Richard Willoughby
Summary
This article examines the seasonal variation in Earth’s reflectivity through the CERES era. Changes in solar forcing over the same period are examined with the objective of identifying possible linkages to the measured change in reflectivity.
The primary driver of the changes in solar forcing over the 15 year observational interval is identified then assessed to show why there will be a reversal of this particular change by 2037. This introduces the prospect of the reducing trend in reflectivity being reversed by 2037; noting that seasonal cycle change in solar forcing will revert to the longer term trend that has caused the NH to gradually warm over the past 300 years.
The article concludes by pointing out the Earth’s reflectivity is primarily a function of ice/snow and the available solar EMR that can be reflected. There is no reflection off ice/snow when the daily solar is zero as occurs each year in the polar regions.
Introduction
The Clouds and the Earth’s Radiant Energy System (CERES) project provides satellite-based observations sufficient to enable fair estimates of Earth’s radiation balance. The satellite based instruments have been calibrated to match the ocean heat content as determined by the Argo ocean submersible drones. The first CERES mission began in 1997 but the reflected electro-magnetic radiation (EMR) for this analysis was not available till 2004. The NASA NEO data used here only has full year data from 2007. The most recent full year is 2024. The analysis considers changes to 2024 relative to 2007.
Chart 1 displays the monthly area averaged reflected solar EMR for both hemispheres.
Both hemispheres exhibit similar annual cycles with reflected EMR peak in mid-summer. The June average in the northern hemispheres is 136.3W/m² while the December average in the southern hemisphere is 152.7W/m². These summer peaks are dominated by high reflectivity of ocean and land ice/snow rather than clouds. Also the polar regions have high monthly average solar EMR in summer.
Chart 2 examines the monthly reflected EMR over just land masses, which includes any permanent ocean ice.
The land exhibits similar annual cycle to the total but the summer peaks are somewhat higher. June average is 154.9W/m² while December average is 219.2W/m². Again the summer highs are due to the high reflectivity of permanent ice/snow.
Changes in Reflected EMR over Land
Land has a faster thermal response to changes in surface insolation than the oceans so the changes in reflected EMR over land give a more immediate response compared with the muted response of the oceans. Accordingly Chart 3 displays the change in monthly area averaged reflected EMR over land and permanent sea ice in 2024 relative to 2007.
The annual average over all land is down by 1.06W/m² but there is considerable month-to-month variation. The NH displays some cyclic regularity while the SH is more random. The November peak of 6.02W/m² is an outlier and begs closer examination per Image 1.
The higher November reflectivity in the SH is the result of increased cloud over tropical and temperate land. This leads the monsoon cycle in these regions so is related to increased moist air advection from the tropical oceans rather than convective instability over the land.
Changing Solar Forcing and Advection
Earth’s positional relationship with the Sun is not perfectly periodic over any time cycle. The two bodies have continual movement relative to each other. The positional variation changes the solar intensity reaching Earth and those changes drive changes in Earth’s climate. Chart 4 examines solar intensity at 15N and 50N through 2024 to consider how the difference in solar forcing contributes to poleward advection in the NH. The Earth to Sun positional data used for these calculations was generated by JPL’s Horizons App.
Apart from early summer, the solar intensity at 15N is higher than the solar intensity at 50N. However the oceans have slower thermal response compared with land so there will be a lagged response between poleward advection and the difference in solar intensity from low latitude to high latitude.
Chart 5 now considers how the difference in latitudinal forcing has changed in 2024 relative to 2007.
The difference curves for 2024 and 2007 appear identical on the left hand scale but the annual cycle becomes apparent when the delta is displayed against the right hand scale. The range from peak to peak over the annual cycle is slightly above 0.6W/m².
Charts 6 and 7 provide similar daily solar EMR for the SH.
The delta 2024 relative to 2007 for the SH has a similar range of 0.6W/m² while the peaks are narrower in the SH compared with the NH.
Solar and Reflectivity Changes
The delta in solar forcing peaking in October in the SH is consistent with increased cloud cover over tropical land in the SH in November. There is also some consistency in the NH between the annual cycle in the delta in solar forcing and the increase then decrease of reflectivity in the NH. Neither of these observations are compelling though. On the other hand the delta in forcing over the 15 year period is of similar magnitude to the reduction in reflectivity.
Looking ahead to 2037
If the delta in solar forcing from year-to-year is a driver of Earth’s reflectivity then the response over the past 15 years can be used as a basis for prediction. Chart 8 offers the delta in solar forcing for both hemispheres to 2037 relative to 2024.
The delta to 2037 relative to 2024 exhibits a reversal in seasons in the hemispheres compared with 2024 relative to 2007 and almost a 10-fold increase in range. This reversal is due to the movement of the Sun in and out of Earth’s orbital plane as shown in Chart 9.
In 2007 the Sun was south of Earth’s orbital plane near a minimum while in 2024 the Sun was North of Earth’s orbital plane close to a maximum. This slight movement out of plane changes the declination of the Sun relative to Earth’s axis of rotation. By 2037, the Sun will be almost in plane with Earth’s orbit and that reduces the solar intensity in the NH but increases solar intensity in the SH.
Discussion
Earth’s reflectivity depends primarily on permanent ice/snow on land, temporary ice/snow that forms on land, permanent ice/snow on oceans, temporary ice/snow on oceans and temporary ice in the atmosphere. The amount of reflected solar is a function of the solar intensity; the reflectivity of the ice or snow surface the EMR encounters and the amount of ice present across the globe on any day. Overall, the complexity involved in solar EMR not being thermalised due to Earth’s albedo cannot be overstated. Over the CERES period, Earth’s reflectivity has reduced. There appears to be some linkage between the changes in reflectivity and changes in the solar forcing that drives poleward advection. The seasonal reversal of the forcing change driving poleward advection over the next decade introduces the prospect of the reducing trend in reflectivity reversing over the next decade.
This analysis shows that permanent ice/snow is the most significant factor in summer reflectivity in both hemispheres and that is obviously linked to the high average daily intensity of the summer insolation at high latitudes. It is also apparent that there is significant year-to-year changes in seasonal solar intensity that could cause changes in advection that would change cloud cover and reflectivity but thorough analysis of that is beyond the scope of this article.
Any year-to-year changes in solar forcing have to be considered in the context of longer climate trends. Chart 10 shows how the solar EMR at 40N and 40S will change from 1850 (the year of perfect weather) to 2100.
The curves in Chart 10 are more indicative of the longer term seasonal changes in solar intensity; possibly slightly lower than the mid range of the extremes from specific year to specific year. The NH is experiencing an increase in the warming season solar intensity from March solstice to June equinox and a similar reduction in the late summer-autumn period. These changes are already apparent in the NH ocean warming and the increased early season snowfall in the NH. The increasing snowfall in the NH is presently offset by accelerating spring melt in most locations. An important exception is that the Greenland plateau is already gaining altitude; keeping in mind glaciers first form at altitude then migrate down slope.
The SH has much lower seasonal swing with the increase in spring solar EMR of about 1W/m² being the only notable change.
Conclusion
This article raises the prospect of solar forcing being a key factor in reducing Earth’s reflectivity through the CERES era but fails in making a convincing connection. It also suggests the trend could reverse in the coming decade as poleward forcing reverses seasons to the long term trend. A reversal to increasing reflectivity over the coming decade would strengthen the connection.
Understanding Earth’s reflectivity requires a comprehensive knowledge of ice formation and disappearance across the globe. That requires an understanding of how the solar intensity is changing because ice forming is energy intensive as is ice loss. All ice began life as water in an ocean. The ice that forms in the atmosphere and then settles on land had to be liberated from the ocean surface and into the atmosphere. Evaporation of water is energy intensive.
Understanding climate change on Earth is primarily based on understanding Earth’s physical relationship with the Sun and the ice forming and ice loss processes on land, oceans and atmosphere. It is also apparent that the solar “constant” is not constant and has a role in climate change.
The misdirected demonising of CO₂ has resulted in climate models that are blind to seasonal changes in solar intensity across the hemispheres and naively embody parameterisation of ice forming and ice loss processes that are disconnected from physical reality. The models have created a widely held cargo cult styled primitive belief that eliminating burning of carbon and hydro-carbon fuels will deliver perfect weather that existed on Earth in 1850. Climate models underpin the notion that eliminating use of carbon and hydro-carbon fuels will deliver perfect weather with no destructive storms; no heat waves; no blizzards; gentler cyclones; just the right amount of rain; no deserts; no floods; perfect seasons; perfect crops and so on – all things good. France would not have experienced destructive wild fires in 2025 if humans had not burnt carbon and hydro-carbon fuels. Childish, naïve beliefs.
The Author
Richard Willoughby is a retired electrical engineer having worked in the Australian mining and mineral processing industry for 30 years with roles in large scale operations, corporate R&D and mine development. A further ten years was spent in the global insurance industry as an engineering risk consultant where he developed an enduring interest in natural catastrophes and changing climate.
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We will probably not see this covered on page one of The New York Times.
So far Rick you’ve produced more useful CERES science than Soon’s CERES Science Team…
The albedo (reflectivity) trend declined as solar was lower, then increased with strong SC25 forcing.
I suspect the long-term albedo trend will change if solar forcing is high again in the next solar cycle.
Chart 9 solar z-axis is anti-correlated to temperature from about 2012-2020. Why the discrepancy?
How/why should the sun’s changing z-axis cause a solar induced climate response?
Bob
I keep slugging away at deriving the physics behind solar activity because I know it has an influence. However it is not possible to predict it unless the physics is understood. I have some good results from the changing orbital torque on the Sun driving the solar cycles but still not as good as I would like. I seriously question whether JPL have the orbital path nailed correctly.
The N-S motion of the Sun relative to Earth’s ecliptic is a significant factor in year-to-year changes in solar forces and can be linked to observed changes in poleward advection. It is really preliminary work but the linkage of some observations to the N-S motion of the Sun was interesting enough to put it out there..
‘The N-S motion of the Sun relative to Earth’s ecliptic is a significant factor in year-to-year changes in solar forces and can be linked to observed changes in poleward advection.”
It would help to first determine the mathematical significance of this very small z-axis motion relative to other indices like solar activity (TSI) or climate before making this claim.
I can show the 2024 change in poleward advection was caused by high solar cycle #25 TSI.
If it’s true that high TSI caused the poleward advection then the relative orbital contribution would need to be assigned less significance.
Your charts #5 and #7 compared 2024 to 2007. 2007 was almost at the solar minimum, thus you showed the difference in poleward advection between a low vs a high TSI state.
I am suggesting that cycle TSI changes are more significant than orbital changes decadally.
The N-S motion alters declination. Hence will have different influence across latitudes.
The variation in TSI is 1 to 2W/m^2. The seasonal variation due to orbital changes are greater than this even over a few years. For example, Chart 8 shows a season swing of 5W/m^2 from 2024 to 2037. So orbital changes can be significant over short time scales.
My objective it to improve predictive capability. Accordingly I recognise that TSI plays a role but it is of no value to prediction unless the physics that drives it is understood.
“Accordingly I recognise that TSI plays a role but it is of no value to prediction unless the physics that drives it is understood.”
People are still trying to figure out how to reliably use physics to predict the next solar cycle!
“The seasonal variation due to orbital changes are greater than this even over a few years.”
Seasonal insolation variation is huge compared to 1AU TSI changes. What we want to do is isolate the orbital variations not associated with seasonal changes and compare those variations to 1AU TSI changes.
The 12-month-average-change (12ma∆) of the orbital forcing removes the seasonal aspect leaving a residual that is the true non-seasonal orbital variation, which can then be compared directly to 1AU TSI anomalies from solar cycles. The 12ma∆ is just like a thirteen-month centered average, but with 12 months.
Until that is done there is literally no basis for discerning relative variations.
Rick I’ve spent the last day determining the relative contribution of orbital variation since 2003, when SORCE TSI data began, through 2024 using TSIS-1 TSI, as LASP also publishes a “True TSI” in both datasets.
For solar cycle #25 so far the orbital contribution since 2019 is -1.1% of the 1au TSI. In other words it is insignificant, well within the uncertainty.
I used the 365-day-average-change (365da∆) with both the daily 1au and True TSI data instead of the 12ma∆. This function allows for the removal of the annual cycles to see just the non-seasonal orbital residual.
The orbital residual is red/blue in these plots. Panel f show cycles #24 & #25 starting from the solar minimum year, 2008 in purple for SC#24, and from 2019 for SC#25.
Obviously SC#25 had a quicker and more powerful start by comparison.
It could not be clearer or starker – there is literally no case for orbital anything compared to solar cycle forcing since 2003. I’d hazard a guess it would be true all the time, and that solar z-axis motion is also insignificant. This doesn’t discount the longer-term orbital influence.
Sorry to be the bearer of bad news. Many climate effects you’ve attributed to orbital variation are actually from solar cycles and accumulated OHC.
The TSI changes by 90 W/m^2 from January to July.
This is due to the distance the sun is to the earth.
148 million km (January) 1406w-m2 (Earth 1316w-m2 normal Jan)
152 million km(July) 1316w-m2 (Earth 1406w-m2 always July)
Jan-March has most reflection (below 1316w-m2) due to the mid latitude land having to much snow and ice.
When the northern hemisphere is above 40 million km, earth is losing more heat. Earth is (1316) at 40 million km snow & ice around April 10th.
Below 10 million km of snow & ice in northern hemisphere earth has gained up-to 80 watts since January.
By June 90% of snow is lost (sea ice takes longer 9 million loss from March to September).
This article incorrectly has reflection high in summer to highlight summer loss from 80’s sea ice which was the minimum summer heat loss and maximum peak of the last century. 21st Century still has to much winter snow. 39 (9.75W-m^2, 2.22°C) watts extra loss in March.
The summer has not exceeded the 1407 W-m^2 (351.75W-m^2) ( peak).
July 26th peaked 1401.14 W-m^2 (350.29 W-m^2).
Below are the details of thermal heat values over Jan-Aug 2025 and Sept-Dec 2024.
The articles does not mention heat other than the means of calibrating CERES and in passing as heat waves.. The article particularly focuses on the solar EMR that is not thermalised. The portion that is reflected. And the monthly reflected portion is based entirely on CERES data.
I have other studies that look at the net radiation but the increase in heat uptake in the CERES era from 2001 to 2023 is due to reducing reflection (down 2.4W/m^2) offset by increasing OLR (up by 1.3W/m^2):
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Is the N-S movement of the Sun represented in any way in the models?
Why the discrepancy – the 2016 temperature spike was not long after a peak in solar activity and was related to an El Nino event. El Nino may be driven by orbital mechanics but I am yet to find a relationship.
The current southward motion of the Sun should result in a warming hiatus similar to what was observed after 1998. If that occurs then it will be evidence that supports the significance of this motion. But it is not the only factor that is changing. The long term trend is much warmer northern hemisphere where snowfall will eventually overtake snow melt. Already apparent on the Greenland plateau.
On day 236 of 2025 the solar intensity at 40N is 1.6W/m^2 down on last year and will be 2.1W/m^2 down on 2024 by September 24. The faster cooling should result in more early season snow. Something to look at in a couple of months.
“The current southward motion of the Sun should result in a warming hiatus similar to what was observed after 1998.”
SST actually increased from 1999 to about 2004 when sunspots > 95 SN. The warming hiatus after 2004 resulted from sunspots < 95 SN. The N. Atlantic is a good example.
“If that occurs then it will be evidence that supports the significance of this motion. But it is not the only factor that is changing.”
Ocean cooling or a “warming hiatus” is a regular feature of solar forcing when sunspot activity is below 95 SN, but you have assigned this cooling exclusively to orbital.
This all comes back to the need to reconcile TSI with orbital, a discussion we had once.
“Something to look at in a couple of months.”
That’s what I like, observation to follow the theory.
Not “The theory proves it”
Nice one Rick
“The faster cooling should result in more early season snow. Something to look at in a couple of months.“
That gave me a Sunday morning good chuckle.
Thanks for the lesson. I can add this to the dozen alternatives to CO2 that might help explain episodic weather changes.
And probably all play a role. I did state in the article that the complexity cannot be overstated. The Sun-Earth position is but one of many. In the long run orbital precession drives climate but these small changes from year-to-year and over decades show up in observations of temperature.
Rick
The included angle of the Suns disc is O.539 degrees and the fig. 9 variation of .0002 AU up/down on our 1 AU from the Sun is only .0115 degrees or .023 degrees from peak to peak. This would make NO PRACTICAL DIFFERENCE to the amount of sunlight reaching our planet. As viewed from Earth would only be a variation of 4% of the diameter of the Sun…4% of the width of your thumb held at arm’s length if you were a Boy Scout.
On a quick calc on 1360 incoming solar, I got 0.4 watts, and it would be 30% less due to albedo. The “official” published “solar constant” has changed by more than that over the last 30 years, so we’re at the limits of our accuracy on this.
Your calculations are close because I show a swing in seasonal range of daily solar of 0.5W/m^2. There are other positional factors involved. One being that the distance changes as well as the declination. And there are slight variations in timing from year-to-year.
Over the same period, CO2 has increased by about 35ppm. How much has its so-called forcing changed? It is minuscule in that time frame.
The point of the article it to show that there are Sun-Earth positional changes that are more significant at seasonal level than any so-called forcing changes from CO2.
Over solar cycles the solar constant shifts up to 2W/m^2 so 0.5W/m^2 area average. So it is of the same order over short time scales as the positional changes. I noted the changing solar constant in the article, However I am yet to accurately predict the solar cycles so I am not currently varying the solar constant but my objective is to understand why the solar output changes and include it in the ToA solar calculations.
In the long run, precession of the orbit dominates over all other factors and it is driving the current observed trends. Earth is on similar trajectory toward glaciation as it was last time it was in an interglacial and the spring solar intensity in the NH started increasing. So far only Greenland plateau is gaining altitude.
Question for the experts:
I was reading Wiki the other day about barycenters. I was amazed at how close the barycenter of the solar system is to the center of the sun when Saturn (and some other planets) and Jupiter were opposite of each other, versus how far the barycenter moved outside of the Sun’s sphere when Saturn and Jupiter were in at least partial alignment on the same side of the sun.
However, I never hear about barycenter position being discussed when considering the impact of other types of solar changes and the observed cycles.
Is the position of the barycenter insignificant, or can it change the solar wind, luminosity, impact of giant solar flares, etc. when the barycenter is positioned directly between the Earth and the Sun, versus when the Earth is quartering, or even opposite?
The barycenter is a mathematical construct with no physical significance. It can be used to describe the movement of the Solar system as a whole around the galaxy, but not to describe inner workings of the solar system.
I believe that Newton would have disagreed. He saw it as the ‘stationary’ point about which everything in the Solar System moved. After all, in an entirely relative universe (having no static ‘centre’) you need some point of reference, and this is the logical point for a system.
So it’s not just mathematical, it’s the gravitational centre, about which everything, including the Sun, rotates.
According to NASA JPL Sun motion database, the Sun does not always orbit the barycentre. It sometimes takes a short cut and loops without the centre tracking around the barycentre. I think 1990 was the last time it did that.
The assumptions made in determining the motion of the Sun could bring in errors in the calculated path. I have formed a view that the relatively rapid changes in the gravitational forces acting on the Sun import spin torque. The Sun equator spins faster than the poles and the spin speed changes over time. There is also reasonable correlation between solar activity and the variation in orbital torque on the Sun; not to be confused with the spin torque.
Then the observer on Earth only sees half the Sun but views the whole surface of the Sun in a bit over a year. So if there is a moving wave of solar activity moving across the surface of the Sun, primarily driven by Jupiter’s 11.8 year orbit, then we observe something different to what is actually occurring. There is a time/frequency shift due to the observer being on an orbiting platform.
One other thing that I have observed is that planets in orbits of high eccentricity spin faster and have fluid cores. Venus has low orbital eccentricity in its orbit, slow spin and solid core. This observation also points to spin torque being linked to varying gravitational forces. And the spin maintaining heat in the core likely from viscous mixing and radiation decay. The Sun experiences the widest range in gravitational field so imparted spin from the changing force would be greater.
If I was a serious climate modeller, I would first want to nail what is going on in the Sun and how it moves relative to Earth. JPL is a good resource but I have not personally verified its accuracy and I am always sceptical of things I have not verified.
You are not so interested in what Landscheidt and his followers wrote about the suns barycenter?
I am very interested in understanding what drives the solar activity but have not yet been able to predict it as I would like.
https://www.researchgate.net/scientific-contributions/Theodor-Landscheidt-2027258242
https://meetingorganizer.copernicus.org/EPSC2010/EPSC2010-819.pdf
https://www.landscheidt.info/
https://landscheidt.info/?q=node/200
The barycentre isn’t the Sun’s, it’s the whooe systems. It’s merely the point around which the system as a whole rotates.
I can’t see how it would affect the Sun as such as the Sun itself passes through it, however. It’s not like an absolute point around which everything is drawn, but the sum total of all gravitational forces. Since the vast majority of that (99%) is from the Sun itself, it shouldn’t matter much.
The Sun does not orbit the barycentre. According to JPL, the centre of its orbit is constantly changing meaning the radius of the Sun’s orbit is constantly changing. There are large swings in angular momentum of the Sun’s orbit due to the large changes in the gravitational forces it experiences. Jupiter is most significant but the late outer planets are also significant because they act over long time frames in a given quadrant.
The distance of the Sun from the barycentre is a measure of its gravitational energy. The Sun experiences a continual exchange of gravitational energy and kinetic energy.
I have no doubt that the gravitation forces (tidal) on the Sun drive the solar activity but I have not nailed that relationship.
The Sun itself does not, but the total mass does. That’s pretty much my point. The barycentre does not relate to the Sun itself, but the whole system.
This is not what the data shows. Albedo is mostly the result of clouds, and the annual variability is contributed about the same by the surface and the atmosphere.
https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2014RG000449
The linked paper does not produce any data for the seasons across the hemispheres as I have done. For overall annual average, the paper give 52.4W/m^2 from surface and 47.2W/m^2 from clouds. So overall land is 10% higher than clouds. They do not give seasonal values for the hemispheres as I have shown. I am pointing out why there are summer peaks in my charts – and it is not clouds.
Excellent paper.
It demonstrates just how all the so called “Climate Science professionals” are just shills and lazy parasitic money grabbing drones.
And the models use an average solar temperature and a mean earth solar orbit radius.
Averages again – do scientific
Thank you. I am so glad that someone has defined 1850 as the perfect year. We now know our mitigation target!