high latitude, i.e latitude wise, Chakraborty et al 2020 [18].…”