Underground Particles Forecast Winter Storms

[HURAKAN]

Underground Particles Forecast Winter Storms
Irene Klotz, Discovery News

Jan. 30, 2009 -- Without getting a weather report -- or even stepping outside -- scientists have found a way to predict when a winter storm is on its way. The tip-off? Tabulating the number of cosmic ray particles reaching detectors a half-mile underground.

Cosmic rays originate from beyond our solar system. Scientists aren't sure what causes them, but they arrive regularly and steadily at Earth's door.

It is not a subtle greeting. As the high-energy beams smash into the atmosphere, they create cascades of subatomic particles, including odd little creatures known as muons -- electron-like bits that can pass through solid rock.

That got atmospheric scientist Scott Osprey wondering if he could track changes in the atmosphere by surveying muon populations.

Osprey, a researcher at the United Kingdom's National Center for Atmospheric Science, reasoned that when temperatures are higher, there are fewer molecules for muon parent particles to collide with, leaving more of them intact to degrade into muons. Over coffee chats with physicist colleagues, Osprey refined the idea and eventually hooked up with Giles Barr at the University of Oxford.

"What we brought together was some specialist knowledge that the other didn't have," Osprey told Discovery News. "We knew it would exist, and we went out to find it."

The two formed a research team and began correlating meteorological reports with muon data collected as part of particle physics experiments, primarily from a detector inside an abandoned iron mine in Minnesota.

The team, which eventually grew to 160 scientists, didn't know just how tightly intertwined the phenomena would be. Most striking: huge jumps in the number of muons during weather events known as sudden stratospheric warmings, which can send temperatures in the upper atmosphere zooming upward as much as 50 degrees in a few days.

The temperature spikes can redirect the jet stream, triggering wind shears that peel off and affect the weather, sometimes causing brutal cold fronts like the one sweeping the United States this week.

"It's very interesting that we can get these correlations using equipment a half-mile underground," Osprey said.

The researchers found that muon counts correlated to stratospheric temperature readings within about one degree in data collected over a four-year period. The study will be published in the journal Geophysical Research Letters.

Osprey said he doesn't see muon meteorology replacing traditional satellite and balloon-based weather forecasting techniques, but it could be useful for round-the-clock atmospheric monitoring and other niche applications.

"This is the biggest step we've taken in terms of interdisciplinary work," notes Robert Plunkett, a particle physicist with Illinois-based Fermilab, which collects muon data to calibrate its instruments for unrelated studies of neutrinos.

"These effects should have been discovered 50 years ago," added Osprey. "It's quite a predictable result. Climate scientists and particle physicists haven't been talking together."