Comments 1 to 21:

1. papertiger at 01:50 AM on 14 September, 2007
   An internal heat source? That would involve gravitational compression. For a planet undergoing gravitational compression to have a climate change, such as a new Red Jr. or increased heat at the equator, the specific gravity would have to change. Jupiter would have had to gain weight.
   Response: Jupiter's internal heat source is not well understood but has been well observed for several decades (eg - Murphy 1975, Fazio 1976). Gierasch 2000 concludes that moist convection from the internal heat source is the dominant factor in converting heat flow into kinetic energy (eg - internal heat fuels the storms). But it's not changes in the internal heat source that is causing climate change on Jupiter at the moment. The predicted climate changes at the equator and poles are due to changes in the vortices that mix heat throughout the planet. I recommend reading this interview with Philip Marcus who explains the process in detail.
2. papertiger at 03:09 AM on 14 September, 2007
   Here is something that I found striking in it's implication for climate change in the Jupiter system.
   

   Although astronomers had studied Jupiter from Earth for several centuries, scientists were surprised by many of Voyager 1 and 2's findings. They now understand that important physical, geological, and atmospheric processes go on - in the planet, its satellites, and magnetosphere - that were new to observers.
   Discovery of active volcanism on the satellite Io was probably the greatest surprise. It was the first time active volcanoes had been seen on another body in the solar system. It appears that activity on Io affects the entire Jovian system. Io appears to be the primary source of matter that pervades the Jovian magnetosphere -- the region of space that surrounds the planet, primarily influenced by the planet's strong magnetic field. Sulfur, oxygen, and sodium, apparently erupted by Io's volcanoes and sputtered off the surface by impact of high-energy particles, were detected at the outer edge of the magnetosphere.
   Particles of the same material are present inside Io's orbit, where they accelerate to more than 10 percent of the speed of light. It is clear to scientists from a comparison of data from Pioneers 10 and 11 (which flew past Jupiter in late 1973 and 1974) and the Voyagers that something changed in the four and one-half years between the Pioneer and Voyager encounters.
   It is not entirely clear just how far-reaching those changes are, or what brought them about. They may be related to Ionian activity. It is difficult to imagine, however, that at least some of Io's volcanoes were not erupting when the Pioneers flew past; it is also, the Voyager scientists say, difficult to believe the Pioneers' instruments failed to see magnetospheric concentrations of sulfur detected by both Voyager spacecraft (Voyager 1 saw greater concentrations than Voyager 2).

   
   Excerpted from Voyager Jupiter Science Summary
   May 7, 1990
   Courtesy of: Jet Propulsion Laboratory (JPL)
   weblink
   
   Let me encapsulate. In the early 70's, Pioneer's 10 and 11 flew through the magnetic field of Jupiter and detected no sulfuric eruptions or particles that were obvious and pervasive in Jupiter's magnetic field in 1979. In short the climate changed.
3. John Cross at 05:52 AM on 14 September, 2007
   Paper Tiger: I found your link interesting but I do not see the connection with what seems to be your premise that the climate change is caused by an increase in solar radiation.
   
   As John Cook pointed out there is a great deal of internal heat, you can argue about its source but not the fact that it is there. Also as John pointed out the energy received by Jupiter from the sun is 1/25 the amount that earth receives. Taking a typical value of 1365 W/m2, that means that Jupiter gets about 55 W/m2. This of course also means that the changes in solar values are 1/25 that of what we see on earth. Taking some typical ACRIM values for the solar output during solar cycles we see a difference of 3 W/m2. In jupiter terms this would be a change of 0.12 W/m2. Much less than current enhanced CO2 forcings on Earth. Can this be responsible for warming Jupiter.
   
   Now, in the tradition of science, let me ask you some questions, specifically how can you exclude the following.
   1) The orbit of Jupiter is somewhat eccentric and at times is 70 million km closer to the sun than other times. Could the your warming be associated with this annual effect?
   2) What was the effect of Shoemaker-Levy 9 on the planet and can you state that we are not seeing residual effects from that?
   
   Finally, based on the above, what would allow you state that the warming is caused by solar output (especially since we haven't seen any increase in solar ouput on Earth)?
   
   My take on this is that we don't really know what cause the climate to change on Jupiter so it can not be taken as evidence of increased solar output.
   
   Regards,
   John
4. Philippe Chantreau at 22:39 PM on 14 September, 2007
   Here are a couple more questions: how much increased solar irradiance would it take to "warm" Jupiter in the extent that you propose (and that you haven't quantified)? And how would that same increased irradiance be felt on Earth (where a significant solar irradiance increase has not been detected recently). By the way, the sheer pressure generated by Jupiter's gravity is enough to produce a lot of its internal heat.
5. papertiger at 04:25 AM on 16 September, 2007
   Lets go ahead and quantify, by all means.
   John Cross has helpfully converted the vague "4% of the level we receive on earth" into the more useful 55 W/m2.
   On to the internal energy source. This is the tricky part.
   How much "heat" is Jupiter giving off? I have seen rather vague discriptions, with qualifiers such as "almost" and "about", but no concrete numbers.
   
   Before Pioneer visited, the heat given off of Jupiter was estimated as "several" times the incident sunlight. After Voyager it was "about" 2 and 1/2 times. Now the author of this post has lited on "almost" twice as much.
   No help here, so I went to the library.
   
   In Reta Beebe's book Jupiter: The Giant Planet page 72, we learn from Rudolf Hanel and his team at Goddard, who developed the duel instrument radiometer and Michelson interferometer used by the Voyager spacecraft, that

   By comparing the intensity of the infrared light that was obtained during daylight and dark intervals, Hanel and his team could separate scattered infrared sunlight from infrared radiation that was emerging from below the clouds. They show that Jupiter emitted energy at a rate of 0.0033 W/cm2.

   
   Well dang. Something doesn't compute. How is 0.0033 W/cm2 "almost twice as much" as 55 W/m2?
   
   Someone explain this to me, because I am stumped.
   Response: John Cross' later comment addresses this but let me clarify a few things. Firstly, your figures are correct. Jupiter emits energy at 0.0033 W/cm². As there are 10,000 square centimetres in a square metre (eg - 100cm x 100cm), this means 0.0033 W/cm² = 10,000 x 0.0033 W/m² = 33 W/m². The surface area of a sphere is 4 x pi x r². So the total amount of energy emitted by Jupiter = 33 x 4 x pi x r² Watts = 414 r² Watts (I can't be bothered looking up Jupiter's radius).
   
   Secondly, the solar flux at Jupiter is roughly 55 W/m². But Jupiter only absorbs solar energy on the half of the planet facing the sun. Eg - the area that absorbs solar energy at 55 W/m² is a circle with the same radius as Jupiter. The area of a circle = pi x r². Hence, the total amount of solar energy absorbed by Jupiter = 55 x pi x r² Watts = 172 r² Watts .

    

   In other words, Jupiter emits about 2.4 times as much energy as it absorbs from the sun. Thanks for your research in quantifying the incoming and outgoing radiation. I've updated the text from "almost twice as much" to "more than twice as much".
6. papertiger at 18:43 PM on 16 September, 2007
   John Cross asks an interesting question.
   1) The orbit of Jupiter is somewhat eccentric and at times is 70 million km closer to the sun than other times. Could the your warming be associated with this annual effect?
   
   Answer: Jupiter is huge. So huge infact that the focii of orbit between Jove and the sun is actually outside the solar surface. This makes the relationship between the two roughly analogous to the relationship between the Earth and moon.
   The Moon's gravitation causes tides on Earth. Likewise Jupiters gravitation causes tides on the sun. This solar tide results in a greater surface area photosphere, hence higher insolation on Earth, when Jupiter is in perihelion.
7. John Cross at 00:45 AM on 18 September, 2007
   Papertiger. I suspect that you have overlooked the fact that Jupiter is a sphere. My 55 W/m2 value looks at the intensity of solar radiation at Jupiter's radius as opposed to earth's radius. However your 33 W/m2 looks at emissions from the whole of Jupiter.
   
   The formula for the surface area of a sphere is 4 pi r2 so we need to divide the 55 W/m2 by 4 to get about 13.75 W/m2. Dividing 33/13.75 gives you 2.4 so I would say the 2.5 value is pretty close.
   
   John
8. John Cross at 01:30 AM on 18 September, 2007
   Papertiger: Interesting idea about the tides on the sun, but I am not sure it is as large as you might think. I took the following quote from PLANETARY TIDES AND SUNSPOT CYCLES by Condon and Schmidt (Solar Physics 42, 1975)
   
   "Thus the maximum tide height produced by the Earth is only Hme = 0.1 mm. The tide due to Mercury is comparable, and those caused by Venus and Jupiter are about twice as large. The tidal effects of all the remaining planets are much smaller."
   
   John
9. papertiger at 05:09 AM on 25 September, 2007
   Let's return to the main thrust of your post.
   You say "Temperature is relatively uniform on Jupiter - the temperature at the poles is nearly the same as at the equator. This is due to the chaotic mixing of heat and airflow from vortices (eg - the White Ovals). The oscillatory motions of the White Ovals ceased after they merged, dampening the movement of heat from Jupiter's equator to its south pole."
   
   This is all falsified by observation of the Shoemaker Levi 9 comet aftermath. When the comet hit it created certain shock chemicals which were tracked over the years by Galileo's CIRS; hydrogen cyanide (HCN), carbon monoxide (CO), and carbon monosulfide (CS).
   The HCN is long lived and provides a footprint to study latitudinal transport. From the paper Jupiter's Atmospheric Composition from the Cassini Thermal Infrared Spectroscopy Experiment -
   

   HCN latitudinal distribution. Once produced by shock chemistry during the SL9 impacts, HCN is stable and almost inert in the stratosphere, so that it is a tracer of atmospheric motions. In fact, the peak abundance is still at the impact latitude [emphasis is mine], and the total HCN mass in Jupiter's stratosphere observed between 1995 and 2000 is comparable to what was inferred right after the SL9 impacts in 1994. The sharp falloff of HCN observed at high latitudes cannot be due to chemistry driven by particle bombardment in the auroral regions. Ion chemistry does not break the CN bond but only efficiently recycles HCN. Thus, a dynamical explanation is the most logical explanation, and HCN should provide a powerful constraint on mixing at mid-latitudes in the southern hemisphere by meridional winds and horizontal wave-induced diffusion. The CIRS observations yield a maximum 5° latitudinal shift in the location of peak abundance from the impact latitude, a behavior consistent with a meridional velocity of zero and a spreading due to diffusion. The equatorward spread of HCN is then mostly by diffusive transport.
   If horizontal diffusion were constant with latitude, the SL9-produced HCN would maximize at the south pole. The most probable dynamical reason for the southward decrease is the inhibition of wave-induced diffusive mixing of HCN in the presence of strong circumpolar winds (vortices) in Jupiter's polar regions. This effect is analogous to the polar vortex that produces a confinement vessel for the Antarctic ozone hole from mid-latitude air in Earth's stratosphere and dynamically isolates polar regions from lower latitudes. Latitudinal temperature gradients measured by CIRS in Jupiter's upper stratosphere indicate the existence of strong polar vortices near 65°N and 65°S, yielding jet streams with eastward velocities of about 20 m s–1 or higher near 1 mbar. Ground-based observations at the Infrared Telescope Facility confirm the presence of a north polar vortex.

   So you can see that there was no appreciable latitudinal heat transport for Red Jr. to interrupt. Also this paper proves that Jupiter's polar regions are heated by solar wind particles accelerated to relativistic energy level by the magnetic flux, rather then heat mixing from the equatorial region.
   Response:

   There are actually "5 thrusts" to my post, any one of which puts paid to the idea that climate change on Jupiter is due to a warming sun:

   1. Jupiter's storms are fueled internally, not by the sun
   2. The changes occuring (eg - disappearance of vortices, creation of Red Spot Jr) are the result of internal turbulence, not an external forcing
   3. Global warming isn't happening on Jupiter - it's a change in the distribution of energy with more in the equator, less in the poles due to disappearing vortices
      
   4. The climate change cited by skeptics (changes of 10 degrees) haven't even been observed yet - they are model predictions
      
   5. The sun isn't getting hotter
      

   However, I appreciate your tenacity and hard work in researching Jovian climate - the comments have been engrossing and John Cross will be chuffed to find a paper on the impact of Shoemaker Levi as that was what got me started on Jupiter in the first place.
10. Philippe Chantreau at 11:31 AM on 25 September, 2007
    Interesting paper. I don't have a subscription so I could not read the full article. I might miss something but from the abstract and the excerpt provided I do not see where it is demonstrated that heat from solar particle winds (?) warms up the polar regions. Any cites on how the particles would generate the heat? Whatever heat is there is unlikely (that's an understatement) to amount to more than the solar irradiance itself, which is, as we have well reviewed, 2.4 times less than the internal heat. I have not read anything suggesting that internal heat is confined to the equatorial regions.
    
    Although the lower latitudes Jovian auroras are somewhat mysterious, the polar ones are mostly similar in nature to those of Earth, as suggested by the Cassini/Galileo data:
    http://www.jpl.nasa.gov/releases/2002/release_2002_46.html
    I don't know of any research attributing a significant part to auroras in the atmospheric heat budget of any planet and I still have not burned my hand by touching a neon tube. If there is some research about that, a cite would be nice.
    From my (modest) recollection of physics, I would think that trying to heat anything with particles is like trying to boil a kettle by throwing hot pebbles at it. Eventually you may succeed with a super-dense barrage of particles, but that's not what the solar wind is.
    Response: Phillipe, for the record, free registration to the Science website will get you access to that article. Science has a window of free access (providing you're registered) - the only articles requiring subscription are recent ones and much older papers but 2004 is fair game.
11. Philippe Chantreau at 11:54 AM on 25 September, 2007
    Hot dog!!
    Thanks for the tip John!
12. Philippe Chantreau at 12:34 PM on 25 September, 2007
    Having the full paper is definitely better. I stand corrected. The warming mentioned by papertiger concerns the upper ionosphere at levels of a few microbars. In that sense, it is true that the atmosphere is heated by particle deposition and other sources not fully understood (Joule effect was mentioned). However, this is more relevant to the upper atmosphere's chemical composition and does not appear to have much implication for its weather, considering how high it is happening and that Jupiter's storms are fueled by heat from below.
13. Philippe Chantreau at 08:31 AM on 26 September, 2007
    I should probably emphasize that the observations show localized hot spots in the upper ionosphere, just for clarity. Saying that solar heats up the polar atmosphere is a little bit of a stretch considering how thick the Jovian atmosphere is.
14. papertiger at 06:56 AM on 27 September, 2007
    Thick Jovian atmosphere. Jupiter is an oblate spheroid. The distance from the center of the planet is shorter from pole to pole then it is across the equator. In the storms are fueled internally model the poles should be warmer then the equator, because the heat would have a shorter distance to travel to reach the surface, less material to heat.
    
    The aurora are dissimilar from Earth's due to two factors. Jupiter's mag field is 1000 times more powerful, the particles are a 1000 times as hot, and Io is erupting fresh material at escape velocity which feeds and augments the mag flux.
15. Philippe Chantreau at 13:45 PM on 27 September, 2007
    Poles should be warmer than the equator? I'm not sure why. Are you sure that the atmosphere (i.e. the layer between the "altitude" at which hydrogen becomes liquid and the one where pressure becomes negligible) is actually thinner at the poles?
    
    The Kunde et al paper mentions the lack of latitudinal heat transport. If there was a mechanism for the heat from the ionospheric hot spots to somehow travel downward, it would still not be moving to the latitudes where heat would be needed to fuel the convective clouds, which have been precisely observed, as in this other pic I linked:
    http://pds.jpl.nasa.gov/planets/captions/jupiter/watercld.htm
    
    Because once again of the lack of latitudinal heat transport and the vortex shaped polar circulation, your argument applies negatively to your hypohesis too. If solar wind heat could warm up the polar atmosphere at the lower levels, that heat would remained confined to the poles.
    
    Also, how likely is it that this heat is quantitavely apt at generating Jupiter's weather?
    
    It seems that the solar wind heat hypothesis creates more problems than it solves.
16. papertiger at 00:39 AM on 11 October, 2007
    Your five points rest on the first point - that Jupiters weather is driven by internal heat source.
    Lets suppose this is true for a minute.
    The heat would be distributed according to distance from the center of the gravitational compression. Since it is a shorter distance from the center of the planet to the pole then it is from the center to the equator, the pole would be warmer. It's not. In fact the poles are already ten or twenty degrees colder then the equator.
    Hot equator, cold poles. Exactly what you would expect from a solar dominated weather system. Funny isn't it?
    
    Then we got this NASA fellow predicting a change that he hasn't bothered to look for, or if he had he would have noticed that it already happened.
    
    You might want to quibble that the sun isn't any hotter then it was in the eighties (interesting that you want to rely exclusively on satellite data for solar irradiance, but then discount the satellite data of Earth's average warming in the troposphere, which shows no trend, in favor of the flawed surface station data manipulations of Hansen's team at GISS), but Jupiter's new red spot gestated in the 30's, slowly gaining momentum over time.
    An exclusive satellite record tells us nothing about the 30's thru the 70's, and is thus useless for explaining the Sun's impact on Jupiter's weather.
    But I can tell you are going to continue truncating history to suit your narrative.
    Some people are always trying to ice skate uphill.
17. Philippe Chantreau at 12:29 PM on 12 October, 2007
    Now we're getting down to the aggressive and personal tone, as if it were going to give more credibility to your assertions.
    
    Satellite data for global temperature is in agreement with GISSTEMP, as shown in this graph:
    http://tamino.files.wordpress.com/2007/08/global2.jpg
    Since Tamino does not share your views, I expect that you'll try to attack the validity of the graph by suggesting dishonesty or bias, so interested readers should know that the thread of that graph's post contains references for all the data.
    
    A Climate Audit blogger used Anthony Watts data to compare with GISSTEMP and, funnily enough, found no significant difference. As a matter of fact, GISSTEMP had the best match with the stations rated by Watts as the better ones:
    http://www.climateaudit.org/?p=2061#comment-138432
    The graph alone:
    http://www.inturnsoftware.com/downloads/crn12_crn5_giss.gif
    See also this work:
    
    
    Your accusation of fraud toward Hansen and GISS is interesting considering that the data gathered by their staunchest critics failed to produce any substantial difference.
    
    You apparently are ignorant of, or chose to ignore the fact that variations in solar irradiance are so small that they were not actually observed and measured until there were satellites. Because of the atmosphere, ground based instruments do not detect them reliably enough. Reconstructions have been done, however, as in the Solanki paper that skeptics like to cite, except for the conclusion section, of course:"It was shown that even under the extreme assumption that the Sun was responsible for all the global warming prior to 1970, at the most 30% of the strong warming since
    then can be of solar origin." The full paper is available as a pdf: http://cc.oulu.fi/~usoskin/personal/nature02995.pdf
    
    Your assertion on Jupiter makes no more sense. I never affirmed that the Sun had no role, but instead pointed to the dominant body of research indicating that the main driver of the weather is internal heat.
    
    Is it distance that best controls heat propagation or other properties? Does distance matter more than density? Convective clouds, fueled by heat from below, have been observed and photographed and I provided a link to one of these photos. Do you have a link to a scientific study attributing the Jovian weather to heat from auroras? How much heat is actually there? What is the mechanism for that heat to travel downward? The most active auroras are at the poles, but as you pointed the poles are cooler, how does that reconsiliate with the "heat from solar particles" idea?
    
    You can throw accusations and insults but the questions posed by your "theory" are still not answered.
18. papertiger at 22:01 PM on 1 July, 2009
    Hello John,
    
    I should have done this long ago but I lost interest. Besides which Phil was being a distraction.
    Your five thrusts starting with number one are answered in Phil Marcus' letters to Nature, "Prediction of a global climate change on Jupiter." Phil posted the link on his EDU homepage at the top of the list, so I imagine he is kind of happy with this work, giving it pride of place above all the rest.
    
    Here is the relevant excerpt:
    

    The Methods section shows that vortex mergers lead to ‘Global temperature changes’, the cycle’s next stage, in which the temperature T near the equator (poles) rises (falls) by ,10 K. Currently the weather layer (containing the clouds and vortices) is nearly isothermal in latitude. This is surprising and not understood. A balance between cooling via blackbody radiation and heating from the Sun (a function of latitude) and internal sources would make the poles ,30 K cooler than the equator. Most solar heat is absorbed in, or just below, the weather layer, so deep convection cannot make its T uniform. Consistent with theory my calculations show that when there are several vortices per westward jet, the velocity v is chaotic and chaotic mixing of T makes the layer isothermal.

    
    He seems to be saying that deep convection ie heat radiating from the planet would result in the pole being 30 K colder then the equator. Also he implys that the weather layer ie everything that we can see is powered by the Sun, that there is an absorbtion threshold below.
    This asumption is further strenghened later with this:
    

    Jovian vortices are robust because
    strong Coriolis forces make the atmospheric flow nearly two dimensional, an environment where vortices thrive. (Three-dimensional flow destroys vortices.) The GRS cannot be part of a street because the street’s cyclones would need to be north of the westward jet stream at 20 degrees S, and no cyclones (not even transients) lie between 20 degrees S and the equator.

    
    
    Interesting note. On Jupiter cyclones are cold air downflow features, where as their opposite, the anticyclone, (Red Spots, white spots, and ovals) are warm air rising features.
    Why would there be no cyclones near the equator?
    Because the air is heated by the sun. All the way to the bottom of the cloud deck.
    Todocha.
19. Philippe Chantreau at 08:02 AM on 15 February, 2010
    One thing I would not want to distract from is consistency of argument, as in papertiger saying in post
    16: "In fact the poles are already ten or twenty degrees colder then the equator.
    Hot equator, cold poles. Exactly what you would expect from a solar dominated weather system."
    
    http://www.skepticalscience.com/global-warming-on-jupiter.htm#66
    
    Then, papertiger goes on putting words in Phil Marcus' mouth that none of the quotes justifies, but that are nevertheless the exact opposite of his previous prediction on the planet's heat distribution:
    
    "He seems to be saying that deep convection ie heat radiating from the planet would result in the pole being 30 K colder then the equator."
    
    That's the very opposite of your previously quoted theory but that's not what Phil Marcus is saying at all. If papertiger truly understood what Marcus is saying why would he use the tentative "seem to be saying"?
    
    Marcus is saying that, in theory, considering the balance of blackbody radiation from internal heat and solar radiation, one would expect to have a certain latidudinal heat distribution. The observations show something different, i.e. "Currently the weather layer (containing the clouds and vortices) is nearly isothermal in latitude."
    
    He then emphasizes that convection can not be responsible for mixing that solar heat to produce the observed uniformity. That would suggest that the amount of solar heat has in fact a modest contribution, although this is not addressed in the letter.
    
    Marcus' letter to Nature can be found here
    http://www.me.berkeley.edu/cfd/people/marcus/nature02470.pdf
    
    It makes no mention whatsoever of a solar influence on Jupiter's 70 year cycle as postulated by the author. Instead, Marcus' hypothesis relies exclusively on fluid dynamics and it is clear from the letter that the 70 years cycle is generated by Jupiter itself. Nowhere in the letter does Marcus suggest that variations in solar irradiance are responsible for the cycle. The climate change consists of a change in the latidudinal heat distribution. Based on this, one could say that, from Marcus' point of view, the single largest influence on Jupiter's climate is the planet's rotational velocity.
    
    His Berkeley page also links to this paper
    http://www.me.berkeley.edu/cfd/people/marcus/icarus162.pdf
    It references this Flasar et al (that includes Gierasch) paper, in which convection and lightning storms are examined in light of the Galileo data:
    http://www.lpl.arizona.edu/~showman/publications/ingersolletal-2004.pdf
20. Colorado Bob at 21:48 PM on 14 September, 2010
    One place the deniers never mention when they take these off world trips ........ Venus.
    Can't be pointing out a planet with a 92 % CO2 atmosphere, and a 900 F surface temperature.
21. Philippe Chantreau at 18:05 PM on 20 September, 2010
    And Bob, let's not forget that Venus is warmer than Mercury, which is closer to the Sun...

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