Other FREE projects
Source: environment.data.gov.uk (2018-06-19)

Flood Risk for Extreme Events (FREE): Radiosonde, Wind Profiles Data and Model Output from the Exploitation of new data sources, data assimilation and ensemble techniques for storm and flood forecasting project. The Exploitation of new data sources, data assimilation and ensemble techniques for storm and flood forecasting Project is a NERC Flood Risk for Extreme Events (FREE) Research Programme project (Round 1 - NE/E002137/1 - Duration January 2007 - April 2010) led by Prof AJ Illingworth, University of Reading. This project investigates possible methods of producing ensemble weather forecasts at high-resolution. These ensembles will be used with raingauge and river flow to improve methods of flood forecasting. The dataset includes radiosonde and wind profiles in England and Wales derived using Doppler radar returns from insects. The radial velocity measurements from insects were converted into VAD profiles by fitting a sinusoid to radial velocities at constant range. All measured profiles have been interpolated to the instrument location. 
Model output files from experiments assimilating radial winds from insects are also available.

Floods in the UK are often caused by extreme rainfall events. At present, weather forecasts can give an indication of a threat of severe storms which might cause flash floods, but are unable to say precisely when and where the downpours will occur, due to the complex range of processes and space-time scales involved. The first stage is to predict the air motions leading to convergence and ascent at a certain location where the precipitation will be initiated, then the development of the precipitation needs to be forecast, and hydrological models used to produce accurate, quantitative, probabilistic flood predictions. Data assimilation is a sophisticated mathematical technique that combines observations with model predictions to give an analysis of the current state of the atmosphere. This analysis may be used to initialise a weather forecast. Although precipitation is well observed by weather radar, attempts to assimilate radar data have had little success; by the time the rain develops the forecast model state is too far from the truth and the air motions are inconsistent with the position of the first radar precipitation echo.

We propose to overcome this problem by assimilating new types of data from weather radars. These provide information on the evolving humidity fields and air motions in the lower atmosphere so that the model can accurately track the developing storm before precipitation appears. The model used will be a new Met Office model that can be run with a resolution (i.e., grid-spacing) of order 1-4km. This enables storm-cloud motions to be explicitly calculated, rather than treated as a sub-grid-scale effect. Furthermore, current operational forecast models are only updated with observations every few hours; in the new approach the model will be updated much more frequently. This should yield weather forecasts with improved locations (in space-time) for rainfall events.

Initialisation errors are not the only cause of inaccuracies in storm-scale weather forecasts. Models are often run only for a small region of the world, and the data on the boundaries of this area provided from a larger-scale model. These data are known as lateral boundary conditions. Errors in these lateral boundary conditions and modelling errors also contribute to the errors in the forecast. Even if these errors were reduced, the nonlinear nature of the storm dynamics ensures that there is a limit, beyond which the value of deterministic forecasts becomes questionable. After that point it becomes important to determine the uncertainties in the forecast precipitation, so an ensemble approach is required. (An ensemble is a collection of perturbed forecasts that may be considered as a statistical sample of the forecast probability distribution.)

The appropriate construction of a storm-scale ensemble is an open question. We propose a structured approach where perturbations will be designed on the basis of physical insight into convective forcing mechanisms. The resulting probabilistic rainfall forecasts can be interfaced to hydrological models used for flood forecasting. For the first time, this project will allow different scales of application of these methods to be supported: ranging from localised flash flooding of small catchments, through to indicative first-alert forecasting with UK-coverage and forecasting of river discharges to the sea. The project will also assess the impacts of improvements in numerical weather prediction on flood forecast performance.

In this project we anticipate fruitful interactions between the different disciplines of observations and measurement, meteorology and hydrology. Radar assimilation software development and ensemble forecasts will take place using Met Office models, so improvements can be implemented operationally very easily. The use of operational radars makes this project well placed to take advantage of data from any extreme events occurring during the period of the study.

Flood Risk for Extreme Events (FREE)

The broad programme objectives embody consideration of the meteorological, hydrological and coastal oceanographic processes involved. Such processes include floods arising either through the occurrence of extreme rainfall and subsequent flows underground, overland or in river channels to the sea, or within estuaries and sea areas generated from storm surges around our coast. These components were highlighted by major flood events during the summer of 2007 in Tewkesbury and Gloucester, and the 9th November 2007 North Sea storm surge which so nearly spelt disaster for east coast communities.

Climate change will probably bring more frequent and intense storms to the UK, in turn bringing more floods. At present, flood damage costs the UK about £1bn each year. So it's essential we improve our ability to forecast, quantify and manage flood risks, and mitigate the effects of climate variability and change, if we're to maintain a sustainable economy. Sound environmental science must underpin our efforts.

FREE brings researchers in the hydrological, meteorological, terrestrial and coastal oceanography communities together in an integrated research programme for the first time.

FREE Mission Statement:

The FREE programme will research what causes and propagates floods, so helping to forecast and quantify flood risk, and inform our society about the likely effects of climate change.

The FREE programme started in 2005 and will end in 2010. There have been three rounds of awards, through which 13 projects (projects_contacts.html) have been funded.
- Changing coastlines: data assimilation for morphodynamic prediction and predictability (coastlines.html) - Dr Sarah Dance, University of Reading.
- Coastal Flooding by Extreme Events (CoFEE) (cofee.html) - Prof J Williams, University of Plymouth.
- Ensemble Prediction of Inundation Risk and Uncertainty arising from Scour (EPIRUS) (epirus.html) - Dr Q Zou, University of Plymouth.
- Exploitation of new data sources, data assimilation and ensemble techniques for storm and flood forecasting (forecasting.html) - Prof AJ Illingworth, University of Reading.
- FRACAS: a next generation national Flood Risk Assessment under climate ChAnge Scenarios (fracas.html) - Mr N Reynard, NERC Centre for Ecology and Hydrology.
- Identification of changing precipitation extremes and attribution to atmospheric, oceanic and climatic changes (identification.html) - Dr TJ Osborn, University of East Anglia.
- Local flood forecasting capability for fluvial and estuarine floods: Use of GridStix for constraining uncertainty in predictive models - Prof Keith Beven, Lancaster University. (gridstix.html)
- Modelling groundwater flood risk in the Chalk aquifer from future extreme rainfall events (groundwater.html) - Prof H Wheater, Imperial College London.
- Quantifying Flood Risk of Extreme Events using Density Forecasts Based on a New Digital Archive and Weather Ensemble Predictions (quantifying.html)- Dr PE McSharry, University of Oxford.
- Uncertainty Assessments of Flood Inundation Impacts: Using spatial climate change scenarios to drive ensembles of distributed models for extremes (fii.html) - Prof GR McGregor, King's College London.
- A data-driven exploratory study of extreme events based on joint probability analysis (explore.html) - Dr C Svensson, NERC Centre for Ecology and Hydrology.
- Land Use Management Effects in Extreme Floods (landuse.html) - Professor PE Oconnell, Newcastle University.
- A hybrid model for predicting the probablity of very extreme rainfall (hybridmodel.html) - Professor R Toumi, Imperial College London.
A further objective of the FREE programme is to collect data from extreme events occurring during the programme. An Arrangement known as FLood Action Team (FLoAT) (float.html), led by Dr Stuart Lane, Durham University, is also in place to assemble specific data should major extreme events occur during the programme as happened during 2007 (Tewkesbury - acquisition of aerial images collected during the Tewkesbury flooding summer 2007).

Due to the multi-disciplinary nature of the projects within FREE, no one NERC data centre is an appropriate archive for all data. Data management for FREE will be coordinated by the BADC and data and metadata will be stored at the data centre most appropriate for the data type: atmospheric data at BADC, marine data at BODC and hydrological data at CEH. Some data may be more appropriately archived at the NEODC (NERC Earth Observation Data Centre), however this will be administered through the BADC. Links to all data locations will be added to the FREE project page (projects_contacts.html) as they become available.

Regardless of the physical location of the data, a copy of the metadata will be lodged in the BADC catalogue and will be browsable through a common portal at BADC which will also link to the actual data location.

Access to the data generated by each project at BADC will be restricted to the FREE participants during a restricted access period ending two years after the end date of the programme. Data will be made publicly accessible after that date.

Documentation
- List of projects (projects_contacts.html) funded under the FREE programme.
- FREE Science Plan (FREE_scienceplan.pdf)
- FREE Implementation Plan (FREE_implementplan.pdf) (January 2008)
- FREE Progress Report (FREE_200805progress-report.pdf) (May 2008)
- FREE Progress Report (FREE_200810progress-report.pdf) (Oct 2008)
- Data Inputs to FREE projects (Data_inputs_to_FREE_projects.html)
Links and References
- National Environment Research Council (NERC) (http://www.nerc.ac.uk/)
- British Oceanographic Data Centre (BODC) (http://www.bodc.ac.uk/)
- NERC Centre for Ecology and Hydrology (http://www.ceh.ac.uk/)
A list of relevant publications (references.html) is available.

Who to contact
- The Programme Science Coordinator is Prof. Chris Collier (mailto:xxx@xxx.xx) (Salford University).
- Any query regarding the data should be sent to the BADC help desk (mailto:xxx@xxx.xx).