1. Snow measurements during N_ICE JC Gallet 1, G. Liston 2 and S. Gerland 1 1 Norwegian Polar Institute, Tromsø, Norway 2 Colorado State University 17 November 2015, NPI, TromsøPicture: Uversøya, Svalbard

2. Albedo (fresh snow): 0.8 to 0.9 Heat loss Thermal insulation kT = 0.04 to 0.6 W/(m.K) Heat transport Deposition of chemicals Wind Permeability Kp = 20 to 500 10-10 m2 h h Light penetration e = 5 to 20 cm (visible) Photochemical activity Physical impacts of snow on climate: land system

3. Physical impacts of snow on climate: sea-ice system Sea-Ice Lead Sea-Ice Ocean Light penetration Photochemical activity h h Albedo: 0.1-0.8 Thermal insulation kT = 0.04 to 0.6 W/(m.K) Growth of Sea-Ice (ΔT)

4. What kind of data have been collected: Leg 1 and Leg 2 (winter snowpack) Transect of snow depth (i.e. snow distribution) together with sea ice thickness have been collected regularly (twice a week approximately) Snowpits looking at snow density, grain size, temperature profile (twice a week approximately) Snow accumulation change using snow stakes along each drift This are basic data collected during the winter that gives minimal info regarding the snowpack conditions. Some sampling have been done in collaboration with chemist guys (Markus: salt profile; Daiki: CO 2 fluxes).

5. What kind of data have been collected: Leg 3 to 6 (spring snowpack) The same as before + Quite some data regarding the snow distribution using lidar measurement (snow surface topography to be linked with snow depth data and melt ponds formation) Transects of albedo data have been done using radiative sledge and snowpit have been dug underneath the measurements

6. What is the strategy we wish to apply regarding the snow data and modeling (discussion between JC, Sebastian and Glen regarding Ioanna’s work) Dig into the data and present a comprehensive data set to be published. Two papers are aimed: winter and spring snowpack. Why ? Because in winter there are more or less no light interaction and no data regarding albedo so we can have a different focus on that main properties to be looked on Because we can split the work between different people and different leading person regarding the publication (more or less JC would lead the winter paper and Ioanna the spring paper) Because the data need to be published before they can get use properly (using references) in the model (presentation later on)

7. Timing regarding the snow work First half of 2016: get the snow papers out Second half of 2016: Glen will stay at NPI during 3 months (August, September, October). Modeling work will start intensively and compared with the field data 2017: continuation of the work and incorporation of the snow into a broader view (sea ice and atmosphere) The publication for the snow data will focus a lot on comparison with the SHEBA project (1998-1999 field work) mostly published by M. Sturm, D. Perovitch and K. Holmgren. Why ? Because SHEBA was on a multi year ice flow (Canadian Arctic) and the purpose of N_ice is to focus on first year ice flow and get to know what are the consequences of shifting a multi-year to a first year system in the Fram Area. The SHEBA papers are also very well describing the snow properties including quite some numbers in it.