It looks like there might be more than fireworks lighting up the night sky in many parts of the world this New Year’s Eve. A large solar storm is approaching Earth, and it is expected hit the outer atmosphere of the planet early on New Year’s Eve. Related to this, meteorologists are forecasting excellent viewing of the Northern Lights on New Year’s Eve this year as far south as Chicago or San Francisco.
The National Oceanic and Atmospheric Administration breaks up solar storms into a scale of one to five (with five being the strongest). The solar event due to hit in the next 24 hours is classified as a G3 storm, and could lead to fluctuations in some power grids, occasional radio blackouts at higher latitudes and some GPS issues are also anticipated.
More on New Year’s Eve solar storm
A solar storm can be caused by a solar flare or the aftereffect of a coronal mass ejection (CME) by the sun. Solar flares (charged protons and electrons) travel faster than CMEs, but when either reach Earth, the particles interact with the magnetic field to create the dazzling colors of the Aurora Borealis (Northern Lights).
NOAA’s Space Weather Prediction Center projects that the “strong” New Year’s Eve storm could mean the Northern Lights will be visible as far as southern Oregon and Illinois.
“It’s certainly possible,” Terry Onsager, an NOAA physicist, said in an interview with local media regarding the chance the Bay Area sees the Northern Lights on New Year’s Eve. “It depends entirely on the strength of the storm. If it turns out to be stronger than that, it could be seen.”
Onsager continued to note: “The whole earth’s magnetic system is embedded in this flowing ‘battery,’ and that is what drives the electric currents around us.”
Details on solar events
Solar flares and CMEs are different solar events, but they are ultimately caused by the same magnetic phenomenon. When the magnetic activity of the sun is fluctuating strongly, the internal magnetic field bursts through the sun’s photosphere (surface). This exposes the inner sun, which is actually cooler than the sun’s chromosphere (the next layer above the photosphere) and corona (the sun’s extended very hot atmosphere). That is why the magnetically active areas on the sun are seen as clusters of dark spots commonly known as “sunspots.”
When the magnetic field lines are forced together above sunspots, a phenomenon called magnetic reconnection occurs and the solar plasma is flung out at near-relativistic speeds together with an intense burst of radiation. These solar flares can hit the Earth in just a few minutes.
CME’s, on the other hand, are something along the lines of giant bubbles of magnetized high-energy plasma that are ejected into space at high speeds, but not at the near-relativistic speeds of solar flares. The speed that CMEs travel varies dramatically. Astronomers highlight that a CME from the sun can reach Earth’s atmosphere in anywhere from several hours to a few days, depending on the size and pressure of the plasma bubble when it burst.