Science writers and news media are invited to a talk at next week’s American Geophysical Union fall meeting to learn about what causes change in the Sun’s powerful activity, from flares that release as much energy as a billion megatons of TNT to planet-sized dark areas on the solar surface laced with strong magnetic fields to eruptions that blast a billion tons of electrified gas into space at a million miles per hour.

Dr. Barbara Thompson, an astrophysicist at NASA’s Goddard Space Flight Center, Greenbelt, Md., will present “Solar Variability” Monday, December 10 from 9:00 – 9:30 a.m. PST in Room 131 of the Moscone Convention Center during the American Geophysical Union’s fall meeting in San Francisco, Calif. Thompson is affiliated with NASA’s Living with a Star program, a multi-mission research effort to understand solar activity and its effects on the Earth.

The talk will be the first of four tutorial presentations geared towards preparing attendees with an overview of the science to be discussed at the meeting.

“I’ll focus on some of the key problems which will be discussed at the meeting, which deal with the many ways the Sun can dump energy into the Earth’s system,” said Thompson. “What makes this such an exciting topic of research is not only the complexity of the Sun, but the Sun-Earth connected system as well. All of these variations have the potential to impact climate or technological systems on Earth.”

The Sun is a highly variable star. Violent explosions occur in the Sun’s atmosphere, and its magnetic field and activity level vary cyclically. The consequences of the Sun’s variability are felt in many ways on Earth and throughout interplanetary space.

Thompson will survey the broad range of the Sun’s variability. “The Sun provides an extremely dynamic system to study, but the many types of variability and the interplay between different phenomena make it an extremely complicated subject,” notes Thompson.

The effects of solar activity on Earth are frequently beautiful, producing a shimmering veil of light, known as the aurora, in the night sky at high latitudes. Occasionally, solar activity is destructive, disrupting satellites, radio communication, and power systems.

The talks are free of jargon (or at least the jargon will be defined first) because they are designed to give scientists attending the meeting a broad overview of current developments in fields other than their own. As such, interested science writers and media are welcome to attend, and there will be a question and answer period at the end.