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S3 – Strong solar radiation storm in progress, active alert for aircrews and pregnant passengers


A powerful X8.2 solar flare erupted from Region 2673, located just around the visible disk, at 16:06 UTC on September 10, 2017, causing R3 – Strong radio blackout and a rapid increase in relativistic proton levels. Within just 3 hours, solar radiation storm reached S3 – Strong levels (on a scale of 1 – 5).

The proton flux exceeded the S1 – Minor threshold at 16:45 UTC and continued to increase to a peak flux of 1 040 pfu at 18:45 UTC – R3 – Strong solar radiation storm threshold. Proton levels still remain at those levels at 07:49 UTC on September 11.

An enhancement in the energetic portion of the solar radiation spectrum may indicate increased biological risk to astronauts or passengers and crew in high latitude, high altitude flights. Additionally, energetic particles may represent an increased risk to all satellite systems susceptible to single event effects.

S3 Strong solar radiation storm - Proton Flux - September 11, 2017

As reported by Dr. Tamitha Skov, a credentialed Space Meteorologist, due to the ongoing S3-level radiation storm, NASA model has an active alert for aircrew and prenatal [pregnant] passengers on transcontinental flights now. Check NAIRAS.

There are, on average, just ten S3 – Strong space radiation storms per one solar cycle (~11 years).

Potential impacts include:

  • Radiation – Passengers and crew in high latitude, high altitude flights may experience increasing radiation exposures. Astronauts on EVA (extra-vehicular activity) are exposed to elevated radiation levels.
  • Spacecraft – Single-event upsets to satellite operations, noise in imaging systems, and slight reduction of efficiency in solar panels are likely.
  • Radio – Degraded or episodically blacked-out polar HF (high frequency) radio propagation.

Strong solar radiation storm hits ESA/NASA SOHO/LASCO C3 coronagraph

Read more: 4th X-class flare: X8.2 erupts from Region 2673, second strongest of the cycle (published September 10 and updated September 11)

What is solar radiation storm

Solar radiation storms occur when a large-scale magnetic eruption, often causing a coronal mass ejection and associated solar flare, accelerates charged particles in the solar atmosphere to very high velocities. The most important particles are protons which can get accelerated to 1/3 the speed of light or 100 000 km/s. At these speeds, the protons can traverse the 150 million km from Sun to Earth in just 30 minutes. When they reach Earth, the fast moving protons penetrate the magnetosphere that shields Earth from lower energy charged particles. Once inside the magnetosphere, the particles are guided down the magnetic field lines such that they penetrate the atmosphere near the north and south poles.

NOAA categorizes Solar Radiation Storms using the NOAA Space Weather Scale on a scale from S1 – S5. The scale is based on measurements of energetic protons taken by the GOES satellite in geosynchronous orbit. The start of a Solar Radiation Storm is defined as the time when the flux of protons at energies ≥ 10 MeV equals or exceeds 10 proton flux units (1 pfu = 1 particle*cm-2*s-1*ster-1). The end of a Solar Radiation Storm is defined as the last time when the flux of ≥ 10 MeV protons is measured at or above 10 pfu. This definition allows multiple injections from flares and interplanetary shocks to be encompassed by a single Solar Radiation Storm. A Solar Radiation Storm can persist for time periods ranging from hours to days.

Solar Radiation Storms cause several impacts near Earth. When energetic protons collide with satellites or humans in space, they can penetrate deep into the object that they collide with and cause damage to electronic circuits or biological DNA. During Solar Radiation Storms at the S2 or higher level passengers and crew in high flying aircraft at high latitudes may be exposed to radiation risk. When the energetic protons collide with the atmosphere, they ionize the atoms and molecules thus creating free electrons. These electrons create a layer near the bottom of the ionosphere that can absorb High Frequency (HF) radio waves making radio communication difficult or impossible. (NOAA)

Featured image: Strong radiation storm hiting ESA/NASA SOHO/LASCO C3 coronagraph at 01:34 UTC on September 11, 2017. Credit: ESA/NASA SOHO/LASCO C3


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  1. Warning: Anyone reading the post by Jamal Shrair should take what is written with an extremely massive pinch of salt. There is no scientific basis for what he has written and his notion that the sun is fueled by an external energy supply is scientifically bogus. He is part of this ‘helical universe’ thing, and I refer you to one site that debunks one of the theories from this ‘group’


    The internet can be a wonderful source of information but more often than not it’s a medium for all sorts of crackpot theories that are often dressed up nicely to look more acceptable. Please be careful.

  2. The Inconvenient Solar-Physics Facts in the Era of the Standard Solar Myth

    I came across an article that was published on the 8th of September 2017 stating, massive sunspots and solar flares: The Sun has gone wrong and scientists don’t know why.”THE SUN HAS GONE WRONG” Not theoretical physicists https://www.yahoo.com/news/massive-sunspots-solar-flares-sun-111955127.html “We’re heading into the bottom of solar minimum, when the sun tends to have fewer sunspots, solar flares and coronal mass ejections—large expulsions of plasma, electrons and ions, and magnetic fields. But despite where we are in the sun’s cycle, activity on the sun has dramatically picked up over the past few days. On and off, these two sunspots have been flaring and shooting out coronal mass ejections, directed toward Earth.” “So what’s going on with the sun? And should we be concerned about this somewhat out-of-character solar behavior? “We don’t yet fully understand everything that is happening. But the activity over the past few days, when the sun should be within its quietest period, shows that significant space weather events are possible at any stage of the 11-year solar cycle”.

    Once again the physical reality of our star is exposing your Standard Solar Myth in a big way. But, solar cycle prediction is not the only obvious defect of the SSM. All the observed basic features of the Sun cannot be explained with your current theory. In fact, in the last three decades observations by advanced space instruments that were found to contradict your SSM were ignored or intentionally misinterpreted with the aid of new theoretical notions. However, solar events like this latest one cannot be manipulated or falsified by theoreticians in order to suit your “well established theory”.

    Anyone who follows solar cycle activity can see that mainstream solar physicists have to make forecast revisions on a continuous basis, resulting in a wobbly track record and plenty of processes designed to correct the corrections. Solar physicists predicted that 2013 would see an upsurge in solar activity and geomagnetic storms will disrupt power grids and communications systems. As we all know that came out to be false. Instead, the peak in the solar cycle in 2013 was the weakest for a century. And at the present time the Sun is supposed to be at its lowest activity. I’m not surprised that physicists cannot predict solar activity and sunspot cycle. Current physics is totally wrong about the Sun’s magnetic field and how it changes and what causes to change. There are external variables that influence the sun’s magnetic field. The variation of the external energy supply that our star receives is the primary driver of its magnetic field and solar cycle activity. Therefore, it is not only solar cycle activity that physicists cannot predict but all basic features of the sun. The physical reality of our star is different from the current dogma. When that physical reality will be understood, the real cause for climate change will be known and the ideal energy source will be produced. More important than the above, the integrity of physics will be restored. https://www.youtube.com/watch?v=EPhX2gu_8pg

    Jamal S. Shrair, Founder of the Helical Universe

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