011-james.txt (2259B)
1 Considerable areas of the polar oceans are covered by sea ice, 2 formed by frozen sea water. The extent and thickness of the ice 3 pack influences local and regional ecology and climate. The ice 4 thickness is particularly important for the ice-cover survival 5 during warm summers. Wind and ocean currents compress and shear 6 the sea ice, and can break and stack ice into ridges. Current sea 7 ice models assume that the ice becomes increasingly rigid as ridges 8 of ice rubble grow. Modeling sea ice as bonded particles, we show 9 that ice becomes significantly weaker right after the onset of ridge 10 building. We introduce a mathematical framework that allows these 11 physical processes to be included in large-scale models. 12 13 Today a [1]new paper of mine is published in the AGU-group journal 14 [2]Journal of Advances in Modeling Earth Systems, and it is written 15 with co-authors [3]Olga Sergienko and [4]Alistair Adcroft at Princeton 16 University (New Jersey, USA). I use my program [5]Granular.jl for 17 the simulations. 18 19 20 ## Abstract 21 22 The Effects of Ice Floe-Floe Interactions on Pressure Ridging in Sea Ice 23 24 The mechanical interactions between ice floes in the polar sea-ice 25 packs play an important role in the state and predictability of the 26 sea-ice cover. We use a Lagrangian-based numerical model to investigate 27 such floe-floe interactions. Our simulations show that elastic and 28 reversible deformation offers significant resistance to compression 29 before ice floes yield with brittle failure. Compressional strength 30 dramatically decreases once pressure ridges start to form, which 31 implies that thicker sea ice is not necessarily stronger than thinner 32 ice. The mechanical transition is not accounted for in most current 33 sea-ice models that describe ice strength by thickness alone. We 34 propose a parameterization that describes failure mechanics from 35 fracture toughness and Coulomb sliding, improving the representation 36 of ridge building dynamics in particle-based and continuum sea-ice 37 models. 38 39 40 References: 41 42 [1] https://doi.org/10.1029/2020MS002336 43 [2] https://agupubs.onlinelibrary.wiley.com/journal/19422466 44 [3] https://scholar.princeton.edu/aos_sergienko/home 45 [4] https://www.gfdl.noaa.gov/alistair-adcroft-homepage/ 46 [5] https://src.adamsgaard.dk/seaice-experiments