Editor's Summary
31 May 2007
Cyclones in the mix
Tropical cyclones are known to mix the upper layers of the ocean, a process that 'pumps' heat downwards and thereby cools the ocean surface on local scales. It has been suggested that they may play an important role in ocean mixing at the global scale, and new calculations suggest that tropical cyclones are indeed responsible for significant cooling and vertical mixing of the surface ocean in tropical regions. Heat pumped downwards must be balanced by heat transport towards the poles, so some 15% of peak poleward oceanic heat transport may be associated with tropical cyclone-induced mixing. The amount of mixing induced by tropical cyclones is also related to sea surface temperature, suggesting that future changes in tropical sea surface temperatures may have significant effects on ocean circulation and ocean heat transport, as both processes are affected by ocean mixing. Climate change models could benefit from taking these effects into account. See also last week's Concepts essay, in which Martin Visbeck argues that the 'pulling power' of upwardly mobile ocean waters is an increasing factor in ocean mixing. Elsewhere in this issue, Quirin Schiermeier takes a broad view of recent work on ocean mixing and the US National Hurricane Center releases its latest storm predictions.
News: Stormy opening to hurricane season
Infighting over money and equipment plagues US agency.
Alexandra Witze
doi:10.1038/447514a
News Feature: Oceanography: Churn, churn, churn
How the oceans mix their waters is key to understanding future climate change. Yet scientists have a long way to go to unravel the mysteries of the deep. Quirin Schiermeier reports.
doi:10.1038/447522a
Letter: Observational evidence for an ocean heat pump induced by tropical cyclones
doi:10.1038/nature05785
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