He was appointed University Lecturer in Meteorology, Oxford. By studying meteorites he noticed that the temperature profile of the tropopause was not constant, as had previously been believed (hence the name stratosphere). In fact there was, he showed, a region where the temperature sharply rose. This, he proposed, was happening because UV radiation was heating ozone in what has become known as the ozone layer. He noted the connection between sunspots and weather, and measured the ultraviolet levels of our star. He built the first Dobson ozone spectrophotometers and studied the results over many years. The Dobson unit, a unit of measurement of vertically integrated atmospheric ozone density, is named after him.