3.029 and 3.606 minute cycles in Solar Wind Speed

The ACE satellite measures the solar wind speed (among other things) of particles traveling from the Sun towards the Earth. Located at the L1 libration point it is always around 1.5 million km in the direction of the Sun and so can give about an hours warning of space weather changes. The solar wind speed is typically in the range of 300 to 700 km/s.

This 1 minute interval real time data remains available for only a short period of time. The  present analysis was done on data recorded on 11th July 2015 and there are 1440 (less about 20 or so missing) measurements at 1 minute intervals. The analysis was done using our free CATS software.

Firstly the rapidly fluctuating solar wind speed is shown.  It can be seen that minute by minute there are substantial changes in solar wind speed. A spectral analysis of the solar wind speed shows a number of cycles significant at p=0.05 level as listed in this table:

no. of    Cycle period    Date of peak    Cycle            Bartell’s
cycles    minutes                                  Strength        Test (p=)

399.28    3.60649    2015.5252621    0.098406    0.00000000
475.39    3.02909    2015.5252634    0.076864    0.00000000
398          3.61809    2015.5252620    0.054579    0.00001875
400.83    3.59255    2015.5252648    0.050971    0.00014225
402.19    3.58040    2015.5252665    0.045818    0.00079066
49.32    29.19708    2015.5253121    0.070705    0.00204380
395.79    3.63829    2015.5252675    0.039579    0.00348685
217.41    6.62343    2015.5252699    0.042097    0.00369764
476.69    3.02083    2015.5252647    0.036243    0.00429099
50.53    28.49792    2015.5252634    0.060138    0.00621892
215.95    6.66821    2015.5252676    0.038759    0.00634786
474.01    3.03791    2015.5252625    0.032432    0.00820103
403.29    3.57063    2015.5252618    0.034605    0.00867797
74.88    19.23077    2015.5252801    0.046984    0.01230259
194.41    7.40703    2015.5252621    0.038716    0.01238090
32.64    44.11765    2015.5252903    0.042015    0.01393355
48.11    29.93141    2015.5253090    0.055255    0.01451557
161.24    8.93079    2015.5252751    0.043495    0.01474822
324.51    4.43746    2015.5252652    0.036788    0.01493206
482.48    2.98458    2015.5252647    0.020699    0.01656507
172.13    8.36577    2015.5252655    0.038061    0.01716400
76.21    18.89516    2015.5252839    0.050419    0.01754671
39.99    36.009    2015.5253088    0.057387    0.01863100
565.36    2.54705    2015.5252626    0.032063    0.02572346
160.07    8.99606    2015.5252717    0.03406    0.02682052
25.42    56.64831    2015.5252675    0.043156    0.02765430
120.2    11.98003    2015.5252833    0.036602    0.02871458
14.77    97.49493    2015.5253709    0.071089    0.03136794
222.09    6.48386    2015.5252709    0.035618    0.03216350
394.53    3.64991    2015.5252657    0.030707    0.03295080
230.47    6.2481    2015.5252618    0.031044    0.03326301
211.72    6.80144    2015.5252714    0.034033    0.03358752
210.13    6.8529    2015.5252671    0.031237    0.03360750
477.93    3.01299    2015.5252662    0.028155    0.03678022
274.73    5.24151    2015.5252660    0.031051    0.03685700
83.61    17.22282    2015.5252927    0.047398    0.03700348
47.23    30.4891    2015.5253041    0.057521    0.03791188
78.49    18.34629    2015.5252890    0.048698    0.03937316
23.15    62.20302    2015.5253658    0.065049    0.04028760
554.02    2.59918    2015.5252628    0.026363    0.04334227
247.27    5.82359    2015.5252616    0.029738    0.04570371
173.65    8.29254    2015.5252681    0.033344    0.04915963

The first two listed cycles in particular are extremely significant and would not occur even one time in a hundred million by chance alone. The Bartell’s test shows the significance of cycles as a probability. They did occur in two different days that I analysed, with extremely similar periods.

The part of the spectrum near to these two cycles is shown because there are other significant cycles nearby:

A graph of the autocorrelation of the minute by minute changes of the solar wind speed up to 200 minutes lag is shown:

This shows how the change in solar wind speed compares to the corresponding change at lags of up to 200 minutes and it can be clearly seen that there is a cycle of 3 minutes or so, and also that there is a modulation of 19 minutes in the autocorrelation. The two dominant cycles periods will produce beats of 18.92 minutes just as we observe. Note that there are two actual cycles near to 19 minutes also.

The author has often found cycles of near 3 and 6 minutes in the solar system previously. Along with 80 and 160 minutes these periods are rather common. We may note that the inner planets are roughly spaced at 3 light minutes apart in distance from the Sun, and the outer planets at 80 light minutes apart.

In my previous post to CRI Blog, I reported on Kotovs method of analysing planetary distances from the Sun gives spacings which are multiples or fractions of 0.376, 0.734, 5.01 and 10.06 AU. Light travels 1 AU in 8.317 minutes, so these distances can be converted to periods of an electromagnetic (or gravitational) standing wave of 3.13, 6.10, 41.7 and 83.7 minutes. In the solar wind speed as well as many cycles around 3 minutes or so there are a number at a little over 6 minutes.

Two periods of 3.17 and 6.34 minutes have also been found by the author in fluctuations in the rate of radioactive decay of Plutonium as measured by Biophysics laboratory at Russian Academy of Sciences in Pushchino. These periods are not perfectly steady but wander about by around 5%.