Details of Award
NERC Reference : NE/R008469/1
Novel physical and numerical methods for simulating water, heat and gas transfer in land surface models, with focus on UKMO JULES model
Training Grant Award
- Lead Supervisor:
- Professor A Verhoef, University of Reading, Geography and Environmental Sciences
- Grant held at:
- University of Reading, Geography and Environmental Sciences
- Science Area:
- Atmospheric
- Terrestrial
- Overall Classification:
- Terrestrial
- ENRIs:
- Environmental Risks and Hazards
- Global Change
- Natural Resource Management
- Science Topics:
- Climate & Climate Change
- Numerical Analysis
- Land - Atmosphere Interactions
- Soil science
- Abstract:
- Reliable weather forecasts and climate predictions rely on realistic model representations of land surface processes, i.e. those involved in the exchange of water and energy between Earth's 'critical zone' (the soil and underlying parent material, and the vegetation growing on it) and the atmosphere. Examples of such processes are evaporation from soil, transpiration from plants and related root water uptake, as well as deep drainage below the rootzone recharging the groundwater, and warming up of the soil in spring time. To get the magnitude and timing right of these processes, and of related variables such as soil moisture content, weather and climate models use mathematical descriptions of the processes, and how they interact with each other. These sets of equations form the core of so-called land-surface models that are an integral part of weather-and climate models. Apart from the scientific equations describing critical zone processes, these models also need appropriate numerical approaches to deal with the fact that model time-steps and soil-layer thickness cannot be infinite. The calculation of water flow in the soil requires particular care, in order to keep the model 'stable' and efficient, so that important, but highly non-linear, equations, such as those dealing with soil moisture conservation, result in reliable and accurate predictions. Meteorological offices worldwide, including UK Met Office (UKMO), have come to realise that improved land surface modelling is critical for providing better forecasts within a changing climate, for example for flood and drought prediction. UKMO are making a big push to drive this improvement and this studentship proposal is an important part of this effort. This requires a paradigm change in the way that the terrestrial water cycle is represented in their land surface model (Joint UK Land Environment Simulator; JULES), hence they have sought help from soil hydrological and mathematical experts at the University of Reading. JULES, like most land surface models, represents the soil hydrology through a discretised form of the one-dimensional partial differential equation (PDE) attributed to Richards that describes unsaturated flow in soils. Such a solution to a highly non-linear equation inevitably leads to numerical and accuracy issues, which impact on their hydrological performance. Hence alternative approaches, that have been advanced within hydrological models, need to be considered. This project concerns the implementation and testing of two novel 1-D unsaturated zone flow solution methods into JULES. One proposed by Professor Ogden (UCAR, USA), who is a project partner, the other by Professor Baines (UoR). Furthermore, the student will aim to extend both approaches to include a soil heat flow and local heat conservation approach. The intellectual challenge will be to derive a consistent method for coupling water and heat transport within the soil, but without degrading the hydrological performance of the scheme. Furthermore, the student will demonstrate the impact of this new scheme, compared to the original JULES, for hydrological components within both the UK Environmental Prediction (UKEP) model and for the UK Earth System Model (UKEMS). Increased efficiency and stability will allow for an increased number of model runs, and hence better estimates of model uncertainty. Also, improved model speed will allow for increased spatial resolution which should lead to improved predictions, in particular for convective rainfall, with implications for flood prediction, for example. The novel model approach should also be useful for any other applications that require reliable modelling of soil water and heat flow, such as agricultural water management predictions, flood risk management, and advice to utilities companies who would benefit from models that predict the soil hydro- (thermal) environment, e.g. in relation to adverse effects on water pipes or telecommunication cables.
- NERC Reference:
- NE/R008469/1
- Grant Stage:
- Completed
- Scheme:
- DTG - directed
- Grant Status:
- Closed
- Programme:
- Industrial CASE
This training grant award has a total value of £89,917
FDAB - Financial Details (Award breakdown by headings)
| Total - Fees | Total - RTSG | Total - Student Stipend |
|---|---|---|
| £17,479 | £11,000 | £61,438 |
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