Center for Astrophysics Research and Technologies Seminar Series
The seasonality of radio wave attenuation through the ionosphere
Presented by Paul Greninger, UNM
I will discuss the seasonal RF attenuation observed by the Demeter Satellite. Using the Quasi Longitudinal (QL) approximation in Appleton's equations, two cases are explored, the Straight Up model and the Crary model. In the Straight Up model waves are launched straight up into the ionosphere. In the Crary model waves are launched from a dipole configuration more resembling the VLF transmitters around the globe used to communicate with submarines. Spatial inputs to the program are latitude and longitude. The temporal inputs are the year, day of year, and time of day. Four cases will be explored using four different VLF transmitters for both day/night and summer/winter. The resulting pattern will be un-mistakable, and will overlay well with the Demeter data. The results conclude that in the Northern hemisphere there is more attenuation in July-August vs. January-February day and nights, while in the Southern hemisphere the pattern is reversed. Applying the Crary Model aligns better with the seasonal attenuation with Demeter data.
2:00 pm, Thursday, April 16, 2015
PAIS-2540, PAIS
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