The Geophysical Observatory in Sodankylä, Finland – past and present

After a preface, we will first try to depict the history of the Geophysical Observatory in Sodankylä (SGO) by referring to the personalities who have run and have shaped the observatory. Thereafter, we describe the history from a technical point of view, i.e., what the measurements were, and which instruments were primarily used at the observatory. We will also refer to present operational forms and techniques. We start with the very first systematic meteorological and geophysical observations made in Finland and end by referring to the involvement in ongoing international scientific programs.