MeteoSwiss operates the EMER-Met wind analysis and forecasting system for nuclear accidents in Switzerland and neighbouring countries. It consists of a special measurement network and the weather forecast model COSMO-1E. The combination of measurements and model provides important bases for emergency response in Switzerland. These can also be used for major events involving the spread of non-radioactive atmospheric pollutants.
In close cooperation with the Federal Nuclear Safety Inspectorate (ENSI), MeteoSwiss has developed the EMER-Met (Emergency-Response Meteorology) wind analysis and forecasting system, which began operating at the end of 2009. In 2019, the Federal Office for Civil Protection joined as an additional partner. MeteoSwiss is currently bringing the system up to the latest state of the art. The system includes a large number of special measuring instruments and the COSMO-1E weather forecast model. The combination of precise measurements and high-resolution model forecasts makes it possible to determine wind fields and weather developments around Switzerland's nuclear power stations and those in neighbouring countries and thus to calculate the dispersion of contaminated air masses. Both the ENSI and the National Emergency Operations Centre (NAZ) use the information to assess the current situation. On this basis, the NAZ is able to take measures to protect the population.
MeteoSwiss has set up its own monitoring network for EMER-Met, which will be renewed over the next few years. It records the atmosphere above Switzerland's Mittelland region in detail, in particular in the direct vicinity of the Swiss nuclear power stations. The monitoring network comprises three different Monitoring systems.
This special monitoring network is supplemented by the SwissMetNet ground-level monitoring network of MeteoSwiss, which comprehensively records the meteorological parameters close to ground level.
The measurements taken by the three wind profilers and by SwissMetNet are fed into the MeteoSwiss local weather forecasting model, COSMO-1E. On a grid network with a horizontal grid box size of 1.1 kilometres, the model calculates the weather developments for the coming 33 hours in the Alpine region every three hours.
In addition to the EMER-Met system, MeteoSwiss also operates the NADAM monitoring network on behalf of the National Emergency Operations Centre (NAZ). More than 60 SwissMetNet stations are equipped with special probes which measure the level of radioactive radiation (local dose rate). Together with the precipitation data, the local snow depths and other meteorological parameters, MeteoSwiss transmits the data to the NAZ every ten minutes. If a specific threshold is exceeded (1 micro-Sv/h), an automatic alarm is triggered at the NAZ.