Tuesday, September 15, 2009

Sun Spots and Atlantic Storms Correlation

In order to comply with the complaining about the low solar numbers quota that every HAMs must comply with as per of FCC rules, Earlier this week while driving I was amusing myself by dreaming about higher solar activity. -- Doesn't everybody?

In this particular day dream, I started to notice that there was an apparent relationship between solar activity chart in my head and the hurricanes I could bring to mind, please remember I'm driving, so my data was more than a little fuzzy. So this PDF is a result of an attempt to do a slightly less fuzzy back-of-an-envelope type of calculation.

I got my Solar Data and chart from the Solar Influences Data Analysis Center - (SIDC) http://sidc.oma.be/sunspot-index-graphics/sidc_graphics.php

and my Storm Data from the National Oceanic and Atmospheric Administration - (NOAA) - http://www.aoml.noaa.gov/general/lib/mgch.html (and a few others)

This seems so obvious that I knew I could not have been the first to notice, so a little google search turned a few references, but the best and cleanest seem to be this wiki entry. Where it names good 'le GATECH as the authors of just such an idea.


OK, so it is not a new idea, but an interesting one all the same. Notice the storms seem to ovoid the peaks (and troughs - except for Betsy). My original idea was that really large US hitting storms would only occur 18 mo ~ 24 mo AFTER the solar peak. This simple chart shows that is not exactly exclusively true. While it is true that storms do seem to follow that pattern, they also seem to happen 18 mo ~ 24 mo BEFORE the solar peak. This needs a little more work before any real conclusions can be made, but there does seem to be a pattern.


  1. The few Atlantic hurricanes posted on the graph of sunspot numbers do not seem to suggest (to me) much of a correlation. It might be more revealing to include every major (cat 3+) hurricane during the study period. An interesting data source is weather.unisys.com/hurricane/atlantic. On the other hand, the Ga Tech study claimed a correlation with low sunspot activity. It may be fertile ground for graduate students to explore.

  2. Well said John; This was just a back of an envolope calculation. I love the unisys site you provided, much detailed than the ones I had used.

    I will attempt to do a 50 year stretch with Cat 3+ storms, and included the non US striking ones too.