Solar storms don't just trigger impressive auroras; they can quietly interfere with the technological world, and for U.S. farmers, this disruption can mean huge financial losses, especially for one major crop: peanuts. The invisible turbulence in the Earth's magnetic field has the power to determine the fate of your next peanut butter sandwich, putting over $100 million in crops at risk.
The Peanut Problem
In the modern world of precision agriculture, farmers rely heavily on Global Navigation Satellite System (GNSS) signals, specifically high-precision Real-Time Kinematic GPS (RTK GPS), which provides sub-centimeter accuracy. While many crops benefit from this technology, peanuts are uniquely vulnerable to solar disruptions.
Peanuts are planted in neat rows, but once the plant canopy grows, the nuts themselves are hidden below the soil. Farmers cannot see where the rows are anymore, making it imperative that they measure the planting path with RTK GPS to ensure they can accurately dig up the crop months later.
According to agricultural economist Terry Griffin, whose research is currently under peer review, any significant degradation of the RTK signal during planting or harvesting means the farmers can't follow the invisible rows, leading to a major yield hit. If farmers do not have their RTK GPS, they stand to lose at least 11% of their production by simply leaving nuts in the ground.
The Perfect Storm and the Million-Dollar Choice
The threat became a reality on May 10, 2024, when the first G5 geomagnetic storm in over 20 years, known as the Gannon Storm, slammed into Earth. The storm, which caused spectacular auroras, also caused GPS-guided tractors in the southeastern U.S. to veer off course, with farmers reporting their autoguidance systems jolting, freezing, and steering erratically.
The timing of this storm was critical, as it struck during the peak peanut planting season. Griffin described it as a "perfect storm," noting that if it had occurred a month earlier, it would have been a non-issue.
When GNNS outages strike, peanut farmers face a costly binary choice:
Continue Planting: Risk misaligned digging months later and face the guaranteed 11% yield penalty.
Stop Planting and Wait: Risk a "biological penalty" by losing precious growing time (heat-unit accumulation) for the crop, which can lead to lower quality and overall yield reduction.
Griffin’s modeling suggests that mistimed decisions could put over $100 million worth of peanut production at risk across the southeastern U.S. In the worst-case timing scenarios, nearly 262 kilotons (577 million pounds) of peanuts destined for human consumption could be lost.
The Need for 'Duration Nowcasts'
The fundamental challenge for farmers is the uncertainty surrounding the length of the outage. A GPS hiccup could last two hours or two days, and the lack of a clear forecast forces farmers to resort to their default—a decision that can be financially disastrous.
To address this, Griffin proposes a new kind of space weather forecast: duration "nowcasts." These short-term predictions would inform farmers of how long RTK-level GPS will be unavailable, allowing them to make the optimal decision: whether to wait or continue operations.
His analysis showed that waiting was generally the optimal choice early in the planting window, while continuing was favored later. The economic value of accurate space weather nowcasts is estimated to be worth $33 million annually for the broader U.S. Southeast agriculture sector—roughly 5% of the total peanut crop value and more than double the economic value typically attributed to terrestrial weather forecasts.
To ensure adoption, Griffin believes these alerts should be delivered through the tools farmers already use, such as their weather apps, alongside simple, in-cab warnings in their equipment to signal when the GPS signal is not trustworthy.
The Turning Point
The May 2024 Gannon Storm was a turning point. As Griffin noted, "May 9 was a different world than on May 11. On May 11, the awareness dramatically increased." Before that weekend, the threat of a widespread GPS outage was often met with skepticism.
The event was the first real-world test of how a severe geomagnetic storm affects the two-thirds of the nation's planted acres that now rely on satellite navigation. This is because high-precision GPS wasn't widely used on farms until the end of a previous solar cycle, and the following cycle was relatively quiet.
Moving forward, the focus is on preparation. New satellites, such as NOAA’s SWFO-L1 satellite observatory and NASA’s IMAP, are set to improve monitoring and forecasting. Scientists hope to deliver clear, actionable guidance that agriculture has never had before: knowing how long a space weather outage will last, and what farmers can do to protect the $100 million worth of peanuts in the ground.