Dr. L. Poustilnik, Dr. G. Yomdin (Sea of Galilee Astrophysical Observatory, Jordan Valley College; Israel Space Weather Center, Israel Space Agency & Tel Aviv University, Israel )

Abstract:

Our study shows that, as the result of the nonlinear causal links between solar activity-cosmic ray flux-cloudiness condition-wheat production-wheat price, bursts and slumps of wheat prices could take place at extreme states (maximums or minimums) of solar activity cycles. We present a conceptual model of possible modes for sensitivity of wheat prices to weather conditions, caused by solar cycle variations, and compare the expected price fluctuations with wheat price variations recorded in the Medieval England.  We compared statistical properties of the intervals between wheat price bursts during years 1249-1703 frome data of Prof. Rogers with statistical properties  of the intervals between extremes (minimums) of solar cycles during the years 1700-2000.  We show that statistical properties of these two samples are similar, both for characteristics of the distributions and for the histograms of the distributions.     In the next step, we analyze a direct link between wheat prices and solar activity in the 17th Century, for which wheat prices and solar activity/cosmic ray intensity data (derived from 10Be isotope) are available. We show that for all 10 time moments of the solar activity minimums  the observed prices were higher  than prices for the correspondent time moments of maximal solar activity  (100% sign correlation, on a significance level < 0.2%). This result, combined with the conclusion about similarity of statistical properties of the intervals between price bursts and solar activity  extremes, we consider as a direct evidence of the causal connection between wheat prices bursts and solar activity.

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