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Earth Science

Snow Falls On the Most Arid Desert On Earth 195

crackspackle writes "The Atacama desert region, a vast expanse of land stretching 600 miles along the Pacific coast of South America from Peru to Chile, is known as the driest region on earth, receiving only .04 inches (1mm) of rain per year. Many weather stations located in the region have no recorded precipitation during their existence. Sterile from the lack of rainfall, sparsely inhabited, and virtually free from electromagnetic interference, the desert hosts several major astronomical observatories. This other-worldly location is also popular among sci-fi film makers, and is a prominent test site for NASA's planned Mars mission. This week, the Atacama received 32 inches of snow, stranding motorists along the Pan-American highway and other roads, prompting numerous rescues. Footage of the snow is available on the BBC."
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Snow Falls On the Most Arid Desert On Earth

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  • by Anonymous Coward on Friday July 08, 2011 @04:13PM (#36699740)

    So, there was a worse snowfall recorded there 20 years ago? And the story here is that snowfalls happen every 20 years there?

    Did I miss something in the story?

    • by interkin3tic ( 1469267 ) on Friday July 08, 2011 @04:50PM (#36700070)

      Did I miss something in the story?

      Not in the story, but I think you missed the part where geography, geology, and climatology are interesting to some nerds.

    • the story here is that snowfalls happen every 20 years there?

      Evidence suggests that the Atacama may not have had any significant rainfall from 1570 to 1971.

      • The Atacama Desert is 600 miles (1,000 km) long and covers over 40,000 square miles in area. I think it's entirely possible that some parts of it got snowed on and other parts have received no precipitation in at least 400 years.

  • *Hint* (Score:2, Informative)

    by Anonymous Coward

    When you add more energy to a large system, you don't just get even warming. Things get mixed. It's like heating up an ice-cream cake. Some parts that were warm will get colder than they were, as other parts melt into them.

    It's why the term has changed to climate change instead of just global warming.

    • Re: (Score:3, Insightful)

      by Toonol ( 1057698 )
      But:

      The Atacama Desert region in Chile was coated with its heaviest snow cover in nearly two decades, the BBC reported. An estimated 31.5 inches (80 centimeters) piled up in the normally arid region.

      If this snowfall was due to 'more energy' being added to the system, what caused the prior snowfalls? You have to include all data. Everytime you hear some claim about 'worst hurricane season in fifty years', or anything similar, you need to realize that means there was a worse event fifty years ago. B
      • But: The Atacama Desert region in Chile was coated with its heaviest snow cover in nearly two decades, the BBC reported. An estimated 31.5 inches (80 centimeters) piled up in the normally arid region. If this snowfall was due to 'more energy' being added to the system, what caused the prior snowfalls? You have to include all data.

        Fine: "Evidence suggests that the Atacama may not have had any significant rainfall from 1570 to 1971." Is that enough data that something probably happened before 1971 - like "more energy in the system"?

    • Another hint: low probability events happen. According the report itself they had worse or similar snow 20 years ago. This isn't "climate change(tm)." At least not anymore than normal climate change that always happens is "climate change(tm)."
    • Another hint (Score:4, Insightful)

      by Sycraft-fu ( 314770 ) on Friday July 08, 2011 @05:04PM (#36700194)

      People like you do nothing to help bolster the argument of man made climate change.

      See any time something happens on a weather level that would seem to be against global warming, like an extra cold winter, if they were related shouts of "Climate is not weather! You can't take something that happened with the weather and apply it to climate!" come up in a hurry.

      However when something perceived to be out of the ordinary (or something bad) happens then people like you come and say "See! Look! Strange weather, climate change must be real and it must be people causing it!"

      This trying to have it both ways is something that makes the argument look flimsy because it is precisely what people like religious zealots do. When something supports their views, they point to it as evidence. When something doesn't, they claim that sort of thing doesn't matter, even if it is the same sort of thing as they were talking about earlier.

      So you can't go and shout down weather as not being climate only to then point at weather when it suits your needs.

      Also it shows rather profound ignorance of the Earth's climate and weather systems to think that a rare event must somehow be an indication of something wrong.

      Please note, none of this is aimed at trying to disprove or prove man made climate change. It is simply pointing out that this is a stupid argument and doesn't help your position at all.

      • You are correct about bad arguments but the specifics are wrong. People who say humans are impacting climate change actually predicted that some areas would be colder and some areas would get more snow, the problem is when you look at global temperatures you realize that Europe and Asia were warmer while people were claiming a cold winter in Maryland as proof that there is no climate change.

        Additionally, crazy weather is also predicted in the same models so in reality, all of these events are lining up w

        • Er, the models even *hindcast* wilder weather: their variance seems to be substantially greater than what is observed (not to mention they're mostly way off base when it comes to getting absolute temperatures right). See this ensemble graph: http://rankexploits.com/musings/wp-content/uploads/2009/03/temperatures_absolute.jpg

          The thing is, we've "observed" about 0.7'C of warming over a century and most of that seems to have happened in Siberia and the Arctic. Given the huge usual temperature variations over a

      • People like you do nothing to help bolster the argument of man made climate change.

        If the data is clear enough, it won't need any bolstering by people: the argument will stand on its own (as it should).

        • If the data is clear enough, it won't need any bolstering by people: the argument will stand on its own (as it should).

          Just like it did with smoking.

          • Is there anyone who believes that smoking is good for you? Seems like the data is speaking pretty well, even convinced skeptics, and outright non-believers.
      • A more important point is ... slashdot comments arent the scientific consensus on climate change.

      • People like you do nothing to help bolster the argument of man made climate change.

        See any time something happens on a weather level that would seem to be against global warming, like an extra cold winter, if they were related shouts of "Climate is not weather! You can't take something that happened with the weather and apply it to climate!" come up in a hurry.

        So because he preempts the "snowing means its cooling!!!" cries, his argument isn't good, because you can now pretend he said "it's snowing because its getting warmer". Nice try. You will certainly convince the usual bunch of fools - but they are only looking for confirmation anyway, and will take much weaker straws.

    • Re: (Score:2, Informative)

      by CPE1704TKS ( 995414 )

      *Hint* When someone changes their initial theory from something that can be quantified (ie. "global temperature will increase because of man-made greenhouse gases") to something that can't be quantified ("ie. global temperature will get both hotter and colder in different parts of the world") it means they have realized their initial theory was incorrect and they are scrambling to find another theory.

      Basically, if you're telling me that the theory of climate change is now "Some places will get hotter and so

      • Re: (Score:3, Interesting)

        by gum2me ( 723529 )
        Wait, so what if someone says in THESE SPECIFIC REGIONS temperatures will go up, while in THESE SPECIFIC REGIONS temperatures will go down. That seems like a disprovable theory, And it seems like an eminently reasonable claim. Now whether that claim can be borne out by the data is a different question.
      • Re:*Hint* (Score:4, Interesting)

        by riverat1 ( 1048260 ) on Friday July 08, 2011 @11:05PM (#36702362)

        *Hint* When someone changes their initial theory from something that can be quantified (ie. "global temperature will increase because of man-made greenhouse gases") to something that can't be quantified ("ie. global temperature will get both hotter and colder in different parts of the world") it means they have realized their initial theory was incorrect and they are scrambling to find another theory.

        No, it means the theory is improving and the tools are getting better. They don't throw out one theory and substitute another. They fix the current theory by incorporating the new insights gained. Did Einstein completely replace Newton or just show it was a subset of the overall reality? The increase in computer horsepower over the years means they can do more detailed simulations that may uncover regional differences. A typical GCM simulation runs for about a month and as the computers get faster they just add more detail. So those regional differences can be quantified somewhat and it's getting better all the time.

        I think your "Some places will get hotter and some places will get colder" would be better stated as "Most places will get hotter and a few places may get colder". That's closer to what actual climate scientists are saying.

    • When you add more energy to a large system, you don't just get even warming. Things get mixed. It's like heating up an ice-cream cake. Some parts that were warm will get colder than they were, as other parts melt into them.

      Yep, increased heat means more turbulence, turbulance in the climate is weather.

      It's why the term has changed to climate change instead of just global warming.

      No, scientists are well aware the two terms have a different meaning, GW is CC in the positive temp direction. It's why the IPCC has had a CC on the end for over 20yrs. CC is actully the older of the two terms (at least back to the 50's), GW was first coined in a scientific paper in the 70's.

      As far as changing the terminology for political purposes goes, the only concrete evidence I have of that is when Frank Luntz while work [guardian.co.uk]

  • by Quila ( 201335 ) on Friday July 08, 2011 @04:22PM (#36699810)

    It's global warming's fault!

    • Quite likely, in a region subject to permafrost.

    • by RichMan ( 8097 ) on Friday July 08, 2011 @04:32PM (#36699920)

      > It's global warming's fault!

      Quite probably. In most really cold places, it is usally to cold to snow as cold air can carry less moisture than warm air.
      Back where I grew up we had lots of -20C clear cold days. It was the "warm" days near 0C when it snowed.

      Global warming is expected to create much more evaporation from the oceans and lead to more rain. (cf the flooded central US).

      • by Toonol ( 1057698 ) on Friday July 08, 2011 @04:48PM (#36700062)
        Quite probably. In most really cold places, it is usally to cold to snow as cold air can carry less moisture than warm air. Back where I grew up we had lots of -20C clear cold days. It was the "warm" days near 0C when it snowed.

        While that phenomenon certainly exists, it can't be used as a justification for this snowfall. There was a heavier snowfall decades ago, so this snowfall does nothing to establish warming, cooling, change, or static climate. You would have to do an analysis of frequency of snowfalls, etc., before drawing any conclusions about it.

        You can draw the conclusion that anybody using this as evidence (a) for, or (b) against, climate change is not going to be somebody you want to take too seriously.
      • I haven't been able to find information yet but this is a very mountainous area. The mountains force the wet air up and that cools it off producing rain.. The deserts are there not because of cold but because there are big mountains in the way of the prevailing wind. This snow fall is most likely due to a temporary change in the prevailing wind which brought moist air into the region.

        I live in Florida and hurricane landfalls depend on jet streams. We had a few years when those winds seemed to steer every ot

      • (cf the flooded central US).

        The flooding in the central US is a result of the Army Corps of Engineers failing to release sufficient water before the snow melt. The last time there was a winter with a similar amount of snow, they released enough water from the dams in the early spring before the snow melt started and then held most of the snow melt in the reservoirs.

      • Global warming is expected to create much more evaporation from the oceans and lead to more rain. (cf the flooded central US).

        The problem I've always had with this theory is that increased evaporation leads to greater cloud cover, which leads to a higher albedo, which leads to cooler temperatures.

        • But clouds both reflect sunlight and absorb infrared energy. Have you ever noticed how much warmer it is on a cloudy night than it is on a clear night? That's clouds holding heat in. Near the terminator clouds can even reflect more sunlight down to the Earth. The net effect of clouds appears to be slightly positive for global warming but the error bars stretch from slightly negative to moderately positive.

      • Re: (Score:3, Informative)

        by arse maker ( 1058608 )

        This is a complete straw man. Few credible climatologists would say something like this. You can't point to events like this as evidence of climate change. There is not enough data. Even if no snow fell there for all recorded human history, it's not proof or really evidence of anything.

        You need far more common events to tease out a change from the background. Once off events are the worst possible examples to use for climate change.

  • They had rain a few years ago in Iquique, another town in North Chile that hardly ever gets rain. It caused quite a disruption because many poorer people have cardboard roofs on their houses, which ,obviously, do not work particularly well when it rains.

    http://www.huffingtonpost.com/2009/07/21/tiny-drizzle-wreaks-havoc_n_242057.html [huffingtonpost.com]

  • This clearly means global warming is a fraud, and it's over!
  • the Antarctica the driest place on earth?

  • The parts of the Atacama that get less than a millimeter are by the ocean. Counterintuitively, the closer you get to the sea, the drier it is. This snowfall happened in the Dry Andes of Bolivia and Chile, which are very dry, but do receive more regular precip. For example, there are glaciers above 6000m (it basically never gets above freezing there, so it's sublimation balancing precip).

    This is a big snowfall, but it's not that bizarre of an event. AGW is happening, but it would be disingenuous to attribute this to climate change.

  • by Alain Williams ( 2972 ) <addw@phcomp.co.uk> on Saturday July 09, 2011 @02:37AM (#36702922) Homepage
    It will be interesting to see what, if anything, will spring up when the snow thaws ? -- given that it is considered sterile.

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