Sonnblick Observatory

A congress, a professor and a mine owner

In 1879 a meteorological congress in Rome named research on the upper atmosphere a key subject. Julius Hann, the Viennese climatologist, argued for a permanent high-mountain station to answer it, and the gold-mine owner Ignaz Rojacher, who ran mines on the Rauris side of the Hoher Sonnblick, offered to build one on the summit. A weather tower and a wooden hut were established in 1886. Rojacher lived in the hut himself for periods and carried supplies up to it.

When Rojacher died in 1891, the observatory's finances were threatened. The Sonnblick Verein, a society of supporters, was founded in 1892 to finance it, a rare early case of a membership organisation keeping a scientific station alive.

Observations in the extreme

The summit has the conditions of a high-altitude laboratory: strong winds, rime ice and deep snow. Observers read thermometers, barometers and wind instruments by hand and later by automatic sensors, and the observation series is among the longest at high altitude in the world. On 1 January 1905 the summit recorded −37.4 °C, a record that still stands for the station.

Because the summit is above most of the boundary layer, its air samples the free troposphere, and the observatory later added measurements of aerosols, trace gases, radiation and snow chemistry.

Today

Government-funded renovations followed in 1986 and 1994. The observatory is run by GeoSphere Austria and is part of the Global Atmosphere Watch network of the World Meteorological Organization, contributing to the same series of high-altitude stations as Zugspitze and Jungfraujoch. The Sonnblick Verein still exists.

A station built on a social contract

The Sonnblick observatory depends on a social arrangement as well as on its instruments: a society of supporters, a public agency and a legacy of volunteers carry it. Its glaciers have shrunk markedly in the years of the record, and its record of snow is used by avalanche services. A station that remains in the same place, at the same height, with the same measurements, can be the control for everything else that changes around it.

Instruments and technologies

• Mountain weather station Thermometers in screens, barometers, anemometers and rain and snow gauges on the summit, with heated and rime-resistant designs for icing conditions.
• Snow and radiation measurements Snow depth and water equivalent, plus radiation sensors for the sun and the sky, used for climate monitoring.
• Aerosol and trace-gas sampling Sampling lines at the summit measure the composition of the free troposphere for the Global Atmosphere Watch.

The people

• Julius Hann Viennese meteorologist who argued for high-mountain observatories.
• Ignaz Rojacher Mine owner who built the summit hut and funded the first years.

Timeline

• 1879 A meteorological congress in Rome names upper-atmosphere research a key subject.
• 1886 Weather tower and wooden hut established on the summit.
• 1891 Rojacher dies and finances are threatened.
• 1892 The Sonnblick Verein is founded to finance the observatory.
• 1905 A summit temperature of −37.4 °C is recorded on 1 January.
• 1986 Government-funded renovation (another follows in 1994).

Key lessons for observation today

• Membership can fund a station The Sonnblick Verein kept the observatory alive after its founder's death. Diverse funders make a station more durable.
• Extreme sites need extreme sensors Rime and gales defeat ordinary sensors. Heated, ruggedised equipment and spares are the cost of working at altitude.
• Mountain stations sample the free atmosphere Above the boundary layer, the air is representative of a large region. Siting rules should say which air a station represents.

Sources

• Sonnblick Observatory, History
• Wikipedia, Hoher Sonnblick
• Schneefernerhaus, Deutscher Wetterdienst (GAW-DACH cooperation)