Paul Dorian: The Sun Is Now Virtually Blank During The Weakest Solar Cycle In More Than A Century

Posted: May 1, 2015 by tallbloke in solar system dynamics
[Current image of the sun with virtually blank conditions; courtesy NASA/SDO]
The sun is almost completely blank. The main driver of all weather and climate, the entity which occupies 99.86% of all of the mass in our solar system, the great ball of fire in the sky has gone quiet again during what is likely to be the weakest sunspot cycle in more than a century. The sun’s X-ray output has flatlined in recent days and NOAA forecasters estimate a scant 1% chance of strong flares in the next 24 hours. Not since cycle 14 peaked in February 1906 has there been a solar cycle with fewer sunspots. We are currently more than six years into Solar Cycle 24 and the current nearly blank sun may signal the end of the solar maximum phase. Solar cycle 24 began after an unusually deep solar minimum that lasted from 2007 to 2009 which included more spotless days on the sun compared to any minimum in almost a century.
Solar maximum
The smoothed sunspot number (plot below) for solar cycle 24 reached a peak of 81.9 in April 2014 and it is looking increasingly likely that this spike will be considered to be the solar maximum for this cycle. This second peak in the cycle surpassed the level of an earlier peak that reached 66.9 in February 2012. Many solar cycles are double peaked; however, this is the first one in which the second peak in sunspot number was larger than the first peak. Going back to 1755, there have been only a few solar cycles in the previous 23 that have had a lower number of sunspots during its maximum phase.
[Sunspot numbers for the prior solar cycle (#23) and the current solar cycle (#24) with its two peaks highlighted; courtesy Hathaway, NASA/ARC]
Consequences of a weak solar cycle
First, the weak solar cycle has resulted in rather benign “space weather” in recent times with generally weaker-than-normal geomagnetic storms. By all Earth-based measures of geomagnetic and geoeffective solar activity, this cycle has been extremely quiet. However, while a weak solar cycle does suggest strong solar storms will occur less often than during stronger and more active cycles, it does not rule them out entirely. In fact, the famous “superstorm” Carrington Event of 1859 occurred during a weak solar cycle (#10) []. In addition, there is some evidence that most large events such as strong solar flares and significant geomagnetic storms tend to occur in the declining phase of the solar cycle. In other words, there is still a chance for significant solar activity in the months and years ahead.Second, it is pretty well understood that solar activity has a direct impact on temperatures at very high altitudes in a part of the Earth’s atmosphere called the thermosphere. This is the biggest layer of the Earth’s atmosphere which lies directly above the mesosphere and below the exosphere. Thermospheric temperatures increase with altitude due to absorption of highly energetic solar radiation and are highly dependent on solar activity.Finally, if history is a guide, it is safe to say that weak solar activity for a prolonged period of time can have a cooling impact on global temperatures in the troposphere which is the bottom-most layer of Earth’s atmosphere – and where we all live. There have been two notable historical periods with decades-long episodes of low solar activity. The first period is known as the “Maunder Minimum”, named after the solar astronomer Edward Maunder, and it lasted from around 1645 to 1715. The second one is referred to as the “Dalton Minimum”, named for the English meteorologist John Dalton, and it lasted from about 1790 to 1830 (below). Both of these historical periods coincided with colder-than-normal global temperatures in an era now referred to by many scientists as the “Little Ice Age”. In addition, research studies in just the past couple of decades have found a complicated relationship between solar activity, cosmic rays, and clouds on Earth. This research suggests that in times of low solar activity where solar winds are typically weak; more cosmic rays reach the Earth’s atmosphere which, in turn, has been found to lead to an increase in certain types of clouds that can act to cool the Earth.

  1. Richard111 says:

    Spots appeared last night. Quite small. 🙂

  2. oldbrew says:

    ‘Finally, if history is a guide, it is safe to say that weak solar activity for a prolonged period of time can have a cooling impact on global temperatures in the troposphere which is the bottom-most layer of Earth’s atmosphere – and where we all live.’

    We’re about to find out – in the next 5-15 years probably.

  3. ren says:

    As NASA prepares for the first manned spaceflight to Mars, questions have surfaced concerning the potential for increased risks associated with exposure to the spectrum of highly energetic nuclei that comprise galactic cosmic rays. Animal models have revealed an unexpected sensitivity of mature neurons in the brain to charged particles found in space. Astronaut autonomy during long-term space travel is particularly critical as is the need to properly manage planned and unanticipated events, activities that could be compromised by accumulating particle traversals through the brain. Using mice subjected to space-relevant fluences of charged particles, we show significant cortical- and hippocampal-based performance decrements 6 weeks after acute exposure. Animals manifesting cognitive decrements exhibited marked and persistent radiation-induced reductions in dendritic complexity and spine density along medial prefrontal cortical neurons known to mediate neurotransmission specifically interrogated by our behavioral tasks. Significant increases in postsynaptic density protein 95 (PSD-95) revealed major radiation-induced alterations in synaptic integrity. Impaired behavioral performance of individual animals correlated significantly with reduced spine density and trended with increased synaptic puncta, thereby providing quantitative measures of risk for developing cognitive decrements. Our data indicate an unexpected and unique susceptibility of the central nervous system to space radiation exposure, and argue that the underlying radiation sensitivity of delicate neuronal structure may well predispose astronauts to unintended mission-critical performance decrements and/or longer-term neurocognitive sequelae.

  4. ren says:

    Two forms of radiation pose potential health risks to astronauts in deep space. One is galactic cosmic rays (GCRs), particles caused by supernova explosions and other high-energy events outside the solar system. The other is solar energetic particles (SEPs) associated with solar flares and coronal mass ejections from the sun.

    Radiation exposure is measured in units of Sievert (Sv) or milliSievert (one one-thousandth Sv). Long-term population studies have shown exposure to radiation increases a person’s lifetime cancer risk. Exposure to a dose of 1 Sv, accumulated over time, is associated with a 5 percent increase in risk for developing fatal cancer.

    NASA has established a 3 percent increased risk of fatal cancer as an acceptable career limit for its astronauts currently operating in low-Earth orbit. The RAD data showed the Curiosity rover was exposed to an average of 1.8 milliSieverts of GCR per day on its journey to Mars. Only about 5 percent of the radiation dose was associated with solar particles because of a relatively quiet solar cycle and the shielding provided by the spacecraft.

    The RAD data will help inform current discussions in the United States medical community, which is working to establish exposure limits for deep-space explorers in the future.

    “In terms of accumulated dose, it’s like getting a whole-body CT scan once every five or six days,” said Cary Zeitlin, a principal scientist at the Southwest Research Institute (SwRI) in San Antonio and lead author of the paper on the findings. “Understanding the radiation environment inside a spacecraft carrying humans to Mars or other deep space destinations is critical for planning future crewed missions.”

    Current spacecraft shield much more effectively against SEPs than GCRs. To protect against the comparatively low energy of typical SEPs, astronauts might need to move into havens with extra shielding on a spacecraft or on the Martian surface, or employ other countermeasures. GCRs tend to be highly energetic, highly penetrating particles that are not stopped by the modest shielding provided by a typical spacecraft.

    “Scientists need to validate theories and models with actual measurements, which RAD is now providing,” said Donald M. Hassler, a program director at SwRI and principal investigator of the RAD investigation. “These measurements will be used to better understand how radiation travels through deep space and how it is affected and changed by the spacecraft structure itself. The spacecraft protects somewhat against lower energy particles, but others can propagate through the structure unchanged or break down into secondary particles.”

  5. oldbrew says:

    Even airline pilots have to be aware of radiation levels.

    ‘Spending 56 minutes behind the controls at 30,000 feet is the equivalent of 20 minutes on a sunbed, the University of California has found’

    Don’t know if being fully dressed makes any difference 😉

  6. E.M.Smith says:


    So it isn’t going to be “tinfoil hats” but rather “leadfoil hats” then?

  7. ren says:

    2. ICRP recommended annual limit for occupationally exposed radiation workers (including aircrew) is less than 20 mSv. If the predicted exposure is less than 1/3 of this limit, the safety signal color will be green – indicating minimal radiation exposure. If the predicted exposure is between 1/3-2/3 of the ICRP recommended limit, the safety signal color will be yellow – indicating that close tracking of individual radiation exposure is advised. If the predicted exposure is greater than 2/3 the recommended limit, the safety signal color will be red – indicating exposure to maximum recommended limit is possible.

  8. E.M.Smith says:


    Did you not notice the 🙂 indicating humor?

    Let me explain: Tinfoil Hats is an expression used to portray someone as a bit nutty. As in “Barycenter folks are from the tinfoil hat brigade” or “D*ni*ers are all tinfoil hats”. So given the very real issue of radiation, I was pointing out that it is not a “tinfoil hat” issue (and by humorous implication, all those asserting folks here are from said quadrant were wrong) and that it required real effective radiation shielding, but again humorously, casting it as lead but in a “foil hat”.

    You sure know how to kill a joke…
    (Or maybe that’s me, who knows that any joke explained is a joke in rigor… 😉

    [mod note] ren is not a native English speaker

  9. E.M.Smith says: May 3, 2015 at 10:07 pm


    Did you not notice the 🙂 indicating humor?

    Chiefio, Ren is very good, he need no ridicule, only support to better express his very accurate measurements and that data. to all of us. 🙂

  10. ren says:

    Czy Janoschka
    The video show a compilation of protons interactions, electromagnetic shower and cosmic ray spallation in a Phywe PJ45 cloud chamber at 2877 m. The sequences come from 8 hours of recording with a HD camera. Dimension of the surface of the machine is 45×45 cm. There is no magnetic field in the chamber;
    The cloud chamber was temporarily put in the Pic du Midi (French Observatory in the Pyrenees) in 2012 for the 100th anniversary of the discovery of cosmic ray.

    As this altitude, there is about 10 times more neutron and proton than in sea level. Theses particles can interact with the matter and break some nucleus which release other protons and neutrons, alpha particles or deuteron. The density of ionisation in a trail is proportionnal to z²/v² where z is the charge of the particle and v it’s velocity. Thus, a proton with a low kinetic energy will make more ionization so the trail will be bigger than the trail of a high energy proton. A 5 MeV (0.1c) proton have a range of 34 cm in air, a 10 MeV one, 1.1 m.
    The range of an alpha particle of 10 MeV in air is 10.4 cm.

    Their is also higly energetic gamma ray (or energetic incoming electrons !), which can make electromagnetic shower (electrons and positon) in the matter (wall of the room, or wall of the machine which is made with 1 cm of glass). Single e+/e- comes from muon or Pi0 decay, or from the 3 interactions process of gamma in matter (photoelectric, compton and pair creation).
    See the website for more pictures and annotations about theses nuclear events. Feel free to give your thought about any interactions of the video.

    Strongly galactic radiation rises above 10 km away.

    My conclusion is this: strong galactic radiation (weak solar wind) strongly alter the chemistry of the atmosphere (and electrical properties) in the zone of the ozone. The closer the magnetic poles of the earth, the more.
    Humor is important, although the translator has problems with the translation. Thanks.

  11. ren says:

    The ta translator didn’t get the joke, but it’s good my daughter (Martyna) did.

  12. oldbrew says:

    Nanoflares – ‘Strong Evidence For Coronal Heating Theory’

    Jim Klimchuk, a solar scientist at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, explained that the new evidence supports a theory that the sun’s corona is heated by tiny explosions called nanoflares. These are impulsive heating bursts that individually reach incredibly hot temperatures of some 10 million Kelvins or 18 million degrees Fahrenheit – even greater than the average temperature of the corona – and provide heat to the atmosphere. The research evidence presented by the panel spotted this super hot solar material, called plasma, representative of a nanoflare.

    “The explosions are called nanoflares because they have one-billionth the energy of a regular flare,” said Klimchuk. “Despite being tiny by solar standards, each packs the wallop of a 10 megaton hydrogen bomb. Millions of them are going off every second across the sun, and collectively they heat the corona.”

  13. oldbrew says:

    Paper – ‘Multifractals suggest the existence of an unknown physical mechanism on the Sun’

    ‘The famous sunspots on the surface of the Earth’s star result from the dynamics of strong magnetic fields, and their numbers are an important indicator of the state of activity on the Sun. Researchers have been conducting multifractal analysis into the changes in the numbers of sunspots. The resulting graphs were surprisingly asymmetrical in shape, suggesting that sunspots may be involved in hitherto unknown physical processes.’