Danish auroral science history

摘要

Danish auroral science history begins with the early auroralobservations made by the Danish astronomer Tycho Brahe during the years from1582 to 1601 preceding the Maunder minimum in solar activity. Included arealso the brilliant observations made by another astronomer, Ole R?mer,from Copenhagen in 1707, as well as the early auroral observations made fromGreenland by missionaries during the 18th and 19th centuries. Therelations between auroras and geomagnetic variations were analysed by H. C. ?rsted, who also played a vital role in the development of Danishmeteorology that came to include comprehensive auroral observations fromDenmark, Iceland and Greenland as well as auroral and geomagnetic research.The very important auroral investigations made by Sophus Tromholt areoutlined. His analysis from 1880 of auroral observations from Greenlandprepared for the significant contributions from the Danish MeteorologicalInstitute, DMI, (founded in 1872) to the first International Polar Year1882/83, where an expedition headed by Adam Paulsen was sent to Greenland toconduct auroral and geomagnetic observations. Paulsen's analyses of thecollected data gave many important results but also raised many newquestions that gave rise to auroral expeditions to Iceland in 1899 to 1900and to Finland in 1900 to 1901. Among the results from these expeditionswere 26 unique paintings of the auroras made by the artist painter, HaraldMoltke. The expedition to Finland was headed by Dan la Cour, who later asdirector of the DMI came to be in charge of the comprehensive internationalgeomagnetic and auroral observations made during the Second InternationalPolar Year in 1932/33. Finally, the article describes the importantinvestigations made by Knud Lassen during, among others, the InternationalGeophysical Year 1957/58 and during the International Quiet Sun Year (IQSY)in 1964/65. With his leadership the auroral and geomagnetic research at DMIreached a high international level that came to be the background for thefirst Danish satellite, ?rsted, successfully launched in 1999 and stillin operation.