Be able to explain what conditions lead to sea ice

This preview shows page 8 - 10 out of 21 pages.

Be able to explain what conditions lead to sea ice formationOnce sweater reaches seawater temp, -> tiny ice crystals= frazil ice (grease ice)-> pancake ice-> medium pancakes ice->large pancake ice->pack ice Rounded shapes because of pieces of ice move and bounce on each other. Bc its constantly moving, you see ridges. -Be able to describe/explain/identify/draw patterns in timing of sea ice extent in Northern and Southern hemispheres-Be able to explain the steps of sea ice formation and why brine channels occurBrine: sea ice formation leaves salt behind creating channels of brine. Doesn’t freeze bc it’s too salty. Under gravity it will sink to the bottom of the ocean. The older the ice= fresh-Be able to explain the difference between first-year and multi-year sea iceFirst-year ice: formed over one winter, thin, weaker, more brine and melts during summer Multi-year ice: thicker, last longer than a year no more than 10. Stronger, less brine-Understand and be able to use the terms “concentration”, “extent”, and “volume” to describe the amount of sea ice presentSea ice concentration: see ice covers more than 15%Extent: how far it runs (easy to measure)Volume: depth of sea level (difficult to measure)-Be able to describe why sea ice moves and explain/identify the features that result from that movementAs it melts, you see melt ponds (light blue) -> absorb more energy and accelerates melting -Be able to describe how the geography of the Arctic and Antarctic is different and Arctic(northern): maximum sea ice extent in March bc it’s an accumulative process. -gyres; circular movement -more multi-year ice Antarctic(southern): maximum in September -winds will carry of sea ice out to sea-what effects this has on sea ice extent, movement of ice, sea ice thickness and agemovement of sea ice: -compression ridges: builds in ice thickness on top -> keels below ice also moves apartanimals will travel along things cracks :-Leads: linear breaks-polynas: rounder areas of open water caused by winds or melting of sea ice(warmer water underneath).
From Lecture 13 – Importance of sea ice to the earth system and polar ecosystems-Be able to explain the importance of sea ice for our climate system:oAlbedo : exposed ocean water absorbs more heat, decreasing albedo, increasingtemperatures & melting ice. oAs a barrier to transfer of heat, water vapor, and other gases between the ocean and the atmosphere-Sea ice Forms a lid oDue to its influence on seawater density and thermohaline circulationBe able to describe what controls seawater density and how sea ice formation and melting will affect seawater densitySeawater density depends on temp& salinity. Warmer temp= increase speed in water molecules= spreading out and less dense. -Warm and fresh water = less dense -cold and salty water is more dense Be able to draw the profiles of temperature, salinity, density with depth at low and high latitudesBe able to describe and explain the thermohaline circulation and how sea ice formation helps drive itThermocline= change in tempHalocline=change in salinity Pycnocline= change in depths

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture

  • Left Quote Icon

    Student Picture