A new study revealed that the Gannon Solar Storm in May 2024 caused over $500 million in damages to U.S. farmers, primarily in the Midwest, by disrupting GPS-guided farming equipment during peak planting season. GPS errors reached up to 230 feet for about six hours on May 10, with lingering issues for two days, causing errors of up to 30 feet during auroral activity. This led to delayed corn and soybean planting, with 70% of U.S. farmland relying on GPS precision, resulting in yield losses and invalidation of multiyear field experiments. Terry Griffin, a Kansas State University agricultural economist, noted the financial impact was significant, with some farms facing up to $17,000 in losses. The storm, the strongest in 20 years, highlighted vulnerabilities in precision agriculture, with no viable contingency plans for many farmers.
Here are the full details:
The Solar Event:
- When: From May 8 to 13, 2024, during Solar Cycle 25, with the most intense period occurring around May 10-11.
- What: A series of powerful solar flares (including multiple X-class flares, the strongest type) and coronal mass ejections (CMEs) were launched from a sunspot region (NOAA AR3664) towards Earth.
- Severity: The geomagnetic storm that resulted from these CMEs was classified as a G5, the highest level on NOAA's geomagnetic storm scale.
It was the most powerful to affect Earth since March 1989 and one of the strongest on record in the past 500 years by some measures. - Effects on Earth: The storm caused brilliant auroras visible at unusually low latitudes (even in the southern U.S. and northern India), disrupted shortwave radio communications, and significantly affected GPS signals.
Impact on Farmers and Agriculture:
- GPS Dependence: Approximately 70% of planted acreage in the United States uses GPS-guided equipment for precision agriculture tasks like planting, spraying, and fertilizing.
This technology allows for highly accurate parallel lines, efficient input application, and data logging. - GPS Outages: During the Gannon storm, GPS signals were thrown off by hundreds of feet in some regions.
In central U.S. states, errors reached up to 230 feet (70 meters), and even in southwestern parts, errors of up to 65 feet (20 meters) were reported. These errors made GPS-guided tractors "mostly inoperative" or caused them to "veer off course." - Delayed Planting: The timing of the storm was critical, as it occurred during the peak planting season for many crops in the Midwest.
Farmers relying on GPS were forced to suspend planting activities, leading to delays. - Economic Losses:
- Direct Losses: The delay in planting led to an estimated $500 million in losses for American farmers, with some individual farms losing around $17,000 each.
This is because late planting can result in reduced crop yields and lower revenue per acre. - Data Loss: Beyond immediate planting delays, the lack of GPS for logging georeferenced farm data (e.g., as-planted, as-sprayed data) means farmers cannot accurately map yields, analyze on-farm experiments, or participate in third-party data services.
This could have long-term negative impacts on farm management and profitability.
- Direct Losses: The delay in planting led to an estimated $500 million in losses for American farmers, with some individual farms losing around $17,000 each.
- Vulnerability: Larger farming operations, which tend to be more highly dependent on satellite positioning and precision agriculture technology, were more vulnerable to these disruptions.
- Mitigation: While farmers cannot stop solar storms, some experts suggested measures like having physical row markers as a backup or waiting for the storm to pass.
The event highlighted the need for more resilient GPS systems and for farmers to be aware of space weather forecasts.
New Study Details:
- The new study that quantified these damages analyzed data not only during the height of the storm but also in its aftermath, when lingering aurora continued to skew GPS signals.
- It revealed that the storm created a "wall of ionospheric plasma" across the North American continent, which was responsible for throwing off GPS signals so significantly.
- The study was published in the journal JGR-Space Physics on June 9 (year not specified, but context suggests 2025).
This event served as a stark reminder of the increasing vulnerability of modern, technology-dependent sectors like agriculture to space weather phenomena, especially as the sun approaches its solar maximum in 2025, increasing the likelihood of more powerful solar storms.