NOAA’s Space Weather Prediction Center

Not science fiction

By Craig Collins

Most of the definitions for the term space buoy read as follows: a common element in science fiction that refers to a stationary object in outer space that provides navigation data or warnings.

This, while true, leaves out an important fact: space buoys are real. Since 2016, NOAA’s Space Weather Prediction Center (SWPC), one of the National Weather Service’s (NWS) National Centers for Environmental Prediction, has been receiving data from its own space buoy – the Deep Space Climate Observatory, or DSCOVR – to help the agency monitor space weather.

A coronal mass ejection bursting from the edge of the Sun on May 1, 2013.

The sun cycles through periods of intense solar storm activity, periodic explosions that emit huge amounts of electromagnetic energy, sometimes forcefully enough to propel a huge cloud of ionized plasma, called a coronal mass ejection (CME). CMEs can reach Earth and disrupt the magnetic balance of our planet. Scary as it sounds, these geomagnetic disruptions rarely pose a hazard to people or other organic life, but they can do serious damage to systems on Earth and in space that rely on electronics. The largest known solar event to impact human affairs, the Carrington Event, occurred in 1859, knocking out telegraph systems from North America to Europe. In 1972, a CME disrupted telephone service across the state of Illinois. A huge solar storm in March of 1989 disrupted the polar orbits of several satellites, interrupted the communications of NOAA’s Geostationary Operational Environmental (GOES) weather satellites, caused sensor glitches in the orbiting Space Shuttle Discovery, disrupted radio and communications signals, and knocked the entire city of Montreal off its electrical grid for a nine-hour blackout. A series of solar flares in October of 2003 caused a 30- hour outage in the Federal Aviation Administration’s GPS navigation support system.

Dave Marshall monitors space weather in NOAA’s Space Weather Forecast Office.

Our power, communications and navigation systems play a more important role in our lives than ever before, and these technologies are exceptionally vulnerable to space weather. The National Research Council estimated that if the U.S. were left unprepared, a disturbance the size of the Carrington Event would cause an immediate $1 trillion to $2 trillion in damages, and take four to 10 years to recover from.

Advance warning of such an event could provide enough lead time to avoid such damages – grid operators, for example, could either implement protective measures, or time a temporary shutdown to coincide with a geomagnetic storm. The Space Weather Prediction Center (SWPC), located in Boulder, Colorado, relies on several platforms, including ground-based solar and magnetic observatories and NOAA’s satellites to monitor the sun for signs of space weather: solar flares, particle events, and CMEs. GOES in particular is useful for space weather forecasting: it can detect solar flares with its onboard ultraviolet telescope, the Solar Ultraviolet Imager (SUVI), and measure their strength with an onboard X-ray spectrometer.

SWPC issues watches, warnings and alerts – just as other NWS centers do with earthly storms – but to notify the public of space weather risks. It utilizes three categories of space weather scales to help communicate the severity of each event. The center recognizes many types of space weather disturbances, each of which carries its own set of hazards. Its space weather scales are focused on geomagnetic storms caused by CMEs and high-speed solar winds; solar radiation storms that can endanger astronauts and high altitude/high-latitude flyers; and radio blackouts caused by disturbances in the ionosphere. Within each of these categories, the severity of the event is graded on a scale from 1 to 5.

SWPC utilizes GOES to determine where a solar flare occurred on the sun and how big it was, the center’s space weather experts next determine whether a CME may be headed toward Earth, and whether it may cause a radiation or geomagnetic storm at the planet. This is where the DSCOVR, the space buoy, comes in: locked in the gravitational pull of the sun and Earth, at a place scientists call Lagrange Point 1 (L1), the observatory is a million miles from the planet – a small fraction of the 93 million-mile distance, but close enough to provide a 15- to 60-minute warning before a CME, and its accompanying surge of particles and magnetic field changes, reach Earth.

(Learn more about space weather and the SWPC at https://www. noaa.gov/explainers/space-weatherstorms-from-sun)