A warning by scientists that solar activity has reached its lowest since 2011 has raised concern that the Sun could reach solar minimum earlier than expected. This has sparked fears that the world could be on the brink of a new mini ice-age.
Signs that the Sun could reach solar minimum earlier than previously expected were obtained from images captured by NASA's Solar Dynamics Observatory (SDO) between November 14 and 18. The images show the face of the Sun unexpectedly blank, with only very few barely-visible sunspots, as reported by the Daily Mail.
The incidence of sunspots is an indication of level of solar activity and, according to NASA, the image indicated that the Sun had reached its lowest level of activity since 2011.
"This week (Nov. 14-18, 2016) the sun was hitting its lowest level of solar activity since 2011 as it gradually marches towards solar minimum," NASA said in a statement posted to its SDO website.
"This activity is usually measured by sunspot count and over the past several days the sun has been almost spotless," the statement continued.
"At this point in time, the sunspot numbers seem to be sliding downwards faster than expected though the solar minimum level should not occur until 2021."
The Sun is currently in Cycle 24, which began in 2008. According to scientists, during the current cycle, the Sun has had the smallest number of sunspots since Cycle 14, which reached its maximum in February 1906.
Earlier, on June 4, scientists reported that the Sun was observed to be completely spotless, with activity remaining very low for about four days in a row. A previous period of low activity occurred in February when, according to NASA scientists, the Sun looked as blank as a "cue ball."
NASA scientists pointed out that the recent observations could mean that the solar activity is plunging toward the next solar minimum faster than expected. This has caused some experts to warn that the trend could trigger a new "mini ice-age" earlier than expected.
Solar activity fluctuates in a cyclical pattern over an 11-year period between solar maximum, characterized by a high number of sunspots and frequent solar storms, and solar minimum, characterized by a low number of sunspots and relatively decreased overall solar activity.
After the solar maximum that occurred in 2014, scientists had expected that the next solar minimum would not occur until 2021. Following the low activity recorded from November 14 to 18, scientists said they were expecting to see a higher incidence of sunspots in subsequent weeks. But if further observations show that the Sun is approaching solar minimum faster than expected it means that we could begin to experience the bitter winters of a mini ice age earlier than previously expected.
Scientists know that prolonged sunspot minimum characterized by rare occurrences of sunspots caused the period of relatively cold weather with bitter winters that occurred in Europe from 1645 to 1715.
Europe's "mini ice-age," known as the Maunder Minimum, lasted 75 years and is the longest solar minimum on record.