Oceans under pressure

High-pressure systems that largely determine the location of subtropical deserts and the tracks of tropical cyclones are set to intensify this century, as reported in a study published online this week in Nature Geoscience. The findings suggest that subtropical highs could play an increasingly important role in regional climate in the coming century.

Wenhong Li and colleagues used climate model simulations to assess future changes in the strength of summertime subtropical highs over the Northern Hemisphere oceans. According to their simulations, these high-pressure systems will intensify over the twenty-first century as a result of increasing greenhouse-gas concentrations. They suggest that an increase in the land-sea thermal contrast is responsible for this intensification.