Letter | Published:

Short term relationships between solar flares, geomagnetic storms, and tropospheric vorticity patterns

Naturevolume 257pages113115 (1975) | Download Citation



IT has been found that the 500—mbar vorticity area index (VAI), which is a rough measure of the strength of the cyclonic activity over the Northern Hemisphere, responds to solar flares in at least two ways. First, there is an increase in the VAI in the first two days after the flare. Then, after the geomagnetic storm which often follows a major solar flare, there is a sharp decrease in the VAI. The results are consistent with earlier studies of the development of pressure troughs in the North Pacific area.

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  1. 1

    Wilcox, J. M., Scherrer, P. H., Svalgaard, L., Roberts, W. O., and Olson, R. H., Science, 180, 185–186 (1973).

  2. 2

    Wilcox, J. M., et al., J. atmos. Sci., 31, 581–588 (1974).

  3. 3

    Wilcox, J. M., Svalgaard, L., and Scherrer, P. H., Nature, 255, 539–540 (1975).

  4. 4

    Roberts, W. O., and Olson, R. H., Revs Geophys. space Phys., 11, 731–740 (1973).

  5. 5

    Dodson, H. W., and Hedeman, E. R., An Experimental Comprehensive Flare Index and its Derivation for ‘Major’ Flares, 1955–69, Rept Mo. UAG-14 (NOAA, EDS, Boulder, Colorado, 1971).

  6. 6

    Langley, R. Practical Statistics Simply Explained (Dover, New York, 1970).

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  1. Department of Astro-Geophysics, University of Colorado, Boulder, Colorado, 80302

    • R. H. OLSON
  2. University Corporation for Atmospheric Research, PO Box 3000, Boulder, Colorado, 80303

    • W. O. ROBERTS
  3. National Center for Atmospheric Research, PO Box 3000, Boulder, Colorado, 80303

    • C. S. ZEREFOS


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