Characterization of black carbon aerosols over Indian Antarctic station, Maitri and identification of potential source areas

Abstract

With the advent of industrialization, aerosol pollutants have gained global attention for being a formidable threat to the human health and climate change. These pollutants travel via long range transportation to the far reaches of the Earth, wreaking havoc. Black carbon (BC) depositories have repercussions in snow and ice profiles such as alterations in ablation and albedo processes leading to accelerated ice melting rates. In the present study, atmospheric BC aerosol concentrations were measured at ‘Maitri’, the Indian Polar research station situated in Schirmacher Hills, East Antarctica during the austral summer of December 2018 to February 2019 on behalf of the XXXVIII Indian Scientific Expedition to Antarctica (ISEA). For that, an AE42 Aethalometer was used and found a maximum concentration of 82 ng m⁻³ for BC aerosol between a timeline of 09.00 and 13.00 LT in the month of February, 2019 whereas a minimum concentration of 37 ng m⁻³ in the timeline of 21.00–22.00 LT, Dec 2018, with the mean of 60 ng m⁻³ being observed throughout the study period. The potential source areas (Patagonia, Australia, New Zealand and South Africa) were examined to study the source of long-range transport of BC to Maitri by backward and forward trajectory analyses. The trajectory analysis confirmed that Patagonia is a definitive BC origin in addition to the day-to-day station related activities. The influence of meteorological parameters on BC aerosols at Maitri was also studied and correlation analysis stated that BC has a negative alliance with RH, temperature and pressure except wind speed denoting meteorological conditions as a driver of spatio-temporal variation of BC.