Solar Cycle on EARTH Magazine

Japanese diaries show sun's cycle sparks lightning on Earth

Tue, 16 Oct 2018 09:40:44 -0400

New research links lightning to the 27-day solar rotational cycle. Credit: ©iStockphoto.com/mdesigner125.

The effects of solar cycles on Earth’s climate over timeframes of thousands of years are well documented, but the shorter-term effects on weather are less understood. A new study using ancient Japanese diaries to track storms in the 18th and 19th centuries suggests that one of the sun’s shortest cycles — the 27-day rotational period — may play a role in stimulating lightning on Earth.

Does the sun trigger autoimmune disease?

Thu, 08 Oct 2015 10:20:23 -0400

Solar activity may play a role in incidences of rheumatoid arthritis and giant cell arteritis, two autoimmune diseases. Credit: SOHO (ESA & NASA).

For hundreds of years, humans have charted the appearance of sunspots, the changing frequency of which marks highs and lows in the sun’s 11-year solar cycle. Peaks in the solar cycle cause surges in the amount of solar radiation reaching Earth, which can lead to changes in weather and climate, and can disrupt radio signals and electrical grids. Now, researchers have found that the solar cycle may also affect human health, with cases of rheumatoid arthritis and giant cell arteritis seeming to spike in concert with solar fluctuations.

Spot-free sun: Is that normal?

Thu, 05 Jan 2012 06:41:58 -0500

These images, four years apart, show the rise and fall of solar activity during the sun's 11-year cycle. SOHO (ESA & NASA)

For the past few years, astronomers and scientists have been looking up at a sun that is, more often than not, rather blank. Almost too blank. That is, the sun has been relatively free of the dark patches, called “sunspots,” that appear within 30 degrees of the sun’s equator and travel across the surface. Although low sunspot counts are normal in a typical sunspot cycle, this period has gone on longer than usual, scientists noted at an international solar conference on “Solar Variability, Earth’s Climate and the Space Environment” held in early June at Montana State University in Bozeman. However, they said, while slightly longer than the past three or four solar cycles, the current minimum is not too out of the ordinary.