Interactions of Arctic Aerosols with Land-Cover and Land-Use Changes in Northern Eurasia and their Role in the Arctic Climate System

Abstract

Atmospheric aerosols have been hypothesized as playing an important role in significant climate and environmental changes that have been occurring in the Arctic. This Chapter concentrates on the role of Arctic aerosols in the energy balance and the hydrological cycle by considering several major aerosol types (sulfates, black carbon and dust) that originate in Northern Eurasia. Aerosols can affect the energy balance directly by scattering, absorbing, and emitting atmospheric radiation as well as by changing the surface albedo. Furthermore, aerosols perturb the radiative energy balance indirectly by affecting the properties, lifetime, and coverage of clouds. Aerosol-induced changes in clouds are also important in the hydrological cycle. An additional complexity arises from the potential connection of aerosols to feedbacks that involve the physical climate, ecological, and human components of the Arctic system. The abundances, chemical composition and spatiotemporal distributions of natural and anthropogenic aerosols, which are controlled by sources and ageing processes occurring during atmospheric transport, are the major factors governing the aerosol climate forcing. Over the past decades, the warming climate, socio-economic changes and changes in land cover and land use occurring in Northern Eurasia have been affecting sources and properties of atmospheric aerosols. These changes were likely to affect not only aerosol burden in the Russian Arctic but through the whole Arctic. Understanding how changes in land cover and land use have been affecting the abundances and distributions of natural and anthropogenic aerosols and how the aerosol-induced varying forcing has been affecting the Arctic climate system is of great importance to understand the overall response of the Arctic region to global warming associated with steadily increasing greenhouse gases.