Winter Storms in North Atlantic Follow the Solar Cycle
Monastersky, Richard, Science News
Winter storms in North Atlantic follow the solar cycle
A tiny, 11-year cycle in the sun's radiation appears to exert a strong influence on the paths of winter storms in the North Atlantic near Great Britain, reports an atmospheric scientist from the National Science Foundation. This finding, to be announced in the May GEOPHYSICAL RESEARCH LETTERS, exemplifies a renewed interest in seeking links between the solar cycle and earthly weather -- a field that has traditionally engendered skepticism and even scorn.
Atmospheric scientist Brian A. Tinsley reexamined a ten-year-old statistical analysis of the relationship between storm tracks in the North Atlantic and the solar cycle. This earlier study found that during a maximum in the solar cycle -- when the total solar output of energy is highest -- the average storm track was 2.5 [deg.] south of the average tracks during a sunspot minimum. However, according to Tinsley's new analysis, the storm tracks during maximum and minimum differ on average by over 6 [deg.], or over 400 miles.
"In fact, this is a very strong pattern," says Tinsley.
For his reanalysis, Tinsley borrowed a concept recently developed by Karin Labitzke of the Free University in Berlin along with Harry van Loon of the National Center for Atmospheric Research in Boulder Colo. (SN: 12/19 & 26/87, p.388). These researchers found last year that stratospheric winds over the tropics seem to be an important element in the relationship between the solar cycle and weather.
These tropical winds reverse their direction in a 26-month cycle called the Quasi-biennial Oscillation (QBO). Labitzke and van Loon found that when they looked only at years from the west phase of the QBO, a strong correlation emerged between the solar cycle and atmospheric temperatures and pressures. …