ESA finds a frigid surprise hiding at Venus’ poles 

Posted: April 25, 2016 by oldbrew in exploration, Measurement, modelling, research, solar system dynamics, Temperature
Tags: , , ,

Ultraviolet image of Venus' clouds [credit: NASA]

Ultraviolet image of Venus’ clouds [credit: NASA]


Is it the cloud cover or the enormous atmospheric pressure at the surface that makes Venus hot? Whatever, it seems the poles are colder than Earth, and by a wide margin, as Astronomy.com reports. Models based on a ‘greenhouse effect’ weren’t expecting this.

Thanks to a thick layer of cloud cover trapping in heat, Venus is the hottest planet in our solar system, with temperatures boiling over at 850 degrees Fahrenheit (454 C). But in a study published last week in Nature Physics, the European Space Agency found something surprising at the planet’s poles: temperatures more frigid than anywhere on Earth.

Even though ESA lost contact with the Venus Express probe two years ago after it ran out of fuel, the agency is still working through the data it returned. As the first spacecraft to explore our nearest neighbor since 1989’s Magellan mission, the probe revealed much about that world.

Many of the observations were made through plunging the craft into the atmosphere above the poles, where the probe encountered an atmosphere thinner than previously modeled, and filled with choppy atmospheric gravity waves, ripples caused by transfers of momentum between layers in the atmosphere.

“Concerning uniformity — models are mostly rather smooth while the reality is much more complex and structured,” ESA scientist and lead author Ingo Müller-Wodarg of Imperial College London said in an email to Astronomy. “We found enormous variability in the atmospheric densities that is explained by a combination of local (horizontal) day-night density variations but above all by strong periodicities, atmospheric waves. These are not captured by models.”

This marks the first time the poles of Venus have been directly studied, owing to Venus Express’ circumpolar orbit, which also allowed a global view. By crashing the probe through these winds on its final descent, the probe made the first ever in-situ observations of polar climates on Venus.

Full report: ESA Finds a Frigid Surprise Hiding at Venus’ Poles | Astronomy.com

Phys.org reports: ‘Some of the final results sent back by ESA’s Venus Express before it plummeted down through the planet’s atmosphere have revealed it to be rippling with atmospheric waves – and, at an average temperature of -157°C, colder than anywhere on Earth.’

Read more at: http://phys.org/news/2016-04-venus-swansong-polar-atmosphere.html

Abstract: http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3733.html

Comments
  1. catweazle666 says:

    So the temperature gradient between the equator and the poles is around 600 deg C?

    Talk about counter-intuitive!

  2. RoswellJohn says:

    There are huge vortexes at Venus’ poles. All vortexes are cooler at the center than at the outer edges. Hilsch tubes, hurricanes, sun spots are all cooler at the center and this is a well known effect and has probably been modeled, just not by these guys.

  3. Oldmank says:

    Rigged with thermocouples, would that count as renewable?

  4. oldbrew says:

    They already knew about ice at Mercury’s poles.

    ‘The first-ever photos of water ice near Mercury’s north pole have come down to Earth, and they have quite a story to tell.

    The images, taken by NASA’s MESSENGER spacecraft (short for MErcury Surface, Space ENvironment, GEochemistry, and Ranging), suggest that the ice lurking within Mercury’s polar craters was delivered recently, and may even be topped up by processes that continue today, researchers said.’

    http://www.space.com/27450-messenger-mercury-water-ice-photos.html

  5. oldbrew says:

    ‘Thanks to a thick layer of cloud cover trapping in heat, Venus is the hottest planet in our solar system’
    but
    ‘Many of the observations were made through plunging the craft into the atmosphere above the poles, where the probe encountered an atmosphere thinner than previously modeled’

    Thick, thin or both?

    ‘The polar atmosphere is also not as dense as expected; at 130 and 140 km in altitude, it is 22% and 40% less dense than predicted, respectively. When extrapolated upward in the atmosphere, these differences are consistent with those measured previously by VExADE at 180 km, where densities were found to be lower by almost a factor of two.’
    ***
    South pole vortex rotates every 44 hours or so.

    ‘These polar vortices form when heated air from equatorial latitudes rises and spirals towards the poles, carried by the fast winds. As the air converges on the pole it then sinks.’
    http://www.universetoday.com/118397/a-swirling-vortex-at-venus-south-pole/

  6. A C Osborn says:

    Temp probe failure anyone?

  7. Paul Vaughan says:

    “Concerning uniformity — models are mostly rather smooth while the reality is much more complex and structured,”

    The uniformity assumption is a clever elite trick to fool the masses. It’s the EXACT SAME trick used by the belief-police employed to waywardly coerce the most naive skeptics into laughable sun-climate submission. Their narrative is a spatial joke and it’s their job to enforce it.

    My advice is this:

    When they come after you with Yankee baseball bats trying to enforce SPATIAL submission to GEOMETRICALLY FALSE assumption (and ALTERNATIVE “logics” thus POLITICALLY engineered):

    Dismiss them.

    Leave.

    Never engage them directly. Walk away. Boycott matches on Yankee turf.

    Discursively their political economy is shrinking on the news of their spatial deception and internationally the effectiveness of their deception is in retreat to home soil. What remains to be seen is how long home soil remains a safe haven for ARTIFICIALLY ENFORCING the FALSE uniformity assumption. We’ll learn how corrupt the nation is. We’ll learn whether it has citizens brave enough to push the false assumptions off center stage.

  8. oldbrew says:

    “We found enormous variability in the atmospheric densities that is explained by a combination of local (horizontal) day-night density variations but above all by strong periodicities, atmospheric waves. These are not captured by models.”

    Re ‘day-night density variations’ note this:

    ‘Because of the retrograde rotation, the length of a solar day on Venus is significantly shorter than the sidereal day, at 116.75 Earth days’
    http://en.wikipedia.org/wiki/Venus#Orbit_and_rotation

  9. oldbrew says:

    Not sure about this one…

    FROM THE JUNE 2016 ISSUE [of astronomy.com/magazine]
    Venus has a weak magnetic field. Being much closer to the Sun than Mars, why has the solar wind not eroded its atmosphere?
    Michael Rodriguez, Corvalis, Oregon
    Published: Monday, April 25, 2016
    RELATED TOPICS: VENUS
    Venus
    One major reason is that Venus has a lot more atmosphere than Earth. So even though Venus is losing some atmosphere to space all the time — at about the same rate as Earth — that loss does not have much effect on the overall density or surface pressure. (Although over time it has likely affected the atmosphere’s composition.)
    http://www.astronomy.com/magazine/ask-astro/2016/04/venus

  10. chris moffatt says:

    “…filled with choppy atmospheric gravity waves, ripples caused by transfers of momentum between layers in the atmosphere…”

    Gravity waves?? I guess everybody was just looking in the wrong place all these years for Gravity waves then.

    [reply] Gravity waves and gravitational waves are not the same thing

  11. Ned Nikolov says:

    Please, note that the frigid polar temperature of about 114 K (-159 C) was measured in the Venusian thermosphere some 130-140 km above the surface. Se the actual paper here:

    In situ observations of waves in Venus’s polar lower thermosphere with Venus Express aerobraking
    http://www.nature.com/nphys/journal/vaop/ncurrent/full/nphys3733.html

    Hence, this is NOT a surface temperature reading! The data, we have, suggest that the surface of Venus is virtually isothermal, so the equator-to-pole temperature gradient is near zero at the surface.

  12. chrism56 says:

    Does this mean that Venus as the exemplar of the greenhouse effect is no longer valid? Or is it more valid than ever, to explain why the ice age could return?
    I had to laugh at the “where the probe encountered an atmosphere thinner than previously modeled,” comment. Didn’t James Hansen do his PhD on the atmosphere of Venus? Another failed prediction perhaps?

  13. wayne says:

    I’ll just ditto Ned… most apparently just assumed it to mean a surface temp, not so, you read carefully. Still hot, hot, hot even at the poles at the surface.

  14. Ned Nikolov says:

    chrism56,

    Our analysis of planetary data revealed that the so-called ‘greenhouse effect’ is in fact a pressure-induced thermal enhancement (which is independent of atmospheric composition). It is the force of atmospheric pressure that boost the surface temperature of Venus some 505 K above the temperature of an equivalent airless planet at the same distance from the Sun…

  15. Ned Nikolov says:

    For comparison, the surface atmospheric pressure on Venus is 93 bar, while average surface pressure on Earth is 0.9855 bar … The Venusian atmosphere is about 100 times more massive than Earth’s atmosphere!

  16. oldbrew says:

    The reports are misleading, or easy to misinterpret, as Ned Nikolov points out.

    Wikipedia says: ‘The circulation patterns in the upper mesosphere and thermosphere of Venus are completely different from those in the lower atmosphere. At altitudes 90–150 km the Venusian air moves from the dayside to nightside of the planet, with upwelling over sunlit hemisphere and downwelling over dark hemisphere. The downwelling over the nightside causes adiabatic heating of the air, which forms a warm layer in the nightside mesosphere at the altitudes 90–120 km. The temperature of this layer—230 K (−43 °C) is far higher than the typical temperature found in the nightside thermosphere—100 K (−173 °C).’ [bold added]
    http://en.wikipedia.org/wiki/Atmosphere_of_Venus#Upper_atmosphere_and_ionosphere

  17. Bitter& Twisted says:

    The fact Venus has a largely CO2 atmosphere (giving Climate Scientists and modellers wet-dreams) may be completely irrelevant;

    “Global Mean Atmospheric Temperatures]of rocky planets can accurately be predicted over a broad range of atmospheric conditions [0% to over 96% greenhouse gases] and radiative regimes, only using two forcing variables: top-of-the-atmosphere solar irradiance and total surface atmospheric pressure [a function of atmospheric mass & gravity].

    Volokin & ReLlez (2015) Emergent Model for Predicting the Average Surface Temperature of Rocky Planets with Diverse Atmospheres. Advances in Space Research. doi: 10.1016/j.asr.2015.08.006

  18. Ned Nikolov says:

    Oldbrew,

    The info on the Wiki page may be consistent with the in-situ measurements reported in the Nature paper – the Wiki page says that typical temperature of the Venusian nighttime thermosphere is 100 K. The Nature paper reports 114 ± 23 K in the thermosphere between 130 and 140 km altitude. It is quite likely that, due to adiabatic (pressure-induced) heating, the temperature rises as one goes deeper into the atmosphere and reaches 230 K below 120-km altitude. This corresponds to a vertical lapse rate of -6 K/km or less, which is a rather believable number …

    [reply] thanks Ned

  19. jim says:

    Interesting, paper. So atmospheric mixing is due to gravity waves, rather the temperature differences. How unique? And the double, that instruments for observation, may not be reading surface conditions accurately, but somewhere above the surface? Boundary layering is supposed to be smooth? Where on earth did they get these ideas? Probably the same place that taught them that 2+2 may or may not equal 4.

  20. JKrob says:

    RoswellJohn said:

    “…All vortexes are cooler at the center than at the outer edges. Hilsch tubes, hurricanes…are all cooler at the center and this is a well known effect…”

    Sorry RJ, your info about hurricanes is quite incorrect. Hurricanes, being warm-core lows (low pressure at surface, high pressure aloft), are the warmest at the center of the storm compared to their surrounding environment and the deeper the surface low, the warmer the core temperature is.

    This has been known for decades.

  21. oldbrew says:

    From space.com in 2014:

    Weird ‘Gravity Waves’ in Venus Clouds Spotted by Spacecraft
    http://www.space.com/24295-weird-venus-gravity-waves-photos.html

    Quote: ‘Not to be confused with ripples in space and time known as gravitational waves, the gravity waves in a planet’s atmosphere can occur when winds whip over geological features like a mountain’s face or crater wall and the updraft rises and sinks in a layer of stable air above. Condensation in the rising air can produce clouds, creating a pattern of waves moving in the same direction, spaced at regular intervals.’

    It’s known that the polar regions on Venus are mountainous.

    ‘The land is rugged around the poles of Venus. There are groups of ridges near each pole. These ridges rise a few kilometers above the lower plains. They are up to hundreds of kilometers wide and thousands of kilometers long.’
    http://www.windows2universe.org/venus/venus_polar_regions.html

    So ‘gravity waves’ over the polar regions would not be that big a deal?

  22. oldbrew says:

    Surprising Shifts in Pluto Atmosphere Point to Gravity Waves (Photos)
    By Elizabeth Howell, Space.com Contributor | April 20, 2016
    http://www.space.com/32627-pluto-haze-gravity-waves-images-new-horizons.html

  23. linneamogren says:

    Thick cloud cover the cause of high temps? The radiative thermal equilibrium on Venus is no hotter or cooler than the law of physics allows. Three factors determine the temp on Venus and they are atmospheric mass ( which is 93 times that of earth) location to the sun and albedo. C02 levels which are almost 100% of the atmosphere have little to no effect since you could replace C02 with nitrogen and still have no real change in temps. The high C02 levels are only a reaction to the high temps much like we discovered in ice core studies. Also since a day on Venus 243 earth days this allows for massive amounts of heat to build which then is distributed to the night side by powerful winds which is why we see almost uniform temps on both sides of the planet.

  24. linneamogren says:

    Also, levels of the atmosphere on Venus are much colder than what’s found in our own atmosphere due to the albedo of Venus, we also see a vapor count of only 0.02% in the atmosphere of Venus which can be explained by C02 freezing out as vapor in the highest levels. Being there most likely was never a high vapor count this also is another nail in the coffin of a runway greenhouse effect. NASA not long ago came to this conclusion regarding water once on Venus when they repotered most likely there were only oceans of C02. http://www.space.com/28112-venus-weird-superfluid-oceans.html

  25. linneamogren says:

    0.002% of vapor sorry

  26. wildeco2014 says:

    It looks like several of the contributors here would agree with this:

    http://www.newclimatemodel.com/the-thermal-regulation-of-planetary-atmospheres/

    The temperature variations within the atmospheric circulation of Venus would comply with that account thus:

    “11) We have already established that the sole determinant of temperature is (atmospheric) mass, gravity and insolation so there must be an effective negative system response otherwise atmospheres could not be retained long term.

    12) The answer is that due to any such imbalance the normal equilibrium distribution of Kinetic Energy (KE) and Potential Energy (PE) is upset and parcels of air start to move around differently relative to each other due to the changes in their respective KE and PE contents. Such changes in PE relative to KE result in density differences which cause different parcels of air to change their weights and rise or fall at different rates.

    13) Thus does the atmospheric circulation reconfigure itself to remove the imbalance by adjusting the energy flows through different sections of the atmosphere both vertically and horizontally. The balance of UWIR and DWIR between surface ad top of atmosphere is restored at every level and the atmosphere is rescued.

    14) Therefore, compositional changes have a zero net effect on temperature but the consequences are regional climate changes as the permanent climate zones change their sizes, intensities and positions relative to each other.”

  27. ren says:

    Linneamogren you are certainly from Venus.

  28. linneamogren says:

    @ren thanks I think lol

  29. ulriclyons says:

    If Earth were moved close in towards the Sun, the Arctic would probably become colder, because positive Arctic Oscillation conditions would increase, and strengthen the polar vortex. At least in an inter-glacial climate when the Arctic is not ice locked.

  30. Brett Keane says:

    linneamogren says:
    April 26, 2016 at 8:46 pm :

    If Earth was rotating slowly like Venus, could we expect rapid cycling to preserve a livable surface? Brett

  31. linneamogren says:

    @ulriclyons

    Good point. If you look at Mercury there is at least one polar ice cap and when you consider that solar flares reach the surface of Mercury we can assume you are correct.

    @Brett

    Well if days were much longer say just 48 hours we would see some temp variation with the extra accumulation of radiation, but we would also see vacillations in the jet stream and oceanic currents which are correlated to the earths rotation rate. In 200 million years earth days will be 25 hours, so this is assured thanks to our moon and the changes will be slight overCoriolis force” time. But let’s take your question and say earth days are that of Venus. In my opinion I can’t see how any livable surface survives the extremes from the day and night side. Not to mention the Coriolis force would be so disrupted from the slow rotation that the magnetic field would no longer function properly or be effaced allowing a massive bombardment of radiation from the sun. That would all put an end of any liveable surface.

  32. ulriclyons says:

    Saturn on the other hand has such strong poleward energy transport that the polar regions are only around 10°C cooler than the mid latitudes.

  33. ulriclyons says:

    This is why more CO2 in theory should cool the Arctic region, because it increases positive NAO/AO. Which means a poleward shift in the jet stream, strengthening the polar vortex, and reducing warm ocean transport into the Arctic.

    http://www.ipcc.ch/publications_and_data/ar4/wg1/en/ch10s10-3-5-6.html

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