How solar flares threaten Earth

BILL MURTAGH from Kells, Co Meath, spends his days observing the sun. Not directly, of course, but on a bank of monitors in the space weather forecasting centre at the US National Oceanic and Atmospheric Administration (Noaa) in Boulder, Colorado, writes FRANK McDONALDEnvironment Editor

Among its many other activities, Noaa is “the nation’s official source of space weather alerts and warnings” and the lead centre for this activity worldwide, issuing forecasts daily. And what it’s looking for is evidence of solar flares from the sun’s molten surface.

As Murtagh explains to a group of visiting European environmental journalists, these flares cause geomagnetic storms that can affect electricity transmission lines anywhere on Earth. Hence uitilities maintaining power grids are especially interested in the forecasts.

Most power outages are caused by other factors, such as wind storms or simple human error. But he recalls that a widespread outage in Montreal in March 1989 was caused by a geomagnetic storm, and left six million people without electricity for more than nine hours.

Solar flares were first observed by English astronomer Richard Carrington on September 1st, 1859. That night, brilliant auroras appeared in skies all over the world and telegraph systems “went haywire” as a result of the geomagnetic storm generated by the flares.

Noaa uses two satellites to monitor the sun daily. “If we see a flare, we can give adequate warning to power generators. And there are a lot of things they can do to protect the grid – for example, by postponing maintenance for a few days until the storm is over,” he says.

Murtagh is a senior forecaster and customer focus representative for Noaa’s Space Weather Prediction Centre, liaising with other agencies such as Nasa. He has previously served as a weather forecaster in the US Air Force for 23 years and joined Noaa in 2003.

But space weather is just one of the activities carried out at its Boulder laboratories, at the foot of the Rocky Mountains. One of the most important is the work it does in quantifying the year-to-year variability in natural sources and sinks of carbon dioxide (CO2).

As Dr Lori Bruwiler explained, its “carbon tracker” programmme combines computer models with atmospheric measurements worldwide to check if the measurements match the models, and vice versa. “This tool will also be very useful in monitoring mitigation efforts,” she says.

Ordinary citizens also contribute directly to the international scientific effort to monitor CO2. For example, there is a woman in Mongolia who volunteers to measure CO2 levels there, taking canisters to the US embassy in Ulan Bator, which sends them to Noaa in a diplomatic bag.

Don Mock, deputy director of its Earth System Research Laboratory (ESRL), says it takes in 24,000 samples a year from every part of the world tracking more than 20 gases in the atmosphere, including CO2 but also sulphur dioxide, nitrous oxide and ozone-depleting chlorofluorocarbons.

Monitoring “can’t all be done by satellites”, he says, adding that the lab needs actual measurements to ensure that its computer models of the atmosphere are “consistent with the laws of physics”. He also stresses that all of the data it collects is publicly available to anyone.

ESRL’s director, Dr AE MacDonald, showed us the “planet theatre” he developed, with projections on a central globe showing the classic Nasa image of Earth from space as well as a range of other scenarios – for example, the staggering number of planes in the air at any given time.

He has no doubts about climate change and dismisses “deniers” saying that, no matter what the evidence is, they just won’t believe it. “But in my experience, it is very hard for scientific sceptics to argue that oceans are not getting warmer, because the evidence is so compelling.”

See nooa.gov