Trend Indicators of Atmospheric Climate Change Based on Global Climate Model Scenarios

The upper troposphere-lower stratosphere (UTLS) region is reacting particularly sensitive to climate change and variations of its key parameters are very good candidates for the monitoring and diagnosis of climate change. This study aims at revealing the most promising atmospheric climate change indicators in this region which are accessible by radio occultation (RO) observations. RO based climatologies show the highest data quality in the UTLS. Due to the availability of continuous RO data only since the end of 2001, longer-term climatologies of three representative global climate models were investigated in this respect. We demonstrate that the RO method can valuably contribute to climate monitoring by providing climatologies of a set of atmospheric parameters such as refractivity, geopotential height, and temperature, which differ in sensitivity at different heights and in different regions and cover the UTLS as a whole.