When soils are drier, afternoon storms are more likely to form. These are the results of a study published inNature, which contradicts the current predictive simulation models of the conditions that would occur in a context of climate change.
The research has been carried out by an international group of scientists from the United Kingdom, the Netherlands, Austria, and France who analyzed images from various satellites that observe the development of storm clouds across the planet. When paired with the soil moisture maps, they came up with a surprising result: “We had already studied the storms in Africa, and we found thatrain clouds tended to form in areas where it had not rained for days“explained Chris Taylor, of the Center for Ecology and Hydrology (UK), and director of the research.” We were surprised to find the same pattern in other areas such as the United States and continental Europe. In these less extreme climates we did not expect to see a significant effect of soil moisture. “
How are these results explained? “On sunny days the earth heats the air, creating thermal currents that rise several kilometers in the atmosphere. If the ground is dry, the thermal currents become stronger, and the probability of rain increases,” Taylor said.
The results are of great importance when developing future climate models. The scientists compared their observations with six predictive models and found that they all started from the premise that a soil with more moisture generates more storms, and therefore in a climate change scenario, with a decrease in rainfall,it would enter a vicious circle in which drought would cause more drought. “We will have to improve climate models to be able to get a more precise idea of the implications of climate change on a regional scale”, explains Françoise Guichard, co-author of the work.
