Solar Minimum

  • Atmospheric Radiation Increased 12% in Last 3 Years


    In January 2020, the students of Earth to Sky Calculus and Spaceweather.com traveled to Abisko, Sweden, to launch a pair of cosmic ray balloons.

    Putting all the data together, 2017+2020, they find that radiation has increased +12% in the past 3 years…

    Solar minimum boosts atmospheric radiation by 12% in 3 years. Picture via SpaceWeather

    The diagram from radiation dose rate (uGy/hr) vs. altitude (feet) shows that atmospheric radiation increases at nearly all altitudes – even in the range where airplanes fly between 25,000 ft and 40,000 ft.

    In other words, passengers and flight crews are absorbing ~12% more cosmic radiation than they did only a few years ago.

    What’s causing the increase?

    It’s solar Solar Minimum, during which the sun’s magnetic field weakens, allowing extra cosmic rays from deep space to penetrate the solar system.

    At the moment, the sun is near the bottom of the 11-year solar cycle.

    After hitting Earth’s atmosphere, the cosmic rays create a spray of secondary cosmic rays (X-rays and gamma-rays in the energy range 10 keV to 20 MeV) which are measured by the radiation sensors onboard the helium balloons.

    Atmospheric radiation increases by 12% in 3 years. And that’s because of the Solar Minimum. Picture by CERN

    Scientists from SpaceWeather.com have been launching radiation sensors almost weekly for 5 years.

    Data show cosmic rays in the stratosphere have been increasing the entire time.

    The new data even show that this increase is not limited to the stratosphere but is also happening at aviation altitudes with a 3-year increase of ~12% even below 40,000 ft.

    And all that’s a sign of a deepening Solar Minimum

  • Big spike in cosmic radiation due to unsettled geomagnetic field

    Solar activity was very low and the visible disk remained spotless for the 16th day in a row, making a total of 32 days in 2020 or 65 percent - we are still in a Solar Minimum.

    No Earth-directed CMEs were observed in available coronagraph imagery.


    Deep-space radiation peaking

    As a result of weakened Sun's magnetic field, deep-space radiation is easily entering our solar system and affecting Earth; reaching a percentage point of the Space Age maximum. This is a result of a very weak Solar Minimum, which is expected to end sometime this year.

    In 2019, the Sun was blank for a total of 281 days or 77%, breaking the Space Age record for most days without sunspots in a year. 

    The previous record was set in 2008, with 268 blank days.

    "That was during the epic Solar Minimum of 2008-2009, formerly the deepest of the Space Age. Now 2019 has moved into first place," Dr. Tony Phillips of SpaceWeather.com said.

    "Solar Minimum is a normal part of the 11-year sunspot cycle. The past two (2008-2009 and 2018-2019) have been long and deep, making them 'century-class' Minima. To find a year with more blank suns, you have to go back to 1913, which had 311 spotless days."

    If you are interested to learn more about the effects of increased deep-space radiation, read the article below:

    Cosmic rays in Earth's atmosphere intensifying

    See Also: Earth Could be Hit by Decades Long Mini Ice Age


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