Scientists: The solar cycle was only 8 years long during the Maunder Minimum in the 1600s
Using archival records gathered in Korea during the 1600s when the Sun was undergoing a long period of almost no sunspots — called the Maunder Minimum — scientists have discovered evidence that the solar cycle during that time was only 8 years long.
You can read their paper here. Since almost no sunspots were visible at that time, the scientists used reports of aurora in Korea to determine periods when the Sun was more active. From their abstract:
By analyzing the variations in solar activity-related equatorial auroras recorded in Korean historical books in the vicinity of a low-intensity paleo-West Pacific geomagnetic anomaly, we find clear evidence of an 8-year solar cycle rather than the normal 11-year cycle during the Maunder Minimum.
This 8-year cycle is shorter than the 9-year cycle that other researchers had estimated based on the few sunspots that did appear during this grand minimum. Both conclusions however challenge what is known of the Sun. Since the 11-year cycle resumed in the 1700s, short cycles have generally been associated with very active periods, the opposite of what has been found during Maunder.
In other words, we know better what happened, but have no understanding of why. Since the Maunder Minimum appears associated with the Little Ice Age of the 1600s, and fits other data that says the climate cools when the Sun produces few sunspots, gaining some understanding of this process is important for understanding past and future changes to the global climate.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit.
The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
Using archival records gathered in Korea during the 1600s when the Sun was undergoing a long period of almost no sunspots — called the Maunder Minimum — scientists have discovered evidence that the solar cycle during that time was only 8 years long.
You can read their paper here. Since almost no sunspots were visible at that time, the scientists used reports of aurora in Korea to determine periods when the Sun was more active. From their abstract:
By analyzing the variations in solar activity-related equatorial auroras recorded in Korean historical books in the vicinity of a low-intensity paleo-West Pacific geomagnetic anomaly, we find clear evidence of an 8-year solar cycle rather than the normal 11-year cycle during the Maunder Minimum.
This 8-year cycle is shorter than the 9-year cycle that other researchers had estimated based on the few sunspots that did appear during this grand minimum. Both conclusions however challenge what is known of the Sun. Since the 11-year cycle resumed in the 1700s, short cycles have generally been associated with very active periods, the opposite of what has been found during Maunder.
In other words, we know better what happened, but have no understanding of why. Since the Maunder Minimum appears associated with the Little Ice Age of the 1600s, and fits other data that says the climate cools when the Sun produces few sunspots, gaining some understanding of this process is important for understanding past and future changes to the global climate.
On Christmas Eve 1968 three Americans became the first humans to visit another world. What they did to celebrate was unexpected and profound, and will be remembered throughout all human history. Genesis: the Story of Apollo 8, Robert Zimmerman's classic history of humanity's first journey to another world, tells that story, and it is now available as both an ebook and an audiobook, both with a foreword by Valerie Anders and a new introduction by Robert Zimmerman.
The print edition can be purchased at Amazon. from any other book seller, or direct from my ebook publisher, ebookit. The ebook is available everywhere for $5.99 (before discount) at amazon, or direct from my ebook publisher, ebookit. If you buy it from ebookit you don't support the big tech companies and the author gets a bigger cut much sooner.
The audiobook is also available at all these vendors, and is also free with a 30-day trial membership to Audible.
"Not simply about one mission, [Genesis] is also the history of America's quest for the moon... Zimmerman has done a masterful job of tying disparate events together into a solid account of one of America's greatest human triumphs."--San Antonio Express-News
24 min about tree rings and how they relate to hurricanes, sinking ships, maunder minimum and the Golden Age of Piracy. Worth a listen.
https://radiolab.org/podcast/fellowship-tree-rings/transcript