Snow Covers impacts on Antarctic Sea Ice (SCASI)

• Applicants: Dr. Marcel Nicolaus; Professor Dr. Detlef Stammer, since 5/2018
• Subject Area: Oceanography
• Term: from 2015 to 2022
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 274947488

The increase of Antarctic sea-ice extent over the last years is in contrast to the observations in the Arctic. The causes are a current topic of research, and numerical models are not able to reproduce the increasing sea-ice extent in the Antarctic. Besides atmospheric and oceanic processes, the heterogeneous and thick snow cover of Antarctic sea ice is a major factor governing the sea-ice mass balance with important feedbacks on global climate and weather. This snow cover also complicates airborne- and satellite-based remote sensing techniques, because it dominates many observations and determines methodologies and uncertainties. These facts raise the need for a better understanding of snow on Antarctic sea ice, especially in order to enhance remote sensing algorithms and climate models.The overall goal of this project is to quantify the amount and distribution of snow on Antarctic sea ice, its physical properties and their evolution over time. The project is designed to develop a new and consistent snow-data product prototype for Antarctic sea ice, representing various length scales and different seasons. Such a product will be of great help in developing and validating new remote sensing algorithms and to improve model simulations. Finally, this project will help to shed light on Antarctic sea-ice mass and energy balance and dynamics. We will also contribute to improvements in biological and geochemical studies of the ice-covered Southern Ocean. To achieve this goal, we will use high-resolution modeling, guided by in-situ data on Antarctic snow cover in combination with remote sensing data sets. The establishment of a new German-Swiss cooperation (D-A-CH program) will enable us to merge sea-ice expertise from field observations and remote sensing of the German partners with snow expertise from observations and modeling of the Swiss partner. Comprehensive in-situ snow datasets are readily available from several successful field experiments, complemented by autonomous measurements from drifting observatories. Satellite data from AMSR-2, SMOS, and CryoSat-2 are available in the project consortium, which will be used to develop new processing algorithms for snow on sea ice. Algorithms and data sets will then be validated through in-situ and autonomous observations. The numerical models SNOWPACK and MEMLS will be coupled to simulate physical snow properties like snow depth, temperature, density, and microwave emissivity. The results from this work will support data analyses and up-scaling of the ground observations as well as interpretation of satellite data. This will finally allow the generation of the snow data and map product.The project will fund three young scientists for their sea-ice research. Two experienced PostDocs will contribute with their knowledge and expertise from their recent PhD theses, using similar methods and data sets for new objectives. A PhD student will benefit from the project by writing his thesis.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1158: Infrastructure area - Antarctic Research with Comparative Investigations in Arctic Sea Ice Areas
• International Connection: Switzerland
• Partner Organisation: Schweizerischer Nationalfonds (SNF)
• Co-Investigator: Professor Dr. Michael Lehning
• Ehemaliger Antragsteller: Dr. Lars Kaleschke, until 5/2018