Monitoring Climate Variability and Change by Means of GNSS Data

Abstract

Although temperature and water vapor are key variables for the detection of climate change, the direct observation of these quantities in the free atmosphere is difficult using conventional techniques like radiosondes or satellites. The main problems are due to inhomogeneities, instrumental changes, sensor drift and lack of global coverage. More reliable information about climate variability and change can be gained from {GNSS} (Global Navigation Satellite System)-based vertical profiles of temperature and humidity. {GNSS} observations are particularly well suited for climate monitoring, since they provide high precision and vertical resolution data under all weather conditions and with time and space independent sampling characteristics, cover the whole globe, have virtually no instrumental bias and are intrinsically self-calibrating.