question

What modulates our Sun? The majority of science work on the principle that the Sun is self modulating and each solar cycle is a product of a random number generator. There are others that suspect the Sun is modulated by the planets with a special emphasis on Uranus & Neptune. Thanks to Carl Smith who has recently left us we have new knowledge that significantly adds to Jose, Landscheidt & Charvàtovà's work.

Geoff Sharp

Solar Wind Speed Continues to Decline

solar wind

The Solar Wind is a large factor in the size of the Heliosphere that protects our solar system from the potentially dangerous and possible climate changing effects of the cosmic ray flux. The Solar wind needs an escape velocity of 250 km/s to overcome the gravitational pull of the Sun and is loosely aligned with sunspot activity. The above graph uses ACE data from early 2006 to 23rd Sept 2009, and includes the relatively active sunspot 1024. Looking at sunspots, 2008 & 2009 were of similar activity but show very different results when comparing solar wind speed. The current slowdown and subsequent shrinking of the Heliosphere will take 12 months to complete which locks in our current position regardless of any future activity (if that happens).

If the Svensmark effect is real we can expect to see a beginning of increased lower level cloud cover over the next few months, which in turn will transpire into less ocean heat uptake and the related global cooling that will follow just as the current moderate el nino is dissipating and the PDO continues its cool phase. Other factors that will come into play include the Earth moving to its furthest point from the Sun in July along with the possible UV related cloud cover and pressure cell changes.

Cosmic ray flux is said to be controlled by the Earth's magnetic field, the interplanetary magnetic field and the overall size of the Heliosphere (the solar wind influencing). All of the indicies are reducing and the CRF levels are at an all time high as measured from the Oulu station. If we are heading into a solar grand minimum can we assume these record levels may become eclipsed?

 

The above graph showing a moving average smoothing of the solar wind and sunspot number. At this small scale the disconnect is obvious between the 2 data sets, although there does look to be some sort of underlying connection. The frequency of the solar wind during 2008 following roughly a pattern of 27 days similar to the TSI records. This frequency changes in other time frames but does suggest an oscillating power source.

I have plotted the solar wind and sunspot record for SC23 and the start of SC24. There are some interesting outcomes. The solar wind really has a mind of its own and is only partly affected by the internal dynamo activities that control sunspot numbers. The early part of SC23 (as the cycle builds) continuing to show a decline in wind speed as we witness today, along with some of the greatest recurring speed recorded throughout 2008 which was a benign year for solar activity. Also the change of frequency at around 2003 in sharp contrast to the rest of the solar cycle which suggests a different beat in the solar wind rhythm, this occurring some distance from cycle max. The increased frequency would possibly have a greater affect on the size of the Heliosphere? I could speculate that the frequency of the solar wind (not speed) is driven by the same factors that drive overall solar modulation.

Click here for a medium size version of the above graph.

Click here for a full size view.

 

The cosmic ray graph (inverse) from 1996 to Feb 2010 matches the sunspot record but is not close to the solar wind record. While the speed of the wind has consequences and its origin is still elusive, the magnetic properties carried by the solar wind look to be the major factor in the modulation of galactic cosmic rays seen on Earth.

Update October 2010:

Below is the Bulk Solar Wind speed for Oct 2009-Oct 2010.


UPDATE 7th DEC 2011

 

The solar wind continues to stay flat. Also the current Ap Index graph showing no sign of increase towards cycle max.

 

 

Many thanks go to Carl's brother Dave for providing the Domain, Server and Software.