BEGIN:VCALENDAR VERSION:2.0 PRODID:researchseminars.org CALSCALE:GREGORIAN X-WR-CALNAME:researchseminars.org BEGIN:VEVENT SUMMARY:Sønke Maus (Norwegian University of Science and Technology) DTSTART:20210421T130000Z DTEND:20210421T140000Z DTSTAMP:20260423T021340Z UID:BAS-PO/15 DESCRIPTION:Title: Digital Sea Ice Physics - A novel approach for computing and parametrising sea ice properties for geophysical applications\nby Sønke Maus (Norw egian University of Science and Technology) as part of BAS Polar Oceans Se minar\n\n\nAbstract\nOne of the large challenges in sea ice science is how sea ice properties (e.g.\, albedo\, thermal conductivity) on small scales influence properties and processes on larger scales (e.g.\, the floe or r idge scale and basin-scale sea ice behaviour). To make progress one has to understand the variability in small-scale properties which can span sever al orders of magnitude (e.g. permeability). For many properties a strong d ependence on temperature and salinity has been found\, yet the detailed ph ysical processes leading to this variability have remained unclear: On the one hand are the bulk fractions of sea ice constituents (gas\, ice\, brin e and solid salts) often insufficiently known or measured. On the other ha nd\, there is the lack in observations of 3D sea ice micro-structure to wh ich the physical properties are related.\n\nIn the present talk I will foc us on the concept of "Digital Sea Ice physics" to improve our understandin g of sea ice properties\, their dependence on microstructure and growth co nditions\, and illustrate several applications to geophysical sea ice prob lems. The concept is adopted from rock science where it has been establish ed as "Digital Rock Physics" (DRP) during the last decade. It is based on 3D X-ray tomographic imaging and digitizing of the sea ice pore space\, fo llowed by direct numerical computation of its effective physical propertie s. In this way the relationship between effective physical properties of s ea ice and its bulk constituents (volume fractions of ice\, air\, brine an d solid salts) is determined and related to micro-scale characteristics of the pore space\, providing an improved understanding of the properties' v ariability.\n\nI will begin the talk with an overview of sea ice propertie s and microstructure and their variability\, to illustrate related challen ges and open questions in sea ice science\, identifying the need of 3D mic rostructure information for many topics. I will then describe the work flo w of “Digital Sea Ice Physics” from field sampling to physical propert y computations\, as well as the challenges for the porous medium sea ice\, when compared to rocks and snow. I will discuss several applications to o btain sea ice properties that are relevant for sea ice and climate modelli ng: (i) transport properties of sea ice and recent results on sea ice perm eability and electrical conductivity\; (ii) the microstructure at the sea ice ocean interface (with relevance for on ice-ocean heat\, salt and momen tum exchange as well as ice-ice friction) and (iii) the ice surface regime (with relevance for albedo and inter-facial processes between sea ice and snow). Digital Sea ice physics is a concept that has large future potenti al due to increasing computational power to handle large 3D images. The ta lk closes with an overview of climate-relevant sea ice properties for whic h the approach opens new paths to fundamental knowledge and understanding. \n LOCATION:https://researchseminars.org/talk/BAS-PO/15/ END:VEVENT END:VCALENDAR