[en] Analysis of hydrogen emissions in pulsating aurora indicates that the periods of the pulsations are correlated with Hβ intensity. The pulsation periods are short (a few seconds) at low Hβ intensity and increase with increasing Hβ emissions. The change in the period appears to be mainly due to a variation in the time between individual pulses. In most of the data recorded at Poker Flat Research Range, Alaska (geomagnetic latitude 64.5^o), the pulsating aurora was south of the main region of the proton aurora. However, on two nights pulsations were also observed within the proton aurora main region, and these pulsations were of short period and the period varied less with Hβ intensity

[en] The spatial scanning camera used on the STS-41-G mission is briefly described and some initial results from the images are presented. It is concluded that the ram-glow on the 41-G mission was significantly less than that recorded on previous shuttle flights. The airglow images suggest that it should be possible to derive atmospheric temperatures when using more sophisticated instrumentation planned for future shuttle and other satellite flights

[en] Studies of the relationship between auroral and concurrent geomagnetic pulsations, PiC, in the auroral zone are reviewed, focusing on the most recent developments. It is concluded that magnetic pulsations observed on the ground are caused by temporal and spatial enhancemnents of the electric conductivity produced by pulsating precipitation of auroral electrons in the ionosphere. The relationship between auroral and concurrent magnetic pulsations has now been firmly established, not only for the magnetic pulsations on the ground, but also for those observed by a low altitude satellite above the ionosphere

[en] The altitude and the altitude distribution of auroral emissions are one of the results of processes in the ionosphere and in the magnetosphere during auroral activity. A bistatic system has been developed to determine the altitude and the altitude distribution of different auroral emissions in the magnetic meridian plane through EISCAT's transmitting station in Norway. The system makes use of intensified one-dimensional photodiode arrays. In April 1985 the first measurements were made. Initital results, system characteristics and system configuration are reported

[en] Dynamics of dayside auroras, including cusp emissions, and their relation to the interplanetary magnetic field (IMF) have been investigated by optical ground-based observations from Svalbard, Norway, and IMF data from various satellites. Combined with the Svalbard program, simultaneous night-side observations from Alaska provide information on the large-scale behaviour of the auroral oval. Drift characteristics, spatial scale, time of duration and repetition frequency of auroral structures on the day-side, occuring at the time of large-scale oval expansions (IMF B_z < 0), are observed to be consistent with expected optical signatures of plasma entry from the magnetosheath, in association with flux transfer events. One case is presented, showing magnetic signatures (the DPY component) and their latitudinal location relative to polar cap and cusp emissions, for IMF B_z positive and negative values

[en] The Skylark 12 rocket contained one hydrogen resonance cell built by the Max-Planck Institute in Lindau, FRG. The paper deals with the Lyman-α observations obtained by this cell

[en] The LeCroy MVL 100 pulse amplifier/discriminator (PAD) has been evaluated for use in single photon counting. The following properties have been studied: Count rate (N) as a function of photon flux (Φ) when used with an EMI 9924B photomultiplier; pulse pair resolution time; power requirements; and necessary additional components. The pulse amplifier has been found to be reliable, fast, and small. The circuit diagram and the printed circuit board layout are shown

[en] This review provides a summary of the principal auroral and airglow emission features and the processes responsible for their excitation. Processes for which our current understanding is incomplete are discussed in more detail

[en] Spectrometric and photometric techniques for the infrared part of the spectrum are used at the University of Wuppertal to obtain several parameters of the upper atmosphere. The long-term behaviour of mesopause temperatures were studied with two ground-based spectrometers. The temperatures were caluculated from the intensity-ratios of the OH(3.1)-P branch lines at about 1.5 μm. Using spectral analysis techniques, the variations of the upper mesosphere temperatures were analysed. Significant variations were found with periods of 4 to 6 days and of 10 to 20 days. The correlation of temperature variations in the stratosphere and upper mesosphere was examined. Latitudinal gradients of temperatures were also considered and compared with a reference atmosphere model

[en] Since Norway is located in and close to the belt of maximum auroral occurrence, this may explain why Norwegian scientists have made such a significant contribution in auroral research. This, however, does not explain why Norwegians have been more active in this field than scientists in our neighboring countries. The same is even true in meteorology. Thus, it seems that Norwegians have concentrated on ''outdoor'' natural sciences. K.O. Birkeland, F.M. Stoermer and L. Vegard were the first to apply precise methods to study aurora and associated phenomena. They were also the first to propose a realistic theory and to calculate the motion of fast electrons from the Sun to the Earth's polar atmosphere. Through their research, these pioneers discovered many new effects and laid the foundation of our present-day exploration of aurora from space