[font face=Serif][font size=5] Weather-Making High-Pressure Systems Predicted to Intensify[/font]

Oct 04, 2012
Contact Tim Lucas at (919) 613-8084 or tdlucas@duke.edu

[font size=4] DURHAM, NC – High-pressure systems over oceans, which largely determine the tracks of tropical cyclones and hydrological extremes in much of the northern hemisphere, are likely to intensify this century, according to a Duke University-led study published online this week in Nature Geoscience.[/font]

[font size=3]The study’s findings suggest that as summertime near-surface high-pressure systems over the northern Pacific and Atlantic oceans strengthen, they could play an increasingly important role in shaping regional climate, particularly the occurrence of drought and extreme summer rainfall, in coming years.

Wenhong Li, assistant professor of earth and ocean sciences at Duke’s Nicholas School of the Environment, and colleagues used climate model simulations to predict future changes in the strength of the annually occurring North Atlantic Subtropical High, also known as the Bermuda High, and the North Pacific Subtropical High.

According to the simulations, these high-pressure systems will intensify over the 21[small]^st[/small] century as a result of increasing greenhouse-gas concentrations. The simulations suggest that an increase in the land-sea thermal contrast – the difference between ocean and land heating, as Earth’s climate warms – will fuel the systems’ intensification.

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