Soil moisture and hot weather linked.
A new study published in the online version of the Proceedings of the National Academy of Sciences has used a global data set to establish the connection between soil moisture and extreme heat.
The water content of the soil influences the way in which energy is exchanged with the atmosphere. As moist soil warms, moisture evaporates, thus slowing down the rate at which the atmosphere heats up. If the soil is completely dry, however, solar radiation will heat up the air unrestrained.
Brigitte Muller and Sonia Senevirante of the institute for Atmospheric and Climate Science in Zurich compared the hottest month for regions around the world with the preceding months' precipitation levels. They found a significant correlation between below-average rainfall and subsequent temperature spikes in several regions, in South America, the Iberian Peninsula and eastern Australia, the probability that days with above-average temperatures followed precipitation shortfalls was more than 70 per cent.
However, the researchers emphasised that the findings aren't a tool for predicting the weather. 'You can proceed on the assumption that moist conditions reduce the risk of heat waves,' said MOiler. 'However, it isn't possible to infer subsequent heat waves from dry conditions with absolute certainty, because both normal and extreme conditions may follow dry conditions. The summer of 2011 is a good example of this. Although the spring in Switzerland was very dry, there was no strong following summer heat wave.'
|Printer friendly Cite/link Email Feedback|
|Title Annotation:||CLIMATE WATCH|
|Comment:||Soil moisture and hot weather linked.(CLIMATE WATCH)|
|Article Type:||Brief article|
|Date:||Sep 1, 2012|
|Previous Article:||Unusual Greenland ice melt.|
|Next Article:||Sceptic's study finds support for anthropogenic warming.|