Effect of model resolution on black carbon transport from Siberia to the arctic associated with the well-developed low-pressure systems in september

Abstract

Atmospheric transport of aerosols such as black carbon (BC) affects the absorption/scattering of solar radiation, precipitation, and snow/ice cover, especially in areas of low human activity such as the Arctic. The resolution dependency of simulated BC transport from Siberia to the Arctic, related to the well-developed low-pressure systems in September, was evaluated using the Nonhydrostatic Icosahedral Atmospheric Model-Spectral Radiation Transport Model for Aerosol Species (NICAM-SPRINTARS) with fine (~ 56 km) and coarse (~ 220 km) horizontal resolutions. These low-pressure systems have a large horizontal scale (~ 2000 km) with the well-developed central pressure located on the transport pathway from East Asia to the Arctic through Siberia. In recent years, the events analysis of the most developed low-pressure system indicated that the high-BC area in the Bering Sea observed by the Japanese research vessel Mirai on September 26 - 27, 2016, moved to the Arctic with a filamental structure from the low’s center to the behind of the cold front and ahead of the warm front in relation to its ascending motion on September 27 - 28, 2016. The composite analysis for the developed low-pressure events in September from 2015 to 2018 indicated that the high-BC area was located eastward of the low’s center in relation to the ascending motion over the low’s center and northward/eastward area. Since the area of the maximum ascending motion has a small horizontal scale, this was not well simulated by the 220-km experiment. The study identified that the BC transport to the Arctic in September is enhanced by the well-developed low-pressure systems. The results of the transport model indicate that the material transport processes to the Arctic by the well-developed low-pressure systems are enhanced in the fine horizontal resolution (~ 56 km) models relative to the coarse horizontal resolution (~ 220 km) models.