Physical and chemical changes in the ocean over basin-wide zones and decadal or longer time-scales: perspectives on current and future conditions - Ocean Sustainability in the 21st Century - page 107

3.9 High-latitude regions
The high-latitude oceans of both the Northern and Southern Hemispheres remain under-
sampled and poorly explored, despite their strong roles in global climate and life-support
systems. The interaction between air, water, and ice is of great importance for the heat bal-
ance of the ocean-atmosphere system and thus the climate. Wind forcing can be extreme,
with large seasonal variations. Sea ice formation accompanies cooling over the shelves
and extracts heat and fresh water from the water column. These processes make the polar
ocean boundaries especially important in understanding global ocean circulation (Royer and
Stabeno, 1998 ) . Sediments of the polar seas hold keys to reconstruction of past ocean circu-
lation and ice ages. But still, documentation of change in the polar regions remains sparse
(Wassmann et al ., 2011 ) . These explanations justify the efforts made during the Internation-
al Polar Year (IPY) 2007-2008, the International Geophysical Year (IGY) 1957-1958, the
International Southern Ocean Studies during the International Decade of Ocean Exploration
(IDOE) 1970-1980, and the calls for continued and upgraded monitoring of these areas.
Global climate models and observations agree that warming will occur first and faster
in high-latitude oceans (Loeng et al. , 2005 , cited by Carmack and McLaughlin 2011 ) . The
IPY observations confirmed that the Arctic is changing faster than models predict. Models
suggest that climate warming can lead to a contraction of the highly productive marginal sea
ice biomes, by 42% in the Northern and 17% in the Southern Hemispheres (Sarmiento et
al. , 2004 ). Change is currently occurring in the Arctic, with potentially major consequences
for the global climate system, marine ecosystem, oil and gas exploration/exploitation, and
shipping.
Carmack and McLaughlin ( 2011 ) present an in-depth review of physical and chemical
observations in the sub-Arctic and Arctic seas around northern North America, obtained
during the joint efforts of Canada's Three Oceans programme and the Joint Ocean Ice
Study. Oceanic domains and linkages between the sub-Arctic and Arctic parts are analysed.
Changes that are identified include: ocean warming, sea ice melting, upper layer freshening,