blimey! solar wind and tropical cyclones
Here are a couple of papers that I’m going to have to find time to read properly:
- Prikryl, P., Ru?in, V., and Rybansk'y, M.: The influence of solar wind on extratropical cyclones ? Part 1: Wilcox effect revisited, Ann. Geophys., 27, 1-30, 2009, and
- Prikryl, P., Muldrew, D. B., and Sofko, G. J.: The influence of solar wind on extratropical cyclones ? Part 2: A link mediated by auroral atmospheric gravity waves?, Ann. Geophys., 27, 31-57, 2009.
Some choice excerpts from the abstracts:
A sun-weather correlation, namely the link between solar magnetic sector boundary passage (SBP) by the Earth and upper-level tropospheric vorticity area index (VAI), that was found by Wilcox et al. (1974) and shown to be statistically significant by Hines and Halevy (1977) is revisited. A minimum in the VAI one day after SBP followed by an increase a few days later was observed. Using the ECMWF ERA-40 re-analysis dataset for the original period from 1963 to 1973 and extending it to 2002, we have verified what has become known as the "Wilcox effect" for the Northern as well as the Southern Hemisphere winters.
Cases of mesoscale cloud bands in extratropical cyclones are observed a few hours after atmospheric gravity waves (AGWs) are launched from the auroral ionosphere. It is suggested that the solar-wind-generated auroral AGWs contribute to processes that release instabilities and initiate slantwise convection thus leading to cloud bands and growth of extratropical cyclones.
It is also observed that severe extratropical storms, explosive cyclogenesis and significant sea level pressure deepenings of extratropical storms tend to occur within a few days of the arrival of high-speed solar wind.
Do I believe in this?
Well, I haven’t read the papers, but I’m on record as believing that upper boundary affects can reach the troposphere, so it’s feasible, particularly in that the basic thesis seems to revolve around small scale waves driving systems across instability boundaries, a non-linear affect that is more than feasible.
William (on Tuesday 06 January, 2009)
More likely, if you want to find “stat sig” effects, use a noisy time series :-)