Sea Ice Flashcards
What is the freezing temperature of water a function of?
Density (salinity) - More saline water will freeze at a LOWER temperature - as temperature decreases density increases
What happens when sea ice forms
Temperature will decrease until the water freezes and salt is released in this processes making surrounding waters more saline
What can delay ice formation>?
Convection
How do convective forces delay ice formation?
Water parcel cools by conduction/ radiation and sinks leaving some parts of sub-artic ocean ice free
What are the stages of sea ice development?
Specules (Frazil Ice); Granular/columnar ice structure; Grease ice, (new ice), Ice sheets
What is Ice rind?
An ice sheet of low salinity that is v.hard
What is Nilas ice?
An ice sheet of high salinity that is more elastic
How does first year form and what are its characteristics?
Wind breaks up ice and it recombines to form first year ice that is up to 2m thick by end of first year
What would characterise ice as second year ice?
When it survives the summer
What is multiyear ice?
Surviving multiple summers
How does ice grow?
Grows by freezing on all sides inc below
How does ice develop
Rate of ice growth will slow down with thickness this is due to insulation from overlying ice that delays heat transfer from below . In arctic anticyclonic winds hamper development and aid dispersal
What contributes to ice growth?
Freezing of the water from above AND below; Coalescence; Winter Snowfall; Supercooled water at base super cooled from above pressure and freezes.
Sea ice feature : what is an Ice Foot?
Surface ice attached to terrestrial land.
Sea ice feature: what is a floe?
A single slab of floating ice
Sea ice feature: What is a Pressure ridge?
Vertically forming ice between two floes - growth under pressure
Sea ice feature: what is a keel?
The underside of a pressure ridge between floes
Sea ice feature: What is rafting?
One floe partially sitting on top of a semi-submerged/submerged floe
Sea ice feature: What are platelets?
The beginning of ice floes - v.small
Sea ice feature: what are pressure hummocks?
A hummock (small mound) caused by pressure of forming sea ice floes/packs
How can Ice cause cumulus cloud formation
Latent heat release - air convects and condensates?
What are the main issues concerning sea ice?
Inhibit or produce shipping transport routes; melting to lead to geo-politcal issues in Arctic. The extent of arctic sea ice has possible implications for atmospheric circulation patterns.
