HiRISE Clocks Hurricane Speed Winds In Martian Dust Devils

Article written: 15 Oct , 2011
Updated: 24 Dec , 2015
by

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“It’s early morning and the Sun comes out…” And from no where a huge Martian dust devil shakes its way across the red sands, flinging debris up into the atmosphere. While planetary scientists have been able to determine how fast these whirling, swirling storms travel across the arid landscape, they’ve never quite been able to tell just how fast the winds within them move. Until now…

Thanks to the work of David Choi, a postdoc at NASA’s Goddard Space Flight Center in Greenbelt, Maryland, we’re now able to reasonably record wind speeds through the use of high resolution images taken from HiRISE onboard the Mars Reconnaissance Orbiter. When lucky, the camera captures the storms as a “work in progress” – detailing small features. By pinpointing these signature marks, Choi was able to determine the wind speeds by knowing the timing between frames.

According to the news release, the winds are traveling at about 45 meters each second — what we Earthlings would consider “hurricane-force,” or above 33 meters per second. However, at other times the winds would slow to between 20 and 30 meters per second. These new findings were then compiled and Choi presented his results October 3 in Nantes, France, at the joint meeting of the European Planetary Science Congress and the American Astronomical Society’s Division for Planetary Sciences.

“As a whole, they’re not like a hurricane, but there are pockets or gusts that exceed hurricane-force,” Choi says.

These storms generally appeared around 3:00 Mars Local Time and measured about 30 meters to 250 meters in diameter, and stretched upwards between 150 meters and 700 meters. Wow… “Here I am… Rock you like a hurricane!”

Original Story Source: Science News Release.

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18 Responses

  1. metamaterials says

    Vortices or Vortexes? Dust devils are a vortex, and a famous scientist Archimedes 10^3 years ago was first to suggest a vortex cosmology. A black hole has been described as a vortex, and spin is extremely important in quantum physics. With spin comes acceleration which creates mass and anti-matter that have opposite spins. The vacuum is not empty, but from it arises everything, p mesons and anti p mesons arise in the vacuum with applied magnetic field, which is normal baryonic matter and its anti-matter of opposite spin. Yet, vortex cosmology is not a theory of everything, nor a cosmology to believe in today. Many things remained unexplained…magnetic fields are believed involved in stabilizing a vortex. Is a wormhole a stabilized vortex connecting matter with its antimatter?

    • Torbjörn Larsson says

      We don’t believe in cosmologies, we remove those that doesn’t work. (Say, EU and vortex theories.)

      That theories work despite remaining uncertainty is no different from a hammer working despite remaining uncertainty in applied strike force.

      I’m sorry, but: “This is elementary”.

      • metamaterials says

        Electric Universe (EU), Plasma Cosmology (PC), and Vortex Cosmology, do have one thing in common. They are all rejected here as rubbish. Scientists today are trying to unite relativity with metamaterial plasmonics, and win a noble prize by finding the answers to unexplainable problems with Einstein’s relativity that everyone admits needs to be replaced with a better yet still unknown theory. One that could unite quantum cosmology with relativity, and be studied in the lab, like optical black holes that trap bend light in graphene. The math equations may only need to be found, like Faraday’s Law, but further formulated integrated by a mathematical genius here. EU nutters do not understand that a magnetic field is due from Faraday’s law, and lack scientific knowledge. Metamaterial branches like spintronics are used in 3-d nuclear magnetic resonance (NMR), and is the foundation basis of the technique in relativity for studying frame-dragging effects that warp space-time. The detection of superclusters on the CMB pattern is another example that uses electromagnetic techniques, and that shows why Einstein’s relativity is still so greatly accepted.

      • Torbjörn Larsson says

        You are writing as if any of that is relevant for winds. Wind is a mechanical force.

        You are writing as if any odd idea is relevant for science. They are not rejected “here” but in science, because they were rubbish.

      • metamaterials says

        vortexes are a discipline of science, not a cosmology. Dust devils like tornadoes, have magnetic fields, and are not merely mechanical forces like wind. There is a vortex motion likely a vacuum force associated with dust devils, that pulls dust and gas. Electrostatic charges build up in the air, which behaves like a charged plasma. I wish I could say that galaxies are kinda like dust devils and tornadoes, with vortexes that attract dust and gas, and warp twist space with magnetic fields?

  2. Member
    Anonymous says

    45 meters per second = 100.66 Miles per Hour YIKES! Think of the hundreds or thousands of images we’ve seen of the little round and frequently pitted, martian ‘blueberries’ we’ve seen….

  3. Anonymous says

    Hurricane force? The Martian atmosphere is less than 1% of the density of earth’s atmosphere. We would feel the impact of the same volume per second of atmosphere, but only 1% of the momentum per second that you would get on Earth.

    If we divide the speed by the square root of the earth-mars atmosphere density ratio then we would get a sense of the equivalent wind on earth. If the Martian atmosphere was 1% of the density of earth’s atmosphere then we should divide by 10. This gives us 4.5 m/s, Beaufort 3: leaves and small twigs constantly moving, light flags extended.

    • Torbjörn Larsson says

      Good idea to run a comparison like that.

      Wind energy scales with the 4th power of wind velocity though. The scale factor would be ~ 1/3. Gusts of ~ 15 m/s would be “near gale”, with “effort to walk against the wind”. It would certainly make your umbrella invert!

      As a comparison, the next step up is gale, when twigs starts to break from the trees. There is no reason not to believe some martian gusts would be this powerful. I’ll bet it happens in Gale crater from time to time… =D

      • Anonymous says

        It’s tricky. The force on some object would go as the square with straight viscous drag, or as the 4th power with turbulence. The onset of turbulence would depend on the size and the geometry of the object. So, I think “effort to walk against the wind” should be a square term, but “breaking twigs from trees” might be a 4th power term, in which case we could both be right..

      • Torbjörn Larsson says

        Um, no, We are both wrong, I misremembered the derivation: it is the 3d power of wind velocity.

        We are moving an air mass. There is an extra factor of wind velocity from that.

        So make that a factor 1/5, and we have a ~ 10 m/s Earth equivalent, or “fresh breeze”. It lofts dust (starts at “moderate breeze”), which is consistent with what we see.

      • Anonymous says

        For laminar flow the energy density is e = ½ ?v^2. Turbulence at subsonic speed attenuates energy at ~ v^3 and supersonic shock waves attenuate energy at ~ v^4.

        It is a bit of a misnomer to think of these as “hurricane force.” An astronaut could stand upright in this wind, where the dust flying around would be the only annoyance. The 1% atmospheric pressure means that much reduction in the energy density of these winds.

        LC

    • Member
      Anonymous says

      Ummm.. Dust storms on Mars may create an effect similar to ‘liquefaction’ as found here on Earth? That is to say, microscopic particles of dust and ices that are sent into motion near the Martian surface during these events, may take on the properties of a much denser atmosphere or even liquids. The erosion potential of those particles and the ubiquitous ‘blueberries’ lofted from the surface by these 100+ mph motions is then in all probability, substantial.

    • Member
      Anonymous says

      Factors that may have been trivialized here and in most considerations of Martian atmospheric disturbances, include the absence of a substantial magnetic field and that gravity on Mars is 38% that of Earth’s surface.

      The absence of a magnetic field allows solar wind components to interact directly upon the Martian surface. The injection of those energies into the Martian environment no doubt plays a role?

      The effects of the increased solar activity we are now experiencing, can be more clearly observed and understood thanks to the dual satellite STEREO mission. With these data we can actually observe the intersecting pathways and strengths of those CME impacts at Mars.

      Thus.. Tornado like/shaped magnetic fields generated in the solar wind (As observed by the Mercury Messenger) interacting with the Martian atmosphere may provide a ‘seed’ for larger storm patterns? The recently discovered water molecules and no doubt charged dust particles high in the Martian atmosphere would then begin to co-rotate in those charged fields… Another consideration is that triboelectric energy at the Martian surface may act to levitate dust particles.

      Given this ‘chain of events’… we will probably see an increase in Martian dust storms in the near future.

      • Torbjörn Larsson says

        Some of those factors (EM) are not “trivialized” as we are doing a first order estimate of important factors (compare Earth), and some are implicitly scaled (density scaled with gravity).

      • Member
        Anonymous says

        10.22.11 SpaceWeather.com reports that a CME is headed toward Mars: “A significant CME blasted off the sun today, Oct. 22nd, around 1100 UT. Analysts at the Goddard Space Weather Lab say the cloud is heading for Mars, due to hit the Red Planet on Oct. 26th.” If my above comment is correct, we should see increased dust storm activity at Mars soon after the CME impacts….

      • Member
        Anonymous says

        “SPACE WEATHER FORECAST FOR MARS: A bright CME blasted off the sun yesterday, Oct. 22nd, and it appears to be heading for Mars. Analysts at the Goddard Space Weather Lab expect the cloud to reach the Red Planet on Oct. 26th (forecast track). A brief discussion of what CMEs can do to Mars follows this SOHO image of the eruption:

        Mars has a unique response to solar storms shaped by the planet’s strange magnetic topology. Unlike Earth, which has a global magnetic field, Mars is patchily covered by dozens of “magnetic umbrellas”–remnants of an over-arching planetary field that decayed billions of years ago. When Mars gets hit by a CME, the resulting magnetic storms take place in the umbrellas. Circumstantial evidence collected by Mars Global Surveyor in the 1990s suggests that the tops of the umbrellas light up with bright ultraviolet auroras during such storms. Because the structures are distributed around the planet, these auroras can appear even at the equator.

        Mars rovers and satellites should be alert for aurora equatoralis on Oct. 26th.

        Bonus: Magnetic umbrellas are at the heart of one of Mars’s greatest mysteries: What happened to the atmosphere? Billions of years ago, the air on Mars was thick enough to protect vast expanses of water on the planet’s surface. Now, however, the atmosphere is 100 times thinner than Earth’s and the surface is bone dry. Some researchers believe that magnetic storms in the umbrellas could rip parcels of atmosphere away from Mars and propel air-filled magnetic bubbles into space. In this way, space weather could be directly responsible for the desiccation of the Red Planet.”

  4. Anonymous says

    Thank you Aqua4U, the purpose of language is to communicate and that 45 meters per second crap doesn’t mean much to most folks. If we want people to understand our articles, we need to express things the way ordinary people understand them.
    (1 mi/hr)*(1 hour/3,600 sec)*(1.61 km/1 mile)*(1000 meters/1 km) = 0.45 m so it follows that 45 m/sec is 100 times that. I am too lazy to do the math.

  5. Member
    Anonymous says

    Question: Are ‘EU nutters’ any more obnoxious than those who would constantly underestimate the effects electro dynamic forces at play in our universe?

    Answer: Yes and no. Depends on the degree of acceptance or denial OR the willingness to accept new data.

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