Rainy Spells Extended For Europe

Like a patient getting a regular checkup, our understanding of climate gets poked and probed in a number of ways. And just as doctors keep a regular clipboard of vital statistics such as blood pressure and weight, meteorologists measure long-term weather patterns hoping to find interesting patterns.

A new study of rainfall in Europe over the period 1950-2008 finds that although the yearly number of rainy days has not increased, the length of wet spells -- periods in which rain falls on a number of consecutive days -- has gone up by about 15-20 percent.

Many scientists believe that the side effects of human technology, especially the extra carbon dioxide it adds to the atmosphere, are driving climate change more than the natural fluctuations that occur all the time. A consequence of this change is an increase in average temperatures in many -- but not all -- places around the world.

Another worrisome outcome of climate change is the increase in extreme weather seen in many places. Rainfall is an example.

Olga Zolina, who works at the University of Bonn in Germany, participated in the rainfall study that measured the increasing length of wet spells over Europe. She said that the more intense events seem to increasingly occur during the longer periods. The results from the study were published in Geophysical Research Letters in March.

If the current pattern continues, "we can hypothesize that the lengthening of wet spells will result in more intense and more frequently occurring floods,” Zolina said. She and her collaborators are now extending their study to include wetness and flooding.

The study also reports that the wet-spell increase is more pronounced in the northern sections of Europe -- such as in Russia and Scandinavia -- which is also in keeping with many projections that climate changes will be more pronounced at higher latitudes.