CMYK RGB Hist. Geo Space Sci., 3, 53–72, 2012 History of www.hist-geo-space-sci.net/3/53/2012/ Geo- and Space doi:10.5194/hgss-3-53-2012 © Author(s) 2012. CC Attribution 3.0 License. Access Open Sciences Advances in Science & Research Sophus Peter Tromholt: an outstanding pioneerOpen inAccess Proceedings auroral research Drinking Water Drinking Water K. Moss1 and P. Stauning2 Engineering and Science Engineering and Science 1Guldborgvej 15, st.tv., 2000 Frederiksberg, Denmark Open Access Access Open Discussions 2Danish Meteorological Institute (emeritus), Lyngbyvej 100, 2100 Copenhagen, Denmark Correspondence to: K. Moss (
[email protected]) Discussions Earth System Earth System Received: 14 November 2011 – Revised: 12 February 2012 – Accepted: 18 February 2012 – Published: 7 March 2012 Science Science Abstract. The Danish school teacher Sophus Peter Tromholt (1851–1896) was self-taught in physics, astron- Open Access Open omy, and auroral sciences. Still, he was one of the brightest auroral researchers of the 19th century.Access Open Data He was the Data first scientist ever to organize and analyse correlated auroral observations over a wide area (entire Scandinavia) moving away from incomplete localized observations. Tromholt documented the relation between auroras and Discussions sunspots and demonstrated the daily, seasonal and solar cycle-related variations in high-latitude auroral oc- currence frequencies. Thus, Tromholt was the first ever to deduce from auroral observations theSocial variations Social associated with what is now known as the auroral oval termed so by Khorosheva (1962) and Feldstein (1963) Open Access Open Geography more than 80 yr later. He made reliable and accurate estimates of the heights of auroras several decadesAccess Open Geography before this important issue was finally settled through Størmer’s brilliant photographic technique.