By Spaceweather.com, 02/14/2017
CO-ROTATING INTERACTION REGION: NOAA forecasters say there is a 45% chance of polar geomagnetic storms on Feb. 15th when a co-rotating interaction region (CIR) is expected to hit Earth’s magnetic field. CIRs are transition zones between slow- and fast-moving solar wind streams. The often contain strong magnetic fields and density gradients that do a good job sparking auroras. A solar wind stream following the CIR could keep the Arctic Circle glowing for the rest of the week. Free: Aurora alerts.
BEST EVER? POLAR STRATOSPHERIC CLOUDS: Around the Arctic Circle, observers are reporting an outbreak of polar stratospheric clouds (PSCs). “Yesterday, Feb. 13th, the sky was filled with their brilliant colors from sunrise to sunset,” says Mia Stålnacke, who sends this picture from Kiruna, Sweden:
These clouds are newsworthy because normally the stratosphere has no clouds at all. Home to the ozone layer, the stratosphere is arid and almost always transparent. Yet, Stålnacke says, “we’ve been seeing stratospheric clouds very often this winter and last.”
According to multiple longtime residents of the area, the Feb 13th display was exceptional. “Everyone I spoke to agrees it was the best they had ever seen,” says Chad Blakley, who operates the Lights over Lapland tour guide service in Abisko, Sweden.
“I’ve been living here all my life (33 years),” says Stålnacke. “I definitely feel that these clouds are appearing more often then they used to. I remember seeing them a few times/year since I was a kid, but these last couple of years we’ve had them much more often–sometimes for almost a week straight. Others seem to feel the same way; I see local groups on Facebook flooded with photos of PSCs and comments on how often they’re appearing now.”
“The clouds were all over Finland, too,” says Matti Helin who took this picture on Feb. 13th:
What’s going on up there?
PSCs are a sign of very cold temperatures in the stratosphere. The clouds are made of ice. Indeed, that is the source of their remarkable color: High-altitude sunlight shining through tiny ice particles ~10µm across produce a bright iridescent glow. For ice crystals to form in the very dry stratosphere, temperatures must drop to around -85º C.
Once thought to be mere curiosities, some PSCs are now known to be associated with the destruction of ozone. Indeed, an ozone hole formed over the UK in Feb. 2016 following an outbreak of ozone-destroying Type 1 PSCs.
To investigate these clouds further, Spaceweather.com and the students of Earth to Sky Calculus will travel to Abisko Sweden for a week in March 2017. We plan to launch a series of space weather balloons into the Arctic stratosphere, measuring temperature, air pressure, and ambient radiation. If PSCs are present, our sensors will pass directly through them, and our cameras can photograph the colorful clouds at point blank range. Stay tuned!
ROUND OBJECT CROSSES THE MOON: As observers around the planet were capturing images of Friday’s penumbral eclipse, one photographer saw something unusual: a round object crossing in front of the Moon. “I was using a 125mm telescope to capture the eclipse when the small black disk appeared,” says Luis G. Verdiales from Loiza, Puerto Rico. “It was moving too slow to be a satellite, so slow that I was able to capture it with my camera four times. It got my attention because it was round!”
Verdiales contacted the Caribbean Island’s largest astronomy organization to find out what it was. Eddie Irizarry of the Sociedad de Astronomía del Caribe explains what happened next:
“After analysing magnified images, we suspected it might be a stratosphere balloon from Google Loon, a project that is testing internet coverage from the stratosphere,” says Irizarry. “We checked FlightRadar24.com and indeed found a balloon at 64,400 ft identified as HBAL176. Further analysis showed the balloon was right between the observer and the Moon.”
All Sky Fireball Network
Every night, a network of NASA all-sky cameras scans the skies above the United States for meteoritic fireballs. Automated software maintained by NASA’s Meteoroid Environment Office calculates their orbits, velocity, penetration depth in Earth’s atmosphere and many other characteristics. Daily results are presented here on Spaceweather.com.
On Feb. 14, 2017, the network reported 9 fireballs.
In this diagram of the inner solar system, all of the fireball orbits intersect at a single point–Earth. The orbits are color-coded by velocity, from slow (red) to fast (blue). [Larger image] [movies]
Near Earth Asteroids
Potentially Hazardous Asteroids (PHAs) are space rocks larger than approximately 100m that can come closer to Earth than 0.05 AU. None of the known PHAs is on a collision course with our planet, although astronomers are finding new ones all the time.
On February 14, 2017 there were 1773 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:
Notes: LD means “Lunar Distance.” 1 LD = 384,401 km, the distance between Earth and the Moon. 1 LD also equals 0.00256 AU. MAG is the visual magnitude of the asteroid on the date of closest approach.
Cosmic Rays in the Atmosphere
Readers, thank you for your patience while we continue to develop this new section of Spaceweather.com. We’ve been working to streamline our data reduction, allowing us to post results from balloon flights much more rapidly, and we have developed a new data product, shown here:
This plot displays radiation measurements not only in the stratosphere, but also at aviation altitudes. Dose rates are expessed as multiples of sea level. For instance, we see that boarding a plane that flies at 25,000 feet exposes passengers to dose rates ~10x higher than sea level. At 40,000 feet, the multiplier is closer to 50x. These measurements are made by our usual cosmic ray payload as it passes through aviation altitudes en route to the stratosphere over California.
What is this all about? Approximately once a week, Spaceweather.com and the students of Earth to Sky Calculus fly space weather balloons to the stratosphere over California. These balloons are equipped with radiation sensors that detect cosmic rays, a surprisingly “down to Earth” form of space weather. Cosmic rays can seed clouds, trigger lightning, and penetrate commercial airplanes. Furthermore, there are studies ( #1, #2, #3, #4) linking cosmic rays with cardiac arrhythmias and sudden cardiac death in the general population. Our latest measurements show that cosmic rays are intensifying, with an increase of more than 12% since 2015:
Why are cosmic rays intensifying? The main reason is the sun. Solar storm clouds such as coronal mass ejections (CMEs) sweep aside cosmic rays when they pass by Earth. During Solar Maximum, CMEs are abundant and cosmic rays are held at bay. Now, however, the solar cycle is swinging toward Solar Minimum, allowing cosmic rays to return. Another reason could be the weakening of Earth’s magnetic field, which helps protect us from deep-space radiation.
The radiation sensors onboard our helium balloons detect X-rays and gamma-rays in the energy range 10 keV to 20 MeV. These energies span the range of medical X-ray machines and airport security scanners.
The data points in the graph above correspond to the peak of the Reneger-Pfotzer maximum, which lies about 67,000 feet above central California. When cosmic rays crash into Earth’s atmosphere, they produce a spray of secondary particles that is most intense at the entrance to the stratosphere. Physicists Eric Reneger and Georg Pfotzer discovered the maximum using balloons in the 1930s and it is what we are measuring today.
Daily Sun: 14 Feb 17
AR2635 poses no threat for strong solar flares. Credit: SDO/HMI
Sunspot number: 16
What is the sunspot number?
Updated 14 Feb 2017
Current Stretch: 0 days
2017 total: 11 days (24%)
2016 total: 32 days (9%)
2015 total: 0 days (0%)
2014 total: 1 day (<1%)
2013 total: 0 days (0%)
2012 total: 0 days (0%)
2011 total: 2 days (<1%)
2010 total: 51 days (14%)
2009 total: 260 days (71%)
Updated 14 Feb 2017
Current Auroral Oval:
Coronal Holes: 14 Feb 17
Solar wind flowing from the indicated coronal hole should reach Earth on Feb. 15-16. Credit: NASA/SDO.
Noctilucent Clouds The southern season for noctilucent clouds began on Nov. 17, 2016. Come back to this spot every day to see the “daily daisy” from NASA’s AIM spacecraft, which is monitoring the dance of electric-blue around the Antarctic Circle.
Updated at: 02-14-2017 15:55:05
Updated at: 2017 Feb 13 2200 UTC
Updated at: 2017 Feb 13 2200 UTC