Radio soundings

MeteoSwiss performs radio soundings twice a day using weather balloons. This allows important meteorology-related atmospheric values to be measured at high altitudes. Conventional radiosounding is one of the foundations of weather forecasting and is of great significance today for the area of climate research.

In order to produce a good weather forecast, the current weather conditions both on the ground and in the atmosphere must be known as accurately as possible. The aerological measurements taken using radiosondes probe the terrestrial atmosphere and deliver precise data on the wind, air pressure, temperature, humidity and ozone concentrations. The recorded data is also used in the field of climate research.

Emagrams as images

Datum & Uhrzeit
15.12.2018 12:00 UTC16.12.2018 00:00 UTC
PayerneGIFPayerne, 15.12.2018 12:00 UTC(120kB)GIFPayerne, 16.12.2018 00:00 UTC(120kB)
Payerne & MünchenGIFPayerne & München, 15.12.2018 12:00 UTC(130kB)GIFPayerne & München, 16.12.2018 00:00 UTC(130kB)
Payerne & StuttgartGIFPayerne & Stuttgart, 15.12.2018 12:00 UTC(130kB)GIFPayerne & Stuttgart, 16.12.2018 00:00 UTC(130kB)
Payerne & TrappesGIFPayerne & Trappes, 15.12.2018 12:00 UTC(130kB)GIFPayerne & Trappes, 16.12.2018 00:00 UTC(130kB)
Payerne & MilanoGIFPayerne & Milano, 15.12.2018 12:00 UTC(130kB)GIFPayerne & Milano, 16.12.2018 00:00 UTC(130kB)
Decoded data as text files

This data is only checked to a certain extent and can include gaps (replacement data).

Datum & Uhrzeit
15.12.2018 12:00 UTC16.12.2018 00:00 UTC
PayerneTXTPayerne, 15.12.2018 12:00 UTC(10kB)TXTPayerne, 16.12.2018 00:00 UTC(10kB)
MünchenTXTMünchen, 15.12.2018 12:00 UTC(10kB)TXTMünchen, 16.12.2018 00:00 UTC(10kB)
StuttgartTXTStuttgart, 15.12.2018 12:00 UTC(10kB)TXTStuttgart, 16.12.2018 00:00 UTC(10kB)
TrappesTXTTrappes, 15.12.2018 12:00 UTC(10kB)TXTTrappes, 16.12.2018 00:00 UTC(10kB)
MilanoTXTMilano, 15.12.2018 12:00 UTC(10kB)TXTMilano, 16.12.2018 00:00 UTC(10kB)

How radiosounding works

The picture shows the circular balloon probe and an employee of MeteoSwiss in Payerne who lets them ascend.
A weather balloon is released into the atmosphere

A radiosonde equipped with various measuring devices is carried up to high altitudes by a balloon filled with hydrogen or helium. This weather balloon rises at a more or less constant speed and is carried away by the wind flow. The radiosonde is equipped with a GPS system for recording its position, allowing the altitude, wind speed and wind direction to be determined. The instruments carried by the balloon record its position and various meteorological parameters at regular intervals and the readings taken are sent to the ground-level station via a radio transmitter on an continuous basis. This allows for the vertical profiles of the different measured parameters to be determined up to the altitude at which the balloon bursts.

Radiosoundings in Switzerland

Switzerland's only aerological sounding station is located at the Payerne regional centre of MeteoSwiss. Two soundings are performed here every day at midnight and 12 noon UTC (universal time coordinated). The balloons are tracked up to an altitude of 30-35 km. With an average ascent rate of 5 m/s, a sounding lasts around two hours. In addition to wind speed and wind direction, the parameters of air pressure, temperature and humidity are measured during the soundings. Three times a week, the ozone concentration is also determined as part of the soundings performed at 12 noon. Using the data collected during the ascent, the operator in Payerne selects and codes the prominent points and transmits these to MeteoSwiss in Zurich, where the information is fed into the international communication network. Payerne is a special climate monitoring station and also belongs to the global reference network for aerological measurements.

Global sounding station network

Worldwide, there are approximately 700 irregularly distributed sounding stations. Soundings are performed simultaneously at these stations every 12 hours. The information obtained here is made available to all national weather services via special communication networks. Here, the information is plotted in the upper-level weather maps and analysed as well as being used as the basis for weather forecasting models. Around 170 of these stations fulfil more stringent requirements and are used for long-term climate monitoring.

Data from radio soundings

The chart shows the first 20 kilometres of an aerological sounding performed from Payerne. Each of the four lines displays the behaviour of a meteorological parameter in relation to the altitude. The green line shows the profile of the relative humidity, while the red line illustrates the temperature profile. The wind speed is plotted in blue. The purple line shows the wind direction; 0° signifies wind from the north, 90° from the east, 180° from the south and 270° from the west.