Space Weather Update: 12/01/2016
By Spaceweather.com, 12/01/2016
SLIGHT CHANCE OF FLARES: NOAA forecasters say there is a 20% chance of M-class solar flares on Dec. 1st. The source, sunspot AR2615, is facing Earth so any eruptions would be geoeffective. Likely effects include minor radio blackouts on the sunlit side of our planet. Free: Solar flare alerts.
REFLECTION RAINBOW: Spaceweather.com reader Chris Erikson was driving to work yesterday when he saw something strange. It was a rainy day on the Columbia River Gorge near the Oregon-Washington border, and a beautiful double rainbow arced across the sky. Suddenly, as passed the riverbank, another rainbow cut across the double 'bow. "I've never seen such a thing before," says Erikson, who snapped this picture through the front windshield:
This is called a "reflection rainbow." To understand where it comes from, remember how normal rainbows form: Sunlight bounces in and out of falling raindrops. Those raindrops act like tiny prisms, spreading sunbeams into their constituent colors. Reflection rainbows form in the same way, except the source of light is not the sun; it's the reflection of the sun from a body of water.
"The sun must have been reflecting from the Columbia River, which was only 200 feet to my left," says Erikson. "Here's a map showing where I was."
Rainbows come in a variety of forms. The reflection rainbow Erikson photographed is just one of many you can see if you are alert for the unusual. Start looking here.
MESOSPHERIC BORE (IT'S NOT WHAT YOU THINK): This month, a lot is happening in the mesosphere. The mesosphere is a layer of Earth's atmosphere above the stratosphere; it is the realm of sprites, noctilucent clouds (NLCs), and airglow. Starting on Nov. 17th, NASA's AIM spacecraft spotted bright noctilucent clouds forming in the mesosphere above Antarctica. Then, in an apparently unrelated development on Nov. 24th, the normal dome of airglow over China split in two. Xiao Shuai photographed the event from Mount Balang in Sichuan:
This is called a "mesospheric bore"--and not because it's dull. A bore is a type of atmospheric wave with deep ripples at its leading edge. Indeed, you can see the ripples in Shuai's photo separating the zone of airglow from clear sky.
Bores fall into the category of "gravity waves"—so called because gravity acts as the restoring force essential to wave motion. Analogy: Boats in water. When a boat goes tearing across a lake, water in front of the boat is pushed upward. Gravity pulls the water back down again and this sets up a wave.
In this case, instead of water, rarefied air is the medium through which the wave propagates. The sudden boundary in the airglow layer is probably akin to a hydraulic jump. But what created the disturbance in the first place? (What is the 'boat'?) No one knows.
"There may be updates in the coming days as scientists from NASA and the Chinese Academy of Science check data from satellites to learn more about this event," says Jeff Dai, who has been helping Xiao Shuai process and communicate his extraordinary images. "Also, we encourage other photographers from Thailand, Myanmar, Bangladesh and India to submit their images of the wave."
BUY A TICKET TO THE EDGE OF SPACE: Christmas shopping for a young scientist? Consider this: For the holiday season only, we're reducing the cost of payload space on Earth to Sky Calculus balloons from $500 to only $299.95. Buy an edge of space gift certificate before Dec. 25th and your student can send an experiment, photo, or keepsake item to the stratosphere, completely supported by an Earth to Sky Calculus launch and recovery team.
This is not only a great Christmas gift, but also a good kickstarter for science fair projects. Experiments will be flown and returned along with video footage, GPS tracking, temperature, pressure, altimetry and radiation data.
To take advantage of the discounted rate, payment must be received before Dec. 25th. However, the flight can take place at any time in the next 12 months.
Conditions: No mammals. Plants and non-pathogenic microbes are allowed. Generally speaking, experiments should weigh less than ~300 grams and occupy a volume less than ~64 cubic inches. A Skype brainstorming session is included with each certificate. Dr. Tony Phillips and other members of the Earth to Sky team will chat with students to help them craft an experiment that will work in the harsh environment of the stratosphere.
More edge of space Christmas gifts may be found in the Earth to Sky Store.
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 Dec. 1, 2016, the network reported 35 fireballs.
(34 sporadics, 1 November omega Orionid)
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 December 1, 2016 there were 1742 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: 368.4 km/sec
density: 7.8 protons/cm3
more data: ACE, DSCOVR
Updated: Today at 1929 UTX-ray Solar Flares
6-hr max: B2 1711 UT Dec01
24-hr: B3 1147 UT Dec01
explanation | more data
Updated: Today at: 1900 UTDaily Sun: 01 Dec 16Sunspot AR2615 poses a slight threat for M-class solar flares and minor radio blackouts. Credit: SDO/HMI
Sunspot number: 75
What is the sunspot number?
Updated 01 Dec 2016
Current Stretch: 0 days
2016 total: 25 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 01 Dec 2016
The Radio Sun
10.7 cm flux: 86 sfu
explanation | more data
Updated 30 Nov 2016
Current Auroral Oval:
Switch to: Europe, USA, New Zealand, Antarctica
Credit: NOAA/OvationPlanetary K-index
Now: Kp= 0 quiet
24-hr max: Kp= 2 quiet
explanation | more data
Interplanetary Mag. Field
Btotal: 3.7 nT
Bz: 2.8 nT north
more data: ACE, DSCOVR
Updated: Today at 1928 UTCoronal Holes: 01 Dec 16
There are no large coronal holes on the Earthside of the sun. 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: 12-01-2016 16:55:04
Updated at: 2016 Nov 30 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 30 2200 UTCMid-latitudes