There were no magnetic storms and field disturbances observed in the last two months related to solar activity, the laboratory said in a news release. Thus, space weather in the vicinity of our planet is increasingly losing its connection with the Sun, which by all indications practically fell to the bottom of the next minimum of the 11-year solar cycle 1.5 years earlier than expected.
At 5.7, the average monthly number of sunspots (one of the main indicators of the level of solar activity) reached a minimum value for the last 8 years of observations in November 2017. The last time the lower value was recorded in the last decade was in August 2009.
The average number of sunspots in September was 43, it dropped to 13 in October and to 5 in November. It is possible that this indicates a faster approximation of the next solar minimum than was expected. Such cases, when intervals between solar minima were reduced from 11 to 10 and even 9 years, are known in the history of astronomy, but occurred quite a long time ago - about 200 years - called the Dalton minimum.
Given that the previous solar maximum in 2012 was one of the weakest in the last century, it is possible, that we are now waiting for an earlier and substantially more ‘severe’ minimum of the cycle. If so, it is impossible to exclude that solar activity is now falling to the bottom of a 100-year or even 1000-year cycle. Although the question of the presence of such global recessions in the Sun is still debatable, radiocarbon analysis of rocks and plants provides much evidence of the existence of such changes in the past.
Featured image credit: NASA/SDO (December 20, 2017)