The Sun Has Lost Its Spots — Part 2

spotless_sun_april_5_2009

Spotless Sun - April 5, 2009

A little over 2 months ago, I wrote about the extended lack of spots on the sun (The Sun Has Lost Its Spots).

The sun has remained essentially spotless since then and has been blank 87% of 2009 through April 4th.  In 2008, the sun was blank 266 out 366 days (73%) and was the blankest year since 1913.

We are currently in the solar minimum phase of the solar cycle — the part of the cycle where the fewest sunspots appear. A typical solar minimum is 485 days.  The current solar minimum is 594 days and counting.

A typical solar cycle is about 11 years in length, with lengths since 1900 varying from 9.8 years to over 12 years. The current solar cycle length, which began in May 1996, is approaching 13 years, though several years ago the end had been projected for Spring of 2007. According to sunspot expert Dean Pesnell of the Goddard Space Flight Center, “We’re experiencing a very deep solar minimum.”

NASA has taken an interest in the current solar minimum and has solicited proposals “to study the causes and consequences of the minimum of Solar Cycle 23.”  Scientists intending to propose a study have to let NASA know of their intent by April 17th and their proposals must be submitted by June 5th.

Besides a dearth of sunspots, other solar indicators are also much lower than normal.

  • Measured by instruments on satellites, the solar wind is 20% below what it was in the 1990s and is at the lowest point since solar wind measurements began in the 1960s.
  • Measurements of solar irradiance by other satellites indicate the sun’s brightness has dropped by 0.02% in visible light and 6% in extreme ultraviolet wavelengths – a 12 year low.
  • The sun’s radio emissions, measured by radio telescopes, are the lowest since 1955.

The sun is the source of the energy that warms Earth and likely has a significant impact on climate and climate change.

What happens when the solar indicators remain low  for an extended period of time?

Astronomy, climate change, environment, global warming, science, sun, sunspot, Uncategorized
5 comments… add one
  • Davina Apr 6, 2009

    Hi Mike. Ah, this is all so fascinating! If the weather is any indication, over the last two winters here in BC, we've seen much colder temperatures and higher accumulations of snow. It would make sense that this is all related.

    <abbr>Davina’s last blog post..When Surgery is a Laughing Matter</abbr>

  • Dot Apr 6, 2009

    I was hoping your post was going to answer that last question, but I guess the answers haven't been found yet.

    <abbr>Dot’s last blog post..Silva CDs 7 and 8</abbr>

  • XUP Apr 6, 2009

    Ya, I was waiting for answers, too! What does this all mean? Why is it like this and what happens if it stays this way for long?

    <abbr>XUP’s last blog post..Scenes from a Hallway</abbr>

  • Patricia Apr 8, 2009

    Wow this is fascinating – thank you for sharing this new information to me.
    Sorry I am late to the show, because it is a great show..

    Sometimes, when it is clear the moon rises over the Lake and it is reflected in the water, which when still helps us see the patterns on the moon. We make up stories about what we see.

    I wonder if the sun was being reflected in the Lake if we could then see it's clarity?

    <abbr>Patricia’s last blog post..Book Review: Everything Bad is Good For You ~ Steven Johnson</abbr>

  • Mike Apr 13, 2009

    Sorry for taking so long to respond to comments. Procrastinating again 🙁

    Davina – I personally think it is all related and I didn't even mention the cool phase of the Pacific Decadal Oscillation which is now beginning – which some say will tend to cool the earth separate from the current solar conditions tending to cool us, in which case it would be colder + colder = much more colder, which I certainly hope is not the case. I'd rather have global warming than global cooling.

    XUP – See the above. Things may be getting colder rather than warmer.

    Patricia – I find it very interesting, too. Of course, if I didn't I probably would not be writing about it, would I? 😉

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