Browsing by Author "Pramit Kumar Deb Burman"

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An intensification of atmospheric CO2 concentrations due to the surface temperature extremes in India
(Springer, 2021) Smrati Gupta; Yogesh K. Tiwari; J.V. Revadekar; Pramit Kumar Deb Burman; Supriyo Chakraborty; Palingamoorthy Gnanamoorthy
The terrestrial biosphere plays a pivotal role in removing carbon from the atmosphere. The removal processes are primarily affected by the presence of extreme temperature in the atmosphere. Little information is available on carbon removal response by the terrestrial biosphere during extreme temperature events over the Indian region. India has witnessed frequent and intense heatwaves in the recent past, and future projections about the frequency of heatwave occurrence suggest a further increase in the changing climate scenario. This study used surface CO2 flux observations and satellite retrieved columnar and mid-tropospheric CO2 concentrations to understand atmospheric CO2 variability and its transport patterns with anomalously high-temperature events such as heatwave conditions over India. Intensification of temperature up to 32 °C has increased the atmosphere-biosphere CO2 fluxes (carbon sink). But further intensification in temperature (> 32–33 °C), like those observed during heatwaves, tends to drive the ecosystem to act as a CO2 source into the atmosphere due to reduced ability to absorb atmospheric CO2. Such excess CO2 fluxes may lead to change in the atmospheric CO2 concentration via atmospheric circulation or the vertical transport of the air masses from the near-surface to the upper levels in the atmosphere. The satellite observed CO2 concentration is elevated by 2–3 ppm during the heatwave conditions over India. The impact of extreme temperature on the biospheric sink capability in the carbon cycle, leading to an increase in the atmospheric CO2 concentration, is one of the significant outcomes of this study. © 2021, The Author(s), under exclusive licence to Springer-Verlag GmbH Austria, part of Springer Nature.
Understanding carbon sequestration trends using model and satellite data under different ecosystems in India
(Elsevier B.V., 2023) Smrati Gupta; Pramit Kumar Deb Burman; Yogesh K. Tiwari; Umesh Chandra Dumka; Nikul Kumari; Ankur Srivastava; Akhilesh S. Raghubanshi
This study discusses carbon sequestration variability in different ecosystems of India. Four different biosphere regions, each over 0.5° × 0.5° area, have been selected considering the geospatial and climatic variability of these regions expanding from Central India (CI), the Northeast region (NER), the Western Ghats (WG), and the Western Himalayan region (WHNI). The climatic conditions of these four regions are different so are the biosphere constituents of these regions. We expect the Gross Primary Productivity (GPP) to enhance during the all India summer monsoon rainfall season but in varied magnitudes suggesting a role of climatic parameters and flora in these regions. The GPP from FLUXCOM for the duration of 2001 to 2019 (19 years) and satellite-derived vegetation indices like the Normalized Vegetation Index (NDVI), Enhanced Vegetation Index (EVI), and Leaf Area Index (LAI) are used in this study to understand the response of regional vegetation to this variability. EVI seems to be better related to GPP in comparison to NDVI in the preliminary analysis. Further analysis suggests LAI correlates better to GPP than EVI and NDVI in different seasons in these four regions. Also, meteorological parameters like surface temperature, rainfall, soil water, and other derived parameters like Vapor Pressure Deficit (VPD) are studied. It is also observed that the year-to-year variability in the climatic conditions could also have a role to play in the observed features. It is proven that the climate around the world is experiencing changes. Vegetation is one of the potent markers to monitor the impact of climate change. These long-term data and trends were studied to understand if there is any significant impact of the changing climatic conditions on the vegetation in these regions. Our study shows that there is an increasing (positive) trend in GPP at these locations though at different rates. WG and WHNI have shown a significant high rate of increase (6.44 and 5.36 gCm−2 y−1, respectively) in GPP over the last two decades. © 2023 Elsevier B.V.