scholarly journals Spectral observations of transient features in the FUV Jovian polar aurora

2003 ◽  
Vol 108 (A8) ◽  
Author(s):  
J.-C. Gérard
Keyword(s):  
Polar Aurora

The Near Infra-Red Spectrum of the Polar Aurora

1950 ◽  
Vol 77 (5) ◽  
pp. 720-720 ◽  
Author(s):  
W. Petrie
Keyword(s):  
Infra Red ◽  
Polar Aurora

HEIGHT OF THE POLAR AURORA IN CANADA

1931 ◽  
Vol 5 (3) ◽  
pp. 285-296 ◽  
Author(s):  
J. C. McLennan F.R.S. ◽  
H. S. Wynne-Edwards ◽  
H. J. C. Ireton
Keyword(s):  
Maximum Frequency ◽  
Northern Ontario ◽  
The Mean ◽  
Polar Aurora ◽  
Lower Limits

Simultaneous photographs of the polar aurora were made at two stations in northern Ontario, Canada, and from them a number of values for the height and position were obtained. For the lower limits of arcs and bands these ranged between 70 and 130 km. with a maximum frequency between 90 and 95 km. The mean height for all such lower limits was 95 km. The distribution of the points with reference to the earth's surface is shown.

scholarly journals On the action of ultra-violet sunlight upon the upper atmosphere

1937 ◽  
Vol 160 (901) ◽  
pp. 155-173 ◽  
Keyword(s):  
Wave Length ◽  
Charged Particles ◽  
Solar Spectrum ◽  
Ultra Violet ◽  
Magnetic Storms ◽  
Upper Atmosphere ◽  
The Sun ◽  
Polar Aurora ◽  
Night Sky ◽  
Photochemical Action

The ordinary solar spectrum extends, as is well known, to about λ2913, the more ultra-violet parts being cut off by ozone absorption in the upper atmosphere. We have thus no direct knowledge of the distribution of intensity in the solar spectrum beyond λ2913, as it will appear to an observer situated outside the atmosphere of the earth. But it is now recognized that a number of physical phenomena is directly caused by the photochemical action of this part of sunlight on the constituents of the upper atmosphere. Such phenomena are (1) the luminous spectrum of the night sky and of the sunlit aurora, (2) the ionization in the E, F and other layers which is now being intensely studied by radio-researchers all over the world, (3) the formation and equilibrium of ozone (see Ladenburg 1935), (4) magnetic storms and generally the electrical state of the atmosphere. Formerly it was a debatable point whether some of these phenomena were not to be ascribed to the action of streams of charged particles emanating from the sun. There seems to be no doubt that the polar aurora and certain classes of magnetic storms are to be ascribed to the bombardment of molecules of N 2 and O 2 by such charged particles, for these phenomena show a period which is identical with the eleven year period of the sun, and are found in greater abundance, the nearer we approach the magnetic poles. But there now exists no doubt that the ionization observed by means of radio-methods in the E and F 1 regions, their variation throughout day and night, and at different seasons is due to the action of ultra-violet sunlight. This was decisively proved by observations during several total solar eclipses since 1932 (Appleton and Chapman 1935). The luminous night-sky spectrum, though it has certain points of similarity to the polar aurora, is on the whole widely different, and is found on nights free from electrical disturbances. The prevailing opinion is that it is mainly due to the ultra-violet solar rays, i. e. in the course of the day sunlight is stored up by absorption by the molecules in the upper atmosphere, and again given up during the night, in one or several steps, as a fluorescence spectrum. According to S. Chapman (1930) the formation of the ozone layer and its equilibrium under different seasonal conditions is also to be mainly ascribed to the action of ultra-violet sunlight. In the following paper an attempt will be made to discuss some of these questions in as rigorous a way as is possible with our present knowledge. It is evident that an adequate discussion is possible only if we have a good knowledge of (1) the distribution of intensity in the solar spectrum beyond λ2900, (2) the photochemical action of light of shorter wave-length than λ2900 on the constituent molecules of the upper atmosphere, which are mainly oxygen and nitrogen. We shall first consider (1).

The morphology of the polar aurora

1960 ◽  
Vol 65 (10) ◽  
pp. 3497-3500 ◽  
Author(s):  
T. Neil Davis
Keyword(s):  
Polar Aurora

Jupiter’s polar auroral bright spots as seen by Juno-UVS

2020 ◽  
Author(s):  
Kamolporn Haewsantati ◽  
Bertrand Bonfond ◽  
Suwicha Wannawichian ◽  
George R Gladstone
Keyword(s):  
Hubble Space Telescope ◽  
Bright Spot ◽  
Time Interval ◽  
Systematic Analysis ◽  
X Ray ◽  
Bright Spots ◽  
Polar Aurora ◽  
The Difference ◽  
Magnetospheric Cusp ◽  
First Time

<p>The instruments on board the NASA Juno mission provides scientists with a wealth of unprecedented details about Jupiter. In particular, the Ultraviolet Spectrograph (UVS) is dedicated to the study of Jupiter’s aurora in the 60-200 nm wavelength range. The images taken by Juno-UVS reveals for the first time a complete view of Jupiter’s aurora, including the nightside part hidden from the Earth-orbiting Hubble Space Telescope (HST). This work aims to study Jupiter’s polar aurora using images obtained from the UVS instruments. Here we present the systematic analysis of one of the most spectacular features of Jupiter’s polar-most aurora, called the bright spot. The emitted power of the bright spots ranges from a few to a hundred GWs. Within a Juno perijove, the spots reappear at almost the same positions in system III. The time interval between two consecutive brightenings is a few tens of minutes, comparable to Jupiter’s X-ray pulsation. The comparison of the time interval with X-ray observation is under the investigation. Comparing the difference perijove sequences, the system III positions of bright spots in the northern hemisphere are concentrated in a region around 175 degrees of system III longitude and 65 degrees of latitude. On the other hand, the positions of bright spot aurora the southern hemisphere are scattered all around the pole. Previous studies suggested that the bright spot could correspond to noon facing magnetospheric cusp. However and surprisingly, we have discovered that the bright spots could map to any magnetic local time, putting this interpretation into question.</p>

An observation of polar aurora and airglow from the ISIS-II spacecraft

1973 ◽  
Vol 21 (5) ◽  
pp. 819-829 ◽  
Author(s):  
G.G. Shepherd ◽  
C.D. Anger ◽  
L.H. Brace ◽  
J.R. Burrows ◽  
W.J. Heikkila ◽  
...  
Keyword(s):  
Polar Aurora
Sign in / Sign up

Export Citation Format

Share Document