In 2006, NASA announced that we were in a solar minimum and the sun is quiet. In 2009, Science News wrote an article claiming the sun had entered the weakest cycle since 1928. So what is the significance of solar activity?
I took Astronomy last semester and here is some great information about the Sunspot Cycle and how we can be affected.
For over 100 years, astronomers have been watching the sun, especially the formation of sunspots on the sun and have found a pattern. There has been 23 sunspot cycles since 1900 and based on observations, each cycle lasts around 11 years. During this cycle, the average number of sunspots gradually increases and then gradually decreases. The sunspot cycle is believed to be caused by a combination of convection and the Sun’s rotation. Convection from within creates magnetic field lines that run from North to South on the Sun. The Sun’s rotation is faster at the equator than the poles causing the magnetic field lines to get twisted thus causing sunspots and solar activity. The solar maximum is when the sunspots are the most numerous and likewise, solar minimums have a few to no sunspots. With solar maximums comes coronal mass ejections and flares and strong solar winds. With solar minimums, it is like the Sun is dormant and no convection is taking place.
As you may know, the Earth’s magnetosphere protects us from the solar wind, flares, storms. The only evidence that we see of solar activity is the auroras present in the skies over the poles. We call these auroras the Northern and Southern Lights. Usually the lights can be seen between 65 to 72 degrees north and south latitudes; however, during solar maximums the view is more widespread. In 1859, the worse solar storm was experienced by the world. It was called the Carrington event. There are claims that during that year, the auroras could be seen in all of North America, Europe, Japan, and even Australia. Some accounts say that at 1am, you could clearly read a book outside due to the brightness of the polar lights. The biggest problem was that the world’s telegraph networks experienced severe disruptions. So what is the big deal?
HERE IS THE BIG DEAL!!! We are due, in fact, past due for a strong solar maximum. In the last 100 years, we have made many technological advances that make our lives easier. From electricity grids to satellites in space to cellular phones, a strong solar maximum could cause havoc and perhaps disaster on Earth. Imagine if the Carrington event happened today. It would affect our electricity….first to go is lights, then we would lose drinkable water. Large cities would lose transportation systems, gas would eventually run out because there would be no electricity to pump gas from reserve tanks. No gas, no back-up generators. Imagine a hospital without modern medicine. It would take years to recover and many people would not survive.
I say all this not to scare you but to prepare you. We have officially began sunspot cycle 24 and we should reach solar maximum in 2012-2013. On October 14, 2010 pictures were posted on http://www.solarcycle24.com/ of images of the sun showing the formation of four sunspots. The sunspots are small and all is still quiet, but it is worthy to keep an eye on.