A team at the University of Michigan, in Ann Arbor, recently made a breakthrough that could help climate scientists fill in one piece missing from today’s climate models. The group, led by Nilton Renno, has shown that electric fields as strong as 160 kilo-volts per meter could double the amount of dust that makes it into the atmosphere. Dust is part of the family of aerosols— suspended particles or molecules in the air—which includes water vapor and soot from coal combustion. Aerosols absorb or reflect radiation, either warming or cooling regions of the earth. Renno, an associate professor of atmospheric, oceanic, and space sciences, had predicted years earlier that electricity might be a missing link, when he noticed that dust devils, the spinning vortexes of air that look like miniature tornadoes, had strong electric fields. But he and Jasper Kok, a doctoral student, proved the extent of electricity’s role in lifting dust into the air only after they created a new kind of electric-field sensor—one that measures a field’s strength without disrupting the field and is immune to the effects of ion currents and the negative charges carried by wind-blown particles colliding with the sensor.
Though it remains unclear just how important natural dust is to climate change, Renno’s work may yield another, largely unintended benefit. The sensor he and his colleagues developed for taking measurements on windswept sand dunes and dusty mesas is being tested for use inside semiconductor fabs. Renno reports that Flextronics—a Singapore-based firm that designs, fabricates, assembles, and tests electronics such as printed circuit boards—is determining the sensor’s usefulness in detecting the buildup of electrostatic charge in clean rooms. Such discharges lower microprocessor yields. Kok notes that the sensor’s value comes from its size, which is “an order of magnitude smaller than traditional sensors of this type, so it can get closer to possible sources of electric discharge.”
To learn more about Nilton Renno and his many areas of research click here.
