Why do auroral substorms occur?
Why do auroral substorms occur?
The magnetic fields in the magnetotail become stretched and then ‘pinch’ together in a process known as magnetic reconnection. This releases energy and accelerates charged particles back towards Earth to create what scientists refer to as the auroral substorm.
Why do substorms occur?
A substorm begins when a near-Earth reconnection re- gion, or X-line, is formed (1), causing a disruption of the cross- tail current and an expansion of the plasma sheet earthward of the X-line. Tailward of the X-line, the plasma sheet quickly thins.
What is the difference between geomagnetic storms and substorms?
The magnetic storms are characterized by the Dst (disturbance storm time) index of geomagnetic activity. The substorms, on the other hand, are characterized by geomagnetic AE (auroral electrojet) index. Magnetic reconnection plays an important role in energy transfer from solar wind to the magnetosphere.
Where do substorms originate in the Earth’s magnetosphere?
Substorms are initiated in the nightside magnetosphere on closed magnetic field lines. As a consequence, it is generally thought that auroral substorms should occur in both hemispheres on the same field line (i.e., magnetically conjugated).
Do other planets experience auroras?
Do other planets have auroras? Any planet with a sufficiently dense atmosphere that lies in the path of the solar wind will have auroras. Auroras have been photographed on Jupiter, Saturn, and even on some planets’ moons. Our moon doesn’t have an aurora because it doesn’t have the requisite atmosphere.
What kind of problems can these magnetic substorms cause?
Because the ionosphere is heated and distorted during storms, long-range radio communication that relies on sub-ionospheric reflection can be difficult or impossible and global-positioning system (GPS) communications can be degraded.
What is a magnetic substorm?
A substorm, sometimes referred to as a magnetospheric substorm or an auroral substorm, is a brief disturbance in the Earth’s magnetosphere that causes energy to be released from the “tail” of the magnetosphere and injected into the high latitude ionosphere.
What is magnetic storm and magnetospheric substorm?
Does aurora mean Rose?
The name Aurora is primarily a female name of Latin origin that means Dawn. Aurora Borealis is a name for the Northern Lights. Nicknames for Aurora include Arie, Rory, and Aura. The most famous fictional Aurora is Princess Aurora from Disney’s Sleeping Beauty also known as Briar Rose.
Which planet has no aurora borealis?
Unfortunately, Mercury is too small and too close to the sun for it to retain an atmosphere, meaning the planet doesn’t have any molecules for the solar wind to excite and that means no auroras.
What would happen if there was a geomagnetic storm?
It has been suggested that a geomagnetic storm on the scale of the solar storm of 1859 today would cause billions or even trillions of dollars of damage to satellites, power grids and radio communications, and could cause electrical blackouts on a massive scale that might not be repaired for weeks, months, or even …
When was the last time a solar flare hit the Earth?
The Solar Dynamics Observatory recorded an X9. 3-class flare at around 1200 UTC on September 6, 2017. On July 23, 2012, a massive, potentially damaging, solar storm (solar flare, coronal mass ejection and electromagnetic radiation) barely missed Earth.
What happens to the auroral oval during a substorm?
During a substorm the auroral oval brightens in a localized area and then suddenly breaks into many different forms that expand both toward Earth’s pole and equator. This is exactly what Shun-ichi Akasofu (1964) drew in his auroral substorm illustration.
How are Dawn storms different from other auroras?
As observed from the Hubble Space Telescope (HST), having only access to the Earth-facing side of the aurora, they consist of a thickening and a major enhancement of the brightness of the dawn arc of the main auroral emission (main oval).
Which is the best description of a substorm?
Visually, a substorm is seen as a sudden brightening and increased movement of auroral arcs. Substorms were first described in qualitative terms by Kristian Birkeland which he called polar elementary storms. Sydney Chapman used the term substorm about 1960 which is now the standard term.
Are there any auroral substorms on Jupiter’s Nightside?
Here, we report on the imaging of all development stages of spectacular auroral events at Jupiter, called dawn storms, including, for the first time, their initiation on the nightside. Our results reveal surprising similarities with auroral substorms at Earth, which are auroral events stemming from explosive magnetospheric reconfigurations.