The Amateur Scientist; May 1998; Scientific American Magazine; by Carlson; 2 Page(s)

As I write this column, I am enjoying my regular Sunday morning bagel at a small café overlooking the ocean. It's raining, and storms at sea have whipped up unusually large waves. These ribbons of energy march thousands of miles in lockstep, finally breaking on Pacific beaches with spectacular effect. Watching these watery monsters roll up onto the nearby sand reminds me of another kind of wave passing by. The world's greatest ocean is the atmosphere, and it, too, contains extraordinarily powerful waves. Like their ocean-going counterparts, atmospheric waves are normally generated by energetic storms. But they can also arise and spread, like ripples on a quiet pond, when a meteor or volcanic explosion violently shocks the air.

Yet even the largest atmospheric tsunamis are quite difficult to detect. The pressure excursions that betray their passage are typically just a few millibars (thousandths of one atmosphere), and these tiny undulations often take tens of minutes, or even longer, to go by. Instruments that can monitor such subtle signals are called microbarographs, and professional units can cost thousands of dollars. But, thanks to Paul Neher, a gifted amateur scientist from Las Cruces, N.M., anyone can now observe these ephemeral waves for about $50.