HOW STORMS WILL VEER IN A WARMER WORLD.

• Position: CLIMATE CHANGE

Under global climate change, the Earth's climatic zones will shift toward the poles. This is not just a prediction; it is a trend that already has been observed in recent decades. The dry, semi-arid regions are expanding into higher latitudes, and temperate, rainy regions are migrating poleward.

In a paper published in Nature Geoscience, researchers at the Weizmann Institute of Science, Rehovot, Israel, provide insight into this phenomenon by discovering that mid-latitude storms are steered further toward the poles in a warmer climate. Their analysis, which also reveals the physical mechanisms controlling this phenomenon, involved a unique approach that traced the progression of low-pressure weather systems both from the outside--in their movement around the globe --and the inside, analyzing the storms' dynamics.

Yohai Kaspi, professor in the Department of Earth and Planetary Sciences, explains that the Earth's climatic zones roughly follow latitudinal bands. Storms mostly move around the globe in preferred regions called "storm tracks," forming over the ocean and generally traveling eastward and somewhat poleward along these paths. Thus, a storm that forms in the Atlantic Ocean, off the East Coast of the U.S., at a latitude of around 40[degrees]N will reach Europe in the region of latitude 50[degrees]N. Until recently, however, this inclination to move in the direction of the nearest pole was not really understood. Talia Tamarin in Kaspi's group...