CN-MET

Project start 19.12.2005
Project end 31.12.2009
Topics Research & cooperation
Measurement & forecasting systems
Region Swiss
Status Completed projects

Introduction

Main purpose of the CN-MET project (Centrale Nucléaire et METéorologie) is to bring up to date the system delivering weather information necessary to the population safety in case of a nuclear hazard. CN-MET represents the coupling of a specifically adapted measurement network and a predictive tool in the form of a fine grid numerical weather prediction model currently developed at MeteoSwiss (COSMO-2). This new tool, calling upon modern measurement and modeling techniques of the atmosphere, represents a solution which will keep all its relevance for the next decades.

In case of a nuclear accident, the necessary atmospheric data used to calculate the diffusion of a contaminated air mass will be provided by a fine grid numerical model, covering the whole Swiss territory. The new measurement network within CN-MET is directly adapted to provide the best information (initial and boundary conditions, and test measurements) for this model. CN-MET not only ensures the emergency preparedness for the concerned population on a local scale, but also enhances it on a regional scale corresponding to the Swiss Plateau.

The measurement network

With the CN-MET project a new measurement network (Figure 1) is being set up which includes:

  • three remote sensing sites measuring wind and temperature profiles within the planetary boundary layer (PBL), located downwind, upwind and in the center of the domain (data examples cf. Figures 2 and 3),
  • surface weather stations from the new SwissMetNet (SMN) network (with additional turbulence measurements) at each of the four nuclear power plants,
  • four SMN boundary layer stations in order to add information on wind and temperature measurement in the PBL, which are integrated in the MeteoSwiss measurement network.
Figure 1: The CN-MET measurement network, including 3 remote sensing sites (green), 4 SMN stations at the nuclear power plants (blue) and 4 SMN Surface Layer stations (red).
Figure 1: The CN-MET measurement network, including 3 remote sensing sites (green), 4 SMN stations at the nuclear power plants (blue) and 4 SMN Surface Layer stations (red).
Figure 2: Top: Vertical temperature profiles measured on 18 March 2006 (time step of ca. 90 sec) with a microwave radiometer installed at the Aerological Station in Payerne. Bottom: Comparison with the sounding in Payerne at 00, 12 and 24 UTC; red: sounding, blue: radiometer.
Figure 2: Top: Vertical temperature profiles measured on 18 March 2006 (time step of ca. 90 sec) with a microwave radiometer installed at the Aerological Station in Payerne. Bottom: Comparison with the sounding in Payerne at 00, 12 and 24 UTC; red: sounding, blue: radiometer.

The fine-grid model COSMO-2

As a part of the CN-MET project, a new fine-grid numerical weather prediction model (Figure 4), COSMO-2, is being developed, with the following caracteristics:

  • data assimilation from the above mentioned network for initial conditions, thus offering a complete and coherent image of the state of the atmosphere and its evolution (wind, turbulence, precipitation, etc)
  • providing input data for the dispersion models in operation at the Swiss Federal Nuclear Safety Inspectorate (ENSI; Eidgenössisches Nuklearsicherheitsinspektorat) for short-distance dispersion calculation around the Swiss nuclear power plants
  • providing an 24 hours forecast every 3 hours, with a 10 minutes output time step, for the whole Swiss Plateau
  • providing an emergency mode, activated on demand by the ENSI, with an hourly computation of a short-range forecast, in order to satisfy the high requirements of a predictive emergency response tool.
Figure 4: Example of a simulated wind field on the Swiss Plateau obtained by the new fine grid model COSMO-2 with a horizontal resolution of 2.2 km. Background colour shading according to terrain height in the model.
Figure 4: Example of a simulated wind field on the Swiss Plateau obtained by the new fine grid model COSMO-2 with a horizontal resolution of 2.2 km. Background colour shading according to terrain height in the model.

Contacts

  • Bertrand Calpini, CN-MET project leader, MeteoSwiss, Aerological Station, P.O. BOX 316, CH-1530 Payerne, Switzerland
  • Dominique Ruffieux, responsible for the CN-MET measurement network, MeteoSwiss, Aerological Station, P.O. BOX 316, CH-1530 Payerne, Switzerland
  • Philippe Steiner, responsible for the development of COSMO-2, MeteoSwiss, P.O. BOX 257, CH-8058 Zürich, Switzerland
  • Olaf Maier, project management, MeteoSwiss, Aerological Station, P.O. BOX 316, CH-1530 Payerne, Switzerland
  • Pirmin Kaufmann, CN-MET operating manager, MeteoSwiss, P.O. BOX 257, CH-8058 Zürich, Switzerland

 

Links

COSMO-Prognosesystem

MeteoSchweiz betreibt das numerische Wettervorhersagemodell COSMO für die Wetterprognose im Alpenraum.

Automatisches Messnetz

SwissMetNet, das automatische Messnetz von MeteoSchweiz, zählt 260 Stationen. Diese erfassen alle zehn Minuten aktuelle Daten zu Wetter und Klima.