Researchers have now measured swells of more than 16 feet in the Arctic’s Beaufort Sea, just north of Alaska. These wind driven waves are breaking up the sea ice faster than the warm temperatures that have been melting the sea ice due to Global Warming. Jim Thompson of the University of Washington states that "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.”
Wiki defines a wind driven wave as:
wind waves (or wind-generated waves) are surface waves that occur on the free surface of oceans, seas, lakes, rivers, and canals or even on small puddles and ponds. They result from the wind blowing over an area of fluid surface. Waves in the oceans can travel thousands of miles before reaching land. Wind waves range in size from small ripples, to 30 m high.[1]
When directly generated and affected by local winds, a wind wave system is called a wind sea. After the wind ceases to blow, wind waves are called swells. More generally, a swell consists of wind-generated waves that are not usually affected by the local wind at that time. They have been generated elsewhere or some time ago.[2] Wind waves in the ocean are called ocean surface waves.
A recent paper in the journal
Geophysical Research Letter reports the grim news.
In the modern Beaufort Sea, the open water distances change dramatically
throughout the summer season, from essentially zero in April (sea ice cover
maximum) to well over 1000 km in September (sea ice cover minimum). In
recent years, the seasonal ice retreat has expanded dramatically, leaving much of the Beaufort Sea ice free at the end of summer. For example, on 18 September 2012 strong winds (up to 18 m s−1) generated 5 m wave heights in the ice-free central Beaufort
Sea (Figure 1). These conditions were measured in situ using a mooring near
the middle of the basin and modeled using a spectral wave action balance code (WAVEWATCH III Ⓡ). There are few previous studies of waves in the Arctic
Ocean; they have focused mostly near the coasts or on local effects. Of the previous studies, Francis et al. [2011] in particular showed a strong trend of increasing surface wave heights in the Arctic. The observations reported here are the only known wave measurements in the central Beaufort Sea,because until recently the region remained ice covered throughout the summer and there were no waves in the central Beaufort Sea, because until recently the region remained ice covered throughout the summer and there were no waves to measure.
The Report summarizes it's findings and it is not good news for our planet.
It is possible that the increased wave activity will be the feedback mechanism which drives the Arctic system toward an ice-free summer. This would be a remarkable
departure from historical conditions in the Arctic, with potentially wide-ranging implications for the air-water-ice system and the humans attempting to operate there.
The increasing wave climate will also have implications for the coasts, which are already eroding rapidly during summer months as a result of climate change and subsequent loss of permafrost. Using the conventional approach that shoreline sediment transport depends primarily on incident wave energy the expectation then is for coastal erosion to increase with a similar 1.6 dependence on the open water fetch of the Arctic Ocean. Although the actual wave effects will of course be site specific and complex, our scaling is a starting point in understanding the rapidly changing wave climate in the Arctic
Ocean and the likely expanding future role of waves in the Arctic system.