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Pollen monitoring network

MeteoSwiss operates the national pollen monitoring network. This consists of 14 monitoring stations which cover Switzerland's most important climatic and vegetation regions. Additional monitoring stations are operated in order to monitor levels of ragweed pollen. The measurements recorded by the respective pollen traps provide valuable information for those who suffer from allergies.

The airborne concentrations of 48 different pollen types are measured at each of the 14 monitoring stations. In order to monitor levels of ragweed pollen more precisely, MeteoSwiss operates additional stations in Ticino as well as near Geneva, where high concentrations of ragweed pollen are sometimes registered.

During the pollen season, the pollen data recorded at each measuring station is made available on the Wednesday of the following week

How a volumetric pollen trap works (Hirst design)

Each monitoring station has a volumetric pollen trap (Hirst type). With the help of a pump, this pollen trap sucks in ten litres of air per minute through a 14 x 2 mm opening. Behind this entry slot is a rotating drum on which there is a silicon-coated plastic strip. The pollen and other organic and inorganic particles sucked in with the air stick to this strip. The drum is changed once a week and then sent to the analysis centre in Payerne where daily specimens are prepared using the strip. The types of pollen are identified and counted under a microscope and concentrations per cubic meter air are calculated. Apart from pollen, other organic particles, such as fungal spores, are also found on the specimen slide, as well as various inorganic particles, such as sand from the Sahara Desert or specks of soot.

Automatic measurement of pollen dispersal

MeteoSwiss has developed expertise in automatic pollen monitoring over the past few years, with the aim of making these data available in real time to the Swiss public. Through collaboration with researchers, as well as  testing of various instruments, the feasibility of automatic pollen measurements has been demonstrated.

A project is currently underway to make real-time data available in Switzerland. The Lucerne-based company, Swisens SA submitted the winning bid in the public call for tenders issued in 2019. After extensive testing having confirmed the efficacy of its "Swisens Poleno" system in the spring of 2020, the company is set to provide the automatic pollen monitors for the MeteoSwiss network. The first stations in the network will be operational from the 2021 pollen season onwards.

From then on, the information will be available within minutes of the measurement, thus providing a precise picture of what is in the air at any given time. These real-time data will allow MeteoSwiss to improve the provision and the quality of available information.

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