Digitization of sunspot drawings

Objective

Since 2016 the ETH Zurich University Archives and the DigiCenter have been indexing and digitizing sunspot activity records, which began at the Eidgenössische Sternwarte in 1884. In 1957 ETH Zurich established an observatory in Locarno-Monti. Until 1980 this solar observatory, an ETH Zurich outpost situated south of the Alps, was one of three suppliers of drawings, photographs and data for the realisation of ETH Zurich’s solar observations. When the Sternwarte was closed in 1980 and the systematic observation of sunspots was stopped at ETH Zurich, the series of observations was continued in Locarno, supervised by the newly founded Associazione Specola Solare Ticinese (ASST) instead of ETH Zurich.

The project’s goal

• archival description of ASST’s original records on sunspot activity from 1981 to 2017.
• archival description and digitization of the original records on sunspot activity from the observatory Locarno-Monti - from 1957 to 2017 and publication via external page e-manuscripta.ch
• preparation and publication of the digital database with sunspot data for the period 1957 to 2017 by the ASST.
• long-term Preservation of sunspot group data from the ASST database at the ETH Data Archive 

Context

In current climatology research, this series of measurements is especially important due to its use in the long-term reconstruction of solar radiation, as the number of sunspots correlates strongly with the total solar radiation. Moreover, the records help validate models of solar activity and thus improve our understanding of past and future solar activity. The importance of these records in a climatological context is also evident in the fact that the observations of sunspots in the recently published implementation plan of the Global Climate Observing System (GCOS) were recognised as a valuable source of information for climate studies.

Description

Thanks to funding from MeteoSchweiz within the scope of GCOS Schweiz and in collaboration with the ASST, the ETH Zurich University Archives and DigiCenter will catalogue and digitize the sunspot records from 1957 to 2017 in a five-year project, and render them digitally accessible to the public on e-manuscripta.ch. The FDD team is also involved in the project and responsible for the long-term preservation of the data on sunspot groups from the ASST database in the ETH Data Archive.Klimabeobachtungssystems GCOS (Global Climate Observing System) als wertvolle Informationsquelle für Klimastudien anerkannt wurden.