Page 19 - living-ice

VARMETAP FRA HAVET
HEAT LOSS FROM OCEAN
VARMETILFØRSEL TIL HAVET
HEAT INPUT TO OCEAN
When the sea ice melts, the resulting fresh water forms a oating lid on the salty sea- water, which means the temperature and salinity in the upper layers of the Arctic Ocean can differ greatly from the deeper layers.
Enormous quantities of seawater freeze and melt each year, during which the salt is separated from the water as brine. As brine is heavier than seawater, it sinks to seabed in a process known as deep water formation. The sinking water displaces the water that is already there, driving a bottom current. This process creates cir-
Brine rivers
KALDT VANN SYNKER
COLD WATER SINKS
VARMT VANN FLYTTER SEG MOT POLENE
WARM WATER MOVES POLEWARDS
KALDT VANN VARMES
COLD WATER WARMS
PHOTO: Rolf Gradinger, UiT
KALDT OG VARMT VANN BLANDES
COLD AND WARM WATER MIXES
POL
POLE
EKVATOR
EQUATOR
Ill.: Reibo
culation between surface water and bottom water and affects the transportation of water into and out of the Arctic Ocean. Along with the Gulf Stream, it contributes to the ocean circulation.
These sinking brine rivers transport more than water and salt. They also transport algae and other organic matter from ice oes down into the depths of the ocean, sustaining the food chain of benthic (or bottom-dwelling) organisms. The brine rivers that run along the seabed from the shallow Arctic continental shelf areas to the depths of the ocean are vital for transporting food to the organisms on the seabed.