Measurements of light-absorbing particles in snow and potential impacts on radiative forcing

Séminaire de Jonas Svensson, IGE, le lundi 20 janvier, 13h, salle Lliboutry Bâtiment Glaciologie

Abstract :

Light-absorbing particles (LAP) consists of different constituents (namely black carbon aerosol, mineral dust, and microbes) that play an important role in the radiative balance of snow. Once deposited onto a snow surface, LAP will decrease the reflectance and accelerate snowmelt. This has been observed in different snow environments of the world, e.g. High Mountain Asia, where abundant snow and ice volumes are in close proximity to high emission sources of LAP. The Arctic is another region, where long-range transported (mostly) LAPs have been shown to affect snowmelt. In this talk, I will discuss different measurement techniques of LAP in snow, with a primary focus on the thermal-optical measurement of particles collected on quartz filters. With an extra optical measurement, it provides additional insight to the microphysical properties of the LAP, allowing a potentially more accurate assessment of the radiative forcing of LAPs in the snow. Examples of ambient results of LAPs in the snow of two Sunderdhunga valley glaciers, Himalayan India, will also be presented, as well as some of the future planned work while at IGE.