EAPSI: Refining Techniques for Remote Sensing of Snow and Ice Impurities on Brewster Glacier, NZ

Khan Alia, Boulder CO

Investigators

Abstract

High elevation snow packs play a major role in the global climate system due to the reflectivity of the large land cover. Aerosol deposition of impurities such as dust and black carbon on snow and ice can reduce the amount of solar radiation reflected by the surface, as well as enhance the generation of melt-water. This can result in both short and long-term impacts on community water resources, as well as downstream impacts such as sea-level rise. Ground-based observations in mountainous regions, such as the New Zealand Alps, are difficult to collect due to the inaccessibility of the terrain. Recent development of remote sensing tools by satellite to quantify surface albedo is enabling more rapid quantification of changes of snow/ice. This aim of this study is to refine remote sensing techniques to identify impurities on snow and ice. The project will utilize Brewster Glacier in New Zealand as a case study to conduct ground validation of the remote sensing estimates. The research will be conducted in collaboration with Dr. Pascal Sirguey and Dr. Nicolas Cullen in the Snow Remote Sensing Group at the University of Otago in New Zealand. The surface albedos of highly reflective snow/ice expanses, such as in the mountains of New Zealand (NZ), play a significant role in the global energy balance. Ground-based observations in mountainous regions, such as the NZ Alps, are difficult to collect due to the inaccessibility of the terrain. Airborne residues from light absorbing impurities (LAIs) such as dust and black carbon (BC) may travel thousands of kilometers before being deposited on these highly reflective surfaces. The dark particles absorb more solar radiation, thereby reducing the surface albedo of the corresponding snow/ice, as well as enhancing melt. This study will utilize cutting edge remote sensing tools to identify changes in surface albedo of Brewster Glacier, New Zealand, provide ground validation of those techniques, as well as quantify the impact of BC and LAIs on the surface albedo of the glacier. This award under the East Asia and Pacific Summer Institutes program supports summer research by a U.S. graduate student and is jointly funded by NSF and the Royal Society of New Zealand.