First detection of climate change on another planet?

Satellite data reveals Venus is going through a change in it’s atmosphere, and the driver seems to be the sun.

From  the Institute of Space and Astronautical Science (ISAS)  part of Japan Aerospace Exploration Agency (JAXA) comes this intriguing bit of research using data from the Akatsuki satellite.

False color image of the nightside of Venus captured with the IR2 camera on Akatsuki at 1.735-µm (blue) and 2.26-µm (red) and mix of the two (green). On the nightside of Venus, IR2 observes infrared light coming from the lower atmosphere through clouds, and the shadow of the clouds can be seen in the image. Here, bright and dark are reversed to show clouds in whitish color.(Credit: JAXA / PLANET-C Project Team)

Akatsuki may have discovered why Venus’s atmosphere rotates so fast. The reason may play a vital role in the habitability of Earth-sized exoplanets.

As a planet nearly the same size and mass as the Earth, Venus is an essential study for understanding the range of possible conditions on rocky planets. A defining feature of our neighboring world is a thick atmosphere whose reflective properties enticed ancient astronomers to name the planet after the mythological goddess of beauty, but whose ability to trap heat renders the surface temperature capable of melting lead.

Yet perhaps the strangest feature of the Venusian atmosphere is its speed. Winds whip around the planet up to sixty times faster than the surface rotates; a phenomenon known as atmospheric super-rotation.

Exceeding 100 m/s (360 km/h) in the upper clouds, wind speeds on Venus are legitimately fast. However, the surface of the planet also rotates extremely slowly. The planet orbits the Sun in 225 Earth days but takes 243 Earth days to rotate on its axis, making the Venusian day (one complete rotation) longer than its year.

Illustration of tidal locking. The green region of the satellite (moon or planet) is never visible from the surface of the central body (planet or star). (Credit: wikipedia / Smurrayinchester)

Such slow rotation may be a common feature among Earth-sized exoplanets such as the TRAPPIST-1 system and Proxima Centauri-b, whose close orbits to their star have likely resulted in tidal lock. Like the Moon orbiting the Earth, a tidally locked world rotates once per orbit so that one side permanently faces the star while the other experiences perpetual night. Slow rotators with Earth-like atmospheres need to transport heat efficiently around the planet or risk the atmosphere collapsing as it freezes on the cold night side of the world. Such a catastrophic end could be avoided if tidally-locked worlds typically had the fast winds of a super-rotating atmosphere.

So what causes Venus’s super-rotation and might it be a common phenomenon?

Classically, there are two main pictures for super-rotation. In the first scenario, frictional drag of the atmosphere over the planet surface results in slowing down the planet’s rotation to accelerate the winds (the Gierasch-Rossow-Williams mechanism). In the second scenario, the winds are excited due to heating from the Sun (known as solar thermal tides).

Models of the first “surface-up” mechanism are notoriously sensitive to the exact starting conditions on the planet. Modest shifts to the temperature distribution of the planet may kill or initiate super-rotation. This would suggest that relatively few slowly rotating worlds would end up with atmosphere-preserving super-rotating winds, as conditions on the planet would need to be just right.

Artist illustration of the Akatsuki Venus Climate Orbiter approaching Venus.

But super-rotation on Venus has been observed both at the cloud tops and down to depths of tens of kilometres. Given that Venus reflects a large fraction of the incident sunlight, could the influence of the Sun really be driving the super-rotation of the middle layers?

The Akatsuki spacecraft (meaning “Dawn” in Japanese) entered Venus’s orbit on 7th December, 2015. It was on the third anniversary of the orbit insertion that a press conference was held in Tokyo to discuss the latest results.

Led by International Top Young Fellow (JAXA’s prestigious postdoctoral fellowship program), Dr. Javier Peralta, the press conference presented results from a new paper published in the Astrophysical Journal Supplement Series in December.

Dr Javier Peralta, ITYF at ISAS/JAXA and lead author of this work.

In this paper, Peralta used 466 images of the Venusian clouds captured by the IR2 camera on Akatsuki at an infrared wavelength of 2.26 microns between March and November 2016. By comparing images taken at different times, Peralta was able to track clouds as they swept around the Venusian globe to measure their speed.

On the Venusian dayside, the atmosphere is illuminated by the incoming sunlight. This is strongly reflected in both ultraviolet and infrared wavelengths by the upper cloud at an altitude of 60 – 70 km above the planet surface. However, the nightside illumination comes from infrared heat emanating from Venus’s hot surface. This is partially blocked by clouds deeper in the atmosphere at altitudes between 48 – 60 km. As the clouds have varying transparency to this infrared glow, their shapes become visible when viewed through Akatsuki’s IR2 camera. It was these deeper, nightside clouds that Peralta tracked.

False color image of the nightside of Venus using 1.735-µm (blue) and 2.26-µm (red) images taken by IR2 camera. (Credit: JAXA / PLANET-C Project Team)

Peralta’s cloud tracking algorithm was semi-automatic, utilizing both humans and computers. Clouds were identified by hand and then mapped a later image using computer code and the result confirmed by hand once again.

The result was 2,947 wind measurements which revealed an interesting pattern. There was a clear acceleration of the clouds that was tied to the location of the Sun, strongly implying that the Sun was having an effect on clouds far below the upper atmosphere.

At lower latitudes, this acceleration was predominantly zonal (wrapping westwards around the planet) with no meridional (north-south) wind acceleration detected. This also pointed to a Sun-driven system, as the surface-up mechanism should have led to winds in both directions. However, Peralta was cautious when he insisted this was not “case closed.”

“There is no clear trend shown in the meridional winds with Akatsuki,” he noted. “But we should confirm this by trying wind measurements with even higher accuracy.”

Peralta hopes that combined results from Akatsuki and the European Space Agency’s Venus Express might reveal even more about this system. Animations, images and the wind measurements made in the Peralta’s paper are available to download and be explored by the community.

Peralta next looked beyond the Akatsuki data, comparing results from previous Venus missions stretching back to 1978. While it is challenging to compare results from instruments on different spacecraft and ground-based telescopes,

Peralta’s results implied that the speeds of Venus’s winds have shifted over the last thirty years. Such a discovery is not only consistent with a solar driver but may be suggestive of the first detection of climate change on another planet.

“If solar tides drive the super-rotating winds, this may imply that the cloud albedo (how reflective the clouds are) may have changed over time and affected the impact of the solar radiation,” Peralta explains.

Such a result is good news for tidally locked worlds. If Venus’s super-rotating winds can be driven by the Sun, then maybe such rapid circulation could be common on slow rotating but potentially more temperate worlds around other stars. While the weather beneath a super-rotating atmosphere would be very different from that on Earth, it might allow the planet to retain its atmosphere and even the desired surface conditions for life.

By comparing the two Earth-sized planets in our own Solar System, we may learn much more about what it takes to be a habitable world.

Source: JAXA Cosmos blog, h/t to an “Al Nonymous” tipster.

Further information: The Akatsuki spacecraft homepage

Journal paper by Peralta et al. (open access)

Nightside Winds at the Lower Clouds of Venus with Akatsuki/IR2: Longitudinal, Local Time, and Decadal Variations from Comparison with Previous Measurements


We present measurements of the wind speeds at the nightside lower clouds of Venus from observations by JAXA’s mission Akatsuki during 2016, complemented by new wind measurements from ground-based observations acquired with the TNG/Near Infrared Camera Spectrometer (NICS) in 2012 and IRTF/SpeX in 2015 and 2017. The zonal and meridional components of the winds were measured via cloud tracking on a total of 466 Akatsuki images of Venus acquired by the camera IR2 using the 2.26 μm filter, with spatial resolutions ranging from 10 to 80 km per pixel and covering 2016 March 22 to October 31. More than 149,000 wind vectors were obtained using an automatic template-matching technique, and 2947 wind vectors were inferred using a manual procedure. The meridional profiles for both components of the winds are found to be consistent with results from the Venus Express mission during 2006–2008, although stronger wind variability is found for the zonal component at equatorial latitudes where Akatsuki observations have better viewing geometry than Venus Express. The zonal winds at low latitudes also suggest a zonal variability that could be associated with solar tides or vertically propagating orographic waves. Finally, the combination of our wind measurements from TNG/NICS, IRTF/SpeX, and Akatsukiimages with previously published data from 1978 to 2017 suggests variations of up to 30 m s−1 in the winds at the nightside lower clouds of Venus.

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Nick Schroeder
January 24, 2019 9:05 am

Mark Twain observed, “The trouble with most of us is that we know too much that ain’t so.”

Adding to the “Δ33C without an atmosphere” (see other article) that completely ain’t so is the example of Venus.

Venus, we are told, has an atmosphere that is almost pure carbon dioxide and an extremely high surface temperature, 750 K, and this is allegedly due to the radiative greenhouse effect, RGHE. But the only apparent defense is, “Well, WHAT else could it BE?!”

Well, what follows is the else it could be. (Q = U * A * ΔT)

Venus is 70% of the distance to the sun so its average solar constant/irradiance is twice as intense as that of earth, 2,615 W/m^2 as opposed to 1,368 W/m^2.

But the albedo of Venus is 0.77 compared to 0.31 for the Earth – or – Venus 601.5 W/m^2 net ASR (absorbed solar radiation) compared to Earth 943.9 W/m^2 net ASR.

The Venusian atmosphere is 250 km thick as opposed to Earth’s at 100 km. Picture how hot you would get stacking 1.5 more blankets on your bed. RGHE’s got jack to do with it, it’s all Q = U * A * ΔT.

The thermal conductivity of carbon dioxide is about half that of air, 0.0146 W/m-K as opposed to 0.0240 W/m-K so it takes twice the ΔT/m to move the same kJ from surface to ToA.

Put the higher irradiance & albedo (lower Q = lower ΔT), thickness (greater thickness increases ΔT) and conductivity (lower conductivity raises ΔT) all together: 601.5/943.9 * 250/100 * 0.0240/0.0146 = 2.61.

So, Q = U * A * ΔT suggests that the Venusian ΔT would be 2.61 times greater than that of Earth. If the surface of the Earth is 15C/288K and ToA is effectively 0K then Earth ΔT = 288K. Venus ΔT would be 2.61 * 288 K = 748.8 K surface temperature.

All explained, no need for any S-B BB RGHE hocus pocus.

Simplest explanation for the observation.

Charles Nelson
Reply to  Anthony Watts
January 24, 2019 10:55 am

Satellite data reveals Venus is going through a change in it’s atmosphere, and the driver seems to be the sun.
Get Leif in to sort them out by explaining how the Sun has absolutely no impact on the atmosphere of planets!

Tom in Florida
Reply to  Charles Nelson
January 24, 2019 12:49 pm

Once again someone who misquotes Dr S. or simply does not understand what he says. It is the CHANGE in solar irradiance that is too small to make a significant impact on changing climate.

Writing Observer
Reply to  Tom in Florida
January 24, 2019 5:57 pm

Sigh. If a the change in solar irradiance has no effect on climate – what is changing the atmosphere on Venus? Venusians driving around their SUVs (made out of tungsten, obviously)?

Although one does not need to call out Dr. Svalgaard specifically. Close to an ad-hom, there.

Tom in Florida
Reply to  Tom in Florida
January 24, 2019 7:35 pm

Again, nobody said it had no effect but rather a very small effect. And that is in regards to Earth not Venue.

Martin hughes
Reply to  Tom in Florida
January 26, 2019 1:06 am

Isn’t the solar effect on earth to do with the effect of an elliptical orbit on seasonal warming and cooling? It isn’t primarily about total solar irradiance.

If there is a solar effect on Venus then since it is more circular in its orbit TSI or variations of the spectra within that are all that can explain the solar effect. My understanding is that TSI is really a minor player, and that variations within the spectra can be much greater than variations of TSI.

UV for example can vary greatly even though overall TSI might only vary slightly. Venus having a different atmosphere to earth would no doubt respond differently than earth. At least that would be my intuition.

Reply to  Nick Schroeder
January 24, 2019 10:02 am

Here’s a link to a good paper describing the atmosphere of Venus.

Figure 2 gives an idea of the processes involved in producing the surface temperature of Venus. Suffice it to say that it is mostly explained by the density and thickness of the atmosphere.

Bryan A
Reply to  Nick Schroeder
January 24, 2019 10:12 am

A far more important factor to the mean surface temperature on Venus is Atmospheric Pressure at the surface which is some 90 times that of Earth.

The Cob
Reply to  Anthony Watts
January 24, 2019 11:56 am

Did you not have your coffee this morning Anthony?

Get this man an esspresso pronto!

Reply to  Anthony Watts
January 24, 2019 5:11 pm

–And again, this study is about the wind speed of Venus, not temperature.–

I guess one gets the question does wind speed affect temperature?
If have faster wind speed, does correlate with warmer or cooler temperature.
Or does wind speed have nothing to do with the temperature at the rocky surface?

Writing Observer
Reply to  gbaikie
January 24, 2019 6:05 pm

Or are both affected by the density? Energy inputs? Etc., etc., etc.

Planetary scientists have one of the worst jobs. There is no way (at least until someone invents an FTL drive) to make observations of a body where only one possible influence is significantly different from a comparison body.

Reply to  gbaikie
January 24, 2019 7:54 pm

Greater temperature differences mean greater wind speeds.

Heat all by itself makes no difference.

richard verney
Reply to  gbaikie
January 25, 2019 7:02 am

Do we really know?

The fastest wind speeds (in our solar system) are said to be found on Neptune, a planet that is rather cold, and one which receives little energy from the sun. To the extent that there are temperature variations on this planet (of course it does not have a surface as such), I suspect that they are largely caused by motion within its interior.

Earth has a temperature variation of about 100 degC, but I very much doubt that Neptune has such variations unless one delves deep into its atmosphere.

Reply to  gbaikie
January 25, 2019 7:48 am

MarkW January 24, 2019 at 7:54 pm

… Heat all by itself makes no difference.

On one hand, WRT planetary atmospheres, the ultimate heat sink is outer space. On the other hand, the heat radiated by a planet will equal the radiated heat it receives.

The trouble is in how you define wind. We tend to think of wind as relative to the Earth’s surface. If we think of air movement relative to a fixed point in space, we see air at the equator moving at around 1000 mph from the lit side of the planet to the dark side. link Depending on the reference point, the Earth’s atmosphere moves a lot faster moving heat between the hot side of the planet and the cold side.

Reply to  Anthony Watts
January 25, 2019 5:57 pm

It’s tough to give up that temperature fixation. It was actually a very interesting article and thank you for including it.

Reply to  Nick Schroeder
January 24, 2019 10:28 am

Nick Schroeder wrote, “The thermal conductivity of carbon dioxide is about half that of air, 0.0146 W/m-K as opposed to 0.0240 W/m-K so it takes twice the ΔT/m to move the same kJ from surface to ToA.”

The thermal conductivity of CO2 is as irrelevant as the carbon in window glass which David Suzuki claimed causes cars to get hot in the sun. It’s the effects of air movement, radiative absorption/emission, and (on Earth) the water cycle, which matter.

Nick Schroeder wrote, “All explained, no need for any S-B BB RGHE hocus pocus.”

I don’t know what “BB” stands for, but the (misnamed) greenhouse effect is not hocus pocus. We’ve been over this before:
(If the link doesn’t take you to the comment, then press Ctrl-F (or ⌘-F on a Mac) and search the page for “big green”.)

(Also, a nit: On average, Venus is 72.33% [not 70%] of Earth’s distance from the Sun, and it receives 1.91× [not twice] as much energy from the Sun per square foot, compared to Earth, which compensates for most of the effect of Venus’s higher albedo.)

Reply to  Nick Schroeder
January 24, 2019 11:18 am

Nick, I verified your numbers, except for the issue of atmospheric thickness. How is that defined? I got a 250 km number for Venus. At what definition? Pressure? Density? How does one compare that to the earths thickness number of yours? Lots of wiggle room there. After you sort that out for me I will look at you conjecture again.

Reply to  EdB
January 24, 2019 12:10 pm

Assuming the ‘Karman’ definition of atmospheric height is valid, (100 km earth, 250 km for Venus), then the conjecture depends upon conductivity.

Conductivity of a gas is: “The thermal conductivity of gases is directly proportional to the density of the gas, the mean molecular speed, and especially to the mean free path of molecule. …”

Gravity plus molar mass density gives pressure.

So your conjecture is the same as the NK paper describing their Atmosphere Thermal Effect, which arrives at a surface temperature using the same density(pressure).

No wonder AW does not like your conjecture, as it appears that NK is verboten as well.

Last New Year there was a long discussion on NK. I conjectured that wind velocities would be higher on a planet without an effective GHG to move heat to the poles, via radiation. Venus is super saturated, ie, the GHG mechanism is rendered useless. Thus only wind speed can move the heat to the poles and the other side of the planet.(which it does)

But, I could be wrong.

Reply to  EdB
January 25, 2019 5:08 am

So no one is interested that Unified Theory of Climate, Nikolov and Zeller ( Pressure-induced Thermal Enhancement (PTE) [PV=nRT] is consistent with Nick’s [Q = U * A * ΔT s] ??


Reply to  EdB
January 26, 2019 9:38 am

Nick.. it turns out that the Karman line is totally arbitrary at 100km. Mathematically, it is closer to 82km.

The key parameter is density. The 250kn for Venus is also arbitrary.

Nick, you need to bin this idea that your numbers mean something. It is circular reasoning.

The Kármán line is therefore the highest altitude at which orbital speed provides sufficient aerodynamic lift to fly in a straight line that doesn’t follow the curvature of the Earth’s surface.

Above 100 kilometers the air density is about 1/2,200,000 the density on the surface.[11] At the Kármán line, the air density ρ is such that

L = 1 2 ρ v 0 2 S C L = m g {\displaystyle L={\tfrac {1}{2}}\rho v_{0}^{2}SC_{L}=mg} L={\tfrac 12}\rho v_{0}^{2}SC_{L}=mg


v0 is the speed of a circular orbit at the same altitude in vacuum

m is the mass of the aircraft

g is the acceleration due to gravity.

Although the calculated altitude was not exactly 100 km, Kármán proposed that 100 km be the designated boundary to space, because the round number is more memorable, and the calculated altitude varies minutely as certain parameters are varied. An international committee recommended the 100 km line to the FAI, and upon adoption, it became widely accepted as the boundary to space for many purposes.[12]

Leonard Weinstein
Reply to  Nick Schroeder
January 24, 2019 11:29 am

without RGHE (both from absorbing gases, but also aerosols) the radiation would be from the surface, not the top of the atmosphere. It is the average location of radiation to space (of sunlight absorbed by both the atmosphere and surface) along with the lapse rate (which depends on specific heat and gravity) that controls surface temperature.

Reply to  Leonard Weinstein
January 24, 2019 1:02 pm

Some million years ago, when the Mediterranian was dried out, down there 4 km below sealevel, midday temps were about …90°C , all scientists agree on that. Laps rate is great.
The whole atmosphere acts like a greenhouse, no glass or plastic roof needed because of gravity! (But the warmth can only escape by radiation, so it is realy a very big greenhouse! Temperature will be at the maximum all the time! )
Seen from the Sun this maximum temperature is 255 °K.
Also seen from the Sun, there is no superficie, there is only TAO.
The laps rate is calculated starting from TAO, downwards to the superficie and upwards in the troposphere. That is the way it goes, on every planet.
And yes, there exsists another kind of ‘greenhouse effect’, the one of the ‘glass roof’, the one that makes radiating to space more difficult and make the lowest temps somewhat higher, yes. But that ‘type of greenhouse effect’ is peanuts compared to the real one!

Reply to  willy
January 24, 2019 1:40 pm

I know all this because I grew tomatos, you know.

Reply to  willy
January 24, 2019 2:07 pm

Make Lapse Rate Great Again.

Paul Agle
Reply to  Nick Schroeder
January 24, 2019 11:58 am


Nice theory.

CO2 is about twice as good as an insulator.

But a much better radiator (it absorbs and emits in IR wavebands), and has about 3.5 times the specific heat of air (much better for convective heat transport).

What stops surface convection on Venus is the 52 times surface atmospheric density (6.7% of the density of water). A 1 m/s breeze on Venus is the equivalent of a tropical storm on earth.

Walter Sobchak
Reply to  Paul Agle
January 24, 2019 2:53 pm

“CO2 … has about 3.5 times the specific heat of air”

I know it’s from Wikipedia, but it matches my memory of chemistry when I took it in a previous millennium:
Air (Sea level, dry, 0 °C) gas 1.0035
Carbon dioxide CO2 gas 0.839
Water at 25 °C liquid 4.1813

Reply to  Walter Sobchak
January 24, 2019 5:16 pm

oh good, I was wondering about whether CO2 was 3.5 times more.
But when allow for CO2 gas being denser, it’s bit closer to the 1 of air

Reply to  Paul Agle
January 25, 2019 5:23 am

“Well… Nice theory. CO2 is about twice as good as an insulator. But a much better radiator (it absorbs and emits in IR wavebands)”

The CO2 bands would be >10,000 times saturated, thus opaque, is it not? Add to that the thermalization of any energized CO2 molecule(Happer), and one would conclude that CO2 functions to cool at extreme altitudes.

Why do you think there is no vertical convection at the equator?

Dr. Strangelove
Reply to  Nick Schroeder
January 25, 2019 6:13 am

Fourier’s law (heat conduction) is for solids and stationary fluids. Venus atmosphere is a moving gas. For moving fluids, heat transfer is by convection and radiation.

richard verney
Reply to  Nick Schroeder
January 25, 2019 7:14 am

Why do gas giants get warmer the deeper one dives into their atmosphere, if this is not due to pressure?

Or consider what NASA says:

However, scientists have obtained readings on what the temperature is at the upper edge of the cloud cover: approximately -145 degrees C.

However, if one were to descend a little deeper into the atmosphere, the pressure would increases to a point where it is ten times what it is here on Earth. At this altitude, the temperature is thought to increase to a comfortable 21 °C, the equivalent to what we call “room temperature” here on Earth.

So even NASA acknowledges the role of pressure on the temperature of the atmosphere.

Even though a gas giant is not in the process of gravitational collapse, the temperature caused by compressional pressure has not appear to have dissipated.

richard verney
Reply to  richard verney
January 25, 2019 7:18 am


The above quote is not a quote from NASA, but rather from the universe today. See:

Joel Snider
January 24, 2019 9:27 am

First Mars. Now Venus.

It’s worse than we thought.

Another Paul
Reply to  Joel Snider
January 24, 2019 9:34 am

Do Mars & Venus also have a 12 year deadline?

Pillage Idiot
Reply to  Another Paul
January 24, 2019 12:23 pm

My models indicate that no humans will be alive on Mars, or Venus, twelve years from this date!

R Shearer
Reply to  Pillage Idiot
January 24, 2019 3:29 pm

I’m not so sure about Mars, but speaking of wind, isn’t it amazing how SUVs on earth impact the climate on other planets?

Reply to  R Shearer
January 24, 2019 5:28 pm

I would like it, if we would have manned mission to Venus.
Going to Venus has less radiation damage as Mars [and quicker].
Though it’s harder to leave the upper atmosphere of Venus, than rocky surface of Mars.
So have get a way to ship rocket fuel to Venus atmosphere and have gas station in the Venus atmosphere in order to refuel the rocket ship.

But things going too slow, and don’t expect crew to visit Mars surface or Venus atmosphere
within 12 years. The Moon could done and could done in about 7 to 8 years. And if that is done, and we don’t build lunar base [don’t think should focus on lunar base] then we could get Mars base and humans landing on Mars within about 12 years

Reply to  Another Paul
January 24, 2019 9:47 pm

Depends, do they drive SUVs?

Sam Capricci
Reply to  Joel Snider
January 24, 2019 10:11 am

I mentioned Mars warming on another thread and someone asked me for a link and I found an old link to the 2003 story. Clicking however on the related original story bring up a 2016 story on, I don’t think the Freepers had the foresight to post an article 13 years before it was written so here is the original story link.

Anyway, I don’t believe our human activity has yet reached the asteroid belt or Jupiter yet but we must be causing the warming (if that is what Venus is experiencing) on our two closest planetary neighbors. /s

Reply to  Sam Capricci
January 24, 2019 10:20 am

Certainly not the first discover of climate change outer earth:
Is our solar system heating up?

During the last years, astronomers have observed some important changes in terms of super storm activities, strong winds and even ice melting. On Neptune, strange storms as wide as Earth have been observed in August 2017, raising questions about how they formed and persisted [5]. On Uranus, the so-called ” boring planet”, is not calm at all. Underneath its placid blue face, there’s some really wild weather going on. In 2014, astronomers from Berkeley reported a record-breaking storm activity [6]. Other super storm events were spotted on Saturn in 2011. One of them was so powerful that it stretched around the entire planet [7]. On Jupiter, some important changes have been seen in the great red spot. The Cassini-Huygens launched in 1997 passed Jupiter and gathered data from it in 2000 and 2001. These measurements revealed to us that Jupiter emits 67% more radiation than it receives from the Sun. This internal heat source is thought to drive much of Jupiter’s weather, including, presumably, the Great Red Spot. However, after years of relative stability, the Great Red Spot is now changing rapidly. The Hubble observations showed in 2012 a new wave structure in a region of cyclones and anticyclones. It’s clear that Jupiter’s atmosphere is moving, and the Great Red Spot is evolving [8]. Also, observations are showing ice caps are melting, but not only on Earth, on Mars too [9]. In 2005 data from NASA’s Mars Global Surveyor and Odyssey missions revealed that the carbon dioxide “ice caps” near Mars’s south pole was diminishing for three summers in a row. And finally, on Venus, in June 2013, the most detailed record of cloud motion chronicled by ESA’s Venus Express has revealed that the planet’s winds have steadily been getting faster over the last six years [10].

Reply to  Joel Snider
January 24, 2019 12:22 pm

Joel Snider
January 24, 2019 at 9:27 am

Yes, it is. And it’s obviously being done by those pesky Venusians…you can clearly see their private jet contrails on the left of the photo! They must have the equivalent of Davos on Venus.

Joel Snider
Reply to  Alastair Brickell
January 24, 2019 4:11 pm

Venusians. Bastards!

Tom in Florida
Reply to  Joel Snider
January 25, 2019 5:03 am

Nope, Venusians (or is it Venetians?) are bitches. Martians are bastards.

January 24, 2019 10:24 am

The atmosphere rotation is not great surprise. Venus is at 2/3 Au from sun (earth 1Au) and it has very weak magnetic field (weak magnetosphere) consequently solar wind impacting upper levels of its atmosphere is number of magnitude stronger than in the earth’s case. As sun rotates nearly 10 times faster than Venus the solar wind following Parker spiral impacts it’s atmosphere at an oblique angle accelerating it’s rotation to a rate exceding rotation of the planet itself. Btw solar wind has blown away most of the Martian atmosphere.

Reply to  vukcevic
January 24, 2019 10:45 am

Parker spiral animation
Venus is the green blob at 90W degrees, the Earth is the yellow one 0 degrees and Mars at about 170.

Reply to  vukcevic
January 24, 2019 3:13 pm


Surprising that the proximity of the sun to Venus has not blown away it’s atmosphere while it did for mars much farther away. But then Venus gravity is also much greater than mars and chemical compositions possibly more likely to create and sustain an atmosphere on venus?

Reply to  JimG1
January 24, 2019 4:03 pm

Venus being bigger, it’s core is cooling down a lot slower than Mars’ did. As a result it’s magnetic field is still a lot stronger than Mars’.

Reply to  MarkW
January 25, 2019 12:34 am

Venus rotation is very slow hence its field is very weak . Planets with high rate of rotation and large mass (all gas giants less than 24h) have strong magnetic field.

Reply to  MarkW
January 25, 2019 10:00 am

Mars lost it’s magnetic field almost completely a long, long time ago.

Reply to  vukcevic
January 24, 2019 3:24 pm

How much of the Venusian atmosphere (given the very weak magnetic field) has been blown away by the (relatively very strong) solar wind?

Reply to  Don
January 24, 2019 3:43 pm


Don’t know since we don’t know what it started with or how much is still being “manufactured” or its multibillion year history.

Reply to  JimG1
January 24, 2019 4:25 pm

… same “don’t know” parameters apply with respect to Mars, but for some reason we are pretty sure that “most” of Mars atmosphere has been removed.

(not criticizing, just curious as to whether there is an accepted reconciliation guess.)

After briefly looking it seems that the guess is that there is an induced field between the solar wind and thick atmosphere that buffers the atmosphere … I don’t get it, but it’s there.

Reply to  DonM
January 25, 2019 12:27 am

Venus atmosphere is at high temperatures and it is easily ionised by solar wind made of charged particles. Solar wind magnetic field will force ionised gas to move thus creating electric current which will in turn create it’s own magnetic field (all governed by basic laws of physics)

January 24, 2019 10:39 am

The way forward is clear. We need more money to find out why Venus is affected by the Sun but Earth is not.

Jaap Titulaer
Reply to  Rob_Dawg
January 24, 2019 12:12 pm

Or why Mars and Venus are affected by the Sun and Earth is not 🙂

Wim Röst
January 24, 2019 10:49 am

Abstract: “The zonal winds at low latitudes also suggest a zonal variability that could be associated with solar tides or vertically propagating orographic waves. Finally, the combination of our wind measurements from TNG/NICS, IRTF/SpeX, and Akatsukiimages with previously published data from 1978 to 2017 suggests variations of up to 30 m s−1 in the winds at the nightside lower clouds of Venus.”

WR: It would be interesting to see whether observed variations* in wind speed on Earth coincide with the suggested variations in wind speed on Venus. If a mechanism like solar tides (or another mechanism) would influence ‘wind’ on both planets in the same way and at the same moment and that mechanism would show a cyclic character, cyclic patterns of temperature change on Earth could come closer to being understood.

On Earth stronger winds result in more cold oceanic upwelling and in more mixing of warm ocean surface layers with the colder subsurface layers. Together those wind-driven processes are cooling ocean surfaces. If the cyclic pattern in wind strength depends (partly) on solar influence and that influence knows a cyclic character, a mechanism that could explain cyclic temperature movements on Earth could have been found.

* from

Joel O'Bryan(@joelobryan)
Reply to  Wim Röst
January 24, 2019 11:15 am

What part of asymmetric heating-cooling of a fluid do you not understand? (That’s a serious question BTW)

Joel O'Bryan(@joelobryan)
Reply to  Joel O'Bryan
January 24, 2019 11:26 am

Apologies Wim,

This comment appeared here by mistake. The above comment was for Robert W Turner
January 24, 2019 at 11:00 am (below).

Joel O'Bryan(@joelobryan)
January 24, 2019 10:54 am

“First detection of climate change on another planet?”

By the IPCC definition, Venus cannot have climate change since mankind’s influence on Venusian atmospheric composition and land use is zero by any measurement.
That UN definition silliness aside, it brings up the necessity of defining what you mean by “climate change,” as everyone seems to use different operational definitions.

Saturn’s north pole changed colors between 2012 to 2016.

Is that climate change?

“Hubble captures Neptune’s changing seasons”
“.. (Neptune’s) growing cloud cover is most likely the result of increased solar heating from the Sun, says Lawrence Sromovsky of Wisconsin-Madison University. The effect is less pronounced near to Neptune’s equator, which is consistent with the effect, he adds.”
Neptune likely has 41 year long seasons associated with its orbital period (165 earth years) and axial tilt, similar to Earth’s seasons. As Neptune receives so little solar energy at 29.81 AU to 30.33 AU distance, small solar TSI changes at such cold gas temperatures may have large effects that we can just begin to study since the age of Hubble to study color changes on Neptune. 1989 Voyager 2 images of Neptune showed a Great Dark Spot in the southern hemisphere. Follow-up images by Hubble have shown Neptune has a dynamic atmosphere, with features coming and going. Weather or climate? Weather change or climate change?

So what is climate change?

Joel O'Bryan(@joelobryan)
Reply to  Joel O'Bryan
January 24, 2019 11:24 am

Which further brings up the point that in any discussion I have with someone who “believes in catastrophic CC”, I first make sure we are both talking about the same definition of Climate Change. I usually ask them try to define for me they think CC is. From there, it usually goes downhill because most people cannot even roughly approximate what the IPCC definition versus other operational definitions of CC. And idea of getting on the same semantics page is even a much simpler intellectual thrashing of an alarmist than having them try to adequately describe what the CO2/GHG GH-effect is in physical terms.

Reply to  Joel O'Bryan
January 24, 2019 12:36 pm

Joel O’Bryan
January 24, 2019 at 11:24 am

Another useful tactic is to ask your warmist friends just what they think the ideal temperature for Earth is and when did Earth reach this Nirvana. Also just what is the ideal level of CO2 and when was this obtained? Was it when Al Gore was born, when Greenpeace was founded, 1900, 2000??

That usually stops them in their tracks.

Robert W Turner
January 24, 2019 11:00 am

“Given that Venus reflects a large fraction of the incident sunlight, could the influence of the Sun really be driving the super-rotation of the middle layers?”

That’s a serious question in the climastrology community? What, were they holding open the possibility that CO2 generates its own heat?

“As the clouds have varying transparency to this infrared glow”

So CO2 is purported as a “heat trapping gas” but clouds of Venus are said to have varying transparency to infrared light. You can’t even see the surface of Venus from orbit, no visible light transmits through the clouds, and there is certainly no IR transmitting from the surface straight to space.

Joel O'Bryan(@joelobryan)
Reply to  Robert W Turner
January 24, 2019 11:27 am

What part of asymmetric heating-cooling of a fluid do you not understand?
(That’s a serious question BTW)

Robert W. Turner
Reply to  Joel O'Bryan
January 24, 2019 4:07 pm

If you take time to seriously read my comment, you might notice that I am essentially saying HOW COULD IT BE ANYTHING ELSE?!

Robert of Texas
Reply to  Robert W Turner
January 24, 2019 12:08 pm

If I understand your remark correctly, you are wondering why they can “see” the clouds?

The clouds would be mostly Sulfur dioxide and absorb and emit at mostly different wavelengths of infrared spectrum then Carbon dioxide. This would make them visible at specific wavelengths of light.

My take on the observation of wind speeds is they would correlate to the physical process of transferring heat from hotter to colder areas – whether land or air or both is not obvious to me. If you increase the heat on one side of Venus, the spinning on its axis is just too slow so heat builds up on one side and that causes air flows to begin. If you turn up the energy, the air flows increase. I am not certain why this is surprising anyone.

The clouds are acting as a proxy for wind speed.

It seems we should have noticed a rise in the infrared emission from Venus if the sun is heating it up more, so the wind increase may be mysterious for that reason.

Robert W. Turner
Reply to  Robert of Texas
January 24, 2019 4:12 pm

I am not wondering how they can see the clouds. I am simply referring to the press release’ claim that the cloud layers of Venus have ANY transparency to IR at all. Whereas in press releases mentioning CO2 as a greenhouse gas, the language often makes it sound like it is simply opaque to IR.

They had to use surface based instruments to collect this data by the way. I’m quite sure this would not be possible with satellites.

January 24, 2019 11:33 am

Didn’t Hansen start his career working on Venus. For some reason I always equated this to Jack Kevorkian starting out as a pathologist. If you’re not careful you become obsessed with an idea.

Joel O'Bryan(@joelobryan)
Reply to  troe
January 24, 2019 11:41 am

That was back in the golden era of NASA, the Apollo era. When scientists expected and demanded their fellow scientists to act and behave with ethics. One can pretty much correlate Hansen’s political changes to GISS and its studies (from hard-edge space physics to “green” earth climate physics) with NASA’s larger transition from Apollo space successes to the disasters of the Shuttle program.

Maybe the demise of the slide rule among scientists and engineers allowed for intellectual laziness to set in? (A conjecture.)

Al Miller
January 24, 2019 12:00 pm

Satellite data reveals Venus is going through a change in it’s atmosphere, and the driver seems to be the sun.

How shocking!! Sarc. Just like earth…

Michael S. Kelly, LS, BSA, Ret.
January 24, 2019 2:37 pm

I understand that they are also predicting that, unless drastic action is taken immediately that the temperature anomaly on Venus will exceed 2.5 C within 100 years. So instead of being 462.2 C, it will be a blistering 464.7 C.

Tom in Florida
Reply to  Michael S. Kelly, LS, BSA, Ret.
January 25, 2019 4:57 am

Is that Venus years or Earth years?

Michael Hammer
January 24, 2019 3:14 pm

Comments such as the quote below from the article worry me

“Slow rotators with Earth-like atmospheres need to transport heat efficiently around the planet or risk the atmosphere collapsing as it freezes on the cold night side of the world. Such a catastrophic end could be avoided if tidally-locked worlds typically had the fast winds of a super-rotating atmosphere.”

Planets don’t “need” to do anything and they don’t respond to risk. If the atmosphere is going to collapse it will simply do so and the planet certainly does not take conscious action to “avoid” that or anything else. The statement is simply unjustified personification. One needs instead to explain the physics of how it might come about “naturally”. One needs to appreciate that moving the atmosphere at high speed entails work and that has to come from somewhere. It occurs to me that a slow rotator results in a massive temperature difference between the sunlit side and the dark side. Such a huge temperature difference might well cause a corresponding pressure difference driving massive convection, further aided by the fact that very slow rotation results in extremely weak Coriolis forces which in turn allows the atmosphere to move much more freely over the surface. In short a heat engine with the circulating fluid (atmosphere) moving between the hot junction (sunlight side) and cold junction (dark side) which can do work. Big question is how the cooled air returns from the cold side to the hot side. Since atmosphere can’t very well move simultaneously in both directions it suggests a global circulation would have to evolve and that in turn would require some sort of, at least, dynamic asymmetry. I think the article is suggesting this is due to solar influence but I am not sure I understood the how.

Somewhat off topic but in response to the very first comment by Nick Schroeder. GHG’s in the atmosphere means that energy loss from the surface (at the GHG wavelengths) is blocked and replaced by energy loss from the top of the GHG column. Thus energy from the surface first has to get to the top of the GHG column before it can be radiated away to space. On Earth this energy transport is dominated by convection which in turn is dominated by the water cycle. Water vapour (molecular mass 18 compared to air 29) is far lighter than air and the high surface concentration driven by evaporation coupled with nearly dry air at the top of the troposphere creates a very strong density difference – much greater than that due simply to the temperature difference of hot air vs cold air. But on Venus there is no surface liquid water and I suspect the atmosphere is well mixed wrt to water vapour. If so one might expect convection to be slower through a thicker atmosphere hence a greater temperature differential surface to OLR radiating elevation. I did not notice any reference to this in Nick’s dissertation.

Tom Abbott
Reply to  Michael Hammer
January 24, 2019 5:31 pm

“The statement is simply unjustified personification.”

Yes, there is way too much of this going on in astronomy. To hear some astronomers talk, objects in space are thinking beings with free will. Astronomy tv programs are the worst at this.


January 24, 2019 3:17 pm

I would predict that the wind speed in the upper atmosphere of Venus could be calculated from the speed required to transport the incoming heat from the sun from the hot side to allow the heat to be radiated from the cold side. Unlike Earth’s troposphere which supports vertical heat transport the Venus atmosphere mainly supports horizontal heat transport from the hot side to the cold side via the high wind speeds.

I think heat transport to or from the planet surface is irrelevant to the heat transport around the plant in the upper atmosphere. The lower atmosphere may always be stable and does not support vertical convective activity.

There will be a mechanism of heat and momentum exchange that enables the high velocities and provides the energy required to overcome the viscous energy dissipation. It maybe similar to Earth’s jet streams.

Moderately Cross of East Anglia
January 24, 2019 3:50 pm

With that rate of atmospheric super-rotation why is no one advocating locating all our wind turbines on Venus? It could hardly be more expensive than the colossal current waste of money.
Oh wait…

Bill Treuren
January 24, 2019 4:30 pm

so the 750C surface temperature is an average or on the hot side?
Those are very long days.

Gary Pearse
January 24, 2019 5:45 pm

I’m always a bit amazed that sceptics don’t tend to sound off more on some of the easy killer evidence against the posited “CO2 control knob”

The shrinking of the polar cap on Mars coincident with the shrinking of the earth’s N polar cap. It was remarked by Dr Adusammatov of the Pulkova Observatory in St Petersburg, Russia and was the subject of a Nat Geographic ~2005 article.

When the first CO2 satellite went up, the unexpected worst concentrations of posited “thoroughly mixed CO2” in parts of the globe in wilderness areas – equatorial Africa and other odd spots were revealed. Anyone seen one of these images lately?

The “Great Greening” took warmologists by surprise with a 15% expansion of global forest cover in 30yrs by 2012, never mind the bumper crops, all other vegetation and masses of plankton. A couple of nonsense, unconvincing papers warning that the greening was a bad thing, then silence both by thunderstruck catastrophists and some kind of team agreement to not publicize updated images – heck the blue planet might be green now! They now are publishing the greening of boreal forests and crop harvests etc is due to the 0.7C watming in 150yrs. There is an agreement that overwhelming evidence of the positive benefits of ” carbon” must not be mentioned.

A wonderful paper on a presently ice-locked Greenland beach on the north coast with big chunks of driftwood dated at 6000yrs and stating that beach development of this kind requires many miles of open ocean with big waves, apoeared and went probably before many even saw it.

Oceans full of top tech Argo floats sealed their fate by reporting cooling of the oceans. So they just stopped reporting the results and substituted ships buckets or something.

It seems that the most active sceptics are math physics majors obsessed with the CO2 forcing equation.

Alan Robertson
January 24, 2019 8:00 pm

I’m just happy that another interesting finding has been made available and discussed, here at WUWT.
Thanks again, noble and wonderful host.

January 25, 2019 4:49 am

So what’s the verdict?
Do I buy a diesel SUV on Venus or not?

January 25, 2019 8:34 am

Rapid mode of circulation from the 1970s to the present on Venus? Same as on Earth!

January 25, 2019 9:11 am

From the article:

“Like the Moon orbiting the Earth, a tidally locked world rotates once per orbit so that one side permanently faces the star while the other experiences perpetual night. ”

I think they missed the most interesting bit here. To wit: Venus is tidally locked with Earth. There are several perplexing things about Venus’s orbit with respect to the Earth, including the five sky-paths that repeat every eight years (well known, even to the Mayan astronomers). But the most puzzling is the observation that at each inferior conjunction with Earth (548 days), Venus has made exactly five (actually 5.001)(retrograde!) revolutions, or Venusian days. This type of orbital lock is usually found with planets and their moons, but is difficult to explain between neighboring planets.

I know it’s a bit OT and not really related to the newly discovered high winds, but it’s an interesting and little known fact.

January 25, 2019 9:23 am

I am surprised Venus’ retrograde rotation was not mentioned at all in the article

seems that might be an important difference to consider

Jeffrey Price
January 25, 2019 11:25 am

Let’s send Al Gore to check it out.

January 25, 2019 5:43 pm

Why do the Polar Caps (CO2, I do believe ) on Mars melt and reform ?Is that “Climate change”? Just asking .

Gordon Dressler
January 26, 2019 1:52 pm

Why are we surprised that there is climate change on Venus? We’ve know for decades the atmosphere of Venus is about 97% by mass CO2 . . . for we’ve “known” for decades that CO2 is just about the only explanation for climate change on Earth.

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