The Maunder minimum in a 400 year history of sunspot numbers

The Maunder Minimum is the name given to the period roughly from 1645 to 1715 A.D., when sunspots became exceedingly rare, as noted by solar observers of the time. It is named after the later solar astronomer E.W. Maunder who discovered the dearth of sunspots during that period by studying records from those years. During one 30-year period within the Maunder Minimum, for example, astronomers observed only about 50 sunspots, as opposed to a more typical 40,000–50,000 spots. Download high resolution version (906x286, 26 KB)400 year sunspot history, measured with Wolfer numbers. ... Download high resolution version (906x286, 26 KB)400 year sunspot history, measured with Wolfer numbers. ... Events January 10 - Archbishop Laud executed on Tower Hill. ... Events September 1 - King Louis XIV of France dies after a reign of 72 years, leaving the throne of his exhausted and indebted country to his great-grandson Louis XV. Regent for the new, five years old monarch is Philippe dOrléans, nephew of Louis XIV. September - First of the... 400 year sunspot history A sunspot is a region on the Suns surface (photosphere) that is marked by a lower temperature than its surroundings, and intense magnetic activity. ... Edward Walter Maunder (April 12, 1851 – March 21, 1928) was an English astronomer best remembered for his study of sunspots and the solar magnetic cycle that led to his identification of the period from 1645 to 1715 that is now known as the Maunder Minimum. ...

Sunspot observations

The Maunder Minimum occurred between 1645 and 1715 when only about 50 spots appeared as opposed to the typical 40–50,000 spots. The minima counts for 10-year periods from 1610-1681 are as follows: Events January 10 - Archbishop Laud executed on Tower Hill. ... Events September 1 - King Louis XIV of France dies after a reign of 72 years, leaving the throne of his exhausted and indebted country to his great-grandson Louis XV. Regent for the new, five years old monarch is Philippe dOrléans, nephew of Louis XIV. September - First of the... Events January 7 - Galileo Galilei discovers the Galilean moons of Jupiter. ... Events March 4 - Charles II of England grants a land charter to William Penn for the area that will later become Pennsylvania. ...

During the Maunder Minimum enough sunspots were sighted so that 11-year cycles could be extrapolated from the count. The maxima occurred in 1674, 1684, 1695, 1705 and 1716. Events January 7 - Galileo Galilei discovers the Galilean moons of Jupiter. ... Events September 6 - English emigrants on the Mayflower depart from Plymouth, England for the future New England and arrive at the end of the year. ... Events February 22 - Native American Quadequine introduces Popcorn to English colonists. ... Events December 1 - Portugal regains its independence from Spain and João IV of Portugal becomes king. ... Events June 23 - Claimant King Charles II of England, Scotland and Ireland arrives in Scotland, the only of the three Kingdoms that has accepted him as ruler. ... Events Expulsion of the Carib indigenous people from Martinique by French occupying forces. ... 1670 was a common year beginning on a Saturday in countries using the Julian calendar and a Wednesday in countries using the Gregorian calendar. ... Events First Portuguese governor was appointed to Macau The Swedish city Karlskrona was founded as the Royal Swedish Navy relocated there. ... Events February 19 - England and the Netherlands sign the Treaty of Westminster. ... Events France under Louis XIV makes Truce of Ratisbon separately with the Empire and Spain. ... Events January 27 - Change of emperor of the Ottoman Empire from Ahmed II to Mustafa II (1695-1703) July 17 - The Bank of Scotland is founded by an Act of Parliament of the old Scottish Parliament. ... Events Construction begins on Blenheim Palace, in Oxfordshire, England. ... Events Natchez, one of the oldest towns on the Mississippi, founded. ...

The sunspot activity was then concentrated in the southern hemisphere of the Sun, except for the last cycle when the sunspots appeared in the northern hemisphere too.

According to Spörer's law, at the start of a cycle spots appear at ever lower latitudes, until they average at about lat. 15° at solar maximum. The average then continues to drift lower to about 7° and after that, while spots of the old cycle fade, new cycle spots start appearing again at high latitudes. Spörers law predicts the variation of sunspot latitudes during a solar cycle. ...

The visibility of these spots is also affected by the velocity of the sun's rotation at various latitudes:

Visibility is somewhat affected by observations being done from the ecliptic. The ecliptic is inclined 7° from the plane of the Sun's equator (latitude 0°). Latitude, denoted φ, gives the location of a place on Earth north or south of the Equator. ... The plane of the Ecliptic is well seen in this picture from the 1994 lunar prospecting Clementine spacecraft. ...

Little Ice Age

The Maunder Minimum coincided with the middle — and coldest part — of the so-called Little Ice Age, during which Europe and North America, and perhaps much of the rest of the world, were subjected to bitterly cold winters. The Little Ice Age (LIA) was a period of cooling lasting approximately from the mid-14th to the mid-19th centuries. ... World map showing location of Europe A satellite composite image of Europe Europe is geologically and geographically a peninsula, forming the westernmost part of Eurasia. ... World map showing location of North America A satellite composite image of North America North America is the third largest continent in area and in population after Eurasia and Africa. ...

Whether there is a causal connection between low sunspot activity and cold winters is the subject of ongoing debate. Some scientists believe that solar variation drives climate change more than carbon dioxide does (see global warming). 20 years of solar irradiance data from satellites Solar variation refers to fluctuation in the amount of energy emitted by the Sun. ... The term climate change is used to refer to changes in the Earths climate. ... Carbon dioxide is an atmospheric gas composed of one carbon and two oxygen atoms. ... Global mean surface temperatures 1856-2004 Global warming is a term used to describe an increase over time of the average temperature of Earths atmosphere and oceans. ...

Other observations

Recently published research suggests that the Sun's rotation slowed in the deep Maunder minimum (1666–1700).^{[1] (http://en.wikipedia.org/wiki/Maunder_Minimum#endnote_Vaquero2002)} At our current level of understanding of solar physics, a larger and slower Sun necessarily implies a cooler Sun that provides less heat to Earth. (The mechanism behind the Sun's expansion and contraction is still unclear, although many stars undergo pulsations to some degree or another; see variable star.) A Sun is the star at the centre of a solar system. ... Events September 2 - Great Fire of London: A large fire breaks out in London in the house of Charles IIs baker on Pudding Lane near London Bridge. ... Events January 1 - Russia accepts Julian calendar. ... Earth, also known as the Earth or Terra, is the third planet outward from the Sun. ... Most stars are of nearly constant luminosity. ...

Solar activity events recorded in radiocarbon.

The lower solar activity during the Maunder Minimum also affected the amount of cosmic radiation reaching the Earth. The resulting change in the production of carbon-14 during that period caused an inaccuracy in radiocarbon dating until this effect was discovered. Download high resolution version (1002x317, 24 KB)Carbon-14 record for last 1,100 years (inverted scale). ... Download high resolution version (1002x317, 24 KB)Carbon-14 record for last 1,100 years (inverted scale). ... Cosmic rays can loosely be defined as energetic particles originating outside of the Earth. ... Carbon-14 is the radioactive isotope of carbon discovered February 27, 1940, by Martin Kamen and Sam Ruben. ... Radiocarbon dating is the use of the naturally occurring isotope of carbon-14 in radiometric dating to determine the age of organic materials, up to ca. ...

Graph showing proxies of solar activity, including changes in sunspot number and cosmogenic isotope production.

Solar activity also affects the production of beryllium-10, and variations in that cosmogenic isotope are studied as a proxy for solar activity. Description This figure shows two different proxies of solar activity during the last several hundred years. ... Description This figure shows two different proxies of solar activity during the last several hundred years. ... General Name, Symbol, Number Beryllium, Be, 4 Series Alkaline earth metals Group, Period, Block 2 (IIA), 2, s Density, Hardness 1848 kg/m3, 5. ... Cosmogenic refers to rare radioactive isotopes created when cosmic radiation interacts with an atomic nucleus. ... Isotopes are atoms of a chemical element whose nuclei have the same atomic number, Z, but different atomic weights, A. The word isotope, meaning at the same place, comes from the fact that isotopes are located at the same place on the periodic table. ...

Other historical sunspot minima have been detected either directly or by the analysis of carbon-14 in ice cores or tree rings; these include the Sporer Minimum (1450–1540), and less markedly the Dalton Minimum (1790–1820). In total there seem to have been 18 periods of sunspot minima in the last 8,000 years, and studies indicate that the sun currently spends up to a quarter of its time in these minima. Carbon-14 is the radioactive isotope of carbon discovered February 27, 1940, by Martin Kamen and Sam Ruben. ... An ice core is a tube of ice removed from an ice sheet. ... Pinus taeda Cross section showing annual rings Cheraw, South Carolina Dendrochronology or tree-ring dating is the method of scientific dating based on the analysis of tree ring patterns. ... The Spörer Minimum was a period of low solar activity which lasted from about 1420 to 1570 (some say 1450 to 1550). ... Events March - French troops under Guy de Richemont besiege the English commander in France, Edmund Beaufort, Duke of Somerset, in Caen April 15 - Battle of Formigny. ... Events January 6 - King Henry VIII of England marries Anne of Cleves, his fourth Queen consort. ... The Dalton Minimum was a period of low solar activity, lasting from about 1790 to 1820. ... 1790 was a common year starting on Friday (see link for calendar). ... 1820 was a leap year starting on Saturday (see link for calendar). ...

References

1. ^  Vaquero J.M., Sánchez-bajo F., Gallego M.C. (2002). "A Measure of the Solar Rotation During the Maunder Minimum". Solar Physics 207 (2): 219. DOI:10.1023/A:1016262813525 (http://dx.doi.org/10.1023/A:1016262813525)