Orographic Processes

Mountains and hills have an important influence on both local weather and large-scale weather systems.

On the local scale mountains can significantly enhance precipitation and give rise to a wide variety of complex flows, some of which are associated with hazardous winds and severe turbulence. On the larger scale, through the generation of turbulent form drag, internal gravity waves and flow blocking, hills and mountains influence the development of weather systems and the global atmospheric circulation. These processes need to be represented in weather and climate prediction models.

Our research explores several aspects of atmospheric flow over orography. These include investigations at the process level using numerical models such as BLASIUS and the Unified Model at very high resolution, the development of parametrization schemes for use in the Unified Model and  operational lee-wave forecasting models. The work is supported by theory and detailed observations from field campaigns. There are strong links to the Observation Based Research (OBR) team and research groups in academia, both in the UK and internationally.

The group also supports Met Office Defence and Consultancy in a wide range of projects concerned with air flow over complex terrain. Recent examples include assessment of potential climatological impacts of mining in mountainous regions and the development of state-of-the-art techniques for predicting wind climatology for the wind energy industry.

Key Aims

  • To understand the impact of hills and mountains on atmospheric flow.

  • To improve the orographic drag parametrizations in all configurations of

    the Unified Model.

  • To develop new techniques for local forecasting in complex terrain.

Current Projects

  • Development of the Unified Model orographic drag parametrization schemes.

  • Development of lee-wave forecasting models

  • Understanding and improving prediction of temperature variations

    in complex terrain

Last updated: 16 November 2010