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blumenkraft

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Re: Solar cycle
« Reply #100 on: July 13, 2020, 10:24:13 AM »
Hefaistos, your point is well received. The sun warms the earth. Heureka!

wehappyfew

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Re: Solar cycle
« Reply #101 on: July 13, 2020, 02:31:55 PM »
Hefaistos,

Your comments do not address the errors I pointed out.

The amount of solar energy impinging upon each square meter of the Earth is ~1360 W/m^2 divided by 4, since the Earth is a sphere.

Until you acknowledge this fact, you will continue to calculate the impact of a Maunder Minimum incorrectly.

anthropocene

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Re: Solar cycle
« Reply #102 on: July 13, 2020, 02:38:28 PM »
Confirming what wehappyfew has just posted:

Hefastios;  You are confusing irradiance with forcing.

THIS IS SHOWN IN FIGURE 2 OF THE LINK WHICH YOU PROVIDED. On the left-hand side is amplitude of solar irradiance (eye-balling the graph about 1.6 watts/m^2   and on the right hand side is the forcing: 0.25 watts/m^2). Hansen et al have done the conversion for you. It says " Left scale is the energy passing through an area perpendicular to Sun-Earth line. Averaged over Earth's surface the absorbed solar energy is ~240 W/m2, so the amplitude of solar variability is a forcing of ~0.25 W/m2."

 Either you are not understanding what is presented, not reading it all or wilfully cherry-picking quotes from scientific papers to make it look like they support what you say.  (Not for the first time either).

Also Figure 3 provides the GHG forcing (approx. 3 watts/m^2). So approx 12 times the amplitude  of a (unusually large?) solar cycle.

As you say yourself - OHC and surface temperatures are almost irrelevant side-effects ( ;-) ) of what happens at the TOA interface. So why do you complicate the discussion with these points? It could be taken as an attempt at a gish-gallop.

Either accept the points made by wehappyfew (and Hansen et al) or provide evidence to refute it and support your point.
 

 

Hefaistos

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Re: Solar cycle
« Reply #103 on: July 14, 2020, 10:30:57 AM »
Hefaistos,

Your comments do not address the errors I pointed out.

The amount of solar energy impinging upon each square meter of the Earth is ~1360 W/m^2 divided by 4, since the Earth is a sphere.

Until you acknowledge this fact, you will continue to calculate the impact of a Maunder Minimum incorrectly.

Yes, of course, I was only mentioning the changes in solar irradiance. As you say, WHF, the incoming absorbed solar energy per unit surface area is S(1-a)/4
where a is albedo. On average, albedo is assumed to be around 0.3

The solar constant varies a bit over time, to get even numbers let's have it at S = 1360 W/m^2
The solar radiation at the TOA averaged over the whole surface of the earth = 340 W/m^2
The solar radiation absorbed by the earth’s climate system around 240 W/m^2 (depending on albedo).
The approximate radiation from the earth’s climate system at TOA also equals 240W/m^2 if we have energy balance (steady state). (which we don't, as the EEI is around 1 W/m^2 .

The solar 'constant' (S) varies a bit over time with the 11 year cycle, as seen in the CMIP6 forcing chart, its amplitude is about 1 W/m^2 during strong solar cycles, whereas only half of that during weak cycles.

Secondly, if we take the above figure for the Maunder minimum, it means a change in S with around -0.8 W/m^2 in S as a long term trend change.
At surface, with constant albedo it then adds about -0.14 W/m^2 in as a long term trend change in forcing.
I attach a chart with satellite measurements during 1978-1999. The absolute irradiation levels are much higher in those readings, but for some reason (why?) they have been aligned at the lower level of around 1361. (Also Hansen use the higher values)
« Last Edit: July 14, 2020, 10:39:30 AM by Hefaistos »

kassy

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Re: Solar cycle
« Reply #104 on: July 14, 2020, 03:20:23 PM »
At surface, with constant albedo

But actually we do not have a constant albedo. There is a year over year decline of ice cover in the mountains, landscape changes in Siberia, declining arctic sea ice and those changes alone will override it.

Also if you think the solar cycle helps us now that means we are in deeper trouble then we thought because of time scales.
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The Walrus

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Re: Solar cycle
« Reply #105 on: July 14, 2020, 09:10:03 PM »
At surface, with constant albedo

But actually we do not have a constant albedo. There is a year over year decline of ice cover in the mountains, landscape changes in Siberia, declining arctic sea ice and those changes alone will override it.

The decline of which you speak amounts to ~0.2% of the total surface of the Earth.  Granted the change in albedo over that portion is rather large.  How much difference does changing cloud cover constitute?  What about the decrease in forest cover from ~40% to 30% since the dawn of industrialization?  Urban areas have roughly doubled to ~3% of the surface, which their contributing albedo changes. 

Incidentally, research has shown that the albedo has been remarkably constant over time:

https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014RG000449

Hefaistos

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Re: Solar cycle
« Reply #106 on: July 16, 2020, 10:30:11 PM »
This is a recent paper estimating TSI, albedo, and OLR

"Measurement of the Earth Radiation Budget at the Top of the Atmosphere—A Review"
by Steven Dewitte and Nicolas Clerbaux,
 Remote Sens. 2017, 9(11), 1143;

"TSI measurements with good stability have been available since 1984. They reveal a variation of the TSI in phase with the 11-year sunspot cycle, with an amplitude of the order of 1 W/m2
. The currently-ending solar cycle 24 has a low amplitude compared to the preceding ones.
The TIM TSI instruments have a different viewing geometry as compared to the classical TSI instruments, which results in a lower absolute value of the measured TSI. Reconciling the classical DIARAD/SOVIM and the new TIM/TCTE instrument, the TSI level at solar minimum is estimated to be 1362.0 +/− 0.9 W/m2
.
The ERB measurements have sufficient stability to track the temporal variability of the EEI driving climate change, but they can not measure its absolute value with sufficient accuracy. Combining the ERB measurements with independent estimates of the EEI from OHC, we obtain the most likely values of the OLR of 238.0 W/m2
and of the RSF of 101.6 W/m2—corresponding to an albedo of 29.8%
—for the period 2000–2005."

https://doi.org/10.3390/rs9111143

https://www.mdpi.com/2072-4292/9/11/1143/htm

morganism

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Re: Solar cycle
« Reply #107 on: August 19, 2020, 02:19:56 AM »
NASA Researchers Track Slowly Splitting 'Dent' in Earth’s Magnetic Field

https://www.nasa.gov/feature/nasa-researchers-track-slowly-splitting-dent-in-earth-s-magnetic-field

" recent observations and forecasts show that the region is expanding westward and continuing to weaken in intensity. It is also splitting – recent data shows the anomaly’s valley, or region of minimum field strength, has split into two lobes, creating additional challenges for satellite missions.

“The observed SAA can be also interpreted as a consequence of weakening dominance of the dipole field in the region,” said Weijia Kuang, a geophysicist and mathematician in Goddard’s Geodesy and Geophysics Laboratory. “More specifically, a localized field with reversed polarity grows strongly in the SAA region, thus making the field intensity very weak, weaker than that of the surrounding regions.”

liefde

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Re: Solar cycle
« Reply #108 on: August 29, 2020, 03:20:35 PM »
As the Earth Energy Imbalance at TOA is less than 1 W/sq.m. this effect is quite substantial.
Mike knows best:

Tom_Mazanec

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Re: Solar cycle
« Reply #109 on: August 29, 2020, 04:04:10 PM »
New research suggests Solar Cycle 25 could be strongest in 50 years
https://www.spaceweatherlive.com/community/topic/1775-new-research-suggests-solar-cycle-25-could-be-strongest-in-50-years/
Quote
Obviously, the thing that stands out the most is that they predict a massive cycle, similar to the solar cycles 19, 21 and 22, which were some of the strongest of the modern era of solar observations. The actual SSN they have predicted is 233, twice the size of the previous SC24 and about 50% stronger than the cycle before that one, SC23 (which peaked in around 2001).
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The Walrus

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Re: Solar cycle
« Reply #110 on: August 31, 2020, 01:35:49 PM »
Did you read the comments and the links to NOAA and SILSO?

Tom_Mazanec

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Re: Solar cycle
« Reply #111 on: September 01, 2020, 12:53:11 AM »
Walrus, we are at the tea reading stage of forecasting solar cycles. Anything could happen.
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The Walrus

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Re: Solar cycle
« Reply #112 on: September 01, 2020, 03:06:56 AM »
Yes, and predictions range from low to high, pretty much the entire gamut.

kassy

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Re: Solar cycle
« Reply #113 on: September 01, 2020, 01:14:38 PM »
I suggest waiting for data from that cycle 25. 
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The Walrus

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Re: Solar cycle
« Reply #114 on: September 01, 2020, 02:44:47 PM »
That would be best.

Tom_Mazanec

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Re: Solar cycle
« Reply #115 on: September 02, 2020, 12:43:59 PM »
But we won't get that for about a decade.
In the meantime, I like to read tea leaves (I'm impatient). Always remembering how shaky their reliability is.
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Alexander555

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Re: Solar cycle
« Reply #116 on: September 05, 2020, 10:48:54 PM »

gerontocrat

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Re: Solar cycle
« Reply #117 on: September 05, 2020, 11:21:21 PM »
One has to give Valentina Zharkova credit - she does not give up & still manages to get stuff printed.

Her work on the solar cycle and her predictions for a new Maunder Minimum is not accepted as credible by most scientists that study the solar cycle as their profession.
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morganism

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Re: Solar cycle
« Reply #118 on: September 07, 2020, 07:42:07 PM »
https://www.nature.com/articles/s41598-020-67860-3
On the correlation between solar activity and large earthquakes worldwide





We found clear correlation between proton density and the occurrence of large earthquakes (M > 5.6), with a time shift of one day. The significance of such correlation is very high, with probability to be wrong lower than 10–5. The correlation increases with the magnitude threshold of the seismic catalogue. A tentative model explaining such a correlation is also proposed, in terms of the reverse piezoelectric effect induced by the applied electric field related to the proton density.

we demonstrate that it can likely be due to the effect of solar wind, modulating the proton density and hence the electrical potential between the ionosphere and the Earth. Although a quantitative analysis of a particular, specific model for our observations is beyond the scope of this paper, we believe that a possible, likely physical mechanism explaining our statistical observations, is the stress/strain pulse caused by reverse piezoelectric effects. Such pulses would be generated by large electrical discharges channeled in the large faults, due to their high conductivity because of fractured and water saturated fault gauge. The widespread observations of several macroscopic electro-magnetic effects before, or however associated to large earthquakes, support our qualitative model to explain the observed, highly statistically significant, proton density-earthquakes correlation. It is important to note that our hypothesis only implies that the proton density would act as a further, small trigger to cause the fracture on already critically charged faults, thus producing the observed large scale earthquake correlation. Such a small perturbation would add to the main factor producing worldwide seismicity, which is tectonic stress.

morganism

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Re: Solar cycle
« Reply #119 on: September 07, 2020, 07:57:23 PM »
https://en.m.wikipedia.org/wiki/Flux_tube

When do solar erupting hot magnetic flux ropes form?
A. Nindos, S. Patsourakos, A. Vourlidas, X. Cheng, J. Zhang
We investigate the formation times of eruptive magnetic flux ropes relative to the onset of solar eruptions, which is important for constraining models of coronal mass ejection (CME) initiation. We inspected uninterrupted sequences of 131 Å images that spanned more than eight hours and were obtained by the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) to identify the formation times of hot flux ropes that erupted in CMEs from locations close to the limb. The appearance of the flux ropes as well as their evolution toward eruptions were determined using morphological criteria. Two-thirds (20/30) of the flux ropes were formed well before the onset of the eruption (from 51 minutes to more than eight hours), and their formation was associated with the occurrence of a confined flare. We also found four events with preexisting hot flux ropes whose formations occurred a matter of minutes (from three to 39) prior to the eruptions without any association with distinct confined flare activity. Six flux ropes were formed once the eruptions were underway. However, in three of them, prominence material could be seen in 131 Å images, which may indicate the presence of preexisting flux ropes that were not hot. The formation patterns of the last three groups of hot flux ropes did not show significant differences. For the whole population of events, the mean and median values of the time difference between the onset of the eruptive flare and the appearance of the hot flux rope were 151 and 98 minutes, respectively. Our results provide, on average, indirect support for CME models that involve preexisting flux ropes; on the other hand, for a third of the events, models in which the ejected flux rope is formed during the eruption appear more appropriate.
Comments:   A&A, in press
Subjects:   Solar and Stellar Astrophysics (astro-ph.SR)
Cite as:   arXiv:2008.04380 [astro-ph.SR]
    (or arXiv:2008.04380v1 [astro-ph.SR] for this version)

Hefaistos

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Re: Solar cycle
« Reply #120 on: September 16, 2020, 07:47:53 AM »
A nice, interactive page where you can follow the progression of SC25, from NOAA. Including the official forecast for the strength and duration of SC25.

https://www.swpc.noaa.gov/products/solar-cycle-progression

Tom_Mazanec

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Re: Solar cycle
« Reply #121 on: September 16, 2020, 12:12:43 PM »
Hope Solar Orbiter and Parker Solar Probe get good observations of this solar cycle, and that Aditya-L1 gets a shot at it.
« Last Edit: September 16, 2020, 12:30:36 PM by Tom_Mazanec »
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kassy

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Re: Solar cycle
« Reply #122 on: September 18, 2020, 05:19:34 PM »
Sea ice Triggered the Little Ice Age, Finds a New Study
https://phys.org/news/2020-09-sea-ice-triggered-age.html


The map shows Greenland and adjacent ocean currents. Colored circles show where some of the sediment cores used in the study were obtained from the seafloor. The small historical map from the beginning of the 20th century shows the distribution of Storis, or sea ice from the Arctic Ocean, which flows down the east coast of Greenland. The graphs show the reconstructed time series of changes in the occurrence of sea ice and polar waters in the past. The colors of the curves correspond to the locations on the map. The blue shading represents the period of increased sea ice in the 1300s.

A new study finds a trigger for the Little Ice Age that cooled Europe from the 1300s through mid-1800s, and supports surprising model results suggesting that under the right conditions sudden climate changes can occur spontaneously, without external forcing.

...

Martin W. Miles et al, Evidence for extreme export of Arctic sea ice leading the abrupt onset of the Little Ice Age, Science Advances (2020)
https://advances.sciencemag.org/content/6/38/eaba4320

Click on the link for the full text.

Also see post #71 up above for more hints that solar activity is not related to the events.
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Alexander555

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Re: Solar cycle
« Reply #123 on: September 21, 2020, 09:27:54 AM »
Lets assume that Valentina is right, that we enter a longer periode of lower solar activity. What would the impact be on rainfall ?

Hefaistos

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Re: Solar cycle
« Reply #124 on: September 21, 2020, 01:41:06 PM »
Lets assume that Valentina is right, that we enter a longer periode of lower solar activity. What would the impact be on rainfall ?

Whether Valentina is right or not in her somewhat speculative forecasts I don't know.

What I know, is that there seems to be a positive relationship between solar TSI and cloudiness. Thus, less TSI in a solar minimum (like now) means less clouds and presumably less rain. That's the global averages.
« Last Edit: September 21, 2020, 01:57:48 PM by Hefaistos »

Alexander555

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Re: Solar cycle
« Reply #125 on: September 21, 2020, 09:46:26 PM »
Yes it is speculative. But that 11 year cycle is pretty constant. And Valentina is talking about that 350 to 400 year cycle, that comes to an end somewhere now. And why would that not be constant ? Something is driving that 11 year cycle up and down, again and again and again.....Last cycle already had low numbers of sunspots. And now we have already many days with no sunspots at all. Something that don't happens that much. So the sun is not very active at all. I agree that there could be less rainfall if these low numbers would continue. Warm air can hold more moisture, so if it cools a little. But probably that will take many years, for the oceans to adjust.  And the same time we have been building mega cities and cutting down rainforests. That's probably the rain we will get less, compared with 20 or 30 years ago. I have a feeling we are going to hear more about it in the next years. Global warming vs solar cooling.

FishOutofWater

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Re: Solar cycle
« Reply #126 on: September 25, 2020, 10:00:44 PM »
Interesting article about rapid sea ice transport leading to a cool period. That may not nix the volcanism theory if volcanic events could have brought on a stronger polar vortex by initiating polar cooling.

Back to the solar cycle. NASA has a new post about cycle 25 which is forecast to be just about the same as the last cycle.

https://www.nasa.gov/feature/goddard/2020/what-will-solar-cycle-25-look-like-sun-prediction-model