Space Weather Update: 01/18/2017
By Spaceweather.com, 01/18/2017
GEOMAGNETIC STORMS LIKELY TODAY: NOAA forecasters say there is 65% chance of polar geomagnetic storms on Jan. 18th when a fast-moving stream of solar wind is expected to hit Earth’s magnetic field. The source of the stream: a large hole in the sun’s atmosphere. Arctic sky watchers should be alert for auroras. Free: Aurora Alerts
EARTH’S MAGNETIC FIELD RINGS LIKE A BELL: In the Lofoten Islands of Norway, Spaceweather.com reader Rob Stammes operates a magnetic observatory. Twenty-four hours a day, he measures the strength and direction of the local magnetic field as well as electrical currents running through the ground. During geomagnetic storms, his chart recordings go haywire. On Jan. 13th, something different happened. They rang like a bell:
“For about an hour, electrical currents in the ground beneath my observatory flowed back and forth with a sinusoidal period near 2 minutes,” says Stammes. “This is rare.”
These are natural ultra-low frequency oscillations known to researchers as “pulsations continuous” (Pc). The physics is familiar to anyone who has studied bells or resonant cavities. Earth’s magnetic field carves out a cavity in the surrounding solar wind. Gusts of solar wind can make the cavity “ring” akin to a bell (references: #1, #2, #3). Human ears cannot hear this ringing; it is electromagnetic rather than acoustic. The physical effect is felt beneath our feet. As the cavity vibrates, magnetic fields swing back and forth, causing electrical currents to flow through the ground below.
The Pc waves Stammes detected are a variety known as Pc4, which oscillate in the frequency range 6.7–22 mHz. Such waves are good at energizing particles trapped in Earth’s magnetic field and often cause local outbursts of bright auroras.
COSMIC RAYS ARE INTENSIFYING: A neutron monitor at the South Pole is detecting an upswing in cosmic rays penetrating Earth’s atmosphere. Here are the data, courtesy of the University of Delaware’s Bartol Research Institute:
This is a sign of changing times on the sun. The solar cycle is shifting from Solar Maximum to Solar Minimum. As the sun’s magnetic field weakens, cosmic rays are having an easier time penetrating the inner solar system. Earth is in the cross-hairs of these high-energy particles.
To find out if cosmic rays are also surging in the atmosphere at mid-latitudes, on Jan. 15th, the students of Earth to Sky Calculus launched a space weather balloon from the shores of Mono Lake in central California. At the time of the launch, the lake was wrapped in a cloud of rare fog called “Poconip” that coated every surface with feathery ice crystals: photos. The payload has since landed at 10,400 feet elevation on the slopes of Basin Mountain near Bishop CA. National Jr. snowboarding champion Carson Reid, a longtime member of Earth to Sky, will lead the recovery expedition on Wednesday. Stay tuned for results!
Our radiation monitoring program receives no support from corporate sponsors or government grants. Instead, we are crowd-funded. To that end, we offer for your consideration a truly far-out Valentine’s gift:
On Dec. 18, 2016, the students of Earth to Sky Calculus flew 30 of these pendants to the stratosphere. You can have one for $69.95–including the rose, which has been pressed for safekeeping. Each order comes with a Valentine’s card showing the pendant+rose in flight and telling the story of their trip to the stratosphere.
More out of this world gifts may be found in the Earth to Sky store. All proceeds support cosmic ray balloon flights and STEM education.
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 Jan. 18, 2017, the network reported 15 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 January 18, 2017 there were 1761 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: 584.0 km/sec
density: 7.2 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 1606 UTX-ray Solar Flares
6-hr max: A8 1047 UT Jan18
24-hr: A9 0600 UT Jan18
explanation | more data
Updated: Today at: 1600 UTDaily Sun: 18 Jan 17Sunspots AR2625 and AR2626 have stable magnetic fields that pose no threat for strong flares. Credit: SDO/HMI
Sunspot number: 26
What is the sunspot number?
Updated 18 Jan 2017
Current Stretch: 0 days
2017 total: 10 days (59%)
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 18 Jan 2017
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: 7.7 nT
Bz: 2.6 nT south
more data: ACE, DSCOVR
Updated: Today at 1605 UTCoronal Holes: 18 Jan 17
Solar wind flowing from this broad coronal hole should reach Earth on or about Jan 18th. Credit: NASA/SDO.Noctilucent Clouds The southern season for noctilucent clouds began on Nov. 17th. 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.
Switch view: Ross Ice Shelf, Antarctic Peninsula, East Antarctica, PolarUpdated at: 01-17-2017 18:55:02
Updated at: 2017 Jan 17 2200 UTC
Probabilities for significant disturbances in Earth’s magnetic field are given for three activity levels: active, minor storm, severe stormUpdated at: 2017 Jan 17 2200 UTCMid-latitudes