What is Space Weather and Why You Should Care
Part 1: Geomagnetic Storms
In creating this article, I draw heavily from NOAA (National Oceanic and Atmospheric Administration) and NASA (National Aeronautics and Space Administration) material – references supplied. This is essentially a simplification of certain technical aspects of Space Weather designed to impart a rudimentary understanding and inspire further research. Or, to be flippant, it’s the reason why the answer to “Can you hear me now?” may be “No.”
We are all thoroughly acquainted with weather here on Earth. Sunny or cloudy, wet or dry, windy or still, we all know weather. Here in New Mexico, you’ll often here someone joke, “We don’t have a climate. We have weather.” But space weather? What is space weather? Straight from the SOHO (Solar and Heliospheric Observatory) website, here’s the definition of space weather: “Conditions on the Sun and in the solar wind, magnetosphere, ionosphere and thermosphere than can influence the performance and reliability of space-borne and ground-based technological systems and can endanger human life or health.”
If you’re like most, when you read the definition, you simply accepted the first part at face value. “Conditions on the Sun and in the solar wind, magnetosphere, ionosphere and thermosphere” (SOHO, 2010). Sure, okay, that makes sense. But then you got to the next part and thought, “Wait. Space weather can impact “ground-based technological systems… and endanger human life” (SOHO, 2010) really? Really.
Here’s some background. Our planet’s atmosphere is made up of layers. Even the Planet itself is composed of layers, but for our purposes today, we don’t need to think much beyond the fact that we live our lives on the lithosphere – the uppermost layer of the earth’s crust. Around and above us are the gaseous layers of the atmosphere that provide us with the air we breathe and the outer layers of the atmosphere that protect us from the stuff that goes on in the rest of the universe.
Around the whole atmospheric package is the magnetosphere (of which the plasmasphere is a part). This magnetic field, working in conjunction with the rest of our atmosphere, protects us from the effects of space weather and serves as a buffer for burning up bits of space trash and tiny asteroids before they can reach the surface of our planet. Pretty spiffy, eh? The magnetic field of our planet looks something like this:
Some people think the whole affair taken together is reminiscent of the shape of a jellyfish. And I’m inclined to agree. As in most things in the natural world, forms follows function. And since the earth moves through space in much the same way that a jellyfish moves through water, it’s not so surprising.
So, now that we’ve looked at the basic structure of out atmosphere, it’s time to stick our heads outside of it and have a look at space weather and why having a basic understanding of it can be important.
Our sun is not constant. It is an ever changing star that, like all other stars, is constantly emitting various types of radiation, radio signals, geomagnetic impulses and making solar wind. People in the northern hemisphere routinely get to see the interactions of our magnetophere with solar particles in the form of auroras. These “geomagnetic storms” are routine occurrences. Scientists classify them according to their intensity – on a scale from G1 (minor) to G5 (extreme). For those of us without the gear to measure what’s going on in the upper atmosphere, we can gauge the intensity of a geomagnetic storm by how far south the aurora is visible. The greater the storm, the further south that people will see the aurora. The greater the storm, the greater potential for disruptions here on the surface.
G1 intensity (“G” for “geomagnetic”, as opposed to “R” for “radio blackouts” caused by x-ray emissions and “S” for “solar radiation”) is also called “Minor.” So, if you hear on the radio that there was a minor geomagnetic event, you’ll know what they’re really telling you. These storms happens about 1700 times per cycle. Solar time is measured in cycles. A “cycle” equals 11 years. Coincidentally, for you 2012 folks, the next cycle begins right about when the Mayan calendar ends. “I ain’t sayin’, but I’m just sayin’.”
Anyway, G1’s happen about 1700 times per cycle. That works out to a G1 event about every 2.36 days – or one every 56-57 hours. But that’s an average. G1 events can cause minor fluctuations in the power grid and have some slight impact on satellite operations. They can also impact the navigation abilities of migratory animals. During a G1, the aurora will be visible at high latitude – like in Maine and Michigan (NOAA, 2010).
A G2 storm is referred to as “Moderate.” These storms happen about 600 times per solar cycle – about once every 6.69 days. Power system in higher latitude may experience voltage alarms. Longer duration G2 events may damage transformers. For our folks in space, it may be necessary for ground control to initiate corrective actions to orientation as potential changes in drag effect impact orbit predictions (NOAA, 2010). HF radio propagation will suffer at higher latitudes. The aurora will be visible as far south as New York and Idaho.
A G3 event is called “Strong.” These events happen about 200 times every cycle – or about once every three weeks or so. They can require voltage corrections to the power grid and even trigger false alarms on protective devices like home and car alarms. During a G3, satellites in low-Earth orbit (LEO) experience increased drag and surface charging can occur on satellite components. Surface charging… think static electricity on a bigger scale. Now, remember that satellites that handle phone communications are in low-Earth orbits. There will be intermittent issues with satellite navigation systems (yep, that your Garmin or Magellan device), HF radio signals will be intermittently disrupted. The aurora will be visible as far south as Illinois and Oregon.
G4 is a “Severe” geomagnetic storm. These events happen, on average, about once every 40 days. During a G4, power grids can experience widespread voltage control problems. Some protective grid systems may mistakenly trip causing temporary blackouts. Spacecraft will experience surface charging (so no spacewalks, guys) and tracking problems. Orientation correction may be required. On the ground, HF radio propagation will be sporadic at best. Satellite nav systems will be useless for hours (hope you have a paper map & some directions). Low frequency radio nav beacons will be disrupted. So, if you’re lost and you activate your personal nav beacon you spent all that money on, it might not work. The aurora will be visible as far south as Alabama and northern California.
A G5 is an “Extreme” geomagnetic event. These things happen only once every handful of year – seriously, only once every three or four years on average. On the power grid, there will be widespread voltage control problems. Some grid systems may collapse or experience blackouts. Transformers may be damaged. Spacecraft will experience substantial surface charging, orientation and uplink/downlink issues. On the ground, HF radio propagation may be impossible in many areas for several days. Satellite navigation will be useless for several days. The grid may experience huge voltage spikes. You can pretty much forget making a clear cell phone call, or updating your Facebook from your iPhone for a while. The aurora can been seen as far south as Florida and Texas.
Yeah, but… does this stuff really happen? You bet it does. On March 13, 1987 a HUGE geomagnetic disturbance (GMD) caused what is now known as the Hydro-Quebec Blackout. The blackout lasted nine hours and the GMD caused extensive damage to transformers and grid surge arrestors. Anecdotal evidence suggest that the aurora was seen as far south as Jamaica that day. That would put the event off the charts as these things go. Since it was 1987, none of us had smartphones and most cell phones weren’t exactly pictures of reliability. So, to try to determine the impact on cell communications and satellite navigation would be speculative at best. But I think you get the idea.
Further (and spookier still) is a paper submitted on December 16, 2010 by G. Anagnostopoulos, A. Papandreou, P. Antoniou of Cornell University. They believe they have found a correlation between geomagnetic disturbances and massive earthquakes. From the abstract of their paper, “Solar activity influences seismic activity… through rapid geomagnetic disturbances.. related with increases of solar wind speed… Our analysis… suggests a mean time response delay of EQs [earthquakes] to fast geomagnetic disturbances of ~ 1.5 days” (Anagnostopoulos, Papandreou, and Antoniou, 2010). Yeah, he said it… one-and-a-half days between sudden shifts in solar wind, the accompanying GMD and strong earthquakes. Now if that isn’t a useful bit of preparedness info, I don’t know what is.
To sum it all up, our sun is a dynamic little critter. Its various emissions cause geomagnetic disturbances which can have an impact on how our tech toys function here on the ground. If the research pans out, these GMDs may even have an impact on how things shake out down here along faults and rifts. Because I’m geeky like that, I’ll be watching my solar weather more closely and comparing it to the earthquake updates I get from the USGS just to see if I can see for myself.
Here’s the thing: even if your batteries are charged, your electronic gizmo may not be reliable or even operational because of geomagnetic storms. Conventional radio communications may get dicey, depending upon the intensity of the GMD (and we haven’t even talked about solar storms or radio blackouts – yet). And even the power grid is susceptible to interruptions from these GMDs. Technology is just a veneer. Turn out the lights and we’re all just naked apes with sticks. Forewarned is forearmed.
Thanks for reading. You guys are the best.
Anagnostopoulos, G. A. Papandreou, P. Antoniou. “Solar wind triggering of geomagnetic disturbances and strong (M>6.8) earthquakes during the November – December 2004 period.” Cornell University. 2010. Retrieved from: http://arxiv.org/abs/1012.3585
NOAA Space Weather Prediction Center: http://www.swpc.noaa.gov/today.html
NOAA/NWS (National Weather Svc.) Space Weather Prediction Center http://www.swpc.noaa.gov/
Spaceweather.com http://www.spaceweather.com/ This site, while much more commercial than the previous two, also has some super links to JPL asteroid tracking and other interesting space-related info.
Solar and Heliospheric Observatory page on space weather http://sohowww.nascom.nasa.gov/spaceweather/ Good info presented in text as well as through videos, pictures and graphs (for the more visual among us). Tons of great space weather related links.
Solar and Heliospheric Observatory European page http://soho.esac.esa.int/ Has some additional links and cool downloads for the “citizen scientist” in all of us. There’s a solar study app you can download so you can study real time solar activity from the comfort of your living room.
Images courtesy of Encyclopedia Britannica © 2009, SOHO © 2010, NOAA ©2010, jellyfishes.com ©2010.