Thursday, 5 September 2013

current activity is very low! And getting lower?

Solar activity - sunspot areas - are now lower than even SC16 in the early 20th century. Where to next! Stay posted.


  1. Hi Harry,

    Love the blog, very informative, keep up the great work!
    Could we be in the beginnings of a extended solar minumum ("solar shutdown"), something that could last thousands, maybe millions of years? With the new models for how martian atmosphere has changed over the aeons coming out; I was wondering if the loss could be caused by a similar event, I tried to do some calculations using evaporation but was struggling to find density data. Still, I was thinking that the protons supplied by the solar wind are generally at a higher density than the air at about 100-200km abv sea lvl, and it seems probable that this flux changes the rate at which the lighter elements boil off, maybe even resulting in a net gain on some high intensity days. What if mars went through a similar lul, or perhaps began with an opposite event; a solar maxim giving it enough energy to have an atmosphere and liquid water, maybe even life!

    Thanks for the blog, would love to hear your thoughts.



    1. Hiya Shannon - thanks for the compliment and the discussion. These are tough questions. It is now certain that solar activity over last half of 20th C was the strongest in 400 years (See Solanki, S in 'Nature' I think, last year); and that we are now in a deep minimum comparable with that of about 1880 (as the graph shows). Implications are not at all clear: tho' it's tempting to speculate.