Sol (Sun) and its phenomena

[Puma]

SOLAR CYCLE 25 ACTIVITY REPORT MARCH 08/2023

Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C4.7 event observed at 04:05 UTC on March 07 from Region 3243 (N18E89)

Filament eruption was the most remarkable event.

https://twitter.com/x/status/1633278557823836161

https://twitter.com/x/status/1633315827033178112

There are currently 12 numbered sunspot regions on the solar disk: AR3238, AR3239, AR3240 AR3241, AR3242. AR3243, AR3244, AR3245, AR3246 AR3247, AR3248 and new region AR3249


The total number of sunspots has increased to 191 (71 of these are grouped into 12 active regions) NOAA forecasts for the next 24h: 95% chance for C flares, 45% chance for M flares and 10% chance for X flares. AR3245 (S23E21) has grown in number of sunspots with 13, in size reaching 300 millionths of a hemisphere but its magnetic field has lost the gamma component.

SUNSPOT MITOSIS: Sunspot AR3245 is splitting in two. This 24-hour movie from NASA's Solar Dynamics Observatory shows the sunspot's primary core dividing like a eukaryotic cell as it turns toward Earth:

The bright, linear gap between the sunspot's two halves is known as a "light bridge." It measures 20,000 km from end to end.​

The nature of light bridges is not fully understood. They often herald the break-up of a sunspot, with jets of plasma shooting up from the chasm as the sunspot decays. Some research suggests that magnetic fields at the base of a light bridge are busy cross-crossing and reconnecting--the same explosive process that sparks solar flares.​

Does this mean sunspot AR3245 will explode--or quietly fall apart? No one can say. Readers with solar telescopes are encouraged to monitor developments. SpaceWeather.com​

● Auroral Activity

The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 653.6 km/s at 05:24 UTC on March 07. Maximum planetary index Kp3

Aurora Oval

https://twitter.com/x/status/1633018137288531969

● Current Conditions at 05:25 UTC on March 08

▪︎ Geospace quiet
▪︎Geomagnetic conditions now : Kp 1. 33
▪︎Solar wind speed record: 456.6 km/sec
▪︎ low density: 4.89 p/cm3
▪︎Neutron Counts today: -0.3% Below Average
▪︎X-ray Solar Flare: C1cat 01:15 UTC
▪︎Sunspot number: 191 (SN 173 March 07)
SpaceWeather.com
SpaceWeatherlive..com

 

[Puma]

SOLAR CYCLE ACTIVITY REPORT MARCH 09/2023

Solar activity has been at moderate levels for the past 24 hours. Two M-class flares were recorded. The first a M1.1 from AR3242 (N10W15) at 19:12 UTC it caused a minor R1 radio blackout over Africa The second and the largest solar event of the period was a M1.3 event observed at 22:44 UTC from AR3245 (S23E09) on March 08 it caused a minor R1 radio blackout over Pacific Ocean. Both regions have grown in magnetic complexity

https://twitter.com/x/status/1633414814625144832

https://twitter.com/x/status/1633605038286467072

There are currently 11 numbered sunspot regions on the solar disk: AR3238, AR3239, AR3240, AR3241, AR3242. AR3244, AR3245, AR3246 AR3247, AR3248, AR3249
AR3243 is gone

The total number of sunspots has decreased to 146 (47 of these are grouped into 11 active regions) NOAA forecasts for the next 24h: 95% chance for C flares, 40% chance for M flares and 10% chance for X flares. AR3245 has grown in size reaching 440 millionths of a hemisphere and it has recovered its gamma component while AR3242 has changed its magnetic field to beta-gamma. Both Sunspot regions have a 'gamma-class' magnetic field that harbors energy for X-class solar flares.




● Auroral Activity

The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 491 km/s at 00:06 UTC on March 08. Maximum planetary index Kp3

Aurora Oval


● Current Conditions at 04:30 UTC on March 09

▪︎ Geospace quiet
▪︎Geomagnetic conditions now : Kp 2
▪︎Solar wind speed record: 425.6 km/sec
▪︎ density: 5.02 p/cm3 (low)
▪︎Neutron Counts today: -0.0% Below Average
▪︎X-ray Solar Flare: M1cat 22:44 UTC
▪︎Sunspot number: 146 (SN 191 March 08)
SpaceWeather.com
SpaceWeatherlive..com

 

[Puma]

SOLAR CYCLE ACTIVITY REPORT MARCH 10_2023

Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C6.2 event observed at 20:24 UTC on March 09 from Region 3245 (S23E07).

https://twitter.com/x/status/1633932281768181766

Looks like a firestorm

https://twitter.com/x/status/1633814189473923072

There are currently 11 numbered sunspot regions on the solar disk: AR3238, AR3239, AR3241, AR3242. , AR3245, AR3246 AR3247, AR3248, AR3249, and new regions AR3250 , AR3251

AR3240 and AR3244 are gone

The total number of sunspots has increased to 155 (45 of these are grouped into 11 active regions) NOAA forecasts for the next 24h: 99% chance for C flares, 30% chance for M flares and 10% chance for X flares. Sunspots AR3242 and AR3245 have 'beta-gamma' magnetic fields that harbor energy for M-class solar flares.

A MONTH OF SUNSPOTS: February 2023 was a busy month on the sun, with the average sunspot number cracking 100 for only the 3rd time since 2014. To illustrate this development, Senol Sanli of Bursa, Turkey, stacked 28 daily sun images from NASA's Solar Dynamics Observatory to create a February montage:

This single image shows every sunspot group in February," says Sanli. "It includes every numbered active region from AR3203 to AR3238."​

Take a look at the progression of sunspot activity over the past 10 years. Solar Cycle 25 is definitely taking off. Originally, forecasters thought Solar Cycle 25 would be about the same as Solar Cycle 24, one of the weakest cycles in a century. February's sunspot activity is the latest sign that Solar Cycle 25 will exceed predictions, bringing a stronger-than-expected Solar Max in late 2024 or 2025. SpaceWeather.com ​

● Auroral Activity

The geomagnetic field has been at quiet to active levels for the past 24 hours. First period of active geomagnetic conditions (Kp4) threshold reached at 07:37 UTC. Solar wind speed reached a peak of 467 km/s at 17:18 UTC on March 09. Second period of active geomagnetic conditions (Kp4) Threshold Reached: 01:06 UTC on March 10 Maximum planetary index Kp4


Aurora Oval

https://twitter.com/x/status/1633862882252271619

● Current Conditions at 05:00 UTC on March 10

▪︎ Geospace active
▪︎Geomagnetic conditions now : Kp 4
▪︎Solar wind speed record: 418 km/sec
▪︎ density: 8.69 p/cm3 (low)
▪︎Neutron Counts today: +0.9% Elevated
▪︎X-ray Solar Flare: C3 at 23:31 UTC
▪︎Sunspot number: 155 (SN 146 March 09)
SpaceWeather.com
SpaceWeatherlive..com

 

[Puma]

WORLDWIDE EARTHQUAKE REPORT MARCH 11_2023

PLASMA FALLS: Imagine a waterfall made of hot plasma falling from a precipice tall enough to swallow Earth 10 times. Here it is:​

"I had the privilege of observing and photographing this magnificent wall of plasma on March 9th," says photographer Eduardo Schaberger Poupeau of Rafaela, Argentina. "It rose some 100,000 km above the solar surface. On my computer screen it looked like hundreds of threads of plasma were dripping down a wall. It really was a spectacle that left me speechless."​

These structures have been seen on the sun many times before. They frequently appear in rings around the sun's poles, and are called "polar crown prominences." Researchers still don't fully understand them. Mysteriously, the plasma threads Poupeau noted plummet faster than ambient magnetic forces seem to allow. Nuclear engineers would like to figure out how this happens, because it also happens on a smaller scale in fusion reactors on Earth, frustrating their efforts to sustain an energy-producing reaction. Studies of these prominences could lead to practical breakthroughs here on Earth.

The plasma is still falling today. Amateur astronomers with solar telescopes can see the structure on the sun's southeastern limb, right here. Take a look! SpaceWeather.com​

A BUTTERFLY CME: A strange coronal mass ejection (CME) just left the sun. It unfolded like the wings of a butterfly:

Most CMEs look like a smoke ring or a halo.

https://twitter.com/x/status/1634018957958021120

This one was different. We will never know what kind of explosion gave rise to its insectoid shape, because the blast site was on the farside of the sun. The sun itself blocked our view.​

This farside CME will not touch Earth. The gossamer wings will, however, strike Mercury on March 10th, according to a NASA model. If the CME overwhelms Mercury's relatively weak magnetic field, it could scour material off the planet's surface creating a temporary atmosphere and adding material to Mercury's comet-like tail. SpaceWeather.com​

Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C7.1 event observed at 07:08 UTC on March 19 from Region 3245 (S23W18).

Ribbon Flares

https://twitter.com/x/status/1634354608926588929

https://twitter.com/x/status/1634356272282718208

There are currently 11 numbered sunspot regions on the solar disk: AR3238, AR3239, AR3241, AR3242. AR3245, AR3246 AR3247, AR3249, AR3250 , AR3251 and new region AR3252, AR3248 la gone

The total number of sunspots has decreased to 135 (36 of these are grouped into 11 active regions) NOAA forecasts for the next 24h: 90% chance for C flares, 25% chance for M flares and 5% chance for X flares. Currently all regions have stable magnetic fields. AR3245 (S23W16) and AR3242 (N10W46) have been decaying and now their respective magnetic fields are beta (stable positive and negative polarity).

● Auroral Activity

The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 473 km/s at 11:00 UTC on March 10 Maximum planetary index Kp3

Aurora Oval


● Current Conditions at 04:20 UTC on March 11

▪︎ Geospace unsettled
▪︎Geomagnetic conditions now : Kp 3
▪︎Solar wind speed record: 448.4 km/sec
▪︎ density: 3.44 p/cm3 (low)
▪︎Neutron Counts today: +0.8% Elevated
▪︎X-ray Solar Flare: C4 at 01:03 UTC
▪︎Sunspot number: 135 (SN 155 March 10)
SpaceWeather.com
SpaceWeatherlive..com

 

[Puma]

Well, I'm back online after my modem failed for the umpteenth time. Interesting things have been happening with the sun

'EXTREMELY RARE' FARSIDE CME: Something big just happened on the farside of the sun. During the early hours of March 13th, SOHO coronagraphs recorded a farside halo CME leaving the sun faster than 3000 km/s:

https://twitter.com/x/status/1635386654595891200

https://twitter.com/x/status/1635218897547988992

https://twitter.com/x/status/1635231647007404032

Because of its extreme speed, this CME is classified as "extremely rare," a fast-mover that occurs only once every decade or so. A NASA model of the event shows the CME heading almost directly away from Earth. Good thing!

Although the CME was not Earth-directed, it has nevertheless touched our planet. See all the snowy dots and streaks in the coronagraph movie above? Those are energetic particles accelerated by shock waves in the CME. They create short-lived luminous speckles when they hit SOHO's digital camera.

NOAA's GOES-16 satellite has detected the particles reaching Earth--all from the CME's backside. Imagine what a frontside blast would have been like. Earth's magnetic field is funneling the particles toward the poles where a type of radio blackout is underway--a polar cap absorption (PCA) event:

Note the broad red areas. Airplanes flying over these regions may find that their shortwave radios won't work due to the ionizing effect of infalling protons. This PCA could persist for a day or more. You can monitor its progress here.

Spaceweather.com Time Machine

https://twitter.com/x/status/1635715380957020177

https://twitter.com/x/status/1635692798774063108

 

[Puma]

SOLAR CYCLE 25 ACTIVITY REPORT MARCH 15_2023

Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C3 event observed at 06:05 UTC on March 14 from Region 3250 (S18W22).

https://twitter.com/x/status/1635814712800575488

https://twitter.com/x/status/1635620901663260674

https://twitter.com/x/status/1635444735887261696

There are currently 9 numbered sunspot regions on the solar disk: AR3245, AR3247, AR3249, AR3250 , AR3251, AR3252, AR3254, AR3255, AR3256
AR3238, AR3239, AR3241, AR3242. AR3246, AR3253 are gone

FARSIDE SUNSPOTS: The source of yesterday's farside CME (described above) is a mystery, but there are two leading suspects. Helioseismic maps reveal a pair of large active regions on the far side of the sun:

Both will rotate around to the Earthside of the sun within a week, potentially bringing potent sunspots into our planet's "strike zone." In the meantime we will keep an eye out for CMEs flying over the edge of the sun, indicating additional farside activity. Stay tuned. SpaceWeather.com

The total number of sunspots has increased to 97 (22 of these are grouped into 9 active regions) NOAA forecasts for the next 24h: 50% chance for C flares, 5% chance for M flares and 1% chance for X flares. All sunspot regions have stable magnetic fields

● Auroral Activity

The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 445 km/s at 08:37 UTC on March 14 Active geomagnetic conditions (Kp4) threshold reached at 11:59 UTC Maximum planetary index Kp4

Minor G1 geomagnetic storm (Kp5) treshold reached at 03:55 UTC on March 15

https://twitter.com/x/status/1635852591199313920

MINOR GEOMAGNETIC STORM WATCH: Minor G1-class geomagnetic storms are possible on March 15th and 16th in response to a number of incoming CMEs. NOAA forecasters believe that 2 or 3 glancing blows are possible, individually weak but collectively effective. SpaceWeather.com

Aurora Oval


● Current Conditions at 05:00 UTC on March 15

▪︎ Geomagnetic storm G1
▪︎Geomagnetic conditions now : Kp 5
▪︎Solar wind speed record: 562.4 km/sec (Moderately high speed)
▪︎ density: 30.15 p/cm3 (Moderate density)
▪︎Neutron Counts today: +0.5% Elevated
▪︎X-ray Solar Flare: C1 at 22:26 UTC
▪︎Sunspot number: 97 (SN 87 March 14)
SpaceWeather.com
SpaceWeatherlive..com

 

[mabar]

Around 1.14 a Solar tornado.

 

[Puma]

SOLAR CYCLE 25 ACTIVITY REPORT MARCH 16_2023

Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1 event observed at 06:30 UTC on March 15 from Region 3254 (S24W28).

https://twitter.com/x/status/1635968193998069764

There are currently 8 numbered sunspot regions on the solar disk: AR3245, AR3247, AR3249, AR3250 , AR3251, AR3252, AR3254, AR3255, AR3256 is gone.

The total number of sunspots has decreased to 96 (16 of these are grouped into 8 active regions) NOAA forecasts for the next 24h: 40% chance for C flares, 5% chance for M flares and 1% chance for X flares. All sunspot regions have stable magnetic fields

● Auroral Activity

The geomagnetic field has been at active to storm levels for the past 24 hours. Solar wind speed reached a peak of 567 km/s at 05:14 UTC on March 15 Moderate G2 geomagnetic storm (Kp6) threshold reached at 05:59 UTC The G2 storm subsided around 09:00 UTC. Minor G1 geomagnetic storm (Kp5) threshold reached at 22:46 UTC Moderate G2 geomagnetic storm (Kp6) threshold reached at 23:22 UTC. Maximum planetary index Kp6

CME IMPACT SPARKS GEOMAGNETIC STORM: A CME hit Earth's magnetic field on March 15th (0428 UT), sparking a moderately strong G2-class geomagnetic storm. NOAA analysts correctly predicted this impact shortly after a dark plasma eruption on March 11th hurled the CME into space. We're still waiting for first reports of auroras

CME IMPACT SPARKS GEOMAGNETIC STORM (UPDATED): Earth's magnetic field is storming again as our planet passes through the wake of a CME that struck during the early hours of March 15th (0428 UT). Storm levels are currently flickering between category G1 and G2. So far auroras have been sighted in New Zealand and several northern-tier US states. SpaceWeather.com

POLAR CAP ABSORPTION EVENT IN PROGRESS
Red zones in this global map show where shortwave transmissions are being absorbed. Frequencies below 15 MHz are almost completely blacked out, while anything below 35 MHz is being attentuated, at least a little.

Aurora Oval

https://twitter.com/x/status/1635767929810845696

https://twitter.com/x/status/1635961736569167873

Grid Problems? Solar Radiation affected mainly Americas

https://twitter.com/x/status/1636217523447136257

Mexico City suffered a power outage a few hours ago.

Power outage reported in several neighborhoods of #CDMX

https://twitter.com/x/status/1636195514692640777

● Current Conditions at 04:30 UTC on March 16

▪︎ Geospace unsettled
▪︎Geomagnetic conditions now : Kp 4
▪︎Solar wind speed record: 547.2 km/sec (Moderately high speed)
▪︎ density: 10.35 p/cm3 (low density)
▪︎Neutron Counts today: -1.1% Below Average
▪︎X-ray Solar Flare: B9 at 22:20 UTC
▪︎Sunspot number: 96 (SN 97 March 15)
SpaceWeather.com
SpaceWeatherlive..com

 

[Puma]

SOLAR CYCLE 25 ACTIVITY REPORT MARCH 17_2023

Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C1.4 event observed at 12:55 UTC on March 16 from Region 3245 (S24W98).
Solar activity was at low levels due to low level C-flare activity:

Solar tornado.

https://twitter.com/x/status/1636426914314240005

https://twitter.com/x/status/1636427457015234578

There are currently 8 numbered sunspot regions on the solar disk: AR3247, AR3249, AR3250 , AR3251, AR3252, AR3254, AR3255
AR3245 is gone.

https://twitter.com/x/status/1636501098193100814

The total number of sunspots has decreased to 84 (14 of these are grouped into 8 active regions) NOAA forecasts for the next 24h: 40% chance for C flares, 5% chance for M flares and 1% chance for X flares. Most regions appeared to be slightly decaying.

● Auroral Activity

The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 588 km/s at 00:34 UTC on March 16 Maximum planetary index Kp4

POLAR RADIO BLACKOUT IS SUBSIDING: Inside the Arctic Circle, shortwave radios are working again as a three-day blackout triggered by Monday's extremely rare CME subsides. The blackout is called a "polar cap absorption event" or PCA. It was caused by energetic protons accelerated toward Earth by the CME. Those protons are now ebbing, so the normal propagation of shortwave radio signals can resume. SpaceWeather.com

Aurora Oval

https://twitter.com/x/status/1636316289894416387

● Current Conditions at 05:00 UTC on March 17

▪︎ Geospace quiet
▪︎Geomagnetic conditions now : Kp 1
▪︎Solar wind speed record: 453.5 km/sec (Elevated speed)
▪︎ density: 4.33 p/cm3 (low density)
▪︎Neutron Counts today: -2.3% Below Average
▪︎X-ray Solar Flare: B7 at 22:50 UTC
▪︎Sunspot number: 84 (SN 96 March 16)
SpaceWeather.com
SpaceWeatherlive..com

 

[Puma]

SOLAR CYCLE ACTIVITY REPORT MARCH 18_2023

Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1 event observed at 15:07 UTC on March 17 from Region 3247 (S24W78). It caused a minor R1 radio blackout over South America

https://twitter.com/x/status/1636907254917070849

https://twitter.com/x/status/1636910731936296961

https://twitter.com/x/status/1636913559195078656

https://twitter.com/x/status/1636740769024229376

There are currently 8 numbered sunspot regions on the solar disk: AR3247, AR3249, AR3250 , AR3251, AR3252, AR3254, AR3255 and new region AR3256

AR3256 is the region to watch in the next week

https://twitter.com/x/status/1636682932864548864

The total number of sunspots has decreased to 58 (12 of these are grouped into 8 active regions) NOAA forecasts for the next 24h: 70% chance for C flares, 15% chance for M flares and 1% chance for X flares. Most of the regions are in slight decay, but the new region AR3256 (S21E76) is producing C-class flares.


● Auroral Activity

The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 510 km/s at 00:18 UTC on March 17 Maximum planetary index Kp3

Aurora Oval


● Current Conditions at 06:00 UTC on March 18

▪︎ Geospace unsettled
▪︎Geomagnetic conditions now : Kp 3
▪︎Solar wind speed record: 413.1 km/sec (Elevated speed)
▪︎ density: 4.84 p/cm3 (low density)
▪︎Neutron Counts today: -1.9% Below Average
▪︎X-ray Solar Flare: M1 at 15:07 UTC
▪︎Sunspot number: 58 (SN 84 March 16)
SpaceWeather.com
SpaceWeatherlive..com

 

[Puma]

SOLAR CYCLE ACTIVITY REPORT MARCH 19_2023

Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C9 event observed at 07:16 UTC on March 18 from Region 3256 (S22E66).

https://twitter.com/x/status/1637121810562191361

https://twitter.com/x/status/1637057957035749377

https://twitter.com/x/status/1637280156652896256

There are currently 3 numbered sunspot regions on the solar disk: AR3251, AR3256 and new region AR3257

AR3247, AR3249, AR3250 , AR3252, AR3254, AR3255 are gone.

https://twitter.com/x/status/1637287327578959873

The total number of sunspots has decreased to 35 (5 of these are grouped into 3 active regions) NOAA forecasts for the next 24h: 95% chance for C flares, 25% chance for M flares and 1% chance for X flares. New sunspot AR3256 is crackling with C-class solar flares and appears capable of much stronger eruptions.

● Auroral Activity

The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 472 km/s at 03:34 UTC on March 18 Maximum planetary index Kp3

Aurora Oval

https://twitter.com/x/status/1636709633229291521

● Current Conditions at 05:10 UTC on March 19

▪︎ Geospace quiet
▪︎Geomagnetic conditions now : Kp 2
▪︎Solar wind speed record: 433.4 km/sec (Elevated speed)
▪︎ density: 4.89 p/cm3 (low density)
▪︎Neutron Counts today: -2.0% Below Average
▪︎X-ray Solar Flare: C2 at 02:15 UTC
▪︎Sunspot number: 35 (SN 58 March 18)
SpaceWeather.com
SpaceWeatherlive..com

 

[thorbiorn]

This NOAA page claims to give short term Aurora forecast, and you can also see where there is darkness.

Colours vary:

Aurora Colors Explained – Southern and Northern Lights
This entry was posted on March 1, 2023 by Anne Helmenstine (updated on March 9, 2023)

They explain:

How the Aurora Works
In order to understand why there are different colors, let’s review the basic process behind the aurora.

• Charged particles in the solar wind strike the ionosphere or thermosphere layer of the Earth’s atmosphere, which contains low density gases, including nitrogen (N2) and atomic oxygen (O), along with small amounts of hydrogen, helium, and other gases.
• Atoms, molecules, and ions absorb the energy from these charged particles, which kicks electrons into an excited energy state.
• The excited state is not stable, so eventually the electrons return to a lower energy state. When this happens, the atom, molecule, or ion releases this extra energy as a photon.
• Photons are light. The color of the light depends on the energy released by the atom or molecule. The energy that gets absorbed and the color of light released is a characteristic of that atom. For example, molecule nitrogen (N2) releases blue to violet light, while atomic oxygen releases red or green light, depending on the energy it absorbs.

Colors of the Aurora
The ionosphere mainly contains nitrogen and oxygen, so these are the key players in producing the colors of the aurora. While they only release a few colors, sometimes you see a whole rainbow of hues because of the way the different wavelengths of light mix.

Moving from the highest altitude in the atmosphere to the lowest, here are the sources of the aurora colors:

• Blue and Violet [300-400 km (> 180 miles)]: Hydrogen and helium release blue and violet light at the top of the aurora. However, these colors are relatively faint and are not usually visible except under very dark skies or with strong solar storms. Also, because these gases are relatively rare, the light is diffuse.
• Red [300-400 km (> 180 miles)]: Red light at the top of an aurora comes from monatomic oxygen (O). At lower latitudes, sometimes only the red aurora appears, facing the north (northern hemisphere) or south (southern hemisphere). The other colors are below the horizon line.
• Yellow-Green [100-300 km (60- 180 mi)]: Vivid lime green is the most common color of the aurora. It comes from monatomic oxygen (O), but while the red aurora comes from oxygen absorbing solar radiation, green comes from oxygen atoms colliding with lower-energy electrons released by excited nitrogen molecules (N2+).
• Blue [100-300 km (60- 180 mi)]: Excited nitrogen molecules (N2+) release blue light when they return to a more stable energy state. Whether an aurora is blue, blue-green, or yellow-green depends on the interplay of light from nitrogen ions and oxygen atoms.
• Deep Red [100 km (60 mi)]: A deep red color at the base of the aurora comes from diatomic nitrogen (N2). When the red light overlaps blue light, you see purple or sometimes vivid pink. Similarly, when the red bleeds into the yellowish green from oxygen, you get orange aurora.
• Blue-Violet [100 km (60 mi)]: Near the base of the ionosphere, ionized diatomic nitrogen (N2+) releases blue and violet light, but the released electrons don’t excite as much oxygen at the lower altitude.

Clouds, moonlight, and sunlight from sunrise or sunset also affect the color you see.

Black Aurora
In addition to colorful light bands, sometimes an aurora has black bands that block starlight. The dark regions likely come from electric fields in the upper atmosphere that block electrons from interacting with gases.

Colors Not Due to the Aurora
Colored lights in the sky sometimes have sources other than an aurora.

• [...]
• Airglow: Like the aurora, airglow results from an interaction between the atmosphere and the solar wind. But, it is visible anywhere there is a dark sky (not just the polar regions). Typical airglow colors are green, red, or blue. Airglow can occur with the aurora or without it.
• STEVE: STEVE (strong thermal emission velocity enhancement) is a rare phenomenon with a purple or mauve arc or green “picket fence” of light. STEVE is not an aurora, instead coming from plasma waves in the magnetosphere.

There are minor variations between the above explanations and this video:

What Creates the Colors in the Northern Lights? - Causes of the Aurora Colors Explained
[...]
Chapters 0:00 Introduction 0:44 What Causes the Northern Lights 1:20 What Creates the Colors in the Northern Lights 1:47 Earth's Atmospheric Composition 2:56 Green Auroras 3:45 Pink, Purple, Magenta Auroras 4:55 Red Auroras 7:12 Sunlit, Blue Aurora 7:59 Stages of Twilight 8:45 Other Colors in the Northern Lights 9:20 Coming Up

 

[Puma]

SOLAR CYCLE ACTIVITY REPORT MARCH 20_2023

Solar activity has been at moderate levels for the past 24 hours. The largest solar event of the period was a M1.2 event observed at 01:47 UTC on March 20 from Region 3256 (S22E54) it caused a minor R1 radio blackout over South Pacific Ocean


A violent eruption from behind Southwest limb

https://twitter.com/x/status/1637617456742125568

https://twitter.com/x/status/1637632410257899521

There are currently 6 numbered sunspot regions on the solar disk: AR3251, AR3256 AR3257, and new regions AR3258, AR3259 and AR3260

https://twitter.com/x/status/1637440015490863106

The total number of sunspots has increased to 73 (13 of these are grouped into 6 active regions) NOAA forecasts for the next 24h: 95% chance for C flares, 25% chance for M flares and 1% chance for X flares. AR3256 has produced a M-class flare and is the most active region.

● Auroral Activity

The geomagnetic field has been at quiet to unsettled levels for the past 24 hours. Solar wind speed reached a peak of 491 km/s at 10:16 UTC on March 19 Maximum planetary index Kp3

GEOMAGNETIC STORM WATCH: Minor (G1-class) geomagnetic storms could happen on March 20-21 due to a possible glancing blow from an incoming CME. The CME was hurled into space on March 17th by the eruption of a magnetic filament containing dark plasma. Because of the "Russell-McPherron effect," even a weak impact around the equinox could spark a good display of high latitude auroras,. SpaceWeather.com

In addition, solar wind flowing from this large southern coronal hole should reach Earth on March 23-24

https://twitter.com/x/status/1637665474715475969

Aurora Oval

https://twitter.com/x/status/1637499118816841728

● Current Conditions at 05:50 UTC on March 20

▪︎ Geospace unsettled
▪︎Geomagnetic conditions now : Kp 3
▪︎Solar wind speed record: 430.2 km/sec (Elevated speed)
▪︎ density: 5.23 p/cm3 (low density)
▪︎Neutron Counts today: -2.0% Below Average
▪︎X-ray Solar Flare: M1 at 01:47 UTC
▪︎Sunspot number: 73 (SN 35 March 19)
SpaceWeather.com
SpaceWeatherlive..com

 

[Puma]

SOLAR CYCLE 25 ACTIVITY REPORT MARCH 21_2023

After the M1.2 flare in the early hours of March 20, solar activity levels remained low. The largest solar event of the period was a C5.2 event observed at 09:37 from Region 3256 (S20E39). From the reports of different solar scientists, most of the solar activity occurred on the far side.

https://twitter.com/x/status/1637974353127022592

https://twitter.com/x/status/1637724763635195904

There are currently 6 numbered sunspot regions on the solar disk: AR3251, AR3256 AR3257,AR3258, AR3259, AR3260


The total number of sunspots has increased to 75 ( 15 of these are grouped into 6 active regions) NOAA forecasts for the next 24h: 95% chance for C flares, 25% chance for M flares and 5% chance for X flares. Sunspot complex AR3256-57 poses a threat for M-class solar flares.


● Auroral Activity

The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 486 km/s at 11:26:UTC on March 20. Active geomagnetic conditions (Kp4) threshold reached at 14:59 UTC due to a close encounter with a Coronal mass ejection. Maximum planetary index Kp4

CLOSE ENCOUNTER WITH A CME: Even a near miss from a CME can spark beautiful auroras. Case in point: Yesterday, March 20th, the interplanetary magnetic field (IMF) near Earth suddenly rotated by almost 180 degrees. This kind of magnetic ripple is a typical sign of a CME passing nearby. The "ripple effect" ignited colorful lights inside the Arctic Circle. SpaceWeather.com

Aurora Oval

https://twitter.com/x/status/1637953844054478848

https://twitter.com/x/status/1637959644927909888

● Current Conditions at 05:50 UTC on March 21

▪︎ Geospace unsettled
▪︎Geomagnetic conditions now : Kp 3
▪︎Solar wind speed record: 401 km/sec (Elevated speed)
▪︎ density: 6.41 p/cm3 (low density)
▪︎Neutron Counts today: -2.5% Below Average
▪︎X-ray Solar Flare: C1 at 04:38 UTC
▪︎Sunspot number: 75 (SN 73 March 20)
SpaceWeather.com
SpaceWeatherlive..com

 

[Puma]

SOLAR CYCLE 25 ACTIVITY REPORT MARCH 22_2023

Solar activity has been at low levels for the past 24 hours. The largest solar event of the period was a C4.6 event observed at 13:54 UTC on March 21 from Region 3257 (S28E40)

https://twitter.com/x/status/1638352046184185858

https://twitter.com/x/status/1638344585905594369

There are currently 7 numbered sunspot regions on the solar disk: AR3251, AR3256 AR3257,AR3258, AR3259, AR3260 and new region AR3261 on the southwest

The total number of sunspots has decreased to 70 ( 27 of these are grouped into 7 y active regions) NOAA forecasts for the next 24h: 95% chance for C flares, 25% chance for M flares and 1% chance for X flares. Sunspot complex AR3256-57 poses a threat for M-class solar flares.

● Auroral Activity

The geomagnetic field has been at quiet to active levels for the past 24 hours. Solar wind speed reached a peak of 543.8 km/s at 23:43 UTC on March 21. Active geomagnetic conditions (Kp4) threshold reached at 02:37 UTC. Maximum planetary index Kp4

CLOSE ENCOUNTER WITH A CME: Even a near miss from a CME can spark beautiful auroras. Case in point: Yesterday, March 20th, the interplanetary magnetic field (IMF) near Earth suddenly rotated by almost 180 degrees. This kind of magnetic ripple is a typical sign of a CME passing nearby. The "ripple effect" ignited colorful lights inside the Arctic Circle. SpaceWeather.com

Aurora Oval

https://twitter.com/x/status/1638344731326570497

https://twitter.com/x/status/1638343587640520706

https://twitter.com/x/status/1637730237415931904

● Current Conditions at 05:10 UTC on March 22

▪︎ Geospace active
▪︎Geomagnetic conditions now : Kp 4
▪︎Solar wind speed record: 520.5 km/sec (Moderately high speed)
▪︎ density: 10.3 p/cm3 (low density)
▪︎Neutron Counts today: -2.8% Below Average
▪︎X-ray Solar Flare: C1 at 23:57 UTC
▪︎Sunspot number: 70 (SN 75 March 21)
SpaceWeather.com
SpaceWeatherlive..com