By Ed Caryl
On May 17th, Willis Eschenbach posted “Sailing on the Solar Wind” on WUWT. In it he used a graph of the daily solar wind data since 1963. I wish to thank Willis for his effort in tabulating the daily data AND for making it available for the rest of us.
That graph had some shapes that were hauntingly familiar. Here it is, repeated, but with the vertical axis reversed. Less solar wind is warming, more is cooling.
Figure 1 is a plot of the daily solar wind data since 1963, courtesy of Willis Eschenbach, here.
I saw two large white-space notches in this plot, one at 1996-7, and another at 2008-9, where the solar wind decreased for long periods. These are just before the two recent El Niños of 1998 and 2010. I downloaded Willis’s data and converted it to monthly averages so that it could be compared to the various available temperature data. Here (Figure 2) is that data with a three-month centered average applied to both the solar wind data and the Hadley Center HADSST3 sea-surface temperature.
Figure 2 is a plot of the solar wind (inverted) and sea surface temperature since 1963.
Note the similarity. The solar wind acts similarly to the cosmic ray impact described in Cosmic Rays and the Impact On Climate. A decrease in solar wind occurs just prior to an increase in temperature. This probably happens because the solar wind acts in a similar fashion as CME’s in producing Forbush decreases in Neutron flux. Both produce an increase in cosmic ray production of cloud nuclei. But why the delay? Several temperature data bases were investigated and compared, using one-month delay steps and computing the R-squared value in Excel for each comparison. Figure 3 resulted:
Figure 3 is a plot of the response to a solar wind change (reduction) on various temperature databases. All temperature data were obtained from www.woodfortrees.org. and de-trended.
Two questions are suggested by this data. Where is the initial temperature change taking place? And why is there a delay? The answers seem to be: 1) The initial warming is in the tropics, specifically in the central Pacific in the El Niño region. In that area, there is no delay, the warming occurs immediately and for the following 3 or 4 months. (The green trace.) The other sea surface temperature data base, HADSST3, and its 3-month average, also reflect the initial immediate warming, but also have a peak at 8 months after, probably for those areas away from the tropics that are warmed later, either by moving currents, or by moving atmosphere.
The land data, HADCRUT4, shows a peak at 8 months and again at 11 months. The reason becomes a little clearer when the hemispheric components are examined. The southern hemisphere reacts quickly then drops off after 8 months, probably because the oceans react faster than the land. The northern hemisphere reacts at 8 months and 11 months because the northern hemisphere has greater land mass.
I recognize that this relationship is speculative. But the relationships seen in Figure 3 are consistent and devoid of “noise”. Delays outside of the range shown have consistently very low R-squared values. It is suggested that this research area bears further study.