March 23rd, 2009 in Space & Earth / Space Exploration
During periods of peak activity (front three images) sunspots, solar flares and coronal mass ejections are more common, and the sun emits slightly more energy than during periods of low activity (back images). The amount of energy that strikes Earth’s atmosphere — called total solar irradiance (TSI) — fluctuates by about 0.1 percent over the course of the sun’s 11-year cycle, even though the soft X-ray wavelengths shown in this image vary by much greater amounts. Credit: Steele Hill, SOHO, NASA/ESA
(PhysOrg.com) — During the Maunder Minimum, a period of diminished solar activity between 1645 and 1715, sunspots were rare on the face of the sun, sometimes disappearing entirely for months to years. At the same time, Earth experienced a bitter cold period known as the “Little Ice Age.”
Were the events connected? Scientists cannot say for sure, but it’s quite likely. Slowdowns in solar activity — evidenced by reductions in sunspot numbers — are known to coincide with decreases in the amount of energy discharged by the sun. During the Little Ice Age, though, few would have thought to track total solar irradiance (TSI), the amount of solar energy striking Earth’s upper atmosphere. In fact, the scientific instrument needed to make such measurements — a spaceborne radiometer — was still three centuries into the future.
Modern scientists have several tools for studying TSI. Since the 1970s, scientists have relied upon a collection of radiometers on American and European spacecraft to keep a close eye on solar fluctuations from above the atmosphere, which intercepts much of the sun’s radiation. When NASA launches the Glory satellite this fall (no earlier than October 2009), researchers will have a more accurate instrument for measuring TSI than they’ve ever had before.
The Total Irradiance Monitor (TIM) on Glory is more sophisticated, but still related in concept to the very earliest ground-based solar radiometers, which were invented in 1838. Where those radiometers used sunlight to heat water and indicate the intensity of the sun’s brightness at the Earth’s surface, Glory’s TIM instrument will use a black-coated metallic detector to measure how much heat is produced by solar radiation as it reaches the top of the Earth’s atmosphere.
Scientists have compiled a three-decade record of total solar irradiance by patching together data from U.S. and European satellites. Fluctuations in irradiance correspond well with the cycling of sunspots. To ensure continuity, data from Glory’s TIM instrument must overlap with data from an earlier TIM (in red on this plot), which launched in 2003. Credit: Greg Kopp, LASP
Solar bolometers, as this subset of radiometers is called, have been flown on ten previous missions. Nimbus-7, launched in 1978, included one of the first spaceborne bolometers, and progressively more advanced instruments have followed on other NASA, National Oceanic and Atmospheric Administration, and European Space Agency missions.In 2003, a first generation TIM instrument went aloft with the Solar Radiation and Climate Experiment (SORCE) satellite. Learning from that instrument, engineers have tweaked the optical and electrical sensors to make the Glory TIM even more capable of measuring the true solar brightness and its fluctuations.
“The Glory TIM should be three times more accurate than SORCE TIM, and about ten times more accurate than earlier instruments,” said Greg Kopp, a physicist at the University of Colorado, Boulder, and leader of the TIM science team.
“There’s no doubt that’s an ambitious goal, but I wouldn’t be surprised if they pull it off,” said Joseph Rice, a physicist at the National Institute of Standards and Technology in Gaithersburg, Md.
Beyond engineering improvements, the Glory irradiance monitor has another advantage: access to the one-of-a-kind TSI Radiometer Facility. Funded by NASA and built by the Laboratory for Atmospheric and Space Physics in Boulder, Colo., the new facility has allowed Kopp’s team to calibrate the instrument in the same configuration and under the same conditions as it will endure in space. In January 2009, the Glory TIM instrument underwent a rigorous battery of tests while being compared to a highly accurate ground-based radiometer.
“This was the first time a TSI instrument has ever been validated end-to-end,” Kopp said. “The improvements in accuracy will make it possible to detect long-term changes in the sun’s output much more quickly.” The data will help scientists say more definitively whether the sun’s output is gradually trending upward or downward, and whether the trend is influencing the pace of climate change.
Existing measurements offer a rough sketch, but they’re not quite accurate enough over decades to centuries to paint a clear picture of whether changes in TSI reflect real changes on the sun or just artifacts of different instrument designs. That’s because the radiometers that have measured TSI so far have all reported values at slightly different levels and have all been calibrated differently, injecting a degree of uncertainty into the record.
The new TIM should be sufficiently accurate to quickly yield definitive data on whether solar irradiance is trending up or down. Modelers estimate that TSI increased roughly 0.08 percent as the Sun exited the Maunder Minimum, which lasted for much of the 1700s. But even if TSI radiometers had been available at the time, the increase in irradiance was so gradual that identifying the trend would have been difficult.
Detecting such subtle changes is where the Glory TIM shines. Prior to SORCE, most TSI instruments had only 0.1 percent accuracy, and could not have reliably detected a 0.08 percent change over a century, Kopp explained. The improved accuracy of the SORCE TIM (0.035 percent) would detect such a change in about 35 years. The Glory TIM, meanwhile, should reduce the time needed to nearly ten years.
Getting TSI right has profound implications for understanding Earth’s climate. Thanks to previous orbiting radiometers, scientists know TSI varies by roughly 0.1 percent through the sun’s 11-year magnetic cycle. Such a variation cannot explain the intensity and speed of the warming trends on Earth during the last century, explained Judith Lean, a solar physicist at the U.S. Naval Research Laboratory in Washington, D.C. But, that’s not to say that the sun has no influence on climate change.
While total solar irradiance changes by 0.1 percent, the change in the intensity of ultraviolet light varies by much larger amounts, scientists have discovered. Research shows such variations in the Sun’s emissions can affect the ozone layer and the way energy moves both vertically and horizontally through the atmosphere.
After examining the historical TSI database, some scientists have suggested that solar irradiance could account for as much as a quarter of recent global warming. But without a continuous and reliable TSI record, Kopp and Lean point out, there will always be room for skeptics to blame global warming entirely on the sun, even when most evidence suggests human activities are the key influence on modern climate changes.
Beyond that, there’s a big “what if” percolating through the scientific community. The 0.1 percent variation in solar irradiance is certainly too subtle to explain all of the recent warming. “But, what if — as many assume — much longer solar cycles are also at work?” said Lean. In that case, it’s not impossible that long-term patterns — proceeding over hundreds or thousands of years — could cause more severe swings in TSI.
Could a modern day Maunder Minimum offset the warming influence of greenhouse gases or even throw us back into another little ice age? “It’s extremely unlikely,” said Lean, “but we won’t know for sure unless we keep up and perfect our measurements.”
Good posts, everybody, one of the best threads I’ve seen since October, 2008. Some of the following may be redundant, but maybe it will help others a little.
Here are the solar & Earth atmosphere spectra. Before you go look at the graph, be very careful to read the ordinate units; they’re logarithmic and not intuitive.
http://science.nasa.gov/headlines/images/sunbathing/sunspectrum.htm
From the graph, the UV appears to vary greatly, but if you read carefully, you’ll see it doesn’t matter much as far as energy balance goes, since UV is minuscule relative to the visible and IR.
What UV does to the ionosphere is another thing, entirely: the ionosphere varies in temperature from 500° to 1500°C (solar min to solar max.) That is an order of magnitude change, large enough to play a part in the putative “iris effect,” which (if found) might explain why small variations in LSI could have a major effect on climate.
Similarly, changes in height of the ionosphere (or “thermosphere”) are also significant and are believed by some to affect the net absorption area of the Earth or to play a role in elevated limbic night-time sky temperatures.
Another area of interest touched on previously is the possibility that terrestrial heat sink(s) may vary in operation, banking small sea-level excesses on decadal scales, then releasing the energy into the atmosphere over a relatively short period. If those heat-sink variations are due to changes in the ionosphere, it would explain a lot.
OK. I finally added a WYSIWYG editor (Xinha) to Firefox. Hopefully I wont mess up the HTML tags quite as much.
anna v (06:17:47) :
Have you had a look at the map in http://earthobservatory.nasa.gov/Features/UVB/Images/z10uvb.gif , of how the UV is absorbed to different depths in the oceans?
Interesting. You might want to look at:
White, Warren B., 2006. Response of tropical global ocean temperature to the Sun’s quasi-decadal UV radiative forcing of the stratosphere. J. Geophys. Res. – Oceans, 111, C09020, doi:10.1029/2004JC002552, September 15, 2006
Abstract
“The quasi-decadal oscillation (QDO) in the Earth’s climate system fluctuated in phase with the 11-year period signal in solar total irradiance (STI) variability throughout the 20th century. The QDO was associated with global average upper ocean temperature variability dominated by the tropical global average from 20°S to 20°N. Earlier diagnosis of the tropical global average oceanic thermal budget found the anomalous warming tendency driven not by the radiative forcing (∼0.15 W m−2) from the 11-year period signal in STI but by the larger anomalous quasi-decadal sensible plus latent heat flux (∼0.5 W m−2) from the overlying troposphere. Now we diagnose the corresponding thermal budget of the tropical global average atmospheric temperature variability, finding it largest in the lower stratosphere (∼0.8°K), decreasing downward into the lower troposphere (∼0.15°K) and the upper ocean (∼0.05°K). These diagnostics find quasi-decadal temperature variability in the tropical lower stratosphere arising from a thermal balance between anomalous radiative forcing (1.0–1.5 W m−2) by ozone absorption of the 11-year signal in solar UV irradiance variability (modified by absorption of mean solar IR irradiance by volcanic aerosol variability) and variable longwave radiation and vertical advection. The latter two processes altered the vertical gradient of equivalent potential temperature in the tropical troposphere that allowed mean vertical circulation to drive an anomalous warming tendency in the lower troposphere. The latter matched the amplitude and phase of the downward quasi-decadal sensible plus latent heat flux anomaly that drove the anomalous warming tendency in the tropical global ocean.”
–Mike Ramsey
vukcevic (09:04:23) :
This increase of the harmful UV radiation is causing reduction in bio-mass of the oceans’ surface phytoplankton, the largest absorber of CO2 on the Earth’s surface, either through direct destruction of its cells or process of sterilisation by irradiation.
Maybe.
http://www.nasa.gov/vision/earth/environment/0702_planktoncloud.html
“It’s almost hard to believe, but new NASA-funded research confirms an old theory that plankton can indirectly create clouds that block some of the Sun’s harmful rays. The study was conducted by Dierdre Toole of the Woods Hole Oceanographic Institution (WHOI) and David Siegel of the University of California, Santa Barbara (UCSB).
The study finds that in summer when the Sun beats down on the top layer of ocean where plankton live, harmful rays in the form of ultraviolet (UV) radiation bother the little plants. UV light also gives sunburn to humans.
When plankton are bothered, or stressed by UV light, their chemistry takes over.
The plankton try to protect themselves by producing a chemical compound called DMSP, which some scientists believe helps strengthen the plankton’s cell walls. This chemical gets broken down in the water by bacteria, and changes into another substance called DMS.
DMS then filters from the ocean into the air, where it breaks down again to form tiny dust-like particles. These tiny particles are just the right size for water to condense on, which is the beginning of how clouds are formed. So, indirectly, plankton help create more clouds, and more clouds mean that less direct light reaches the ocean surface. This relieves the stress put on plankton by the Sun’s harmful UV rays.”
Mike Ramsey (17:23:43) :
Thanks, all this shows how much unsettled the science of climate is.
vukcevic (09:04:23) :
This increase of the harmful UV radiation is causing reduction in bio-mass of the oceans’ surface phytoplankton, the largest absorber of CO2 on the Earth’s surface, either through direct destruction of its cells or process of sterilisation by irradiation.
Mike Ramsey (17:37:08)
Maybe.
http://www.nasa.gov/vision/earth/environment/0702_planktoncloud.
“It’s almost hard to believe, but new NASA-funded research confirms an old theory that plankton can indirectly create clouds that block some of the Sun’s harmful rays.
“It’s almost hard to believe, but new NASA-funded research confirms an old theory that plankton can indirectly create clouds that block some of the Sun’s harmful rays. The study was conducted by Dierdre Toole of the Woods Hole Oceanographic Institution (WHOI) and David Siegel of the University of California, Santa Barbara (UCSB).
The study finds that in summer when the Sun beats down on the top layer of ocean where plankton live, harmful rays in the form of ultraviolet (UV) radiation bother the little plants. UV light also gives sunburn to humans.
When plankton are bothered, or stressed by UV light, their chemistry takes over.
The plankton try to protect themselves by producing a chemical compound called DMSP, which some scientists believe helps strengthen the plankton’s cell walls. This chemical gets broken down in the water by bacteria, and changes into another substance called DMS.
DMS then filters from the ocean into the air, where it breaks down again to form tiny dust-like particles. These tiny particles are just the right size for water to condense on, which is the beginning of how clouds are formed. So, indirectly, plankton help create more clouds, and more clouds mean that less direct light reaches the ocean surface. This relieves the stress put on plankton by the Sun’s harmful UV rays.”
Thanks for that, absolutely fascinating. I assume that plankton ability to provide this defence mechanism at certain point reaches limit, above which further rise in UV would cause certain amount of damage to the plankton. This would mean that level of protection would be gradually reduced; result less cloud coverage, more UV, more damage to the plankton. Lest cloud coverage would also mean higher global temperature. Now if rise in UV is linked to the rise in solar activity then we have a link between level of solar activity and the global worming.
Does this make sense or is it a false logic?
vukcevic (02:03:37)
Correction
… if rise in UV is linked to the rise in solar activity then we have a link between level of the solar activity and global warming.
I must disable auto spell-check.
vukcevic (02:03:37)
Correction
… if rise in UV is linked to the rise in solar activity …
That much seems certain.
…then we have a link between level of the solar activity and global warming.
we have a link yes. How strong that link is relative to other causes / moderators of global warming is the question. Because of thermodynamic considerations (http://miskolczi.webs.com/2007.pdf) I believe that the sun must be behind global changes in temperature. Proving that is the challenge.
I must disable auto spell-check.
I will not throw the first stone. 🙂
–Mike Ramsey
28 03 2009
vukcevic (03:23:19) :
Does this make sense or is it a false logic?
It makes sense. In combination with the map that shows the depth of penetration of UV http://earthobservatory.nasa.gov/Features/UVB/Images/z10uvb.gif and the stronger variation of UV during maxima and minima of the solar cycle a rhythm could be set up that would affect cloud formation and therefore albedo and thus global temperature correlated with the cycle . Global temperature is extremely sensitive to albedo. Instead of galactic cosmic rays, UV rays .
anna v (06:17:47) :
Mike Ramsey (03:17:28) :
Thanks.
Now consider that the UV, X-Ray (wavelength less than 300nm) radiation
varies across a solar cycle (in lock step) by about 8%. Below is a sample:
200 nm, 8%
220-260 nm, 5%
greater than or equal to 300 nm, 0.1%
Where did you get those numbers from?
You are making a point that the real difference in the energies coming from the sun are about nine times more from peak to valley of the sun cycle than what is being generally accepted.
The 200nm wavelength is referred to as vacuum UV because it is absorbed by the oxygen in the air. The wavelengths up to 260nm are strongly absorbed in the stratosphere and above and their contribution will be more related to Ozone production. Just as well since DNA absorbs strongly at 260nm!
anna v (21:14:16) :
Thanks, all this shows how much unsettled the science of climate is.
I have always been bothered by the phrase “settled science”. Science isn’t supposed to be settled. Rather, new observations turn up unexplained phenomena which in turn drive new science. Newton’s theory of gravity was as settled as science got in the 19th century. Then Einstein came along.
Scientist aren’t supposed to hold to the doctrine of stare decisis (http://en.wikipedia.org/wiki/Stare_decisis). Those that do are politicians and God knows that there are more than enough politicians masquerading as scientist these days.
–Mike Ramsey
Phil. (10:02:10) :
The 200nm wavelength is referred to as vacuum UV because it is absorbed by the oxygen in the air. The wavelengths up to 260nm are strongly absorbed in the stratosphere and above and their contribution will be more related to Ozone production. Just as well since DNA absorbs strongly at 260nm!
I appreciate the ozone that we have every day. Especially now that as the northern hemisphere heads into spring and I find myself checking my supply of sun screen. 🙂
–Mike Ramsey
Phil. (10:02:10) :
“Now consider that the UV, X-Ray (wavelength less than 300nm) radiation varies across a solar cycle (in lock step) by about 8%. Below is a sample:
200 nm, 8%
220-260 nm, 5%
greater than or equal to 300 nm, 0.1%
The lowest wavelengths vary relatively, but the actual variation in energy units is minute. And UV in the band 242-310 nm actually varies opposite to the solar cycle:
http://www.leif.org/research/Erl70.png
Leif Svalgaard (12:19:45) :
The lowest wavelengths vary relatively, but the actual variation in energy units is minute. And UV in the band 242-310 nm actually varies opposite to the solar cycle:
http://www.leif.org/research/Erl70.png
If you look at the right-hand scale you see that flux of 240-310 UV is more than ten times the flux of 180-242 nm UV, so in term of energy the total variation of UV is not in lockstep with the solar cycle, but varies opposite to solar activity: less solar activity, more UV in W/m2
Leif Svalgaard (12:19:45) :
Phil. (10:02:10) :
“Now consider that the UV, X-Ray (wavelength less than 300nm) radiation varies across a solar cycle (in lock step) by about 8%. Below is a sample:
200 nm, 8%
220-260 nm, 5%
greater than or equal to 300 nm, 0.1%
The lowest wavelengths vary relatively, but the actual variation in energy units is minute. And UV in the band 242-310 nm actually varies opposite to the solar cycle:
http://www.leif.org/research/Erl70.png
The data that you pointed to (thanks by the way) is for 2005 through mid-2008. As you know, the last solar max was in 2001.
“SUSIM’S ll-YEAR OBSERVATIONAL RECORD OF THE SOLAR UV IRRADIANCE”, by L.E. Floyd’, J.W. Cook2, L.C. Herring’, and P.C. Crane, Adv. Space Res. Vol. 31, No. 9, pp. 211l -2120.2003
doesn’t show this anti-correlation for the Hartley band. They show UV integrated irradiance time series data for:
Lyman alpha
170-175 nm
200-205 nm
230-235 nm
Mg II Core-to-Wing Ratio (V21r2)
The changes in intensity all track together. The Mg II absorption feature is near 280 nm is a complex measure loosely defined to be the ratio of irradiance at the center of the Mg II feature to that of its adjoining wings.
“It is interesting to note that while sunspot number peaked in 2000, the peak in the Mg II index occurred in very early 2002. The sunspot number is a derived quantity based on human counting of dark solar surface features while the Mg II index is a ratio based on direct spectral irradiance measurements. Other than an observed overall long-term correlation, there is no physical description that explicitly links sunspot number with the Mg II index. Accordingly, it is not unexpected that the sunspot number and the Mg II index will significantly deviate from one another from time to time. Differences among solar indices and their proxy relationships to solar total and spectral irradiance are currently actively studied (Pap, et al. 2002; Sprigg and Pap: 2003).”
The Total Irradiance Monitor (TIM) is needed to get better data on UV variation. If we are heading into a sustained minimum than Glory’s timing will be unfortunate.
–Mike Ramsey
Mike Ramsey (11:59:10) :
anna v (21:14:16) :
Thanks for your encouraging comments; I would welcome your views on the following:
Some 3-4 years ago when I first suggested such a link I included another factor.
Along increased UV there is also rise in Gamma radiations, that is reaching the oceans’ surface during periods of high sunspot activity. Collisions between protons and gas atoms of the upper atmosphere produce Gamma rays. Clouds provide protection from UV rays, Van-Allen belt provides partial protection from charged particles and the atmosphere to some extent from Gamma rays. Coincidently, the strength of the Earth’s magnetic field has been decaying since 1860s from 61 to 54 micro Tesla, or by about 11%, so radiation protection of Van-Allen belt has also been reduced.
If solar activity is on increase (as it has been since 1860-s, with rise in global temperatures ) then amount of both kinds of radiation would be on increase.
Although plankton may fight UV, to a certain extant, I do not think there is a viable mechanism against Gamma rays, except diving deep down, but that would deprive plankton of the necessary sunlight.
vukcevic (00:49:27) :
I think gamma rays are orders of magnitude less in the spectrum than UV and visible. Though they are penetrating, fortunately they are few.
Here is the energy spectrum:
http://www.leif.org/research/Erl74.png
vukcevic (00:49:27) :
Thanks for your encouraging comments; I would welcome your views on the following:
Some 3-4 years ago when I first suggested such a link I included another factor.
Along increased UV there is also rise in Gamma radiations, that is reaching the oceans’ surface during periods of high sunspot activity.
Sunlight has a black-body spectrum that indicates that the photosphere has a temperature of about 5,800 K. We see this as yellow light. However the temperature rises to 3 million Kelvins in the Sun’s outer atmosphere (the corona). These high temperatures are needed to generate high energy UV and X-ray light.
So what heats the corona to millions of degrees? We are note sure. One hypothesis is given that sunspots mark magnetic loop bases, as the magnetic loops get twisted by the sun’s rotation they snap releasing vast amounts of energy and mass. This heats the sun’s atmosphere to the millions of degrees needed to generate X-Ray and UV light.
Although the Sun produces gamma rays as a result of nuclear fusion at its core, these very high energy photons are converted to lower energy photons before they reach the Sun’s surface where they are emitted out into space. Therefore the Sun doesn’t give off gamma rays.
Collisions between protons and gas atoms of the upper atmosphere produce Gamma rays.
http://adsabs.harvard.edu/abs/1986AdSpR…6..133L
“Measurement of gamma-ray line intensities from the earth’s atmosphere
Letaw, J. R.; Share, G. H.; Kinzer, R. L.; Silberberg, R.; Chupp, E. L.
(COSPAR, Plenary Meeting, 26th, Topical Meeting on Gamma-Ray Astronomy, Toulouse, France, June 30-July 11, 1986) Advances in Space Research (ISSN 0273-1177), vol. 6, no. 4, 1986, p. 133-137.
The authors report measurements of gamma-ray lines from the earth’s atmosphere observed by the gamma-ray spectrometer on the Solar Maximum Mission satellite. The data are summed over 3.5 years and have excellent statistical accuracy. 20 line features within the range 0.3 to 8 MeV have been observed. Line intensities are consistent with models attributing them to neutron absorption by nitrogen and oxygen. The relative intensity of scattered radiation from the 0.511 MeV line suggests production at an average atmospheric depth of 21 g/cm2. These data allow a detailed comparison of gamma-ray production models with experiment in a medium with known composition, geometry, and irradiation level and therefore serve as a good test subject for models of astrophysical gamma-ray line sources.”
Gamma ray’s can’t penetrate very far through the earth’s atmosphere. This is why gamma ray astronomy was not achieved until balloons or spacecraft could gain sufficient altitude. Even gamma-rays that are produced by neutron absorption don’t get very far.
Now lightening is a different story.
http://www.physorg.com/news3959.html
–Mike Ramsey
Hi Leif,
Thanks for that extra info re: the various UV wavelengths. Seems to pretty much settle the question for me *why* total UV w/m^2 doesn’t vary that much with solar cycles, with the different bands offsetting ea/ other in different parts of the cycle.
Which brings us back to the more opaque case for changes in heliomagnetism, cosmic ray-driven increases in cloud nuclei of SO2. If a credible case can be made for a cosmic ray role in natural ozone hole cycles due to SO2 & NO2 ionization cycles, I don’t see why cosmic-ray moderated global cloud cover would be any less likely an avenue for research.
I recall one team – a team skeptical of some of the more enthusiastic research on cosmic ray influence on climate – had relegated the long-term role of cosmic ray variance to something in the range of a 15 – 25% role in climate variation. But I believe it was Spencer (?) who pointed out that if cosmic rays contributed to just 1% of variation in cloud cover over a long term period then the cumulative effect could perhaps even explain significant outcomes like the LIA.
To discount the LIA as a marginal continental effect is a bit too facile. Even the ice ages started off slow. When I compared the geological data for interglacial CO2 levels and light oxygen (a bellweather of total available water vapor) I found that LO tracks more consistently with temperatures than greenhouse gases over the past two glacial & interglacial eras. At first this might seem a tautology, since the vast stades locked up LO as the climate dried and cooled. However the data showed that during the depths of the ice ages variations of LO tracked much more consistently with temperature than did CO2, drawing further into question the case for CO2 driving climate at any point in time.
http://www.americanscientist.org/issues/feature/2002/1/the-eurasian-arctic-during-the-last-ice-age/4
leebert (06:19:33) :
Thanks for that extra info re: the various UV wavelengths. Seems to pretty much settle the question for me *why* total UV w/m^2 doesn’t vary that much with solar cycles, with the different bands offsetting ea/ other in different parts of the cycle.
But what if the plankton is most sensitive to a specific window? It may then get a rhythm from the solar cycle. It is something that has to be looked at more carefully than here.
Mike Ramsey and anna v
Thanks for notes on Gamma rays, I take a point about intensity and accept your estimates that the effect is minimal if at all exists .
UV path sounds far more promising, be it a 2nd or 3rd order derivative linking solar activity to global warming. I can think of another one, even further removed, but I’ll leave it for another occasion.
If you intend to pursue the “plankton link” I would love to know how far you get on with it.
Good luck.
leebert (06:19:33) :
Hi Leif,
Thanks for that extra info re: the various UV wavelengths. Seems to pretty much settle the question for me *why* total UV w/m^2 doesn’t vary that much with solar cycles, with the different bands offsetting ea/ other in different parts of the cycle.
Offsetting each other? Come again?
For the record, it hasn’t settled it for me. 🙂
–Mike Ramsey
CO2 hype risks the truth.
It should be studied if there is a risk.
The distance from sun to earth varies from 146 to 152 x106km. A area of a sphere is A=4Pi r^2. TRI Intency I should vary theoritically 100%-100%(146/152)^2=7.7 %. TRI varies less than 1 % . Why so ?
I think that there are indications that studies approved by IPCC have mannipulated data sets, secret datasets and guessed data set and secret methods which are not reproducable. If the truth does not match the IPCC politics , the political issue wins. IPCC CO2-theory is based on an idea that C02 varies input energy less than 1 % and there is no stabilization ( negative feedback).
Earth’s temperature’s negative feedback is based on H20 vapour and clouds. Stabilization require negative feedbackin the control system theory. If earth did not have stabilization the average temperature would change much more than 10 Celcius or even that 1 C. Also there is a theory that higher solar radiation induces clouds, which lowers input energy. New studies approve that H20 and clouds are efficient energy pumps that radiate heat from the surface.
The magnetic field of earth has decreased 5-15 % within 150 years. It has been measured for centuries. This correlates with the global warming measurements. Magnetic fiels are complex. It is not homogenous on the earth and in and around the atmosphere. Fields can be added together to get resultant vectors. The field decreases by 1/r2. The fields is weak on earth. Resently man has discovered new cloud types. Man has discovered abnormalities and holes in the earths magnetic field. (Even there is unknown magnetic vortexes in the Bermuda ? ) There are reports of satellite damages due to solar radiation. Also metal objects reacts with magnetic fields, especially when they move in the field, and cause forces etc. Especially alternating current (AC) induced magnetic field can also demagnetize atleast ferretic materials, like rocks. DC generates permenant fields. Compass does not operate ok close to AC lines.
The earth magnetic field is not well known. There are theories. One states that field generated by running liquid metal inside the core.
There are many man made magnetic field on the surface, which are stonger than earth’s. Man has woulded coils of power grids on the surface which react with earth magnetic fields. The global magnetic coils are power by power plants. Use of AC has increased 150 years. Solar radiations and magnetic fields can influence power grids. And I think that it is possible that power grids can influence earth’s magnetic field or generator. It should be possible to measure such fields in the atmosphere and above. Perhaps the lines should be designed to induce zero far magnetic field. Some, especially DC systems use earth as return wire.
If earth magnetic field decreases to zero and reverses we will die due the radiation and heat. A polarity change has happened before. Perhaps this artificial magnet influence earth. Perhaps this should be studied more.
Jarmo Kanerva, Finland, Europe. M.Sc.