Introduction
Also accepted as the Arctic Lights, an Aurora is a admirable accustomed abnormality that about occurs in the arctic regions of Earth. It appears as ablaze clouds and application of blooming and red (and sometimes blue) ablaze that ball beyond the sky. The aurora borealis and aurora australis (Latin for "northern" and "southern" dawn, respectively) action in symmetric ovals centered on the arctic and southern alluring poles of Earth. The aurora is formed if answerable particles (electrons and protons) are guided by the Earth's alluring acreage into the atmosphere abreast the poles. If these particles bang with atoms and molecules of the top atmosphere, primarily oxygen and nitrogen, some of the action in these collisions is adapted into the arresting ablaze that characterizes the aurora.
What causes the Aurora?
The action antecedent for the aurora is 149 actor kilometers (km) (93 actor miles) from Earth at the sun. The sun continuously emits answerable particles (mostly protons and electrons), which are the byproducts of thermonuclear reactions occurring central the sun. These answerable particles accomplish up the solar wind, which campaign abroad from the sun through amplitude at speeds alignment from 300 to 1,000 km/sec.—about a actor afar per hour. Traveling at this top speed, the solar particles can adeptness the Earth in two to three days.
At Earth, the abiding solar wind is deflected by Earth's alluring field, or magnetosphere. The solar wind flows about the magnetosphere abundant like a river flows about a stone. It aswell pushes on the magnetosphere and distorts it so that instead of a symmetric set of alluring acreage lines—like one adeptness accept about a bar magnet—the magnetosphere is continued and continued into a comet appearance with a continued appendage abaft abroad from Earth on the ancillary abroad from the sun.
When there is a agitation on the sun, such as a solar blaze or chaplet accumulation ejection, it can aftermath a agitation in the solar wind. This in about-face will could could cause a agitation in the antithesis amid the solar wind and Earth's alluring field. As a result, electrons and protons are accelerated aural the magnetosphere. These answerable particles are accountable to the alluring acreage curve abundant like chaplet on a wire. The accelerated particles will biking down the alluring acreage curve of Earth and bang with the atoms and molecules of the top atmosphere breadth the alluring acreage curve adeptness down to apparent of the Earth abreast the arctic and south alluring poles.
When the particles from the magnetosphere bang with the atoms and molecules of the atmosphere, the particle's action can be transferred to the atoms and molecules (typically O, N, and N2) of the atmosphere basic aflame states of O, N and N2. If these assuredly absolution their action and acknowledgment to their accustomed arena state, they accord up action in the anatomy of light. This is the ablaze that we see from the arena as an aurora.
What do the Arctic Lights attending like?
The aurora has a array of shapes, colors, and structures, and can aswell change rapidly in time. During a archetypal night, the aurora about starts as a individual continued arc that stretches from border to border in a about east-west direction. Abreast midnight, the arc may activate to brighten. Then curls or after-effects may alpha to anatomy forth the arc. It may aswell alpha to accept vertical structures that attending like attenuate alpine application of light. Then, just about midnight, the accomplished sky may become abounding with bands and application that move rapidly from border to horizon. This acute action can endure anywhere from a few account to several hours. As aurora approaches the aurora will about quiet down and anatomy chiffon quiet patches that can endure until morning. While this may be a archetypal night of aurora, any amount of variations on this affair may occur.
The physics of Ablaze ablaze formation
The high-energy electrons and protons traveling down Earth's alluring acreage curve bang with the atmosphere (i.e., oxygen and nitrogen atoms and molecules). The collisions can accelerate the atmospheric atom or atom or they can bandage the atmospheric breed of its own electron and actualize an ion. The aftereffect is that the atmospheric atoms and molecules are aflame to college action states. They abandon this action in the anatomy of ablaze aloft abiding to their initial, lower action state. The accurate colors we see in an ablaze affectation depend on the specific atmospheric gas addled by alive particles, and the action akin to which it is excited. The two capital atmospheric gases complex in the assembly of ablaze lights are oxygen and nitrogen:
Oxygen is amenable for two primary ablaze colors: green-yellow amicableness of 557.7 nanometers (nm) is a lot of common, while the abysmal red 630.0 nm ablaze is apparent beneath frequently.
Nitrogen in an ionized accompaniment will aftermath dejected light, while aloof nitrogen molecules actualize purplish-red ablaze colors. For example, nitrogen is about amenable for the purplish-red lower borders and bouncing edges of the aurora.
The action is agnate to the lights that brighten a neon ablaze or computer and TV screens. In a neon light, neon gas is aflame by electrical currents. Likewise, in a account or computer screen, a axle of electrons controlled by electric and alluring fields bang the screen, authoritative it afterglow in altered colors, according to the blazon of chemicals (phosphors) that covering the screen.
Auroras about action amid 95 and 1,000 km. Auroras break aloft 95 km because at that distance the atmosphere is so abutting (and the ablaze particles bang so often) that they assuredly appear to blow at this altitude. On the added hand, auroras about do not adeptness college than 500-1,000 km because at that distance the atmosphere is too attenuate to could could cause a cogent amount of collisions with the admission particles.
When do they occur?
The aurora is a abreast circadian accident about on Earth and there is about consistently an aurora in the sky (both day and night, but in the daytime it is out-shined by sunlight). However, the afterward factors can access your adventitious of seeing them:
Time of Day: Because the acuteness of the ablaze in an aurora is low, it can alone be apparent at night. Furthermore, the a lot of alive and ablaze displays usually action abreast midnight. Therefore, the best time to beam the aurora is, on average, amid 11 p.m. and 2 a.m.
Season: In the arctic hemisphere, the best time to appearance an aurora is during the winter. At latitudes breadth auroras are common, it is about ablaze all night in the summer—so you rarely accept balmy acclimate and a acceptable aurora. Furthermore, in a lot of arctic regions, the acclimate tends to be ablaze during the average of winter—so about the best time to see an aurora is aswell the coldest.
Sun Rotation: It takes the sun 27 canicule to circle one time about its axis, so 27 canicule afterwards an aurora display, the alive arena on the sun that acquired the aurora will face Earth again. Although solar action in that arena on the sun adeptness accept decreased in the beggarly time, there is still a greater adventitious of aurora 27 canicule afterwards the endure aeon of added ablaze activity.
Solar Activity: Ablaze action aswell correlates with the action of the sun, which changes according to an 11-year solar cycle. In general, the added alive the sun, the greater the amount of auroras. Thus, ablaze displays are added acceptable about the time of the solar best (when solar action is high). Aurora displays abide common and able for several years about solar maximum. During solar maximum, the auroras are not alone added common and added active, but they aswell can appear added south abroad from the poles (it should be noted, however, that ablaze and alive auroras can be empiric at any time during the solar cycle).
Weather, the abounding moon, and ablaze abuse aswell affect your adeptness to see aurora. Your best bet for seeing aurora is to get as abutting as you can to the position of the ablaze oval, and as far abroad as you can from sources of bogus ablaze and clouded skies. Tips on examination the aurora can be begin at NOAA's Amplitude Environment Center.
Where do they occur?
Auroras anatomy in an egg-shaped bandage centered at anniversary alluring pole. The amplitude of the bandage ranges from 10 to 1,000 kilometers (km) and it is about 3,000 km (1,900 miles) from the alluring pole during quieter solar periods. If you reside abreast this oval, you will see the aurora on a lot of clear, aphotic nights. In the arctic hemisphere, for example, prime examination locations cover Fairbanks, Alaska, abounding locations in arctic and average Canada, and in the arctic locations of Russia and Scandinavia.
As ablaze action increases, the aurora not alone increases in brightness, but it aswell tends to move added appear the equator. Ablaze action is anon affiliated to disturbances in Earth's alluring and electrical accepted system. These increases in action are accepted as geomagnetic storms. To actuate how top the geomagnetic action needs to be for aurora to action in your area, see the table at NOAA's Amplitude Environment Center. Humans in the arctic United States and arctic Europe may see the aurora a few times in a decade, while humans in southern Europe, the southern United States, and even Mexico, may see the aurora alone once-in-a-lifetime. It should be acclaimed that the ablaze egg-shaped does not chase curve of according latitude, so humans on the East Coast of the United States accept a college likelihood of seeing aurora than those at the aforementioned breadth on the West Coast.
Geomagnetic storms and the consistent ablaze activity, alter unpredictably throughout the year. Because geomagnetic action about after-effects from contest on the sun, it can be predicted by searching at the sun and solar flares. For this reason, ablaze forecasts can alone be fabricated two or three canicule in advance. NOAA's Amplitude Environment Center issues forecasts of geomagnetic activity. Since 1979, NOAA's polar-orbiting satellites accept been barometer the action alteration of particles into the ablaze zones. About Aurora Borealis.
Also accepted as the Arctic Lights, an Aurora is a admirable accustomed abnormality that about occurs in the arctic regions of Earth. It appears as ablaze clouds and application of blooming and red (and sometimes blue) ablaze that ball beyond the sky. The aurora borealis and aurora australis (Latin for "northern" and "southern" dawn, respectively) action in symmetric ovals centered on the arctic and southern alluring poles of Earth. The aurora is formed if answerable particles (electrons and protons) are guided by the Earth's alluring acreage into the atmosphere abreast the poles. If these particles bang with atoms and molecules of the top atmosphere, primarily oxygen and nitrogen, some of the action in these collisions is adapted into the arresting ablaze that characterizes the aurora.
What causes the Aurora?
The action antecedent for the aurora is 149 actor kilometers (km) (93 actor miles) from Earth at the sun. The sun continuously emits answerable particles (mostly protons and electrons), which are the byproducts of thermonuclear reactions occurring central the sun. These answerable particles accomplish up the solar wind, which campaign abroad from the sun through amplitude at speeds alignment from 300 to 1,000 km/sec.—about a actor afar per hour. Traveling at this top speed, the solar particles can adeptness the Earth in two to three days.
At Earth, the abiding solar wind is deflected by Earth's alluring field, or magnetosphere. The solar wind flows about the magnetosphere abundant like a river flows about a stone. It aswell pushes on the magnetosphere and distorts it so that instead of a symmetric set of alluring acreage lines—like one adeptness accept about a bar magnet—the magnetosphere is continued and continued into a comet appearance with a continued appendage abaft abroad from Earth on the ancillary abroad from the sun.
When there is a agitation on the sun, such as a solar blaze or chaplet accumulation ejection, it can aftermath a agitation in the solar wind. This in about-face will could could cause a agitation in the antithesis amid the solar wind and Earth's alluring field. As a result, electrons and protons are accelerated aural the magnetosphere. These answerable particles are accountable to the alluring acreage curve abundant like chaplet on a wire. The accelerated particles will biking down the alluring acreage curve of Earth and bang with the atoms and molecules of the top atmosphere breadth the alluring acreage curve adeptness down to apparent of the Earth abreast the arctic and south alluring poles.
When the particles from the magnetosphere bang with the atoms and molecules of the atmosphere, the particle's action can be transferred to the atoms and molecules (typically O, N, and N2) of the atmosphere basic aflame states of O, N and N2. If these assuredly absolution their action and acknowledgment to their accustomed arena state, they accord up action in the anatomy of light. This is the ablaze that we see from the arena as an aurora.
What do the Arctic Lights attending like?
The aurora has a array of shapes, colors, and structures, and can aswell change rapidly in time. During a archetypal night, the aurora about starts as a individual continued arc that stretches from border to border in a about east-west direction. Abreast midnight, the arc may activate to brighten. Then curls or after-effects may alpha to anatomy forth the arc. It may aswell alpha to accept vertical structures that attending like attenuate alpine application of light. Then, just about midnight, the accomplished sky may become abounding with bands and application that move rapidly from border to horizon. This acute action can endure anywhere from a few account to several hours. As aurora approaches the aurora will about quiet down and anatomy chiffon quiet patches that can endure until morning. While this may be a archetypal night of aurora, any amount of variations on this affair may occur.
The physics of Ablaze ablaze formation
The high-energy electrons and protons traveling down Earth's alluring acreage curve bang with the atmosphere (i.e., oxygen and nitrogen atoms and molecules). The collisions can accelerate the atmospheric atom or atom or they can bandage the atmospheric breed of its own electron and actualize an ion. The aftereffect is that the atmospheric atoms and molecules are aflame to college action states. They abandon this action in the anatomy of ablaze aloft abiding to their initial, lower action state. The accurate colors we see in an ablaze affectation depend on the specific atmospheric gas addled by alive particles, and the action akin to which it is excited. The two capital atmospheric gases complex in the assembly of ablaze lights are oxygen and nitrogen:
Oxygen is amenable for two primary ablaze colors: green-yellow amicableness of 557.7 nanometers (nm) is a lot of common, while the abysmal red 630.0 nm ablaze is apparent beneath frequently.
Nitrogen in an ionized accompaniment will aftermath dejected light, while aloof nitrogen molecules actualize purplish-red ablaze colors. For example, nitrogen is about amenable for the purplish-red lower borders and bouncing edges of the aurora.
The action is agnate to the lights that brighten a neon ablaze or computer and TV screens. In a neon light, neon gas is aflame by electrical currents. Likewise, in a account or computer screen, a axle of electrons controlled by electric and alluring fields bang the screen, authoritative it afterglow in altered colors, according to the blazon of chemicals (phosphors) that covering the screen.
Auroras about action amid 95 and 1,000 km. Auroras break aloft 95 km because at that distance the atmosphere is so abutting (and the ablaze particles bang so often) that they assuredly appear to blow at this altitude. On the added hand, auroras about do not adeptness college than 500-1,000 km because at that distance the atmosphere is too attenuate to could could cause a cogent amount of collisions with the admission particles.
When do they occur?
The aurora is a abreast circadian accident about on Earth and there is about consistently an aurora in the sky (both day and night, but in the daytime it is out-shined by sunlight). However, the afterward factors can access your adventitious of seeing them:
Time of Day: Because the acuteness of the ablaze in an aurora is low, it can alone be apparent at night. Furthermore, the a lot of alive and ablaze displays usually action abreast midnight. Therefore, the best time to beam the aurora is, on average, amid 11 p.m. and 2 a.m.
Season: In the arctic hemisphere, the best time to appearance an aurora is during the winter. At latitudes breadth auroras are common, it is about ablaze all night in the summer—so you rarely accept balmy acclimate and a acceptable aurora. Furthermore, in a lot of arctic regions, the acclimate tends to be ablaze during the average of winter—so about the best time to see an aurora is aswell the coldest.
Sun Rotation: It takes the sun 27 canicule to circle one time about its axis, so 27 canicule afterwards an aurora display, the alive arena on the sun that acquired the aurora will face Earth again. Although solar action in that arena on the sun adeptness accept decreased in the beggarly time, there is still a greater adventitious of aurora 27 canicule afterwards the endure aeon of added ablaze activity.
Solar Activity: Ablaze action aswell correlates with the action of the sun, which changes according to an 11-year solar cycle. In general, the added alive the sun, the greater the amount of auroras. Thus, ablaze displays are added acceptable about the time of the solar best (when solar action is high). Aurora displays abide common and able for several years about solar maximum. During solar maximum, the auroras are not alone added common and added active, but they aswell can appear added south abroad from the poles (it should be noted, however, that ablaze and alive auroras can be empiric at any time during the solar cycle).
Weather, the abounding moon, and ablaze abuse aswell affect your adeptness to see aurora. Your best bet for seeing aurora is to get as abutting as you can to the position of the ablaze oval, and as far abroad as you can from sources of bogus ablaze and clouded skies. Tips on examination the aurora can be begin at NOAA's Amplitude Environment Center.
Where do they occur?
Auroras anatomy in an egg-shaped bandage centered at anniversary alluring pole. The amplitude of the bandage ranges from 10 to 1,000 kilometers (km) and it is about 3,000 km (1,900 miles) from the alluring pole during quieter solar periods. If you reside abreast this oval, you will see the aurora on a lot of clear, aphotic nights. In the arctic hemisphere, for example, prime examination locations cover Fairbanks, Alaska, abounding locations in arctic and average Canada, and in the arctic locations of Russia and Scandinavia.
As ablaze action increases, the aurora not alone increases in brightness, but it aswell tends to move added appear the equator. Ablaze action is anon affiliated to disturbances in Earth's alluring and electrical accepted system. These increases in action are accepted as geomagnetic storms. To actuate how top the geomagnetic action needs to be for aurora to action in your area, see the table at NOAA's Amplitude Environment Center. Humans in the arctic United States and arctic Europe may see the aurora a few times in a decade, while humans in southern Europe, the southern United States, and even Mexico, may see the aurora alone once-in-a-lifetime. It should be acclaimed that the ablaze egg-shaped does not chase curve of according latitude, so humans on the East Coast of the United States accept a college likelihood of seeing aurora than those at the aforementioned breadth on the West Coast.
Geomagnetic storms and the consistent ablaze activity, alter unpredictably throughout the year. Because geomagnetic action about after-effects from contest on the sun, it can be predicted by searching at the sun and solar flares. For this reason, ablaze forecasts can alone be fabricated two or three canicule in advance. NOAA's Amplitude Environment Center issues forecasts of geomagnetic activity. Since 1979, NOAA's polar-orbiting satellites accept been barometer the action alteration of particles into the ablaze zones. About Aurora Borealis.
No comments:
Post a Comment