WASHINGTON: US scientists say the familiar sunspot cycle seems to be entering a hibernation period unseen since the 17th century, a pattern that could have a slight cooling effect on global temperatures. For years, scientists have been predicting the Sun would by around 2012 move into solar maximum, a period of intense flares and sunspot activity, but lately a curious calm has suggested quite the opposite. The signs include a missing jet stream, fading spots and slower activity near the poles, said a trio of studies presented Tuesday at the annual meeting of the American Astronomical Society's Solar Physics Division in Las Cruces, New Mexico. “This is highly unusual and unexpected,” said Frank Hill, associate director of the National Solar Observatory's Solar Synoptic Network. “But the fact that three completely different views of the Sun point in the same direction is a powerful indicator that the sunspot cycle may be going into hibernation.” Solar activity tends to rise and fall every 11 years or so. Experts are now probing whether this period of inactivity could be a second Maunder Minimum, a 70-year period when hardly any sunspots were observed between 1645-1715 known as the “Little Ice Age.” Solar flares and eruptions can send highly charged particles hurtling toward Earth and interfere with satellite communications, GPS systems and even airline controls. Geomagnetic forces have been known to occasionally garble the world's modern gadgetry, and warnings were issued as recently as last week when a moderate solar flare sent a fiery coronal mass ejection in the Earth's direction. However, the temperature change associated with any reduction in sunspot activity would likely be minimal and not enough to offset the impact of greenhouse gases on global warming, according to scientists.
