Solar Storms Could Knock Out GPS, Scientists Warn

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A massive explosion on the surface of the sun on Aug. 9 sent a wave of radiation sweeping outward into space in a scene that will likely spell intermittent trouble for GPS approaches and satellite-based communications for the next decade or perhaps longer, according to scientists.

It was the largest solar flare since 2006 and heralded the coming of an active solar storm season, the National Business Aviation Association warned on its website.

Although the Aug. 9 flare wasn’t aimed at the Earth, Joe Kunches, a scientist at the National Oceanic and Atmospheric Administration (NOAA), told the Los Angeles Times, “We are now seeing more eruptions this year and we will see even more the year after that. They are going to get bigger and they are going to get more frequent.”

The eruptions could cause temporary disruptions in signals from global positioning satellites, making GPS approaches sometimes unreliable, a story on the NBAA website stressed.

Kunches predicted the solar cycle just now beginning will likely be “in the moderate to strong level,” and will likely peak in 2013. Before the decade ends, NOAA predicts four “extreme” solar storms could disrupt GPS navigation and lead to power outages and communications disruptions.

NBAA warns that solar radio bursts can drown out GPS signals with so much background noise that Earth-based receivers have difficulty picking them up. Wide-Area Augmentation Systems (WAAS) receivers are unable to fully lock onto GPS satellite signals. FAA officials pointed out, however, that only vertical WAAS guidance is lost during solar bursts, while lateral guidance is unaffected.

The FAA is studying the effects of solar storms on GPS and WAAS systems. The agency points out that so far, even during some of worst solar storms, WAAS disruption has generally been minimal, although maintaining Approaches with Vertical Guidance (APV) has been a challenge.

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Submitted by Michele on August 18, 2011.

"FAA officials pointed out, however, that only vertical WAAS guidance is lost during solar bursts, while lateral guidance is unaffected."

Oh well then, that make me feel a lot better knowing that if I crash, it will be right on the center line.

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Submitted by SocalFlyer on August 18, 2011.

Wow, gee, solar flares increasing, what a revelation! We've only known about the 11-year sunspot cycle since, what, the 1840's?

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Submitted by DigDug on August 19, 2011.

Yeah, Socal, but we've only had GPS since 1994 -- meaning this is just the second full sunspot cycle we've experienced in the satnav era. Since we're are planning to base our entire air traffic control system on GPS, I'd say this is worth talking about.

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Submitted by usad on August 19, 2011.

HF is always noisy. Wonder what it will sound like now? !!!

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Submitted by air_n_water on August 19, 2011.

Ummm wonder if there is a fee from Garmin for this?

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Submitted by Mtweiss on August 19, 2011.

I can hear it now...the enviro terrorists trying to ban leaded avgas will hire Al Gore and argue that GA airplanes are causing "solar warming..."

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Submitted by Breakroom on August 20, 2011.

Well, The radiation MAY have adverse effect on satellites, but how much effect is unclear. The birds are shielded from these effects, and have redundant systems built in. Since science can't test how robust they are against strong gamma radiation, we will have to wait to see any effects. The built-in test programs will reveal this. Satty is cool.

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Submitted by RHalstead on August 21, 2011.

First, this is nothing new and scientists have been saying this for many years. His prediction of a strong solar cycle is contrary to predictions for a weak cycle peak based on indicators, but the important point is that no one knows for sure what each cycle is going to bring ahead of time. Also some of the largest CMEs have occurred during relatively inactive periods of sunspot activity.

There are Coronal mass Ejections (CMEs) and then there are CMEs. The strength varies by many orders of magnitude as does the speed.

In the past just a glancing blow from a CME took out a good portion of the power grid in Quebec. I think that may have been in 76 or thereabouts.

Earth directed CMEs are rare, but they do happen. A direct hit from an X-Class CME would do far more than affect vertical guidance and would likely wipe out satellites in the direct path. They could easily affect the electronics in aircraft rather than just provide an increase in background noise. Also, high flying aircraft could find themselves in a very hostile environment that they would want to vacate in a hurry.

CMEs present a very serious threat to GPS, aircraft, the occupants of high flying aircraft, and our power grid. A direct hit from an X-10 CME would likely be similar to a large EMP destroying many of the transformers in our power grid. Transformers that could take many months to replace. Solid state equipment could also be destroyed. Stereo will hopefully give us time to actually shut down the power grid to prevent its destruction, but at a cost estimated to be in the Billions of dollars, but the savings would be far greater.
High sunspot activity *usually* means that upper range HF signals will be strong world wide while lower HF in the 3 to 10 MHz range will end up short range, but during disturbed conditions the entire HF range can and does end up useless. During strong solar activity the VHF range may take on the characteristics of normal upper range HF, meaning propagation for thousands of miles. The effect of the solar cycle is complex and varies widely between normal and disturbed conditions.

The point they article seems to neglect is that sooner or later we will take a direct hit from a large X-Class CME which could easily disable the power grid nation wide, or even world wide and permanently disable even hardened satellites, but at that point GPS loss might be the least of our worries.

At least the solar monitoring satellite system, "Stereo" gives us a good figure as to speed and direction of CMEs and flares. It also finally gives us a complete 360 degree view of the sun's surface.

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Submitted by RHalstead on August 21, 2011.

Another point that should be taken into consideration is the Earth's magnetic field has been losing strength. That field protects us from solar radiation and in particular CMEs. There is a spot in the South Atlantic called the South Atlantic Anomaly http://en.wikipedia.org/wiki/South_Atlantic_Anomaly. "The South Atlantic Anomaly (SAA) refers to the area where the Earth's inner Van Allen radiation belt comes closest to the Earth's surface. This leads to an increased flux of energetic particles in this region and exposes orbiting satellites to higher than usual levels of radiation. The effect is caused by the non-concentricity of the Earth and its magnetic dipole, and the SAA is the near-Earth region where the Earth's magnetic field is weakest." In general it appears the earth's magnetic field is weakening which allows radiation to get closer to the surface. This means satellites and high flying aircraft are exposed to much more radiation than they would have been in the past. These can easily reach dangerous levels for passengers and crew let alone the high flying satellites with CMEs

The point is that CMEs are becoming far more dangerous due to the reduction in the strength of the earth's magnetic field.