Extract of Important Points Related to Solar Activity and Surface Climate.
Primary Data Reference Source.
If we look for a cross reference between the recorded events in which we are interested and Sunspot Number records, we can find little that would support the idea of a relationship. However, as we have already said, the existence of a sunspot does not imply the existence of a CME, much less a terrestrial impact -nor, indeed does the absence of spots imply the absence of incoming material – we need to look more closely at other solar behaviour.
If, then, we turn our attention to the ‘Solar Ap Progression’ records we find that there is a somewhat startling cross correlation. A sharp spike is recorded occurring 2003 and a consecutive series of sharp dips December 2009/10/11 and 12. Indeed, if we examine in detail the Ap index for several ‘Carrington Rotations’ around the latter periods in question http://eng.sepc.ac.cn/ApIndex.php we find that it is persistently inactive throughout those periods. An up-to-the-minute measurement of the ‘K’ index may be found here – http://www.swpc.noaa.gov/products/planetary-k-index – forecasts for Ap activity may be found here http://eng.sepc.ac.cn/ApForecast.php – and details of current solar activity here – http://www.n3kl.org/sun/noaa.html – .
From these an assessment of the interrelationship between activity and observed climate response can be estimated, it should, however, be remembered that a short term ‘spike’ may not appear in the longer term records when the ‘Monthly’ or ‘Smoothed’ values are recorded although there may be some correspondingly short term reaction from the atmosphere itself.
We need then, to establish whether simple but powerful solar wind, as distinct from the impact of a CME blast, can in fact inject significant amounts of energy into the Earthly environment. We can assess this most easily by measuring the Earth’s magnetic field and possible ground currents resulting from the incoming solar wind energy impact.
During the period April 21st to 25th, 2017, we had the opportunity to directly compare the impact of a CME glancing blow, and that of the solar wind from a coronal hole. Both impacts show similar amplitudes but the solar wind is significantly more prolonged.
Such activity implies that a significant response may be expected from solar wind disturbances, within the upper atmosphere, in the form of energy induced pressure variations with a resultant ‘tidal’ movement likely at lower levels.
It would seem unreasonable to assume that the injection of energy from Ap influences – or the lack of such energy in the case of a down-spike – would be sufficient of itself to distort the upper atmosphere profiles in the manner observed. What we can say is that it appears that pre-existing normal profiles are exacerbated, expanded, even intensified, by the influence of externally originating geomagnetic activity, especially if that activity is prolonged or repetitive.
This response may be viewed as similar in nature to the activity of ocean tides, where a very slight change in gravity causes a slight bulge in the ocean but often massive tidal response at sensitive coastal areas; so the incoming solar energy causes a slight bulge in the upper atmosphere, resulting in significant movement at sensitive points in the atmospheric profile, with the consequent response in surface level weather patterns.
It is also relevant to note that Geomagnetic activity tends to be lower around times of the Solstice. Consequently, if activity is generally low at any given time, then it will fall to very low levels during the winter months giving an increased possibility of unusually severe winter weather, as has been noted in the years we have considered.
This tendency has been known for some time but not fully understood. NASA’s launch of the THEMIS satellites which, in 2007, detected magnetic ‘Ropes’ connecting Earth’s upper atmosphere directly to the Sun, thereby providing a pathway for solar wind to inject energy into the terrestrial atmosphere and the geomagnetic environment. The magnetic interconnection is at its lowest when the Earth’s magnetic field is at aligned to the solar plane and the heliospheric sheet. A detailed explanation of the geomagnetic ‘Rope’ theory may be obtained here …..
In examining the Ap chart for the 1990’s decade, the first thing to note is that the lower extremities during the Solar minimum between cycles 22 & 23 were far shallower than those for the 23-24 minimum, only one single trough being lower than 5, the average being around 7-8, while those we have examined for 2009/12 reached as low as 2 to 4 on the Ap scale. This would imply that the 1990’s decade would have seen far fewer cold excursions than the 2000’s.
An interesting article here… https://science.nasa.gov/science-news/science-at-nasa/2010/15jul_thermosphere … outlines the collapse in the Thermosphere during the period 2009/2010. We are now, of course, able to cross reference that decline with the drop in values of the Ap index in the same period, which reveals that the decline in solar activity was significantly greater than previously thought and included factors other than just the measured sunspot number.
Ap Index 1932 – 2017 This Chart shows that what changed in 2004 was the magnetic output of the Sun, shown in this instance by the Ap Index. Prior to that, there seemed to be a floor of activity at solar minima, just as the floor of activity for the F10.7 flux is 64. It also clearly shows the 2003 ‘Spike’ and the 2009/2010, ‘Dip’ that we have already discussed.
It is important to note in all of our investigations that, although conditions may exist capable of causing a significant surface weather event, it does not follow that it always will – nature does not follow those rules. We can only assess an event and try to analyse the causal influences and estimate the likelihood of future events or occurrences of a similar nature arising.
As an incoming solar event or influence exerts what may most easily be visualised as a positive or negative ‘tidal’ pressure on the upper atmosphere structure, the result of that pressure will depend on the state of the atmosphere at that particular point in time. A northward or southward movement or tendency can be accelerated or delayed by the pressure applied; this will in turn influence the tracks of surface structures which may then reinforce the original distortion by dragging surface level air masses further north or south than would otherwise have been the case, thus exaggerating the intensity of those structures in a ‘positive feedback’ loop.
To extrapolate further the observed tendencies of lower sunspot activity, together with lower coronal hole and solar wind activity, this does create the circumstance whereby an increased tendency towards more severe cold winters may be anticipated over coming decades; however to seriously assess long term behaviour we need to examine other factors such as the solar related increase in cosmic ray activity and the consequent increase in average cloud cover.
It is well established that reduced solar activity allows an increase in cosmic ray bombardment, the climatological impact of which is considered to cause an increase in cloud cover. The principal effect of this obviously being to increase the planetary albedo, or reflectivity, reducing the amount of solar radiation reaching the surface.
If, in conclusion, we now combine the reduction in sunspot activity associated with the expected ‘Maunder/Dalton Style’ decline over next few solar cycles; the anticipated decline in coronal hole / solar wind activity, plus the consequent cosmic ray/cloud cover behaviour, then we are inescapably left to conclude that a steady decline in surface climate and temperatures over the next few decades is almost beyond doubt.