Monday, April 13, 2009

Thirty Five Days In A Row Without A Sunspot

The blank sun continues in 2009. It marks the third year in a row that solar activity has been at a minimum.

In fact, today marks the absence of a observed sunspot for the thirty fifth consecutive day in 2009.

The current decrease in sunspot activity is beginning to look like the long solar minimum that occurred from 1795 to 1830, known as the Dalton Minimum. During this period of time global temperatures dramatically decreased and volcanic eruptions increased. In the northeast United States, 1816 became known as the year without a summer with snow in the month of June.

A correlation of a lack of sunspot activity and frigid global temperatures also occurred in a period lasting from 1645-1715 when sunspots were 1/1000th of normal. This period was called the Maunder Minimum. It heralded the arrival of the Little Ice Age, a period when glaciers advanced and bitterly cold winters occurred in many regions of the Northern Hemisphere.

The lack of sunspots in this solar cycle (cycle 24) may well mean much colder times are ahead. Sunspot activity during recent decades has been the highest seen in the past 8,000 years and is probably the reason that the global climate has warmed during the 20th century.

The lack of current solar activity has ramifications for the global climate of the next few decades. Its now been more than a month since the last observed sunspot. The longer the sun remains blank and solar activity remains weak, the more interesting this solar cycle minimum will become.

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