1 Seasonal timeline for snow-covered sea ice processes in Nunavik’s Deception Bay from TerraSAR-X and time-lapse photography Sophie Dufour-Beauséjour 1,2 , Anna Wendleder 3 , Yves Gauthier 1,2 , Monique Bernier 1,2 , Jimmy Poulin 1,2 , Véronique Gilbert 4 , Juupi Tuniq 5 , Amélie Rouleau 6 , Achim Roth 3 5 1 Centre Eau Terre Environnement, Institut national de la recherche scientifique (INRS), Quebec, G1K 9A9, Canada 2 Centre d’études nordiques (CEN), Université Laval, Quebec, G1V 0A6, Canada 3 German Aerospace Center (DLR), Oberpfaffenhofen, 82234 Weßling, Germany 4 Kativik Regional Government, Kuujjuaq, J0M 1C0, Canada 10 5 Salluit, J0M 1S0, Canada 6 Raglan Mine (a Glencore Company), Laval, H7S 1Z5, Canada Correspondence to: Sophie Dufour-Beauséjour (sophie.dufour-beausejour@ete.inrs.ca) Abstract. Inuit have reported greater inter-annual variability in seasonal sea ice conditions. For Deception Bay (Nunavik), an area prized for seal and caribou hunting, an increase in solid precipitation and a shorter snow cover period is expected in the near future. 15 In this context, and considering ice-breaking transport in the fjord by mining companies, we monitored sea ice in the area for three seasons of ice between 2015 and 2018. This article presents a case study for the combined use of TerraSAR-X and time-lapse photography time-series in order to monitor snow-covered sea ice seasonal processes. The X-band median backscattering is shown to reproduce the seasonal evolution expected from C-band data. Two different freeze-up and breakup processes are characterized. New X-band backscattering values from newly formed ice types are reported. The monitoring approach presented in this article 20 has the potential to be applied in other remote locations, and processes outlined here may inform our understanding of other fjords or bays where ice-breakers transit. 1 Introduction 1.1 Context Salluimiut (people of Salluit, Nunavik, in Canada) have reported changes in their environment which affect activities on the land 25 in Deception Bay (Tuniq et al., 2017). This area is prized by local Inuit for fishing, as well as seal and caribou hunting (Petit et al., 2011). People from neighboring community Kangiqsujuaq have reported warmer and longer fall seasons, later freeze-up, and thinner ice (Nickels et al., 2005), as well as less snow and earlier sea ice breakup in spring (Cuerrier et al., 2015). The evolution of seasonal sea ice conditions in Deception Bay is expected to continue, with climate projections for the region showing shorter snow cover periods and an increase in solid precipitation (Mailhot and Chaumont, 2017). Further, two nickel mines have marine 30 infrastructure in Deception Bay. Their ice-breakers transit in the bay from June 1st to mid-March, avoiding the seal reproduction period (GENIVAR, 2012). Monitoring seasonal snow-covered sea ice processes in the area is relevant in light of local community members’ reliance on the fjord’s rich ecosystem for subsistence, as well as for shipping-related operations by the mines. Lessons learned from this work further have the potential to be applied in similar contexts elsewhere in Inuit Nunangat (Inuit regions of Canada, including Nunavik), and by other researchers studying the cryosphere, particularly those using X-band radar remote 35 sensing. https://doi.org/10.5194/tc-2019-199 Preprint. Discussion started: 10 September 2019 c  Author(s) 2019. CC BY 4.0 License.