Using amateur radio to validate model‐based properties of earth's protective shield

Amateur radio has the capability of assisting researchers with the validation process of model‐based studies of the magnetosphereionosphere (M‐I) system. Over the years many model‐based studies have demonstrated that several key M‐I systems exhibit a Universal Time (UT) dependence. Our recent study shows that the dayside of the open/closed boundary of the geomagnetic field exhibits a UTdependent variation. We demonstrated that this variation can be as much as 15 degrees in latitude. Recent results have shown that the proton energy cutoff latitude for protons with energy between 1‐20 MeV shows a significant UT‐dependent variation. This variation could have important consequences related to predicting the level of high frequency (HF) absorption in the D‐region of the ionosphere during so‐called polar cap absorption (PCA) events. HF communication continues to be of considerable importance in and around earth's Polar Regions. Commercial aviators use HF radio communications during transpolar flights. During PCA events it is critical that commercial airlines have up‐to‐date information regarding HF communication forecasts to properly route their aircraft to ensure crewmember and passenger safety. Generating observational evidence for this suggestion is particularly challenging. A ground station is by definition located at one longitude. Hence, a unique UT and Local Time (LT) are associated with its location. Therefore, many ground‐based sites would be needed to have long‐term data sets such that the UT dependence could be separated from space weather effects. Satellites perhaps have a better likelihood to have data streams capable of identifying the cutoff latitude, but this would require large satellite constellations coordinated in such manner that the spacecraft would be near the polar cusp region simultaneously. Such a constellation does not yet exist. Amateur radio could assist with gathering observational data to test the model‐based results. Using existing systems such as WSPRnet it could be possible to gather HF propagation data near earth's Polar Regions during quiescent times as well as during PCA events. The newly‐proposed Personal Space Weather Station could prove useful. Over time, a substantial data set could exist that would allow examination of the proposed UT‐dependent variation. This presentation will discuss the model‐based results and potential amateur radio involvement.