The Representation of Drought in Observations and Climate Models

Drought is an inherent part of climate variability, significantly affecting ecosystems and economies. Effective monitoring of drought is crucial, and drought indices have been developed to do this by tracking variables such as precipitation, evaporation and soil moisture. However, indices are affected by uncertainties from measurements in observations and parametrizations in climate models. This thesis shows that given the uncertainties in measurements, precipitation alone is often sufficient for drought detection. The behaviour of the indices in climate models also reveal systematic limitations in the representation of drought processes, including an overestimation of the importance of evaporation for drought.