Space Weather Update: 03/04/2017
By Spaceweather.com, 03/04/2017
EXITING THE SOLAR WIND STREAM: After three days inside, Earth is beginning to leave a fast-blowing stream of solar wind that has sparked bright auroras around the Arctic Circle in the early days of March. NOAA forecasters estimate a 45% chance of polar geomagnetic storms on March 4th as the solar wind speed subsides below 550 km/s. Free: Aurora alerts.
WHY ARE WE GOING TO SWEDEN? Spaceweather.com is going to Sweden--and we're taking a team of student researchers from Earth to Sky Calculus with us. For a week beginning on March 9th we plan to launch a series of space weather balloons equipped with cosmic ray sensors and cameras into the stratosphere above the Arctic Circle. At the same time, Earth to Sky launch teams in Chile and California will be sending up identical payloads, forming an intercontinental balloon network:
We're doing this for three reasons:
1. To understand Earth's changing radiation environment: Regular monitoring of the stratosphere over California shows that cosmic rays have intensified more than 10% since 2015. Because of a recent decline in the solar cycle, more and more cosmic rays are reaching the inner solar system and penetrating the atmosphere of our planet. Earth's magnetic field should protect us against these rays, but geomagnetism is weakening. Globally, Earth's magnetic field has declined in strength by 10% since the 19th century with changes accelerating in recent years, according to measurements by Europe's SWARM satellites. To understand Earth's global response to these changes, we must launch balloons and sample radiation from widely-spaced locations. The upcoming network launch will span three continents, more than 14,000 km of linear distance, and 90+ degrees of latitude.
Above: Auroras over Abisko, Sweden, on Mar. 3rd. Credit: Peter Rosén/Lappland Media
2. To photograph the Northern Lights: We will be launching balloons from Abisko, Sweden, 250 km inside the Arctic Circle. Abisko is famous for spectacular auroras. One of our payloads will carry a low-light camera capable of photographing these lights from the stratosphere. Even at 120,000 feet, the balloon will be well below the auroras, but we will be a lot closer than any camera on the ground.
Above: Polar stratospheric clouds over Kiruna, Sweden, on Feb. 14. Credit: Mia Stålnacke
3. To sample polar stratospheric clouds: During winter months, the stratosphere above the Arctic Circle sometimes fills with icy clouds so colorful, they are likened to the aurora borealis. Polar stratospheric clouds (PSCs) are a sign of extremely cold temperatures in the stratosphere and some types of PSCs are responsible for ozone destruction. Our space weather balloons can fly right through these clouds, sampling their temperature, pressure, and ambient levels of radiation. We can also photograph them from the inside--a possible first!
Stay tuned for daily updates beginning March 9th.
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 Mar. 4, 2017, the network reported 11 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 March 4, 2017 there were 1777 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: 04 Mar 17
Not one of these fading sunspots poses a threat for strong solar flares. Credit: SDO/HMI
Sunspot number: 36
What is the sunspot number?
Updated 03 Mar 2017
Current Stretch: 0 days
2017 total: 11 days (19%)
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 03 Mar 2017
The Radio Sun
10.7 cm flux: 79 sfu
explanation | more data
Updated 03 Mar 2017
Current Auroral Oval:
Coronal Holes: 03 Mar 17
Earth is inside a stream of solar wind flowing from the indicated coronal hole. 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: 02-24-2017 17:55:02
Updated at: 2017 Mar 03 2200 UTC
Updated at: 2017 Mar 03 2200 UTC