Use of radar observation in hydrological and NWP models

Objectif

1.BACKGROUND

The European Doppler radar networks now provide a unique basis for use of radar information. Many countries have begun to investigate the use of radar data in Numerical Weather Prediction (NWP) and fluvial flow forecasting models, but few have developed an operational capability. However, the benefits of radar data are clearly recognised by the NWP and hydrological modelling communities in the fields of:

model validation;

physical parametrisation development;

data assimilation;

forecast verification;

initialisation of antecedent conditions.

Techniques are being developed in many of these areas and promise improvements to a number of applications, notably: validation of high resolution cloud models, the parametrisation of convective processes, four-dimensional variational analysis (4DVAR) and examination of the impact of the error characteristics of radar-derived precipitation information on the output from hydrological models. Moreover, improvements in flood forecasting can be anticipated from assimilation of radar data within NWP models whose output is used to drive operational hydrological models.

Before large scale effort is committed to using radar data in modelling studies, there is a need to assess the benefits of such methods, and their relative strengths and weaknesses. This requires the experience and information that exists across many countries within Europe. The COST forum offers the ideal approach to bring these groups together.

2.OBJECTIVES AND DELIVERABLES OF THE PROJECT

The main objectives of the proposed project may be summarised as follows:

2.1.investigate how radar data can be most effectively utilised in model assimilation schemes and in combination with other observations;

2.2.identify the requirements from NWP assimilation for quality control and international transmission of radar data in line with the developments under EUMETNETS's OPERA project;

2.3.identify and demonstrate the potential contribution that radar-based observation techniques can make to the development of physical parametrisations for NWP models, in particular for representing convective processes, and identify examples of studies undertaken to date;

2.4.examine and define the requirements on European radar data for use in hydrological models, for river flow in rural and urban catchments, and for the real-time control of urban drainage systems;

2.5.provide standardised European methods and algorithms for validating model performance against observations from radar networks and other sources for "ground truth";

2.6.document the improvements (both established and potential) to modelling by the use of radar information as vertical wind profiles, radial Doppler winds, rainfall and reflectivity;

2.7.recommend algorithms for quality control of radar data and on-line error estimation.

3.SCIENTIFIC CONTENT OF THE PROJECT

The Signatories intend, on the basis of the present state of development of observational systems, NWP and hydrological modelling in their countries, to investigate, collate available results and, where possible, carry out research and development work to establish operational benefits and recommendations on the topics of interest in this project. These topics will cover the following areas.

3.1.Using radar information in hydrological modelling

3.1.1.Review current use of radar data in hydrological models;

3.1.2.identify the error characteristics of different radar measurements at a range of scales (temporal and spatial) and examine how these impact on hydrological models;

3.1.3.provide a list of requirements for radar data in differing hydrological models for rural and urban catchments, and for urban drainage models;

3.1.4.evaluate the use of radar data and calibration techniques in hydrological models to provide quantitative precipitation forecast (QPF) information for hydrological models, over and above that provided by raingauge networks;

3.1.5.investigate how radar measurements of precipitation type can improve precipitation rate estimation for input to hydrological models;

3.1.6.examine how radar observations can provide a better means of coupling atmosphere and surface models;

3.1.7.establish a requirement for radar developments needed for future distributed hydrological models and urban drainage models;

3.2.Using radar observations for parametrisation and validation of atmospheric models

3.2.1.Identify how the advanced radar measurements reviewed under COST 75 can be used to improve parametrisations in NWP and climate models and to validate cloud resolving models;

3.2.2.define measurement requirements for use in parametrisation of convective and stratiform systems;

3.2.3.establish a European standard for archiving of radar data including a quality index and supporting observations for use in model validation studies. Collate a list of interesting cases. Establish an internet based European radar archive for modelling studies through OPERA, with a diary of key meteorological events.

3.3.Using radar information in atmospheric models

3.3.1.Review current methods for assimilating radar data;

3.3.2.identify the error characteristics of various radar measurements at a range of scales (temporal and spatial) and examine how these impact on assimilation schemes;

3.3.3.provide a list of requirements for radar data in NWP models, and investigate the need for development of models to process radar data before input to NWP;

3.3.4.assess the impact of introducing radar (precipitation or reflectivity) data more directly into models, for example via 4D-variational techniques, rather than through moisture fields or by latent heat nudging schemes;

3.3.5.examine the relative merits of using Velocity Azimuth Display and Doppler radial velocities in NWP models and the possible use of spectral width information in conjunction with windprofiler information from COST 76;

3.3.6.identify the benefits for assimilation of international exchange of single site radar data over and above those gained from using a National composite;

3.3.7.compare different approaches to verification of NWP precipitation forecasts using radar data and other "ground truth" data sources, with a view to recommending standardised methods within Europe.

4.TIMETABLE AND INTERACTION WITH OTHER PROJECTS

The project will last for five years. It will build on existing work in several countries and the activities under the Fourth Framework (and proposed Fifth Framework) Programme. The project will build directly on work from COST-73 (European radar networking) and COST-75 (advanced radar systems). It will exploit expertise developed in COST-76 (wind profilers), COST-78 (nowcasting) and COST-712 (microwave radiometers). The project will interact with OPERA, and benefit particularly from progress with improvements in radar site data availability and products.

Work undertaken will provide added information and benefits to integrated observations, and for the use of other remotely-sensed information in modelling activities.

Tasks within the sciences programme will be undertaken in parallel and organised into separate working groups. An Annual Report will be produced for the COST Senior Officials and the Technical Committee for Meteorology.

5.ORGANISATION MANAGEMENT AND RESPONSIBILITIES

A Management Committee will be set up following signing by the appropriate number of signatories to the Memorandum of Understanding with no more than two nominated delegates from each participating country. A Chairperson, a Technical and Scientific Secretary and the working group chairmen will be elected and together entrusted with drafting an outline project plan based upon the items in Section 3. The plan will be approved by the Committee and submitted in the Technical Committee for Meteorology to be approved.

For the work to proceed in parallel, it is suggested that three Working Groups be established with their own chairperson to report to the Management Committee.

WORKING GROUP 1
WORKING GROUP 2
WORKING GROUP 3
Using radar information in hydrological models
Using radar observations in parametrisation and validation of atmospheric models
Using Radar information for assimilation in atmospheric models

All Working Groups must include radar expertise and will contain representatives from National Meteorological (and Hydrological) Services, Research Organisations and interested Private Sector Organisations.

The MC will meet in plenary session and delegates will also meet in working groups. These working groups will provide a report based on collated information and short studies undertaken at national level. Each working group will hold a dedicated workshop over the duration of the Action. Working groups will run in parallel with each other and be held immediately before the management committee meeting. Each working group chair will report progress against WG targets in plenary session to the MC. This will further facilitate interaction between working groups and national delegates.

The Committee will report formally to the Technical Committee on an annual basis, but will also provide verbal or written information on each meeting that will be held quarterly. It is anticipated that each Working Group will hold a workshop in the duration of the project, and that an international seminar will be held towards the end of the project time-scale. The Final Report of the project will be based on a series of technical reports written throughout the project by working group members on the topics being considered.

6. DISSEMINATION OF SCIENTIFIC RESULTS

All publications arising from research carried out under this COST Action will credit COST support, and the Management Committee will encourage and promote all co-authored papers. Results of research carried out by working groups under this COST Action will be submitted to international journals and reviews.

Joint meetings among different working groups in the COST Action and with relevant working groups from other COST Actions will be organised in such a way as to best promote interdisciplinary communication.

The Management Committee of this COST Action will, in conjunction with the different working groups of the Action, meet every year with the main aim of presenting results to the Management Committee as a whole and, where possible, invite potential users and interested parties to this meeting.

The Management Committee will, during the first year of the Action, also set up a workplan for interdisciplinary events for the dissemination of results of the Action.

7. ECONOMIC DIMENSION OF THE PROJECT

It is estimated that each country would allocate up to five years of the effort of the project over its duration. Assuming the involvement of 12 countries, the Project's total value of activities would be in the region of EUR 25 million, including overheads.

Programme(s)

IC-COST - European cooperation in the field of scientific and technical research (COST), 1971-

Thème(s)

10 - Meteorology

Appel à propositions

Data not available

Régime de financement

Data not available

Coordinateur

N/A

Contribution de l’UE

Aucune donnée

Adresse

Suisse

Coût total