On the statistical properties of sea ice lead fraction and heat fluxes in Arctic

Speaker: 
Sea Ice Modelling (Einar Olason)
Seminar Date: 
17. October 2017 - 11:15 - 11:45
Location: 
Cinema, Ground Floor, NERSC

Heat flux through leads and polynyas is an order of magnitude larger than that through unbroken ice. In this presentation we explore some statistical properties observed in Arctic sea ice lead fraction, showing that our model (neXtSIM) does a good job at reproducing the observed statistics. Given the importance of heat flux through leads we then use the model to explore the statistical properties of the modelled heat fluxes. We show that the model reproduces well the probability density function (PDF) and the mono-fractal spatial scaling of observed lead fluxes in the Central Arctic. We then explore the PDF and spatial scaling of simulated heat fluxes, showing that the heat fluxes have a multi-fractal scaling in the Central Arctic which we attribute to lead formation, while coastal polynyas destroy the scaling in the wider Arctic. Finally we show that the scaling of simulated lead fraction is preserved for different model resolutions, while further work on a sub-grid scale parametrisation of surface heterogeneity is required to preserve the scaling of heat fluxes for different model resolutions.