Space Weather Update: 10/15/2016
By Spaceweather.com, 10/15/2016
SOMETHING DIFFERENT ON SPACEWEATHER.COM: Readers who frequently visit Spaceweather.com to check solar wind data should note an important change: Our primary data source has shifted from the aging ACE spacecraft to NOAA’s newDSCOVR spacecraft, our planet’s flagship space weather buoy located 1.5 million km upstream of Earth. Links to ACE are still available, but the main numbers you see are ticking in from the Deep Space Climate Observatory.
HERE COMES THE SOLAR WIND (AGAIN): A stream of solar wind flowing from a coronal hole on the sun is expected to reach Earth on Oct. 16th. High-latitude sky watchers should be alert for auroras in the moonlight. NOAA forecasters estimate a 30% chance of G1-class geomagnetic storms. Free: Aurora Alerts.
NASA’s Solar Dynamics Observatory took this picture of the coronal hole on Oct. 13th
Coronal holes are places in the sun’s atmosphere where the magnetic field opens up and allows normally-trapped solar wind to escape. This coronal hole is broad, and the emerging stream of solar wind could influence our planet for several days. We’ve seen this coronal hole before, by the way. About one month ago it was also facing Earth. The solar wind it sent our way on Sept. 20-21 did not trigger a full-fledged geomagnetic storm, but it did spark pretty auroras around the Arctic Circle.
ELECTRIC MOONBOW: There’s a full Moon this weekend. That means it’s time to be alert for moonbows. Ian Glendinning spotted this one arcing over a lightning bolt in Northumberland UK:
“The moonbow framed the lightning nicely–a rare and beautiful coincidence,” says Glendinning.
Everyone knows what lightning is. But a moonbow? It’s the same as a rainbow with the Moon playing the role of Sun. Raindrops falling in the Northumberland night caught the rays of the waxing full Moon and spread them into a fan of prismatic color.
Glendinning’s exposure revealed something even more rare: a secondary moonbow. It’s the faint ‘bow arciing above the brighter primary. Primary rainbows are caused by single reflections inside raindrops; secondary bows are caused bydouble reflections. Watch for them both this weekend.
SUBSIDING STORMS: Geomagnetic activity is subsiding as Earth exits the wake of a CME that struck our planet three days ago–but not before sparking a bright display of auroras on Oct. 13-14. At the peak of the G2-class storm, Northern Lights spilled across the Canadian border into the lower United States. In Minnesota, “the show erupted with naked eye visible colors and movement,” reports Thomas Spence who snapped this picture from the Boundary Waters Canoe Area Wilderness:
“It was an incredible display over a beautiful wilderness,” says Spence.
Auroras are receding as Earth exits the CME’s wake. Nevertheless, more lights are possible tonight, especially around the Arctic Circle, as the geomagnetic storm sputters to an end. Monitor the realtime photo gallery for sightings.
Cosmic Rays in the Atmosphere
Updated: Sept. 29 2016 // Next Flight: Oct. 1, 2016
Sept. 20, 2016: 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.
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 Oct. 15, 2016, the network reported 22 fireballs.
(17 sporadics, 2 epsilon Geminids, 2 Southern Taurids, 1 lambda Draconid)
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 October 15, 2016 there were 1735 potentially hazardous asteroids.
Recent & Upcoming Earth-asteroid encounters:Asteroid
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.
speed: 529.1 km/sec
density: 4.6 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 2107 UTX-ray Solar Flares
6-hr max: B1 1505 UT Oct15
24-hr: B3 0324 UT Oct15
explanation | more data
Updated: Today at: 2100 UTDaily Sun: 15 Oct 16All of these sunspots are quiet and stable. Solar flare activity remains very low. Credit: SDO/HMI
Sunspot number: 38
What is the sunspot number?
Updated 15 Oct 2016
Current Stretch: 0 days
2016 total: 21 days (8%)
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 15 Oct 2016
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/OvationPlanetary K-index
Now: Kp= 3 quiet
24-hr max: Kp= 3 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 7.3 nT
Bz: 0.5 nT north
more data: ACE, DSCOVR
Updated: Today at 2105 UTCoronal Holes: 15 Oct 16
Solar wind flowing from this broad coronal hole could reach Earth as early as Oct 15. Credit: NASA/SDO.Noctilucent Clouds NASA’s AIM spacecraft has suffered an anomaly, and a software patch is required to fix it. As a result, current noctilucent cloud images will not return until late September 2016.
Switch view: Europe, USA, Asia, PolarUpdated at: 08-06-2016 16:55:02
Updated at: 2016 Oct 14 2200 UTC
Probabilities for significant disturbances in Earth’s magnetic field are given for three activity levels: active, minor storm, severe stormUpdated at: 2016 Oct 14 2200 UTCMid-latitudes