Observatory data as a proxy of space weather parameters: The importance of historical archives

0481984 - GFÚ 2018 RIV IN eng J - Journal Article
Hejda, Pavel
Observatory data as a proxy of space weather parameters: The importance of historical archives.
Journal of Indian Geophysical Union. Roč. 20, Č. 2 (2016), s. 47-53. ISSN 0257-7968
R&D Projects: GA MŠMT LM2010008
Institutional support: RVO:67985530
Keywords : geomagnetic observatory * geomagnetic indices * sunspot members * space weather
OECD category: Physical geography

Old geomagnetic observations are traditionally understood to be an important source of information about the structure and temporal behaviour (secular variation) of the internal geomagnetic field. A compilation of geomagnetic data from various parts of the world, recorded over several years allowed Gauss (1839) to separate the magnetic field into its parts of internal and external origin, and to prove that most of the geomagnetic field was of internal origin. Each day satellites produce a huge amount of data on processes on the Sun, in the solar wind and in the Earth's environment, however, their span of operation is too short to allow for understanding of these processes and changes therein in the long term. On the other hand, geomagnetic observatories have been in operation for about 180 years. Back ward reconstruction of solar processes may be possible based on the time series of various indices derived from observatory data that reflect responses to different combinations of solar wind parameters. Thus, digitization of these analogue observatory records and their printed records has become nowadays an exigent task. This paper contains a historical review of magnetic studies and measurements since the 16th century, followed by a case study in digitizing old magnetograms from the Prague-Clementinum Observatory. The problems connected with digitization, scaling and further processing of the data are discussed and preliminary results presented.
Permanent Link: http://hdl.handle.net/11104/0277404