My main research interests center around the global land surface hydrological cycle and particularly the question of whether the hydrologic cycle is intensifying in response to climate change and global warming. The potential effects of intensification on the environment and society in terms of changes to the availability or absence of water, such as through flooding or drought, is relatively unknown but potentially large and damaging. In an attempt to address these issues my research has looked at a number of inter-related themes:

• Recent collaborative research has looked at how changes in the global and continental hydrologic cycle can be detected against a background of natural variability. To this end, I have developed a framework for estimating the time required to detect significant trends in the components of the hydrologic cycle.
• Detection of change in the global hydrologic cycle requires monitoring at high temporal and spatial resolutions for long time periods. My research has investigated the potential use of "indicator basins", which are representative of the larger scale, as a monitoring tool. In tandem with this, I am looking at current and future planned observation networks and campaigns to assess their suitability for monitoring change.
• The possible mechanisms of change include alterations to the precipitation recycling regime in a region and changes to climate and weather patterns via shifting atmospheric transport pathways. I have been studying the global and regional impacts of climate change on precipitation recycling through the analysis of simulations of future climate scenarios from global climate models.
• Some of the potential effects and consequences of change include the intensification and increased occurrence of natural hazards such as floods, droughts and wildfire. In relation to this, I have been analyzing the historical and contemporary drought regime in the US using a new hydrologic model based drought indicator to help in the prediction of future drought and the impacts thereof.
• Much of this work is based on the analysis of observed and simulated global hydrometeorological datasets. A large portion of my research involves creating such datasets through the use of high spatial and temporal resolution computational modeling of the land surface hydrologic cycle and the generation of consistent meteorological forcing datasets.