A massive X-class flare blasted Earth today as a tempest on the Sun continues; while creating radio black-outs today, this solar disturbance could continue to impact the Earth significantly in the days ahead. An X1 class flare occurred at 1:37 pm ET today, March 30. According to NOAA’s Space Weather Prediction Center (SWPC), the flare source location was from the magnetically complex sunspot group, Region 2975. “Initial indications are this flare was associated with a new coronal mass ejection (CME) and SWPC forecasters are currently examining data to confirm any CME, and if verified, analyze further to determine whether there may be any Earth-directed component,” the SWPC said in a statement.
This same sunspot group has been the source of multiple M-class flares (R1 – Minor) over the past few days, with the strongest prior flare being an M4 at 28/1129 UTC. Yesterday’s sunspot is sending a cannibal CME to Earth late tonight and early tomorrow; this is the merging of two Earth-facing CMEs that’ll impact Earth as one. Due to that event, a Geomagnetic Storm Watch for a strong storm (G3) is up for tonight/tomorrow.
More than 17 solar flares erupted from the sun yesterday; 11 were C-class and 6 were M-class. Solar flares are giant explosions on the sun that send energy, light and high speed particles into space. These flares are often associated with solar magnetic storms known as coronal mass ejections (CMEs). Flares are ranked on a classification system that divides solar flares according to their strength. The smallest ones are A-class (near background levels), followed by B, C, M and X. Similar to the Richter scale for earthquakes, each letter represents a 10-fold increase in energy output. So an X is ten times an M and 100 times a C. Within each letter class there is a finer scale from 1 to 9. C-class and smaller flares are too weak to noticeably affect Earth. M-class flares can cause brief radio blackouts at the poles and minor radiation storms that might endanger astronauts. According to NASA, although X is the last letter, there are flares more than 10 times the power of an X1, so X-class flares can go higher than 9. NASA says the most powerful flare measured with modern methods was in 2003, during the last solar maximum, and it was so powerful that it overloaded the sensors measuring it. Those sensors cut out at X28.
If the SWPC determines yet another CME is headed towards Earth, they will issue Geomagnetic Storm Watches for it.
Coronal holes can develop at any time and location on the Sun, but are more common and persistent during the years around solar minimum. Coronal holes are most prevalent and stable at the solar north and south poles; but these polar holes can grow and expand to lower solar latitudes. It is also possible for coronal holes to develop in isolation from the polar holes; or for an extension of a polar hole to split off and become an isolated structure. Persistent coronal holes are long-lasting sources for high speed solar wind streams, also known as “CS HSS”. As the high speed stream interacts with the relatively slower ambient solar wind, a compression region forms, known as a co-rotating interaction region (CIR). According to the SWPC, from the perspective of a fixed observer in interplanetary space, the CIR will be seen to lead the CH HSS.
Strong CIRs and the faster CH HSS can impact Earth’s magnetosphere enough to cause periods of geomagnetic storming to the G1-G2 (Minor to Moderate) levels; although rarer cases of stronger storming may also occur.
While typically known for their weather forecasts, the National Oceanic and Atmospheric Administration (NOAA) and its National Weather Service (NWS) is also responsible for “space weather.” While there are private companies and other agencies that monitor and forecast space weather, the official source for alerts and warnings of the space environment is the Space Weather Prediction Center (SWPC). The SWPC is located in Boulder, Colorado and is a service center of the NWS, which is part of NOAA. The Space Weather Prediction Center is also one of nine National Centers for Environmental Prediction (NCEP) as they monitor current space weather activity 24/7, 365 days a year.