Long range Transport of black carbon and the effect on Snow albedo in north-east China and in the Arctic

Black carbon (BC) atmospheric particles originate from the incomplete combustion of fossil fuel and biomass. These particles are black due to their strong absorption of solar radiation. Via long range transport, BC particles reach the Arctic and deposit i n the snow where even relatively small amounts of BC can reduce the snow albedo. Recently, BC in snow and ice has been identified by IPCC as a potentially large climate forcing agent especially to the Arctic. However, the lack of observations and poor pro cess understanding makes estimates of their climate impact highly uncertain. By performing measurements of BC in air and snow at the same location we aim to arrive at a better understanding about how BC is embedded in the snow. Concurrent spectral measur ements of the snow albedo will serve to find direct relations of the change in albedo to the levels of BC present in the snow. This knowledge will be fed into numerical models to improve simulations of BC transport, fate and radiative forcing in order to identify contributions from different regions and sources and to ultimately make better climate predictions. We use the opportunity within this research call to establish a location for measurements of BC in air and snow in China (Tongyu station), which w ill be compared with an identical setup for observations of BC in air and snow in Svalbard (Ny-Ålesund). In addition observations of BC in air from Barrow (Alaska) will be provided by NOAA in order to better link large-scale transport of BC to the Arctic. The proposed project, which aims at improving the understanding around BC as a climate driver, will be of interest to a wide scientific community. An important part of this project involves transfer of knowledge between the Norwegian-Swedish and Chinese groups. The project aims at increasing the Norwegian-Chinese collaboration, as well as linking this project to a larger international network group.