And today's space weather forecast is... more accurate

Posted by Emma Woollacott

Space weather forecasts are about to get more accurate - just in time for a period of increased solar activity.

NASA’s Goddard Space Flight Center in Greenbelt, Maryland, is to startimplementing 'ensemble forecasting', a computer technique already used by meteorologists to track potential paths and impacts of hurricanes and other severe weather events.

Instead of analyzing one set of solar-storm conditions, as now, Goddard forecasters will be able to simultaneously produce as many as 100 computerized forecasts by calculating multiple possible parameters.

"Ensemble forecasting will provide a distribution of arrival times, which will improve the reliability of forecasts. This is important," says Michael Hesse, chief of Goddard's Space Weather Laboratory and the recently named director of the Center's Heliophysics Science Division.

"Society is relying more so than ever on space. Communications, navigation, electrical-power generation, all are all susceptible to space weather."

The new capability is expected to come online within three years - great timing, considering the sun's current state of activity. As part of its 11-year cycle, the sun is entering solar maximum, peaking next year.

Solar flares and coronal mass ejections (CMEs) like last week's are likely to become more common, potentially disrupting power grids and damaging satellite instrumentation, and even threatening astronauts' health.

"No one knows exactly what the sun will do, says Antti Pulkkinen, one of the laboratory's chief forecasters. "We can't even tell in a week, let alone a year or two, what the sun will do. All we know is that the sun will be more active."

Currently, the laboratory is running one CME model at a time, based on parameters derived from near real-time data gathered by several different observatories.
And the data's far from perfect, containing errors that increase over time, leading to forecasts that don't agree with the evolution of actual conditions.

Ensemble forecasting, however, overcomes these weaknesses by allowing forecasters to tweak the conditions.

"We'll be able to characterize the uncertainties in our forecasts, which is almost as important as the forecast itself," says Pulkkinen.

"We certainly don't want to miss the solar maximum with this capability. We're really pushing the envelope to have it done. When we do, we'll be the first in the world to have it."