Ray-tracing simulation and experiment of High-Frequency radio wave between McMurdo Station SuperDARN and e-POP during the December 4, 2021 eclipse

In this work, we will present a comparison between High Frequency (HF; 3-30 MHz) ray-tracing simulations and the data collected by the Radio Receiver Instrument (RRI) on the Enhanced Polar Outflow Probe (e-POP) for an observation campaign centered on the December 4, 2021 total solar eclipse in Antarctica. Specifically, we analyze the Doppler shift between the McMurdo Station Super Dual Auroral Radar Network (SuperDARN) system and RRI at 10.3 MHz during the eclipse along with several other conjunctions between November 29 and December 11, 2021. Of note in our analysis is the implementation of a 3D HF ray tracing honing algorithm. This algorithm significantly increases the simulation efficiency and accuracy and allows us to set a 100 m receiving zone centered at e-POP locations, which approximately equates to 3 Hz uncertainty in Doppler frequency.

Of the 18 conjunctions between SuperDARN and e-POP from November 29 to December 11, two occurred on the day of the eclipse—December 4, 2021, occurring from 06:54:15 to 07:04:12 UT (first conjunction) and 8:36:15 to 8:46:12 UT (second conjunction). We use the other 16 conjunctions as a baseline reference for the eclipse passes and to provide overall context to the measurements from the campaign. The Provision of High-Frequency Raytracing Laboratory (PHaRLAP) toolbox is used to ray trace through a SAMI3 simulation of the region for December 4 (a simulated eclipse and non-eclipse case are considered) and the other baseline passes, while the geomagnetic field is generated by International Geomagnetic Reference Field (IGRF) 2016 model. Our preliminary results show good agreement between the simulations and observations, with some moderate differences, which will be discussed in our presentation.