Written in EnglishRead online
Bibliography: p. 4.
|Series||Danish Meteorological Institute. Geophysical papers, R-16, Geofysiske meddelelser ;, R-16.|
|LC Classifications||QC801 .D45 no. R-16, QC971 .D45 no. R-16|
|The Physical Object|
|Number of Pages||17|
|LC Control Number||78599388|
Download The position of the auroral oval over Greenland and Spitzbergen.
The Aurora Borealis manifests itself in a huge ring above the Earth’s Geomagnetic North Pole which is referred to as the Auroral Oval. You might expect this oval to be visible from the same altitude around the globe but because it is centred on true north rather.
the auroral oval. 3 Auroral Oval Figure 2 is a downward view from above the north pole, showing the circles of dipole latitude and various time markers. The heavy line in Fig.
2 represents the projection on the earth's surface of the mean position of the auroral oval. This same line can also be interpreted as defining the inter. The auroral oval is the footprint in the atmosphere of the boundary between the highly stretched field lines of the polar cap and the more normal field lines at lower latitudes.
When the solar wind blows hard, this boundary moves equatorward - sometimes as far as Huntsville, Tel Aviv, or Kyoto - as more high latitude field lines are blown out.
During the First Polar Year, he made very high class visual auroral observations at Cap Thordsen, Spitzbergen. Figure 1 shows some of his results as presented in one of my papers [Alfvén, ] and in my book [Alfvén, ], where a more detailed discussion of the `auroral oval Cited by: 9. Auroral oval.
Auroral oval determines the range of polar lights. It is a belt around the magnetic poles of the Earth. Its width varies depending on the so-called space weather — during the periods of low solar activity it is getting narrow, and it is expanding when there is.
Abstract “The Poetic Edda” and “The King’s Mirror” are well preserved Norse documents from the period between and A.D. The latter states that the aurora was known to people living in Greenland but probably not observed in Norway at about A.D. Embedded in the auroral oval are discrete, small-scale structures with sizes ranging from a few hundred meters to a hundred kilometers that are in most cases east-west aligned auroral arcs [Borovsky, ].
These discrete arcs are more dynamic then the diffuse auroral oval itself and change size, shape, and location within seconds or minutes. A curve fitting procedure for mathematically representing the auroral oval is described.
It is shown that the Feldstein ovals and quiet auroral ovals of the night side in DMSP photographs can be approximated by an offset circle, plus a small (≲ 1° magnitude) Fourier component in. The position of auroral oval is also shown. HILAT scintillation over Spitsbergen effect leading to the increased scintillation intensity at the magnetic zenith.
The region of strongest scin- tillation intensity (SI > ) is located at the poleward boundary of the auroral oval, and extends into the dayside polar cap. Using the location of the inner and outer limits of the auroral oval obtained by Bond and Thomas (), Bond and Paine () provided a method of presenting the UT, 10 June Kp=1+ FIG.
THE MEAN AURORAL OVAL IN THE SOUTHERN HEMISPHERE FOR Kp = 1 PLOTTED IN GEOGRAPHIC COORDI- NATES FOR UT ON 10 JUNE The part of the northern hemisphere where the northern lights are most visible is known as the ' auroral oval ', which extends over northern Scandinavia, Alaska, Siberia and the whole of Canada.
Star Attraction: Fevv sights are more dramatic than a star-filled sky at night. Auroral Oval and Zone The pattern or distribution of auroral light around Earth's north and south magnetic poles.
The auroral oval expands and contracts over a period of hours and days, depending on geomagnetic activity. The auroral zone is about six degrees wide, centered on a magnetic latitude of 67°.
Auroral oval--the region in which aurora appears at the same time, corresponding to the. The Spin‐Scan Auroral Imager mounted on the Dynamics Explorer 1 satellite provides image data from towhich were used for this purpose. Geometrical analysis of the oval's intensity maximum for each image, transformed into quasi‐dipole coordinates, gives the center of the oval and its radius.
With This Ring When we look up and see the Northern Lights, we are only seeing a tiny section of a huge auroral oval.
Auroras form in rings centered over the Earth's Geomagnetic Pole - the pole of the Earth's geomagnetic field closest to the Geographic North Pole (True North). The geomagnetic field surrounds the Earth and extends into space as the magnetosphere, and the Geomagnetic Pole.
Cite this chapter as: Akasofu SI. () Auroras and Auroral Particles. In: Physics of Magnetospheric Substorms.
Astrophysics and Space Science Library (A Series of Books on the Recent Developments of Space Science and of General Geophysics and Astrophysics Published in Connection with the Journal Space Science Reviews), vol The brightness and location of the aurora is typically shown as a green oval centered on Earth’s magnetic pole.
The green ovals turn red when the aurora is forecasted to be more intense. The sunlit side of Earth is indicated by the lighter blue of the ocean and the lighter color of the continents. Wilhjelm: Ground Based Geomagnetic Measurements In Greenland with an Account of a Survey in and a General Summary of Observations Performed Since The Position of the Auroral Oval.
Accurate mapping of the auroral oval into the equatorial plane is critical for the analysis of aurora and substorm dynamics. Comparison of ion pressure values measured at low altitudes by Defense Meteorological Satellite Program (DMSP) satellites during their crossings of the auroral oval, with plasma pressure values obtained at the equatorial plane from Time History of Events and Macroscale.
Dynamics of aurorae in the cusp region (Spitzbergen and Heiss Isl.) on three days: Dec. 30, ; Dec. 17, ; Jan. 10, is studied. There is shown that the poleward motion of auroral arcs. Aurora is the result of the interaction between precipitating energetic electrons and protons with the upper atmosphere.
Viewed from space, it generally occurs in continuous and diffuse ovals of light around the geomagnetic poles. Additionally, there are localized regions of aurora that are unrelated to the ovals and exhibit different morphological, spatial, and temporal properties. The Earth’s two auroral ovals produce the Aurora Borealis in the northern hemisphere and the Aurora Australis in the southern hemisphere.
Of the two, the Aurora Borealis is better known simply because it passes over more populated areas. If penguins could talk then the Aurora Australis would be just as famous.
The Auroral Oval in the Northern Hemisphere From the ground the aurora can usually seen at night on Earth at the latitudes shown in this image. Those latitudes span Fairbanks, Alaska, Oslo, Norway, and the Northwest Territories.
This compilation of Spitsbergen webcams shows what it looks like in different parts of Spitsbergen right now. It includes a map that shows the location of the camera (if known).
The link “show webcam” will open a frame with the webcam. The copyright of the webcam-images remains with the respective owner or operator. Longyearbyen. Poring over a map, it was clear Jan Mayen Island, Spitsbergen, and Greenland were among the best locations for gathering and sending weather data.
All were in the Arctic regions where European weather fronts form, and all were remote enough to give the Germans at least a hope of success. In addition, weather stations were already in place. Greenland is a fantastic place to check out the Northern lights.
The country is located in a place which makes the Aurora Borealis as clear as possible, between the months of August and April. Moreover, Greenland itself is an incredible country packed with tons to see and places to explore. The area of most frequent and concentrated auroral events, called the “auroral oval,” is not centered over Earth’s geographic pole (the North Pole as marked on a globe, where the lines of longitude converge).
Instead they are centered over Earth’s geomagnetic pole, which is the point on Earth’s surface above the natural magnetic field. An aurora (plural: auroras or aurorae), sometimes referred to as polar lights (aurora polaris), northern lights (aurora borealis), or southern lights (aurora australis), is a natural light display in the Earth's sky, predominantly seen in high-latitude regions (around the Arctic and Antarctic).
Auroras are the result of disturbances in the magnetosphere caused by solar wind. The world’s brightest aurora doesn’t necessarily occur in the very highest latitudes, but rather in an oval about 20 degrees around the magnetic North Pole.
This means that with clear skies, darkness, patience, preparation, and a little luck, some of the world’s best northern lights can be seen in Greenland. We have analyzed the role of auroral processes in the formation of the outer radiation belt, considering that the main part of the auroral oval maps to the outer part of the ring current, instead of the plasma sheet as is commonly postulated.
In this approach, the outer ring current is the region where transverse magnetospheric currents close inside the magnetosphere. The aurora is beautiful, spectacular, splendid, and appears quite frequently – almost nightly in the polar sky.
Appearing in the form of majestic, colourful, irregular lights in the night sky, the aurora has a variety of shapes, colours, and structures, and continuously changes in time.
The solar wind is the start of Earth's auroral energy. The others are the magnetic field and the interaction of that field with molecules in the upper atmosphere which causes visible light. Alaska. Where to go: In Alaska, Fairbanks is a popular hub for northern lights tourism thanks to its international airport and its prime position under the “aurora oval”—a ring-shaped zone where aurora activity is city is located approximately miles south of the Arctic Circle and sits north of Denali National Park, which makes it an accessible base from which to travel.
Auroral displays can also be seen over the southern tip of Greenland and Iceland and over the coastal waters north of Siberia. Southern auroras are not often seen as they are concentrated in a ring around Antarctica and the southern Indian Ocean.
The auroral oval is the footprint in the atmosphere of the boundary between the highly stretched field lines of the polar cap and the more normal field lines at lower latitudes. When the solar wind blows hard, this boundary moves equatorward – sometimes as far as Huntsville, Tel Aviv, or Kyoto – as more high latitude field lines are blown.
On Matwo rockets were launched from Soendre Stroemfjord, Greenland, into the dusk auroral oval. Three trimethyl aluminium trails were released to measure the neutral wind profiles between 95 and km of altitude at two points separated by km normal to the invariant latitude circles and at a third point separated from the first two by km along the invariant latitude circles.
Right: A composite of UVI views of the aurora borealis - seen from space - is on the cover of the Oct. 15 Geophysical Research Letters. It shows a small notch in the auroral oval above the tip of Greenland, which then was at local midnight. Credit: Damien Chua, University of Washington, and the American Geophysical Union.
around the magnetic poles of the Earth. These rings are known as auroral ovals. The northern oval traces a path across central Alaska and Canada, Greenland, and northern Scandinavia and Russia. In the southern hemisphere, the auroral oval hovers mostly over the oceans circling Antarctica, but it can occasionally reach the far edges of New Zealand.
Parameter: Mathematical representation of the auroral oval Brief Description: Holzworth and Meng () provide a parameterization of the Feldstein () auroral ovals. Feldstein specified seven different ovals for seven levels of magnetic activity. The model describes the Corrected Geomagnetic Latitude (CGL) of the equatorward and polward.
Baly (21), making use of the observations of the Russian expedition in Spitsbergen inaccepts as the wave-lengths of the three principal auroral lines o, and ; and he identifies all three and ten other auroral lines ranging between and with krypton lines measured by.
The aurora isn't constant; it is always on the move. The auroral oval can be regarded as fixed in space with reference to the sun. As the earth revolves underneath, the daily variations in the aurora's position occur.
Observing the aurora is a test of your patience and the aurora itself. Possibly Spitzbergen. Spitzbergen is Norwegian land, and is entirely inside the Arctic Circle. Norway, except for a tiny strip at it's northernmost end, is below the arctic circle.Spitsbergen offers you an authentic Arctic experience in the realm of the Polar Bear.
Participate in exciting excursions in spectacular surroundings. Harness your own dogs and mush into the wilderness, track the northern lights by snowcat, snowmobile or husky, delve in ice caves under the frozen glacier.Two rocket payloads launched from Greenland in December and January into the dayside auroral oval measured large scale electric fields.
Sunward convection in regions of polar cusp type particle precipitation argues for the existence of a turbulent entry region at the magnetopause.