New studies by Chinese scientists indicate that particular thermodynamic effects have caused ozone depletion over the Qinghai-Tibet Plateau. Zou Han, a researcher from the Institute of Atmospheric Physics of the Chinese Academy of Sciences, said that a recent study shows that the Qinghai-Tibet Plateau is a major geothermal source for the atmosphere. "And as a result, air with a low content of ozone is heated and rises to the ozone layer and dilutes its density," said the scientist.