WP 202: Wind, waves and storm surges (Use cases: France and Bulgaria)

Objectives:

Simulation of historical storm situations is a key tool in examining potential coastal hazards. Therefore, it is crucial to build forecasting/hindcasting capability using model renanalyses offering complete space and time coverage in order to manage rare and extreme events.. Storm surge and wave models will be used for the hindcast study in the frame of IncREO Project, in order to identify the hazard zones along the French and Bulgarian coastal zones.

The main source of information about historical weather phenomena and processes are the reanalyses performed by the European Centre for Medium range Weather Forecast -ECMWF (Reading). The data from these reanalyses are available at every six hours and with a coarse spatial resolution. In this form these data are not suitable for detailed evaluation of meteorological parameters leading to extreme events such as storms, sea level variations, and the related adverse effects.

The special procedure for the transition to a finer spatial grid and smaller time intervals is called dynamical “downscaling”. Downscaling of the reanalysis of meteorological observations plays a crucial role for the accurate representation of past events (extreme storms, etc.) and for the successful identification of the vulnerable areas at a regional scale.

One of the priorities of WP 202 is to generate high resolution atmospheric data (wind at 10m and sea surface pressure) that occurred in the past, to be able to simulate the high waves and storm-surges. While for France an appropriate solution could be the use of the global model ARPEGE with its stretch geometry, for the region of Bulgaria definitely better results are expected from the use of the regional model for weather forecast ALADIN.

Description of work:

The activities of WP 202 will include the choice of historical situations with stormy conditions along the coastal zones of France and Bulgaria , simulations of sufficient number of past storms (hindcast) in order to provide an up to date identification of the marine hazards for the French and Bulgarian coastal zone using the high resolution wind fields obtained from the downscaling procedure.

Transferability:

Downscaling, proposed in the framework of this project, targets the study of risks of extreme winds and dangerous coastal events (strong winds, high waves and storm surges) for France and Bulgaria. The downscaling methodology and the obtained results will be of significant importance at European level, because of their further usage for other European areas. (Ref. Letter of Support from ECMWF).

Deliverables:

List of historical situations with stormy conditions from the recent and more distant past for the coastal zones of France and Bulgaria (D202.1, D202.3).
Downscaled meteorological quantities: (wind at 10m and sea level pressure) for these situations for the coastal zones of France and Bulgaria (D202.2, D202.5, D202.6).
Storm surges and wave products associated with downscaled meteorological quantities for the coastal zones of France and Bulgaria (D202.4, D202.7).
End-users expectations (MF & end user SHAPI; NIMH & end user Civil Protection):

A more comprehensive and better documented historical background on the coastal hazards (strong winds, high waves, storm surges, flood events) would allow, from the past events, a better calibration of the wave, storm surge and flood forecasting models; better storm surge and wave forecast; improvement of the coastal hazard Early Warning Systems and meteorological vigilance map EUROPEAN METEOALARM