Letter | Published:

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

Nature volume 257, pages 113115 (11 September 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.

Access optionsAccess options

Rent or Buy article

Get time limited or full article access on ReadCube.


All prices are NET prices.


  1. 1.

    , , , , and , Science, 180, 185–186 (1973).

  2. 2.

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

  3. 3.

    , , and , Nature, 255, 539–540 (1975).

  4. 4.

    , and , Revs Geophys. space Phys., 11, 731–740 (1973).

  5. 5.

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

  6. 6.

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

Download references

Author information


  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


  1. Search for R. H. OLSON in:

  2. Search for W. O. ROBERTS in:

  3. Search for C. S. ZEREFOS in:

About this article

Publication history






Further reading


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.