A team led by Scripps researcher Emma Beer observed the changes taking place in the Arctic Ocean, which is largely covered by sea ice for most of the year. There, an unusual situation exists where the water is warm at depth and cold near the surface. The deeper waters are fed by the relatively warm Pacific and Atlantic oceans, whereas the near-surface waters are in contact with sea ice and remain close to the freezing point. Heat flows upward from the warmer water to the colder water.
The average temperature of the Arctic has increased 2. By , polar bears could face starvation and reproductive failure even in far northern Canada. Around 35, walruses came ashore on the Alaska coast in September US government agencies estimated that 60 young walruses were crushed in the crowd. Warmer winter temperatures have also increased the layers of ice in snow, making food more difficult to dig up in winter. Fish stocks in the Barents Sea are moving north at up to kilometres per decade as a result of climate change.
The fish are sensitive to changes in water temperature. This poses a risk for commercial and subsistence fisheries that may see fish resources move away from where they can harvest them. The moving fish also change the ecosystems into which they move. Not only does the newcomer colonise their dens, it can also kill the smaller Arctic foxes. In the ocean, both scientists and Inuit say killer whales appear to be increasing in numbers, and in the length of time they stay in the Arctic.
Killer whales prey on narwhals and bowhead whales. In , a large bulk carrier transited the Northwest Passage for the first time. In , the first cargo ship transited the Arctic north of Russia. Reduced ice cover is making offshore oil production in the Arctic more commercially viable.
In , the first commercial development of offshore oil Prirazlomnoye was pumped from Russian Arctic waters. WWF brings the effects of climate change in the Arctic to a global audience, and makes the connections between Arctic warming and global impacts. As Finland's climate warms, the country is seeing less snow cover. WWF is helping the extremely endangered Saimaa ringed sealsfind suitable places to nest by creating man-made snow banks.
As the Arctic warms at a faster rate than the tropics, this results in a weaker atmospheric pressure gradient and hence lower wind speeds.
The links between Arctic amplification, slowing or meandering jet streams, blocking highs and extreme weather events in the mid to high latitudes of the northern hemisphere is controversial.
One view is that the link is strong and the major driver behind recent severe summer heat waves and winter cold waves. But more recent research questions the validity of these links for the mid latitudes. Here we look at the larger body of evidence that supports the relationship between Arctic warming and slowing jet streams.
This rapid loss of ice affects the polar jet stream, a concentrated pathway of air in the upper atmosphere which drives the weather patterns across the northern hemisphere.
The weakened jet stream meanders and brings the polar vortex further south, which results in extreme weather events in North America, Europe and Asia. Global climate models project stronger surface warming in the Arctic than the Antarctic under climate change. But as the tropics continue to warm and expand , we may expect an increase in the pressure gradient between the tropics and Antarctica that will lead to increased circumpolar westerlies winds.
The recent intensification and more poleward location of the southern hemisphere belt of westerly winds have been linked to continental droughts and wildfires, including those in Australia. We can also expect strengthening westerlies to affect mixing in the Southern Ocean, which could reduce its capacity to take up carbon dioxide and enhance the ocean-driven melting of ice shelves fringing the West Antarctic Ice Sheet.
These changes in turn have far-reaching implications for global ocean circulation and sea level rise. Newsletter Disclaimer: The translations are automatically generated by Google Translate and may contain errors. The ISC is not liable for any damage or issues that may arise from these translations. You can provide your feedback by emailing us at webmaster council. Urban Health and Wellbeing in the Anthropocene May 20, Explore further.
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