Terry Griffin, a precision agriculture economist with Kansas State University Research and Extension, has a question for you – “How would your farm operate if you didn’t have access to GPS? And do you even have a Plan B?” Griffin asks because he has been investigating the potential impacts of “space weather” on the agriculture industry, which could be at risk if satellites are knocked out.
We’ve run a few articles about space weather in the report before but Griffin’s research is specific to precision agriculture equipment. Many of these systems utilize Global Navigation Satellite Systems (GNSS), such as the Global Positioning System (GPS). Griffin’s research is supported in part by the Aerospace Corporation under an initiative to better understand the risks presented by “ionospheric disruptions”, and how to communicate those challenges to end users. The first focus area chosen was precision navigation systems with an emphasis on the precision agriculture user community.
Precision agriculture can involve both terrestrial and aviation equipment. Various field equipment, such as tractors, often rely on GPS for precision position, navigation, and timing data. Furthermore, both crewed aircraft and uncrewed aerial systems (UAS) are used for various applications, such as aerial spraying of pesticides or fertilizer, surveying, and crop monitoring.
Griffin says that end users may not be aware of the contribution of space weather on system anomalies and/or issues they may be experiencing. The sun is the main source of space weather. Two phenomena that can produce intense energy releases are solar flares and coronal mass ejections (CME). Solar flares, the largest explosive events in the solar system, release energy in the form of radiation traveling at the speed of light and more slowly traveling plasma. The other type of intense energy releases, CME’s, consist of massive high-density bubbles of plasma containing a billion tons of material.
While the sun’s energy is released constantly, it can vary significantly depending on the current stage of its approximately 11-year cycle. During periods of solar cycle maximum conditions, the probability of large solar storms and disturbances is increased. The current cycle — solar cycle 25 — began in December 2019, and solar activity is expected to ramp up until the predicted solar maximum in 2025. Solar flares and CME events occur a few times per week during solar minimum to a few per day at peak solar activity.
Earth’s magnetic field provides some protection against the solar wind and CME materials, but enough solar wind energy enters the near-Earth space environment to produce a variety of space weather effects. Heightened solar activity poses a risk to electricity grids and can interfere with high-frequency radio communications. It can also adversely affect global navigation satellites that provide things like GPS, resulting in cycle slips and loss of signal loss.
Griffin notes that due to the cyclical nature of agriculture, an outage of GNSS would have different effects on agriculture depending on what time of year the event occurred. While a GNSS outage during harvest may not stop harvest operations, the georeferenced yield data will not be collected, which could impact next-year planning, as well eligibility for various programs. An outage occurring during spraying time or planting time may result in the operator opting to not continue activity due to lack of guidance, especially if VM guidance alternatives are not available, having a much greater impact on the final yield.
To give some insight into regional impacts from a period of complete GNSS outage, example loss was estimated using 2004 data. “If we assume that we lose GNSS access for an entire year, it could be a billion dollar loss in efficiency just for the Midwest,” Griffin said. That’s an extreme example, of course, but even brief outages can cause significant disruptions. “We would have inefficiencies. We can still do some things, but just not as efficiently. Add all those (inefficiencies) up across large regions, and it becomes a lot of money.”
Griffin says he isn’t suggesting that farmers go back to using row markers, but he does think it’s extremely important to consider that initial question – what would you do if you didn’t have access to GPS? “I am suggesting having a conversation with their partners, service providers, manufacturers, and dealers about things they can actually get done if they don’t have GPS,” Griffin adds. You can check out Griffin’s work HERE. Producers can also sign up to receive space weather email watches, warnings, alerts and more from the NOAA’s Space Weather Prediction Center (SWPC) HERE.
