Wintertime Radiative Effects Due to Black Carbon (BC) Over Indo-Gangetic Plain as Modeled With Recently Estimated BC Emission Inventories in CHIMERE
Abstract
Black carbon (BC) aerosols over the Indian subcontinent have been represented inadequately so-far in chemical transport models restricting the accurate assessment of BC-induced climate impacts. The divergence between simulated and measured BC concentration has specifically been reported to be large over the Indo-Gangetic Plain (IGP), India, during winter when a large BC burden is observed. Here we present the wintertime radiative perturbation due to BC with an efficiently modeled BC distribution over the IGP in a high-resolution (0.1°×0.1°) chemical transport model, CHIMERE, implementing new BC emission inventories. The model efficiency in simulating the observed BC distribution was examined executing five experiments, namely, Constrained and bottomup (Smog, Edgar, Pku and Cmip), implementing respectively, the recently estimated India-based constrained BC emission and the latest bottom-up BC emissions (India-based and global). The lowest value of normalized mean bias (NMB) and root mean square error (RMSE) for Constrained estimated BC concentration (NMB: 14%-17%) and aerosol optical depth due to BC (BC-AOD; NMB: 11%) indicated that simulation with constrained BC emissions in CHIMERE could simulate the distribution of large BC pollution over the IGP more efficiently than with the bottom-up. The large BC pollution covering the IGP region comprised of wintertime all-day (daytime) monthly mean BC concentration (14-25 (6-8) µg m-3) and BC-AOD (0.04-0.08) from the Constrained, with a strong correlation between the variance in BC emission and simulated BC mass concentration or BC-AOD. The wintertime radiative perturbation due to BC aerosols from the Constrained included an enhancement in atmospheric warming by 2-3 times, compared to the atmosphere without BC. The net warming due to BC at the top of atmosphere (TOA) was of 10-15 W m-2. These perturbations were spotted being the strongest around megacities (Kolkata and Delhi), and were inferred as 30%-50% lower from the bottomup than the Constrained.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMA112.0003G
- Keywords:
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- 0305 Aerosols and particles;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 0394 Instruments and techniques;
- ATMOSPHERIC COMPOSITION AND STRUCTURE;
- 3359 Radiative processes;
- ATMOSPHERIC PROCESSES;
- 3360 Remote sensing;
- ATMOSPHERIC PROCESSES