A couple of items to whet your appetite for the end of week fare.
Big waves in the Arctic
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| Off to surf the Arctic |
With the ice retreating further and further from the shores, the waves are able to grow bigger and bigger. It's suggested that these bigger waves will churn up ice and hasten its demise. Less ice means more waves - a feedback loop. While bigger waves might be great news for surfers, it will make it harder for shipping and will also exacerbate shoreline erosion. From ScienceDaily.com:
Arctic ice used to retreat less than 100 miles from the shore. In 2012, it retreated more than 1,000 miles. Wind blowing across an expanse of water for a long time creates whitecaps, then small waves, which then slowly consolidate into big swells that carry huge amounts of energy in a single punch.
The size of the waves increases with the fetch, or travel distance over open water. So more open water means bigger waves. As waves grow bigger they also catch more wind, driving them faster and with more energy.
Shipping and oil companies have been eyeing the opportunity of an ice-free season in the Arctic Ocean. The emergence of big waves in the Arctic could be bad news for operating in newly ice-free Northern waters.
"Almost all of the casualties and losses at sea are because of stormy conditions, and breaking waves are often the culprit," Thomson said.
It also could be a new feedback loop leading to more open water as bigger waves break up the remaining summer ice floes.
"The melting has been going on for decades. What we're talking about with the waves is potentially a new process, a mechanical process, in which the waves can push and pull and crash to break up the ice," Thomson said.
Waves breaking on the shore could also affect the coastlines, where melting permafrost is already making shores more vulnerable to erosion.
The observations were made as part of a bigger project by a sensor anchored to the seafloor and sitting 50 meters (more than 150 feet) below the surface in the middle of the Beaufort Sea, about 350 miles off Alaska's north slope and at the middle of the ice-free summer water. It measured wave height from mid-August until late October 2012.
Jim Thomson and Erick Rogers have written a paper about this (open access). You can read it here, or read about it at ScienceDaily.com.
Extreme drought in California
The other bit of news this week was that while drought conditions are improving in some parts of the USA, they are getting much worse in California. 58.4% of California is now in extreme drought.
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| Source: The National Drought Mitigation Centre |
Funnily enough Anthony Watts, who hails from California, hasn't written about it on his blog. In fact for all his moaning about manners, he is scorning the suffering that the drought is bringing to farmers and others in his home state. He tweeted "and that's nothing that the state has not experienced before".
By some measures the state may not have experienced a drought like this one before, at least not as part of the USA. The megadroughts happened well before there ever was a US state of California. It only formally became part of the United States in 1850.
Back in Australia, Queensland isn't faring too well at the moment, either. This is the latest map I could find, from May this year:
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| Source: The Long Paddock, Qld Government |
Meanwhile south of the Queensland border, fires have been busting out early in NSW.
Jim Thomson, W. Erick Rogers. "Swell and sea in the emerging Arctic Ocean". Geophysical Research Letters, 2014; 41 (9): 3136 DOI: 10.1002/2014GL059983
