Details

Autor(en) / Beteiligte

• Ramachandran, S.
• Rupakheti, Maheswar
• Lawrence, Mark G.

Titel

Black carbon dominates the aerosol absorption over the Indo-Gangetic Plain and the Himalayan foothills

Ist Teil von

• Environment international, 2020-09, Vol.142, p.105814, Article 105814

Ort / Verlag

Netherlands: Elsevier Ltd

Erscheinungsjahr

2020

Quelle

Access via ScienceDirect (Elsevier)

Beschreibungen/Notizen

• [Display omitted] •Contribution of BC, BrC and dust to aerosol absorption over Himalayas quantified.•SSA over Kathmandu is the lowest of all the locations in Himalayas.•SSA decreases with increasing elevation in the Himalayas.•BC dominates (≥75%) the aerosol absorption over the IGP and the Himalayas.•Aerosol absorption over South Asia is very high, compared to East Asia. This study, based on new and high quality in situ observations, quantifies for the first time, the individual contributions of light-absorbing aerosols (black carbon (BC), brown carbon (BrC) and dust) to aerosol absorption over the Indo-Gangetic Plain (IGP) and the Himalayan foothill region, a relatively poorly studied region with several sensitive ecosystems of global importance, as well as highly vulnerable populations. The annual and seasonal average single scattering albedo (SSA) over Kathmandu is the lowest of all the locations. The SSA over Kathmandu is < 0.89 during all seasons, which confirms the dominance of light-absorbing carbonaceous aerosols from local and regional sources over Kathmandu. It is observed here that the SSA decreases with increasing elevation, confirming the dominance of light absorbing carbonaceous aerosols at higher elevations. In contrast, the SSA over the IGP does not exhibit a pronounced spatial variation. BC dominates (≥75%) the aerosol absorption over the IGP and the Himalayan foothills throughout the year. Higher BC concentration at elevated locations in the Himalayas leads to lower SSA at elevated locations in the Himalayas. The contribution of dust to aerosol absorption is higher throughout the year over the IGP than over the Himalayan foothills. The aerosol absorption over South Asia is very high, exceeding available observations over East Asia, and also exceeds previous model estimates. This quantification will be valuable as observational constraints to help improve regional simulations of climate change, impacts on the glaciers and the hydrological cycle, and will help to direct the focus towards BC as the main contributor to aerosol-induced warming in the region.