Danish Arctic Ionosphere Research

Abstract

The Danish Meteorological Institute celebrated its centennial on 1 April this year and on the same date the Ionosphere Laboratory, a division under the Meteorological Institute, observed its tenth anniversary, although its history goes back almost twenty years. The idea of establishing an Ionosphere Laboratory was first conceived by the active and foresighted Professor P. O. Pedersen .... During the Second Polar Year 1932-33 Pedersen wanted to build an ionosphere station in Godhavn ... but it was not until 1951 that his wish was fulfilled by his assistant and later successor, Professor Jørgen Rybner. The year before, the U.S. Department of Commerce's National Bureau of Standards had established an ionosphere station at the American military base in southern Greenland and in 1957 when the U.S. Armed Forces left what is now called Narssarssuaq, Professor Rybner also undertook the responsibility for this station in his capacity as the Chairman of the Danish National Committee of the International Radio Union (URSI). It was realized that operation of the Greenlandic stations would only be feasible if there were an active group in Copenhagen to analyze the ionosphere data obtained and to train the station personnel before leaving for Greenland. To fill this need Professor Rybner founded a laboratory at the Technical University based upon support from local URSI funds. At the same time rapid technological development made possible measurements in the ionosphere with instruments launched with rockets or from satellites. Using the resources at the new laboratory, Professor Rybner in 1961 accepted a Norwegian proposal for a joint campaign with rocket launchings from Andøya in Lofoten, Norway, in cooperation with the National Aeronautics and Space Administration (NASA). This project formed the basis later for a Greenlandic ionosphere rocket program. ... it was deemed desirable to change the laboratory supported under the Danish URSI Committee to an official laboratory under the Technical University of Denmark. ... on 1 April 1962 the Ionosphere Laboratory was established at the University .... Recordings of naturally generated electromagnetic noise at very low frequencies (VLF recordings), and studies had been made at Godhavn and Narssarssuaq for some years when , in 1964, a "VLF-station" was established at the Danish site Thule, approximately 80 miles north of Thule Air Base [AB]. Financial support was given by the U.S. National Science Foundation (NSF) and locally by the U.S. Army Research Support Group (USARSG). When in 1966 the American scientific camp situated approximately 16 miles east of Thule AB was closed down, the U.S. ionosphere station there was transferred to the Danish station at Thule; an ionosonde was made available from the U.S.A. and a building of 150 sq. m. was moved from the camp to the station by helicopter! The U.S. National Science Foundation supported the operation for the following three years until the Danish Government took over financial responsibility. Between 1966 and 1968 the Ionosphere Laboratory was reorganized involving among other administrative changes the establishment of an independent Danish Space Research Institute for work with balloons, rockets and satellites. Today, ten years after it was officially established with a staff of four, the Laboratory with a staff of twenty, is continuing its ionospheric research based largely upon the operations of the Greenlandic observatories at Godhavn, Narssarssuaq, and Thule. Although it is administered and financed by the Danish Meteorological Institute, it is still located at the Technical University north of Copenhagen, and maintains close cooperation with other laboratories at the University in teaching and providing guidance to graduate students. [Included are summaries of research under the following headings: ground-based measurements, vertical soundings, cosmic noise absorption measurements, whistler and VLF emissions, auroral electrojet activity, the polar ionization, geomagnetic micropulsation studies, the polar slant E condition, stratospheric balloon measurements, high altitude meteorological observations, ionospheric rocket experiment, and electric field measurements].