[ad_1]
 |
Weather Eye with John Maunder |
A sunspot is a relatively dark and clearly defined region on the solar disk – marked by a shadow (dark zone) which is 2000 degrees Celsius cooler than the actual temperature photosphere.
The average diameter of a sunspot is 4000 km, but may exceed 200 000 km
The website of NASA Solar Physics (and other sites such as the Observatory Royal of Belgium) contains information on the number of sunspots. & # 39; and sunspot cycle predictions. The sunspot index is updated monthly and available from 1749. The last time the monthly number of sunspots was greater than 100 for a significant period was in September 2002 when the value was 109 6. the value was 200.3
The peak of the last solar cycle number 24 was reached in April 2014, with a maximum of the number of sunspots smoothed over 13 months at 81.8. Since then, solar activity has steadily declined. The average monthly number of sunspots is now about 20, and for the 16 days to July 16, 2018, there have been no sunspots.
As this late maximum comes more than 5 years after the previous minimum in December 2008, Cycle 24 has now entered its long phase of decline because none of the cycles observed previously had longer delays between the minimum and the maximum. Therefore, the average solar activity should gradually decrease to a minimum around 2020. However, over the next 2 or 3 years, we can still expect strong but brief peaks of activity caused by l & rsquo; Emergence of some large complex groups
We are currently more than seven years in the solar cycle 24. It is the smallest solar cycle since solar cycle 14 which had a maximum of 64.2 in February 1906.
Since mid-2016, the sun has sometimes been devoid of sunspots. These flawless records will gradually become a familiar feature as the solar cycle moves towards its next minimum, currently expected by the end of the decade. The number of flawless days can vary significantly from one solar cycle transit to the other. For example, during the previous minimum (around 2008), no less than 817 flawless days were recorded, while the minimum period leading to solar cycle 23 (around 1996) was only 309 days without blemishes.
As the current solar cycle 24 will gradually give way to the new solar cycle 25, several consecutive days and even weeks without sunspots will become the norm. In order to have an idea of the number of perfect days, and how these figures compare to past solar cycles, the SILSO website has created a "Spotless Days" page. This page contains charts and tables on the accumulated number of flawless days, days without spots and comparisons with other solar cycles – all supplemented by an explanation word.
The previous minimum surprised scientists and solar observers. almost 90 years old. Will the next cycle of the upcoming solar cycle show as many flawless days, or will the solar cycle take off much faster than expected? The "Spotless Days" page will give you a first place on the current state of the minimum solar cycle and the number of perfect days. Enjoy! Maybe a new era "Maunder Minimum" is in place!
For more information, see: https://sites.google.com/site/johnmaunder/the-maunder-minmium—300-years
Source link
