Space Weather Update: 11/18/2016
By Spaceweather.com, 11/18/2016
CHANCE OF MINOR STORMS ON NOV. 19TH: A minor solar wind stream is expected to buffet Earth’s magnetic field on Nov. 19th. This could cause geomagnetic activity and auroras around the Arctic Circle. A live aurora webcam is monitoring the sky over Sweden’s Abisko National Park. Watch now!
BIG CORONAL HOLE: A large hole in the sun’s atmosphere is rotating into view over the sun’s northeastern limb. NASA’s Solar Dynamics Observatory photographed the structure on Nov. 18th:
This is a “coronal hole”–a region in the sun’s atmosphere where the magnetic field peels back and allows solar wind to escape. It is too soon to say whether the emerging stream of solar wind will hit Earth head on when it reaches our planet next week. We will know more in the days ahead as the hole turns toward us to reveal its full dimensions and internal structure. Stay tuned for updates. Free:Aurora Alerts.
SUNSPOT CYCLE AT LOWEST LEVEL IN 5 YEARS: The sun has looked remarkably blank lately, with few dark cores interrupting the featureless solar disk. This is a sign that Solar Minimum is coming. Indeed, sunspot counts have just reached their lowest level since 2011. With respect to the sunspot cycle, you are here:
The solar cycle is like a pendulum, swinging back and forth between periods of high and low sunspot number every 11 years. These data from NOAA show that the pendulum is swinging toward low sunspot numbers even faster than expected. (The red line is the forecast; black dots are actual measurements.). Given the current progression, forecasters expect the cycle to bottom out with a deep Solar Minimum in 2019-2020.
Solar Minimum is widely misunderstood. Many people think it brings a period of dull quiet. In fact, space weather changes in interesting ways. For instance, as the extreme ultraviolet output of the sun decreases, the upper atmosphere of Earth cools and collapses. This allows space junk to accumulate around our planet. Also,the heliosphere shrinks, bringing interstellar space closer to Earth; galactic cosmic rays penetrate the inner solar system and our atmosphere with relative ease. (More on this below.) Meanwhile, geomagnetic storms and auroras will continue–caused mainly by solar wind streams instead of CMEs. Indeed, Solar Minimum is coming, but it won’t be dull.
COSMIC RAYS CONTINUE TO INTENSIFY: As the sunspot cycle declines, we expect cosmic rays to increase. Is this actually happening? The answer is “yes.” Spaceweather.com and the students of Earth to Sky Calculus have been monitoring radiation levels in the stratosphere with frequent high-altitude balloon flights over California. Here are the latest results, current as of Nov. 11, 2016:
Data show that cosmic ray levels are intensifying with an 11% increase since March 2015.
Cosmic rays are high-energy photons and subatomic particles accelerated in our direction by distant supernovas and other violent events in the Milky Way. Usually, cosmic rays are held at bay by the sun’s magnetic field, which envelops and protects all the planets in the Solar System. But the sun’s magnetic shield is weakening as the solar cycle shifts from Solar Max to Solar Minimum. As the sunspot cycle goes down, cosmic rays go up.
The sensors we send to the stratosphere measure X-rays and gamma-rays which are produced by the crash of primary cosmic rays into Earth’s atmosphere. In this way we are able to track increasing levels of radiation. The increase is expected to continue for years to come as solar activity plunges toward a deep Solar Minimum in 2019-2020.
Recently, we have expanded the scope of our measurements beyond California with launch sites in three continents: North America, South America and soon above the Arctic Circle in Europe. This Intercontinental Space Weather Balloon Network will allow us to probe the variable protection we receive from Earth’s magnetic field and atmosphere as a function of location around the globe.
EDGE OF SPACE CHRISTMAS ORNAMENTS: Would you like to hang something truly far out from your Christmas Tree this year? We offer for your consideration the Apollo 8 Christmas ornament. The ceramic disk shows an iconic photo from the Apollo program: Earth rising above the Moon as seen by Apollo 8 astronauts on Christmas Eve 1968. The students of Earth to Sky Calculus recently flew eight of these to the edge of space:
You can have one for $49.95. Each ornament comes with a Christmas card showing your ornament in the stratosphere and telling the story of its flight.
The cosmic ray research of Spaceweather.com and Earth to Sky Calculus is completely crowd-funded. Everyone who sponsors a balloon flight or buys an item from the Earth to Sky store contributes to this important body of knowledge. Thanks!
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 Nov. 18, 2016, the network reported 63 fireballs.
(38 sporadics, 20 Leonids, 5 Northern Taurids)
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 November 18, 2016 there were 1743 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.
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.
speed: 330.5 km/sec
density: 3.1 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 2238 UTX-ray Solar Flares
6-hr max: A9 1626 UT Nov18
24-hr: B1 0820 UT Nov18
explanation | more data
Updated: Today at: 2200 UTDaily Sun: 18 Nov 16Neither of these sunspots poses a threat for strong solar flares. Credit: SDO/HMI
Sunspot number: 27
What is the sunspot number?
Updated 18 Nov 2016
Current Stretch: 0 days
2016 total: 23 days (7%)
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 18 Nov 2016
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/OvationPlanetary K-index
Now: Kp= 1 quiet
24-hr max: Kp= 2 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 5.0 nT
Bz: 0.8 nT north
more data: ACE, DSCOVR
Updated: Today at 2238 UTCoronal Holes: 18 Nov 16
A minor stream of solar wind flowing from this small coronal hole could reach Earth on Nov. 19th. 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, noctilucent cloud images will not return until further notice. AIM science team members are optimistic that the
Switch view: Europe, USA, Asia, PolarUpdated at: 08-06-2016 16:55:02
Updated at: 2016 Nov 18 2200 UTC
Probabilities for significant disturbances in Earth’s magnetic field are given for three activity levels: active, minor storm, severe stormUpdated at: 2016 Nov 18 2200 UTCMid-latitudes