RING OF FIRE SOLAR ECLIPSE--TODAY: If you're in the Americas, you can witness a solar eclipse today. The action begins at daybreak on Saturday, Oct. 14th, when the Moon's shadow makes landfall on the Pacific coast of North America; it ends at sunset in Brazil. At peak coverage, the Moon will turn the sun into a bright "ring of fire."
SpaceWeather.com
THE FORECAST CALLS FOR QUIET: With no CMEs heading for Earth and no solar flares in the offing, the forecast calls for quiet. Solar and geomagnetic activity should remain low for the rest of the weekend. SpaceWeather.com
Sunspots on the Earth-viewed side of the sun are either stable or in decay. Only active region AR3460 shows a beta-gamma complexity. The rest show a beta configuration or even an alpha.
EarthSky.org
A SOLAR ANTI-FLARE? To detect solar flares, Earth-orbiting satellites monitor X-rays. A big flare can boost the sun's X-ray luminosity by orders of magnitude. On Oct. 14th, the opposite happened. The sun's X-ray output suddenly dropped. Was it an anti-flare? For the answer, watch this movie from NOAA's GOES-16 satellite. SpaceWeather.com
Monday blues? Sun still on break
The fun eclipse weekend is over for most of us. But the sun is still taking a bit of a break. All of the current sunspot regions are small in size and magnetically simple. Sun activity remains low, with a trickle of solar flares. EarthSky.org
SOMETHING WICKED THIS WAY COMES! Looking over the NE limb of the Sun we can see a region that is very active, and just produced a C9 flare from behind the limb (so was probably much larger). Hopefully this will be a growing region when it rotates on to the disk, not a dying one.
MASSIVE EXPLOSION ON THE SUN: A long-duration flare expelled a large mass of plasma from the Sun. The dark filament on the disk is rooted in the bright spot region. It becomes unstable and explodes away from the Sun (compare to size of the Earth). It is too far east to affect us.
GEOMAGNETIC STORM WATCH (G1): A magnetic filament connected to sunspot AR3467 erupted today, Oct. 16th, and hurled a CME into space. It is not heading directly for Earth. However, NASA models suggest it might deliver a glancing blow late on Oct. 19th. If so, the off-target CME could cause a minor G1-class geomagnetic storm. SpaceWeather.com
GEOMAGNETIC STORM WATCH (G1): A magnetic filament connected to sunspot AR3467 erupted on Oct. 16th, hurling a CME into space. It is not heading directly for Earth. However, a NASA model suggests it might deliver a glancing blow late on Oct. 19th. If so, the off-target CME could cause a minor G1-class geomagnetic storm
SpaceWeather.com
Sun activity for October 16-17, 2023. This two-panel display shows the sun in wavelengths of 304 angstrom on the left and 131 angstrom on the right. First, you can see a very quick filament eruption near the sun’s limb (edge) around 11:30 UTC, October 16. Then, higher on the northeast limb, a C9.9 flare was fired at around 16:00 UTC. The flare was almost certainly actually an M flare, since it occurred beyond the horizon and so was partly blocked by the sun. Images via SDO and JHelioviewer. EarthSky.org
#Norma strengthens to a hurricane!
Location: 545 km from Manzanillo
Wind: 130 km/h
Movement: north at 15 km/h
It will be a major hurricane (cat 3 or 4) approaching BCS over the weekend with a somewhat uncertain path:
Scenario 1: open ocean
️Scenario 2: toward Sinaloa
GEOMAGNETIC STORM WATCH: A minor G1-class geomagnetic storm is possible today, Oct. 19th, when a CME is expected to graze Earth's magnetic field. The CME was hurled into space 3 days ago by an erupting magnetic filament connected to sunspot AR3467. That sunspot no longer exists, but the debris from its explosion should arrive later today. SpaceWeather.com
SUNSPOT NUMBER DROPS: The Sun has been unusually quiet this last week, with few flares and CMEs, the X-ray background below C1 level, and sunspot number dropping to a 6-month low. Solar cycles often have several peaks, this my signal the end of the first peak. Keith Strong vía X
POSSIBLE CME IMPACT (UPDATED): Solar wind data from NOAA's DSCOVR spacecraft suggest that a CME may have grazed Earth's magnetic field midday on Oct. 18th. It could be the early arrival of a CME expected today--or a previously unrecognized CME taking us by surprise. Either way, it sparked naked-eye auroras over parts of Canada and Norway, and very faint photographic auroras as far south as Nebraska. SpaceWeather.com
A LULL IN SUNSPOT ACTIVITY: In the past two weeks, sunspot counts have sharply dropped, leaving the solar disk without any complex or very active sunspots. Does this mean Solar Cycle 25 is ending prematurely? No. "Sunspot lulls" are normal statistical fluctuations observed during even very strong solar cycles. Solar Cycle 25 will soon bounce back as it heads for a maximum in 2024-25. SpaceWeather.com
IMPACT SPARKS AURORAS: Arriving earlier than expected, a CME hit Earth's magnetic field on Oct. 20th. Although it was a weak impact (indeed, it was initially overlooked), the CME's wake contained strong magnetic fields that opened a crack in Earth's magnetosphere. Solar wind poured through the gap to fuel auroras in both hemispheres. Ian Griffin photographed the display from the Otago Peninsula in New Zealand:
"I was out getting ready to photograph the Orionid meteor shower, which is in the Northern sky from here in New Zealand," says Griffin. "But at around 9:30 local time my attention was focused entirely in the opposite direction as a wonderful display of the aurora australis exploded in the southrern sky."
Auroras were also visible in the northern hemisphere. Fantastic shapes including beads and swirls were observed over Canada, while photographic auroras descended into the United States as far south as Kansas and Missouri. SpaceWeather.com
MYSTERY OF ORANGE AURORAS: A recent display of auroras over Canada has experts scratching their heads. The mystery? They were orange:
"This was a first for me," says Harlan Thomas, who photographed the display over Sibbald Pond west of Calgary, Alberta, on Oct. 19th. "The orange was sublime, just incredible. The pillars in the center stayed there glowing for more than 20 minutes."
Auroras get their colors from atoms and molecules in Earth's atmosphere. During geomagnetic storms, energetic particles rain down from space, striking the air and causing it to glow. Red, green, purple and even pink are common signs of excited oxygen and nitrogen.
The problem is, there's nothing in the air capable of making bright orange. Theoretically, nitrogen and oxygen (N2, N2+, and O2+) can produce emissions at orange wavelengths. However, these emissions are very weak compared to other colors produced by the same molecules. Orange should be overwhelmed.
The answer may be hiding in plain sight. Take another look at Thomas's photo. Bright red auroras appear on top, overlapping the green auroras lower down. Red and green mixing together may have produced the yellow-orange glow.
Aurora physicist Kjellmar Oksavik of the University of Bergen in Norway believes that's the correct explanation:
"The red auroras are formed by low-energy electrons colliding with atomic oxygen at high altitudes (200-400 km). Here, oxygen atoms are excited into a quantum state called O(1D), where they can emit a red photon at 630.0 nanometers," Oksavik says.
"The green auroras are formed by higher-energy electrons colliding with atomic oxygen at lower altitudes (100-150 km)," he continues. "Here, oxygen atoms are excited into a state called O(1S), where they emit a green photon at 557.7 nanometers."
"In between, there can be a mixing of the two processes, which fools the camera and eye to believe that it is orange. In reality, it is both red and green at the same time," he says.
"Another beauty of this picture," Oksavik points out, "is that it reveals the alignment of Earth’s magnetic field. The bright pillar in the center is a textbook example of a very tall auroral ray. These are aligned along the magnetic field and caused by a broad spectrum of electrons raining down from Earth’s magnetosphere. Slower electrons collide high up (red light), while more energetic electrons travel further down into a much denser atmosphere (green light)." Such a continuum of red to green should naturally produce a yellow-orange transition zone--no mystery molecule required. SpaceWeather.com
SUN MAGNETIC REVERSAL IS UNDERWAY!
First, don't freak out - this is a normal feature of the 11-year sunspot cycle, but it does have important meaning for space weather. This dark coronal hole is stretching across the solar equator. That means the solar magnetic fields have begun to reverse for this sunspot cycle.
.......The reversal of the solar fields heralds the beginning of the peak of sunspot maximum (usually lasts 2-3 years) and the coronal holes also deliver enhanced solar wind streams. We should expect 2024-2025 to be the height of geomagnetic activity until the next cycle maximum which is expected ~2035 (+/- 2 years). We should be seeing more equatorial coronal hole placement and enhanced sunspot activity in the coming months.
SpaceWeatherNews vía X