Stubbe, P.; Kopka, H.: Stimulated electromagnetic emission in a magnetized plasma: A new symmetric spectral feature. Physical Review Letters 65, pp. 183 - 186 (1990)
Derblom, H.; Thidé, B.; Leyser, T. B.; Nordling, J. A.; Hedberg, Å.; Stubbe, P.; Kopka, H.; Rietveld, M. T.: Tromsø heating experiments: Stimulated emission at HF pump harmonic and subharmonic frequencies. Journal Geophysical Research 94, pp. 10111 - 10120 (1989)
Rietveld, M. T.; Stubbe, P.; Kopka, H.: On the frequency dependence of ELF/VLF waves produced by modulated ionospheric heating. Radio Science 24, pp. 270 - 278 (1989)
Barr, R.; Rietveld, M. T.; Stubbe, P.; Kopka, H.: Ionospheric heater beam scanning: A realistic model of this mobile source of ELF/VLF radiation. Radio Science 23, pp. 379 - 388 (1988)
Wright, J. W.; Kopka, H.; Stubbe, P.: A large-scale ionospheric depletion by intense radio wave heating. Geophysical Research Letters 15, pp. 1531 - 1533 (1988)
Barr, R.; Rietveld, M. T.; Stubbe, P.; Kopka, H.: Ionospheric heater beam scanning: A mobile source of ELF radiation. Radio Science 22, pp. 1073 - 1083 (1987)
Kohl, H.; Kopka, H.; La Hoz, C.; Stubbe, P.: Propagation of artificially excited Langmuir waves in the ionosphere. Radio Science 22, pp. 655 - 661 (1987)
Rietveld, M. T.; Mauelshagen, H.-P.; Stubbe, P.; Kopka, H.; Nielsen, E.: The characteristics of ionospheric heating-produced ELF/VLF waves over 32 hours. Journal Geophysical Research 92, p. 8707 (1987)
Rietveld, M. T.; Stubbe, P.: Ionospheric demodulation of powerful pulsed radio waves: A potential new diagnostics for radars suggested by Tromsø heater results. Radio Science 22, pp. 1084 - 1090 (1987)
Barr, R.; Stubbe, P.; Rietveld, M. T.; Kopka, H.: ELF and VLF signals radiated by the ``Polar Electrojet Antenna'': Experimental results. Journal Geophysical Research 91, pp. 4451 - 4459 (1986)
Barr, R.; Stubbe, P.; Rietveld, M. T.; Kopka, H.: ELF and VLF signals radiated by the "Polar Electrojet Antenna": experimental results. Journal Geophysical Research 91, pp. 4451 - 4459 (1986)
Hanuise, C.; Hedberg, A.; Oksman, J.; Nielsen, E.; Stubbe, P.; Kopka, H.: Comparison between the ionospheric plasma drift and the motion of artificially induced irregularities as observed by HF backscatter radars. Annales Geophysicae 4, p. 49 (1986)
Hedberg, Å.; Derblom, H.; Hamberg, G.; Thidé, B.; Kopka, H.; Stubbe, P.: Measurements of HF backscatter cross section for striations created by ionospheric heating at different power levels. Radio Science 21, pp. 117 - 125 (1986)
Solar Orbiter is the first space probe to look at the Sun's poles – and finds the magnetic field there in a state of turmoil. The Sun's magnetic field is currently undergoing a flip.
First Light! The spectro-polarimeter of the world's largest solar telescope in Hawaii looks at the Sun for the first time. The instrument was developed in Germany.
Dr. Theodosios Chatzistergos receives award by the European Space Weather and Space Climate Association for his research findings on the historical activity of the Sun.
The Zdenĕk Švetska Senior Prize of the Solar Physics Division of the European Physical Society (EPS) recognizes Solanki’s pioneering contributions to solar research.