Floes can be less than a meter to over a kilometer wide and are usually only 2-3 meters thick. The distribution of sea ice varies throughout the year depending primarily upon the angle of incoming solar radiation reaching the higher latitudes. The southern ice cover has its equatorward extent unrestrained by land and is bounded by land poleward. The effects of land upon sea ice formation allow northern sea ice to extend well into the middle latitudes. Sea ice distribution in the polar regions became much better understood with the successful remote sensing of the polar regions by satellites using passive microwave radiometers.
Sea ice restricts the flow of all of the items listed.
Sea ice formation releases heat during freezing conditions, and the melting of sea ice absorbs heat. This results in a moderation of temperature extremes. If the water increases its volume or if the mass decreases as it changes state from liquid to solid, then its density must decrease also. The transpolar drift stream transports ice from the shallow Eurasian continental shelves, over the North Pole, to the Nordic Seas. Dynamic processes are characterized by continuous change and activity.