Global water cycle

The Global Water Cycle Group investigates the processes involved in the hydrological cycle and how they are simulated in the Unified Model. We examine the role of water in large-scale modes of variability such as monsoon systems and ENSO, and we examine the processes involved in how such systems behave under climate change. The group collaborates with other research areas in the Met Office developing improved representations of physical processes and with external scientists working on hydrological cycle issues.

Key aims

• Improving understanding and modelling of hydrological processes
• Understanding the role of water in large-scale modes of variability
• Quantifying and reducing uncertainty in hydrological predictions

Current projects

• Study of monsoon systems in different regions of the world. Monsoons in Africa and Asia are major components of the atmospheric circulation, and the economies and livelihood of the populations in these regions depend heavily on the rainfall associated with them. Simulation of monsoons and their variability remains a significant challenge for Climate modelling. This project brings together scientists from the Met Office, the University of Reading,  National Centre for Medium Range Weather Forecasting (India) and Korea Meteorological Administration. It also forms part of the JWCRP.
• Improving understanding and representation of African climate: A major focus for the Met Office climate prediction model: HadGEM3 family is on delivering improved predictions of climate for vulnerable regions of Africa, including predictions of extremes for critical variables such as rainfall. This project aims to evaluate key local processes and modes of variability, and to develop improved understanding of both local and remote influences driving African climate. Our particular focus is on the role of the land surface in influencing African weather and climate.
• Examination of the global hydrological cycle in models, including their representation of the Hadley and Walker circulations, and the role of water in large-scale modes of climate variability and their teleconnections.
• Study of the response of the hydrological cycle to climate change and to various mitigation and geoengineering options. Recent work suggests that the hydrological cycle may continue to intensify for a time even if carbon dioxide emissions are reduced.
• Examination of aspects of the hydrological cycle in the CMIP5 model ensemble, including the effects of different model components (aerosols, carbon cycle, chemistry) on climate change projections.