On The Properties Of And Ionospheric Conditions Associated With A Mid-Latitude Scintillation Event Observed Over Southern United States

While low and high-latitude ionospheric scintillation have been extensively reported, significantly less information is available about the properties of and conditions leading to mid-latitude scintillations. Here, we report and discuss scintillation observations made in the Southern United States (UT Dallas, 32.99 degrees N, 96.76 degrees W, 43.2 degrees N dip latitude) on June 1st, 2013. The measurements were made by a specialized dual-frequency GPS-based scintillation monitor which allowed us to determine main properties of this mid-latitude scintillation event. Additionally, simultaneous airglow observations and ionospheric total electron content (TEC) maps provided insight on the conditions leading to observed scintillations. Moderate amplitude scintillations (S-4>similar to 0.4) occurred in both L1 and L2C signals, and severe (S-4 > similar to 0.8) events occurred in L2C signals at low (<30 degrees) elevation angles. Phase scintillation accompanied amplitude fadings, with maximum sigma(phi) values exceeding 0.5 radians in L2C. We also show that the observed phase scintillation magnitudes increased with amplitude scintillation severity. Decorrelation times were mostly between 0.25 and 1.25 s, with mean value around 0.65 s for both L1 and L2C. Frequency scaling of S-4 matched fairly well the predictions of weak scattering theory but held for observations of moderate and strong amplitude scintillation as well. Scintillation occurred during the main phase of a modest magnetic storm that, nevertheless, prompted an extreme equatorward movement of the mid-latitude trough and large background TEC enhancements over the US. Scintillations, however, occurred within TEC and airglow depletions observed over Texas. Finally, scintillation properties including severity and rapidity, and associated TEC signatures are comparable to those associated with equatorial spread F.