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Earth Moon Science

Exploiting Tomorrow's Solar Eclipse To Help Understand Sea Levels 92

Posted by timothy from the world-in-miniature dept.
mdsolar writes "Tomorrow at dawn on the U.S. East Coast, a partial solar eclipse will rise. Solar eclipses have many uses. They can confirm the Theory of Relativity, allow study of the solar corona, and this week, help prepare for global warming induced sea level rise. The tides induced in the oceans when the Sun and Moon are aligned are particularly high (and low) and give a foretaste of the effects of sea level rise in the coming decades. Maryland's Department of Natural Resources is asking for photos of these King Tides to help with preparation for the effect of sea level rise. Way to get out front, Maryland."
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Exploiting Tomorrow's Solar Eclipse To Help Understand Sea Levels More

Exploiting Tomorrow's Solar Eclipse To Help Understand Sea Levels

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  • Isn't this what we have math for?

    • Re:Nice, but.... (Score:4, Insightful)

      by gmuslera ( 3436 ) on Saturday November 02, 2013 @08:29PM (#45315183) Homepage Journal

      Math is nice, let you build models, make predictions and so on, but it could describe anything possible or impossible in any potential universe, To be sure that it fits in our universe, you must contrast it with reality. Einstein's theory was a bunch of complex equations, but was matching those equations predictions with reality that gave them validity.

      In this particular case, observing it could tell that our guesses had some ground, or that were more or less severe of what is really happening, because maybe some factors we aren't measuring or aren't fully understood yet.

      • Re: (Score:1)

        by Anonymous Coward

        Mmm hmm; I get the impression that a lot of "science" graduates that came after my time didn't get that lecture about avoiding extrapolation like the plague.


        • FItting an arbitrary model with many degrees of freedom to one data set? yeah extrapolation is worrisome.

          Extrapolating consequences of fundamental microscopic laws of physics interlinked and verified by millions of experiments and observations over a century of human civilization? No other extrapolation in the known human world is as useful or as secure.
    • Mathematical models is like software, in that in theory they work great, but in practice the fail many times, in many unexpected ways. Also, complex models require real data to calibrate. ie there tend to be many parameters that we need results to find their specific values.

    • Re:Nice, but.... (Score:5, Funny)

      by symbolset ( 646467 ) * on Saturday November 02, 2013 @08:46PM (#45315245) Journal
      We really need to get to the root of how antropogenic climate change is causing solar eclipses. If this keeps happening eventually the moon will come between the Earth and the sun permanently, leading to an eternal night cursed with ever increasing temperatures. Crops will simultaneously wilt and catch fire. With the right global publicity board report we should be able to get a bunch of powerless scientists to achieve a high degree of consensus about the subject, and then do nothing.

      • We're assholes for trying to crush our economy currently. It's like people in 1900 crushing their economy, slowing technological advancement to "help" us here in 2013.

        In 50-100 years, maybe less, we will be able to (for one example among a dozen) be able to create giant sheets in space similar to space sails already being proposed, tested, and actually used, and just block some sun. A few percent should be more than enough (1% of the sun's energy is less than 3 degrees of temperature). The worst issue wi

        • Re: (Score:2)

          by Layzej ( 1976930 )
          We don't have to wait for some future technology (I'm still waiting for my flying car...). We have cheap and available technologies today that are underutilized.

    • Re: (Score:2)

      by jamesh ( 87723 )

      Isn't this what we have math for?

      Most people don't understand math and think you are just trying to baffle them with bullshit. If you do an experiment though, which most people also don't understand, they'll think you're dazzling them with brilliance. There are some stupid "experiments" on youtube about the GFC involving balloons and weights and strings that operate on this principle.

    • Re: (Score:2)

      by dov_0 ( 1438253 )
      Talking of math and science in general, this idea isn't related to either. What the hell are pictures and videos of a single king tide going to tell us about about anything EXCEPT the level of that single king tide. There simply isn't enough data to show anything. No real measurements, no real data.

      • You don't think pictures and videos are real time data? There is a wealth of information that can be gleaned from them. If we compare the real world results to our expectations of what they would be they provide a reality check on the science that led to those expectations.

      • It will tell us how the incoming water distributes as it comes in. There are some non-intuitive ways that the flow of incoming water reacts to obstacles and other features of the land (such as low points) as a result of fluid dynamics. While our understanding of fluid dynamics can explain what happens, the complexity of the interactions with a rising tide make it impractical to fully catalog those effects in advance. The data that can be gleaned from these pictures will be useful for dealing with storm surg

  • I'm Going To Use It (Score:3)

    by Greyfox ( 87712 ) on Saturday November 02, 2013 @08:19PM (#45315133) Homepage Journal
    I'm going to use it to convince a primitive culture that my God has eaten the sun and that if they don't worship him and agree to build a pyramid, that they will never see their precious sun again! Muahahahahahahah! I figure I can get that all wrapped up by the time it pops back out again.

    • I'm going to use it to convince a primitive culture that my God has eaten the sun

      So just like AGW, only convincing people to give you money directly to save them from the doom you insist is real, instead of proxying funds through the government first.

      It's always good to cut out the middle man.

      • Re: (Score:2)

        by Greyfox ( 87712 )
        I could try over at the Fox News building, but I don't think it'd fly. They strike me as being scientifically illiterate over there, but I don't think they're THAT scientifically illiterate. I'm sure a few of them accidentally learned something in school before signing on with Rupert Murdoch.

  • Did anyone else notice that the USA Today logo was custom-tailored to the article? Thought that was a nice touch.

  • Eclipse not needed (Score:5, Informative)

    by Geoffrey.landis ( 926948 ) on Saturday November 02, 2013 @09:33PM (#45315445) Homepage

    This is cute, but the difference in tidal forces between an eclipse and any other full moon is not very much-- the moon and sun are still pretty closely lined up. If it's within a few months of an eclipse, the difference is trivial. Or, for that matter, a lunar eclipse would also be as good.
    Next month's full moon will have (very slightly) higher tides-- the Earth is a month closer to perihelion.

    • I think you meant new moon, not full moon.

      • New moons and full moons have essentially the same tides, because the tidal force is quadrupolar. [wikimedia.org]

        • Re:Eclipse not needed (Score:4, Funny)

          by Will.Woodhull ( 1038600 ) <wwoodhull@gmail.com> on Sunday November 03, 2013 @12:44AM (#45316011) Homepage Journal

          But full moon eclipses are quite rare. Granted they can be devastating and in fact indicate severe climate and geologic upheavals.

        • New moons and full moons have essentially the same tides, because the tidal force is quadrupolar.

          You are wrong. At new moon, moon and sun are almost in a straight line, so the force of moon and sun are added up. At full moon, moon and sun are in opposite directions, so their forces subtract.

          The lovely image that your link shows demonstrates that there is a tide at the side pointing to the moon, and on the other side. Totally true, that's why we have high tide every twelve hours. Still, the side pointing to the moon has a slightly higher tide because it is closer. And a big influence is that the moon

          • At new moon, moon and sun are almost in a straight line, so the force of moon and sun are added up. At full moon, moon and sun are in opposite directions, so their forces subtract.

            No. Tidal forces come from the gravity gradient, not the gravity magnitude, and the gradient works both ways. If the Earth and Moon orbits were exactly circular and coplanar, full moon and new moon tides would be the same.

            Lunar tides are larger than solar tides because, yes, the moon is closer, so its gravity gradient is larger even though the magnitude of its gravitational force is smaller. We have lunar tides because the side of Earth away from the moon is 0.034% farther from the Moon than the near side;

    • Re:Eclipse not needed (Score:5, Informative)

      by Will.Woodhull ( 1038600 ) <wwoodhull@gmail.com> on Sunday November 03, 2013 @12:42AM (#45316007) Homepage Journal

      I don't think parent post is quite right.

      The spring tide of an eclipse day is probably not significantly higher than any other spring tide when all other things are equal. But the existence of perigee and perihelion means that other things may not be equal.

      This particular eclipse happens near perigee, as the Moon nears its closest approach to the Earth. This does make for a king tide, a high tide that is significantly higher than other spring tides. Also the Earth is coming up on perihelion in a few weeks, as parent post states, when it is at its closest approach to the Sun. That will also push the tide higher.

      Additionally, Maryland is positioned relative to the line of the eclipse such that the tidal bulge will be higher at Maryland's shores than at, say New York or Georgia, that are at roughly the same longitude.

      • Thanks for the correction. http://en.wikipedia.org/wiki/King_tide [wikipedia.org]

      • This particular eclipse happens near perigee, as the Moon nears its closest approach to the Earth. This does make for a king tide, a high tide that is significantly higher than other spring tides. Also the Earth is coming up on perihelion in a few weeks, as parent post states, when it is at its closest approach to the Sun. That will also push the tide higher.

        Except that the new moon in December is even closer to lunar perigee. The December new moon is one day away from lunar perigee, while this new moon is three days off.

        In January, we get perigee and the new moon at the same time, with perihelion only three days off. This is probably the highest tide of all, although the moon is slightly further inclined off the sun-Earth line. In any case, though, the point is that there really isn't a significance to the eclipse-- an eclipse isn't really much different in

    • Re: (Score:1)

      by khallow ( 566160 )
      What I thought made this pretty pointless is that one gets pretty close to that every two weeks with new and full moons. Even when the Sun and Moon aren't lined up well, it's not that much of a difference.

    • Re: (Score:2)

      by rossdee ( 243626 )

      "Next month's full moon will have (very slightly) higher tides-- the Earth is a month closer to perihelion."

      And you'll get even more extreme tides when the Sun passes between the Earth and the Moon.

  • Oh don't think of it as man induce global warming, so much as, ever changing real estate values in the evolution of a planet.
    I confess, It's my fault. In order to bring surf tourism to Kansas, I've calculated the precise amount of beans fed to cattle to produce the correct results.
    Call me a nut, but I farm beans and raise cattle and manufacture my "special feed" sold at cost around the state. It is a Holy thing to bring the masses to the rental property.I cite the "Surfi-ism" lectures by St. Lex of the Luth

  • Comment removed (Score:3)

    by account_deleted ( 4530225 ) on Saturday November 02, 2013 @10:27PM (#45315641)
    Comment removed based on user account deletion

  • Eclipse as Propoganda (Score:5, Informative)

    by SuperKendall ( 25149 ) on Sunday November 03, 2013 @12:29AM (#45315969)

    Nothing like using an unusually high tide to scare people about global warming, even though ocean levels are now predicted to rise something like 4" over 100 years (NOT four feet as the government website sadly parrots) ... the variance of a good spring tide can be more than that.

    It's just really sad to see people conned in the name of science.

    • 4"? Where does that nonsense come from?

      • The IPCC. Keep reading the other replies to my post for the informative AC response that includes a link, rather than your contentless fear-mongering.

        The EPA report someone else links to was from the older study before the IPCC realized they'd been had. Sorry you have not come to the same realization yet.

        The question you have to ask yourself is, are you truly capable of making an informed decision based on real facts? Or are you going to allow yourself to be led by insular opinions that agree with your

    • Actually, this may be using the hype over global warming to gather data that is useful for other things. This data should be useful for making plans for dealing with storm surge. While storm surge occurs often, it is difficult to gather data on it while it is happening because of the danger to those who attempt to actually do so. Tides happen slowly enough that untrained people can take pictures and make measurements without endangering themselves (not that it is completely safe, there are people who are fo

      • I don't know, like you say it's quite a lot of difference between a really high tide and a storm surge, which can be pretty bad in any high tide... what could you really glean from studying a normal tidal movement that would help understand a surge?

        A surge means water many feet higher than even an unusually high tide will bring.

        In any case the Maryland website makes it pretty clear they aren't out to understand anything better, they want images to further propaganda. I'm not sure what kinds of images they

    • According to the EPA [epa.gov], sea level rise is predicted to be 30 to 70 inches over the next 100 years. That sounds much closer to all the other estimates I have heard. That sea level rise is enough to cause hundreds of millions of people and the corresponding infrastructure to relocate. And there's no reason that the sea level will magically stop rising after 100 years. It'll keep rising unless we can somehow scrub the excess CO2 out of the atmosphere.

    • Reference for the 4" (Score:1)

      by Anonymous Coward

      For some data in supporting change in the range of 4 inches, consider:

      - Wikipedia's chart [wikipedia.org] shows that the change in sea level for the past hundred years has been 6 inches. This chart comes from from the US EPA.

      There is no evidence that the rate of sea level rise is increasing. Sea level rose rapidly after then end of the last ice age; since then it has been levelling off since. [wikimedia.org] Even IPCC states recently published estimates of sea level rise over the last decades remain within the range of the TAR values (i.e [www.ipcc.ch]

      • Re: (Score:3)

        by Layzej ( 1976930 )

        There is no evidence that the rate of sea level rise is increasing

        No evidence except for the measurements and data. Here's a graph from NOAA. [noaa.gov]

        Sea level rose rapidly 10,000 years ago at the end of the last glacial period. They have been fairly stable for the last 8000 years until levels began to climb again in the 20th century.

        Records and research show that sea level has been steadily rising at a rate of 1 to 2.5 millimeters (0.04 to 0.1 inches) per year since 1900.

        Since 1992, new methods of satellite altimetry indicate a rate of rise of 3 millimeters (0.12 inches) per y

    • Re: (Score:2, Troll)

      by Layzej ( 1976930 )

      ocean levels are now predicted to rise something like 4" over 100 years (NOT four feet as the government website sadly parrots)

      That can't be right. The current rate of sea level rise is 3.6 mm/year. The rate is accelerating - it was 1.7 mm/year in the early 70's. 3.6 mm/year * 100 years is over 1 foot. With continued acceleration 4 feet sounds reasonable. 4 inches is not. - http://www.climatechange2013.org/images/uploads/WGIAR5-SPM_Approved27Sep2013.pdf [climatechange2013.org]

  • Hey, asking citizens to just get out their cameras and document how a king tide affects their properties is fine with me. That's cheap, easy, and makes sense. Sure beats questionable schemes like carbon "taxes".

  • ... as they would be any new moon. Sure, the sun and moon aren't precisely aligned in the sky, but they are still in the same general direction. Would the precise angle make *THAT* much of a difference in height?

    • Would the precise angle make *THAT* much of a difference in height?

      No. Because the tidal bulge of water on the Earth's surface leads (mental check ... yes, leads) the sub-lunar point by a substantial degree as the bulge is dragged to the east by the rotation of the Earth relative to the Moon and the Sun (that's why both Moon and Sun rise in the east, unlike on Mars where one moon rises in the east and one (the faster-orbiting one) rises in the west.

      The degree of lead varies with roughness of the seabed an

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