Sunspot update for June 2017

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Today NOAA posted its monthly update of the solar cycle, covering sunspot activity for June. As I have done every month since 2010, the graph is posted below, with annotations.

June 2017 Solar Cycle graph

The graph above has been modified to show the predictions of the solar science community. The green curves show the community’s two original predictions from April 2007, with half the scientists predicting a very strong maximum and half predicting a weak one. The red curve is their revised May 2009 prediction.

Sunspot activity in June was almost exactly the same as in May, and thus continued the overall downward trend that is below the 2007 low prediction and that suggests that this very weak solar maximum will end much earlier than predicted, and will make it an unprecedented short but weak cycle. The Sun is once again blank today for the first time in about two weeks, repeating the pattern we have seen for several months where, because one hemisphere of the Sun is blank while the other hemisphere has some sunspots, the rise and fall of the sunspot counts tracks the 27-day solar rotation almost precisely.

There continues to be evidence that the Sun is undergoing significant changes this solar cycle, all of which are pointing to the possibility that a grand minimum is coming, with no sunspots for decades. And as I have said now monthly for six years, past grand minimums have consistently occurred at the same time the Earth’s climate has cooled. The scientific link remains unclear, but if we should undergo a grand minimum in the coming decades, we will finally have the opportunity to find out what that link is.



  • steve mackelprang

    Take a look at this paper, I suspect the results will be come apparent rather more quickly.

  • LocalFluff

    steve mackelprang
    Since you understand this stuff, could you summarize the conclusions here?
    The first sentence of the executive summary in the link to your paper hardly enlightens anyone like the Sun does:
    “This paper describes the recommended solar forcing dataset for CMIP6 and highlights changes with respect to CMIP5.”

  • wodun

    all of which are pointing to the possibility that a grand minimum is coming, with no sunspots for decades. And as I have said now monthly for six years, past grand minimums have consistently occurred at the same time the Earth’s climate has cooled.

    Taking this a different direction, what does this mean for satellites, space stations, interplanetary probes, and humans in space? A weaker sun means more cosmic rays right?

  • wodun

    The quantitative assessment of radiative solar forcing has
    been systematically hampered so far by the large uncertainties
    and the instrumental artifacts that plague SSI observations,
    and to a lesser degree TSI observations (e.g., Ermolli
    et al., 2013; Solanki et al., 2013). Another problem
    is the sparsity of the observations, which only started in the
    late 1970s with the satellite era. These problems have deprived
    us of the hindsight that is needed to properly assess
    variations on timescales that are relevant for climate studies.
    Another issue is the uncertainty regarding their absolute
    level. Since CMIP5, the nominal TSI has been reduced to
    1361.0 ± 0.5 W m−2
    (see Prša et al., 2016, and also Kopp and
    Lean, 2011). This adjustment has inevitable implications for
    understanding the Earth’s radiation budget.

    I am not sure that paper will be much help. There are many paragraphs like this. The introduction chronicles many things left out of earlier studies, things not well know, great uncertainties, a chaotic system with chains of interactions, poor data, and poor models leading to other distortions.

    It can’t be relied on for anything predictive but it should be interesting to see how reality changes their assumptions and modeling in the future.

  • wodun

    The interesting thing about the paper is when it goes into what factors were ignored in earlier CMIP’s. I am not sure how anyone could read these things and then come away with the conclusion that there is little uncertainty and everything is settled science.

  • Wodun: A less active sun means the atmosphere shrinks, which causes the orbits of satellites to decay less. This was why Skylab fell out of orbit sooner than expected. In the mid-1970s the Sun was very active, so the atmosphere expanded and caused Skylab’s orbit to decay faster than predicted.

    A less active Sun also means more cosmic rays will be hitting the top of the atmosphere, which is one of the phenomenon that is suspected to cause the cooling. The theory is that cosmic rays interact with water particles and produce more clouds.

  • Wodun: The paper linked to is merely a computer model. It is not actual data obtained from observations, though they try hard to make their model match those observations.

    I generally don’t pay much attention to these models, even ones that confirm my own theories. As the saying goes, garbage in, garbage out.

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