The lubricated hurricane
According to a new study, without sea spray, hurricane-force winds wouldn’t exist. The spray kicked up by large waves and falling raindrops lubricates the air above the ocean, which decreases the amount of turbulence. This lack of turbulence allows the winds to increase in force until they become a hurricane. Researchers estimate that wind speeds would peak around 25mph if there were turbulence to sap the budding hurricane’s energy.
The equations, when applied to a cloud of water droplets sandwiched between flowing air and water, indicate that large water droplets thrown up by cresting waves in rough seas inhibit the turbulence in the air over the ocean. Without this turbulence to drain energy from the swirling winds, winds can build to tremendous speeds. Without turbulence, friction between the air and water would be reduced by a factor of 1,000, Chorin said, sometimes allowing winds to rise to speeds eight times greater than would be the case with turbulence.
The turbulent vortices in the air are suppressed by the droplets when they rain back into the sea, somewhat like “combing unruly hair,” Chorin said. These droplets are about 20 microns across (8 ten-thousandths of an inch) or larger.
The smaller the droplets, the less ability they have to suppress the turbulence, he said, which suggests one way to calm hurricanes.
Not as crazy as it might sound at first, Chorin points to ancient times when sailors used to carry oil to pour on the ocean to help calm the waves, which isn’t superstition as it turns out. (I would question its effectiveness, though. How much oil would you need to calm a storm on the Mediterranean or Aegean, even in just a small area?)
Whereas [Sir M. James] Lighthill thought that evaporation of the droplets cooled the atmosphere and led to accelerated winds, Chorin, Barenblatt and Prostokishin have showed that more important is the reduction of turbulence by falling droplets. Nevertheless, they note that evaporative cooling also serves to reduce turbulence and thus allow winds to build.
Somehow I think it’s only a matter of time before someone trademarks “Hurricane” brand sex jelly.
The military’s new “Active Denial System”
Where “Active Denial System” is a nice way of saying “long-distance microwave oven.”
Some people were actually crazy enough to volunteer to stand in front of the US military’s new Active Denial System (ADS) microwave. The ADS is part of the Petagon’s new “less-lethal” weapons program — I wonder if “less-lethal” is like saying “a little pregnant?” — anyway, the weapon fires a 95GHz microwave beam at rioters, intruders, obstreperous children, bags of unpopped popcorn, whatever. This beam is supposed to cause pain but no injury. The weapon was tested in 2003 and 2004, but little was heard about the tests afterwards, until Edward Hammond requested the documents about the tests under the Freedom of Information Act.
Several tests were conducted, two to measure pain tolerance levels and one to determine its efficacy in driving away simulated rioters or intruders. The weapon created pain within two seconds of its activation, and the pain levels become intolerable within five seconds. The idea is that the pain will force the rioters or what have you to disperse, which seems like a good idea. After all, I don’t know many rioters interested in suntanning while they’re rioting, no matter how convenient it might seem.
There are some big problems with such a system, however. The main one is what happens if someone is unable to get out of the path of the beam. Would the weapon cut out to prevent overexposure? Living in downtown Boston, near Fenway Park, I “attended” the Red Sox riots last year after the Sox beat the Yankees, and then again when they won the World Series. (No, I wasn’t a rioter; I was a spectator.) Anyway, in a situation like that, I was lucky to be able to move at all. In some cases, it took me a good five minutes just to move 100 feet. Now, if the police had turned on their lovely ADS guns in an attempt to move the crowd, there would have been injuries: tramplings from people trying to avoid the beam, and burns on people unable to do so. Now the military is considering using a vehicle-mounted ADS in Iraq and other places as a means, again, of crowd control. This strikes me as a really bad idea.
During the experiments, the volunteers threw up their arms when they were hit with the beam, and were given a 15 second “cooling off” period before they were targeted again. In one test, a volunteer ended up with burns because the beam was accidentally used on the wrong power setting. Oopsie.
Hmm. I wonder if I could explode a potato at 200 yards?
The new Earth model
NASA has combined several models of the Earth to create a new picture of how our climate operates. The new system combines models of the atmosphere, ocean, land surface, and sea ice into one framework that promises to improve predictive capabilities for both short-term forecasts like one sees on TV to long-term climate models spanning a century or more.
Under a partnership, groups from NASA, the National Science Foundation (NSF), the National Oceanic and Atmospheric Administration (NOAA), the Department of Energy (DOE), the Department of Defense and research universities are using ESMF as the standard for coupling their weather and climate models to achieve a realistic representation of the Earth as a system of interacting parts, unifying much of the modeling community. ESMF makes it easier to share and compare alternative scientific approaches from multiple sources, uses remote sensing data more efficiently and eliminates the need for individual agencies to develop their own coupling software.
ESMF allows researchers to combine their efforts to create one comprehensive picture of the Earth. Whereas before, isolated groups worked on one part of the model, ESMF allows them to combine all of the pieces together, which would have been too large an undertaking for any one group to do.
The article goes into detail on how the pieces are layered together to create a cohesive whole.
Whither Einstein?
kuro5hin, which posts some pretty bad stuff and some pretty good stuff depending on the whim of the masses, has a shallowly-insightful (how’s that for an oxymoron?) post on why there is no “new Einstein.”
The answer, the article states, is simply because the emphasis on academia is on quantity rather than quality: the worth of a great scientist is in how many papers he publishes rather than in what he publishes. I find this idea intriguing, and I wonder if it’s true. Faculty postitions at research institutions are difficult to come by for everyone except Nobel laureates — and as a result, these academics are forced to churn out papers in order to continually prove their worth.
It’s a short, interesting read. Check it out.