The following graph shows the yearly and monthly SSN averages (sunspot numbers) for the solar cycles since 1865, using data of the WDC-SILSO of the Royal Observatory of Belgium, Brussels.
WDC-SILSO web-site: http://www.sidc.be/silso/datafiles
data file used in the graph: http://www.sidc.be/silso/DATA/dayssn.dat
The monthly averages show fast drop in radiations at the end of the maximum of every cycle, usually defining a step-change-like variation in intensity.
The data for cycle 24 is lower than the WDC-SILSO and uses the LSC estimate, Layman’s Sunspot Count, from the “landscheidt.info” site: http://www.landscheidt.info/?q=node/50
I believe the LSC estimate for the present cycle correlates better with the Geomagnetic AA-index recorded by the UK Solar System Data Centre– since 1868– than the WDC-SILSO data, but I still have no explanation of why it does so.
The correlation becomes clear if we use the trimester and yearly averages of the aa-index data,
The first 7 years of the present cycle are similarly low as cycle 14, but the trend then was to increasing geomagnetic perturbation since the beginning of the cycle, while now we seem to have reached a maximum in 2011-12 and have been declining ever since.
The correlation also shows very well in the monthly average
From Fig.2 it is clear that the aa-index yearly averages were very low up to the beginning of cycle 14, with values rarely going above 20 nano-T, but in 1904 the index started to increase steadily, in correspondence with the increasing intensity of the solar cycles, in that period. The acceleration stopped in the strong cycle C19, which registered the highest daily SSNs of the last century.
From the years of the WWII to approximately 2004, the yearly average reached it’s maximum and defined a plateau where it rarely went below 20 nano-T.
At last, after 2004, another important reversal happened and, in the present cycle, it reached below 10 nano-T for the first time since the early XX century.
In the present cycle the index also has shown the feature of having a peak at the beginning of the period of the solar maximum of the cycle– corresponding to year 2012– and steady decrease since then, despite the recent second peak of the maximum, during 2014.
This seems to correspond closer to the behavior during cycles C12 and C13, instead of C14, during which the index showed steady increase during almost the entire cycle.
This seems to indicate that although cycle C14 was similarly low, as much as the present one, during the initial years of the cycle, it was also the initial cycle of a series of increasingly strong ones, while the present cycle seems to correspond to a period of accelerated decline of intensity of the solar radiations.
During the period of more than 20 years, between the end of cycle C20 and the end of C22, the yearly average stayed always above 20 nano-T, and this measurement coincides with the period of the peak of the grand solar maximum of the XX century, according to the recent study of Lockwood et al.
The link to the UK Solar System Data Centre is: http://www.wdc.rl.ac.uk/Help/aa.html
and the data retrieval form is at the following link
altering the period and the amplitude of the oscillation.
The very warm PDO of the last ~2 years is the main cause of the strong oscillations of the Antarctic ice extent, from the quite stable previous state of positive anomalies since 2012.
The increasing anomalies should return after the PDO goes down to neutral and negative again in about 6 months, more or less.
One thing I don’t understand though is why it got so warm, especially at the end of 2014 and beginning of this year.
A possible reason is a spike of the EUV (E10.7 index) that happened exactly during this period, which was also the highest – in the present solar cycle – since the end of 2011,
The first spike of E10.7 flux corresponds to the Sun’s N. Pole maximum, the second spike is more prominent and corresponds to the the stronger S.Pole maximum.
The magnetic NP of the Sun has been around zero micro-T since it crossed zero in 2011 (http://www.solen.info/solar/polarfields/polar.html)
This is more than 4 years of low fields, after crossing. I believe it could be an indication of the LP-effect being proved correct. The anomalous PDO+ could be an indication of chaotic behavior due to the anomalous intensity of the NS-poles of the Sun.
There are always strong winds around Antarctica, if you look at the NSIDC map for ice extent daily you’ll notice the ice moving / bulging around the continent as if pushed by a strong wind in the clockwise direction
This is normal there due to the large mass of oceans around the continent that allow the atmosphere move over the surfaced unimpeded.
I think the increased ice of recent years is due to progressive cooling of the region (the entire S Hemisphere has been cooling in recent years, specially the oceans),
The difference in 2015 with respect to previous years, since ~2011, is the strong warming of central Pacific (El NIno) that is taking its toll on the ice extent.
I believe this will cease in a few months, the extent is already not so low as a couple of months ago, but it’s not yet as high as in 2013 and 14.
… BTW looks like SH ice is again taking off big time (anomaly)
The following is an impressive graph,
No wonder the Antarctic ice is growing so steadily in recent years.
I believe it’s possible to identify a step-change in temperatures at the beginning of the present solar cycle.
I have no proof but it looks like the El Nino (EN) and the PDO have somewhat complementary effects on climate.
EN seems to correlate with sudden increases in tropospheric temperatures, which then plunge into the opposite direction when the subsequent La Ninas occur.
Usually the EN and the spikes of the PDO don’t coincide, but when they do it would cause a global change in Earth’s climate- either a step change or not, but a clear change in the “derivative” of the graph of the average temperatures.
This happened in 1982-83 when Earth’s temperatures started to increase fast and was one of the main fuels of the AGW propaganda (to a certain extent AGW looked a reasonable hypothesis at that time and fooled many, me included). It also happened with the strong EN of 1997-98 which coincided with a strong warming of the Pacific.
I’m considering the following data for EN,
and the graph above of “climate4you” for the PDO since 1979.
In 1992-93 there was another spike of the PDO but no strong EN, and the relatively strong EN of 2009-10 had no correspondent sudden increase of the PDO, and in both cases the tropospheric temperatures didn’t change their general trend (“derivative”).
Now, we’re having the great warming of the PDO of the last 1 + 1/2 years coinciding with EN conditions.
I think this indicates that the direction of Earth’s temperatures is about to change again.
I believe it’s toward a cooling period, similar but opposite to the warming phase of the last 2 decades of the XX century.
The following graph
shows an obvious step change, and a totally different “picture” than the one usually presented in the climate debate.
On the other hand, if we extend the first period up to 1997 and jump the ENSO of 1998-2001, we get two periods of opposite linear trends instead
The 1st graph reminds me of the 2 step-changes that happened at the tropopause in the same period
and similar also to the step-like decreases– in 1986 and 1998– in atmospheric humidity at 9 km altitude (300 mb)
As a possible explanation, I believe these step changes are related with the rapid excursion of the magnetic N. Pole since the 1980’s,
Note how the excursion also seems to have two “step changes” of speed, again at the beginning of the 1980’s and the end of the 1990’s.
Now, if we think that:
/1/ The beginning of the 1980’s coincides with the maximum of cycle #21– which is considered by some researchers (like Lockwood et at. in the paper “Centennial variations in sunspot number, open solar flux, and streamer belt width: 2. Comparison with the geomagnetic data”
as the highest point of the grand solar maximum of the XX century,
as indicated by the following figure,
/2/ “According to Professor Mike Lockwood the late 20th century was a period when the sun was unusually active and a so called ‘grand maximum’ occurred around 1985.
Since then the sun has been getting quieter.
By looking back at certain isotopes in ice cores, he has been able to determine how active the sun has been over thousands of years.
Following analysis of the data, Professor Lockwood believes solar activity is now falling more rapidly than at any time in the last 10,000 years.“
/3/ An important change happened in the Sun at the mid-to-end of the 1990’s– i.e., the beginning of solar cycle #23– when the solar magnetic polar fields started to behave in an “unusual way”, possibly indicating the beginning of a new grand minimum,
Then, a pattern seems to emerge, and it is related with the main forces at play in this scenario, which are, in my opinion, the solar radiations and Earth’s magnetic field.
This pattern could be indicating that Earth’s climate is nearing or is at the point of a new glacial inception, i. e., the end of the present Interglacial.
The graph below shows the Geomagnetic AA-index recorded by the UK Solar System Data Centre from 1868 to present.
The link to the UK Solar System Data Centre is: http://www.wdc.rl.ac.uk/Help/aa.html
The data retrieval form is at the following link
You’ll have to do a quick sing up before retrieving the data.