Dr. Bortrum
12/25/2008
Ice from the Sky/Bortrum on Vacation
Old Bortrum is on vacation until January 8,2008. Meanwhile this column of 12/18/2008 will continue to be posted. However, one brief note. The day after posting this column, I saw on the TV news that a big chunk of ice had fallen throught the roof of a building in the Los Angeles area. The report indicated that the belief was that the ice was from a plane either landing or taking off from the LA airport.
Thank you, Lucille! Lucille comes to our house every other Friday for a couple hours to help keep our house in some semblance of cleanliness and order. You may recall that last Friday a widespread storm laden with moisture was passing through a large portion of the country, including our area and New England, where ice was a major problem. We had only rain, enough rain that I was greeted in the morning by an inch or so of water covering our basement /rec room floor everywhere but in the location of our sump pump! I had spent about two hours sweeping the water into the sump but was making little headway. Then Lucille arrived and, with the two of us in action (mostly Lucille), we cleared almost all of the water. She was great!
At this point, I’m definitely dreaming of a white, not a wet, Christmas. Water in the form of snow and trees in the form of Christmas trees are two of the benign presences at this time of year. So, let’s talk about water and trees and even a combination of the two to accomplish an environmental cleanup.
First, let me continue on from last week’s column on Discover’s top science stories of the year. Discover’s story number 73 had to do with dangerous water in its solid form, ice. As if we aren’t in enough peril with meteorites and space debris falling from the sky, what about twenty-pound chunks of ice falling out of the sky on clear cloudless days. We often read about hailstones the size of golf balls or even softballs. But a twenty-pounder is not something to dismiss lightly.
By my reckoning, using the "a pint’s a pound the world around" rule of thumb, that 20-pound chunk of ice would be the size of two gallon-size containers of milk with a half-gallon more tacked on. One of those hits you and you’re gone! I seem to recall mentioning in a previous column an incident involving one of these big ice chunks, possibly the one in Spain in 2007 in which crashed through the roof of an industrial warehouse in Madrid.
I don’t recall knowing that these ice chunks are called megacryometeorites and can weigh more than a hundred pounds. According to Karen Wright, who wrote the Discover article, more than 50 of these hefty chunks of ice dropping from the sky have been reported in the past seven years. In Madrid, Jesûs Martinez-Frias of the Center for Astrobiology in Madrid is of the opinion that the surprising frequency of these icy incidents may be a result of global warming.
These megacryometeorites are thought to be formed when ice crystals are driven repeatedly through cold water vapor in the atmosphere, each time picking up an additional coating of ice. What troubles me is that, to do this repeatedly must requre some pretty forceful turbulent winds up there to keep that heavy chunk of ice from falling as it grows layer by layer. I can recall experiencing some quite severe turbulence on a number of plane trips in my life so I suppose it’s not out of the question. The other thing that strikes me is that, if 50 icy incidents have been witnessed, how many large chunks of ice have fallen that nobody saw? Offhand, I would guess there must have been hundreds or thousands!
There are skeptics, of course, who suggest that the ice comes from water in toilets on aircraft. The reply is that such chunks of ice would be blue due to the disinfectant used in the airplanes. Others suggest the chunks are ice built up on the fuselage of planes, the ice braking off and falling. Martinez- Frias and his colleagues have analyzed the ice from apparently more than one fall of ice and conclude that the composition is the same as that of rainwater originating in the troposphere, the lower, innermost layer of our atmosphere.
Hey, I don’t really care where they originate, as long they don’t come near me! You’re right, that’s not very scientific of me but I’m disgusted with water in any form after our latest basement event. And just an hour ago, water caused a disruption in my schedule - I was taking my wife to the hairdresser and was just exiting our driveway when suddenly sleet and snow started falling heavily. I drove back in the driveway and we cancelled the appointment, following which the precipitation stopped completely and it would have been perfectly safe.
Oh, I almost forgot, I promised to talk about trees. So, let’s get to the case of the pumping poplars. Many years ago, I visited the Argonne National Laboratory near Chicago, Illinois. (I don’t remember who was governor then.) I believe the reason for my visit was to look at some work on batteries but my feeble brain won’t supply any confirmation that was the case. I do recall, however, that Argonne had quite an area of forested land around the main complex and I seem to remember seeing some deer on the property. This would have been novel to me at the time. Today, not so novel - there was a deer in my backyard last week.
It was not one of the top stories in the January Discover but a "Field Note" in that issue that drew my attention to Argonne. The field note, by Dava Sobel, concerns the work of agronomist Cristina Negri and the work she is doing to help clean up the contamination left over at Argonne from the early days of atomic energy. Specifically, water underneath the Argonne property is contaminated with organic compounds, notably chlorinated solvents such as trichloroethane. Mechanical pumping of the water hasn’t resolved the problem.
Negri and her colleagues have planted some 900 poplars on a four-acre site on the Argonne Lab grounds in an attempt to rid the place of the offending solvents. Poplars are quite thirsty trees and a single poplar will pump up 26 gallons of water a day during the peak summer months. The 30-foot high poplars’ roots will search out sources of water and Negri has used that feature to both clean up and analyze contamination problems. Instead of allowing the poplars to suck up surface water, the Argonne workers planted the trees in pits lined with plastic. That forces the roots of the trees to spread down and out deeper underground in search of water. They not only go down vertically but also spread out horizontally following the water trail. The water and the contaminants are sucked up through the roots and end up in the branches and leaves, where the water evaporates and the sunlight decomposes the solvents. The researchers sample leaves and bits of branches periodically to monitor how the cleanup process is proceeding.
Some might say that the poplars are so thirsty that they will deplete the water level and use up precious water. However, the plan assumes that as the poplars do their job over the next two or three decades the water will become purer and oaks and other trees native to the Great Lakes region will take over. These slower growing trees are less thirsty and the aquifer presumably will come back to its normal volume.
The poplar trees not only serve as pumps to get rid of contaminants, but can also be used as markers to map out polluted areas such the one in Murdock, Nebraska. Back in my early days as a chemist, we often used carbon tetrachloride as a solvent and it was widely used in dry cleaning. In the 1960s in farm country, carbon tet was also used to keep pests out of drums containing grain. Well, the carbon tet ended up contaminating groundwater and even today some water supplies in various areas of the corn belt have this problem.
So, Argonne now has a test plot of poplars and willows, also very thirsty trees, in the Murdock region. In addition to helping clean up the pollution the trees are useful in mapping out just where the plumes of underground contamination are located. To help make the forest more attractive to residents, the Argonne plot also has other varieties of trees and wild flowers. Ladybird Johnson should be happy.
Finally, congratulations to our cartoonist Harry Trumbore on his promotion to Editor of a neighboring town’s weekly newspaper. Inasmuch as our own StocksandNews Editor Brian Trumbore has graciously suggested I take the next two weeks off, I’ll wish you a Merry Christmas, Happy Hanukkah and/or Season’s Greetings and a Happy New Year. I’ll be back on January 8, 2009 or perhaps a bit earlier.
Allen F. Bortrum
