NSF Award
8814442
The influence of the 11 year solar cycle on weather has been suspected for centuries, but only within the last year has real progress been made on describing with confidence the changes that are occurring. The work of Labitzke and van Loon has shown that the effects are very different depending on the direction of stratospheric winds at equatorial latitudes, and it is necessary to sort the atmospheric data (winds, temperatures, pressures, location and frequency of storms) according to the phase of the oscillation of equatorial stratospheric winds. These winds change direction with a period of a little over two years, and are said to undergo a "quasi-biennial oscillation" or QBO, and it has been found, for instance, that in the West phase of the QBO the storm tracks in the North Atlantic above 50o latitude move equatorward by about 6o at solar maximum as compared to solar minimum. This award is for an analysis of tropospheric wind data from 170 radiosonde stations for the years 1950 through 1987, with sorting according to the phase of the QBO, to evaluate the strength of the correlations with solar activity. Hopefully, specific variations will emerge that will provide a clue as to the nature of the causitive mechanism.
