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LOFAR Observations of Substructure Within a Traveling Ionospheric Disturbance at Mid-Latitude
| Author | Dorrian, Gareth; Fallows, Richard; Wood, Alan; Themens, David; Boyde, Ben; Krankowski, Andrzej; Bisi, Mario; browski, Bartosz; Vocks, Christian; |
| Keywords | Parker Data Used; traveling ionospheric disturbance; ionospheric scintillation; LOw frequency ARray |
| Abstract | The large scale morphology and finer sub-structure within a slowly propagating traveling ionospheric disturbance (TID) are studied using wide band trans-ionospheric radio observations with the LOw Frequency ARray (LOFAR; van Haarlem et al., 2013, https://doi.org/10 .1051/0004-6361/201220873). The observations were made under geomagnetically quiet conditions, between 0400 and 0800 on 7 January 2019, over the UK. In combination with ionograms and Global Navigation Satellite System Total Electron Content anomaly data we estimate the TID velocity to \ensuremath\sim60 ms$^-1$, in a North-westerly direction. Clearly defined substructures with oscillation periods of \ensuremath\sim300 s were identified within the TID, corresponding to scale sizes of 20 km. At the geometries and observing wavelengths involved, the Fresnel scale is between 3 and 4 km, hence these substructures contribute significant refractive scattering to the received LOFAR signal. The refractive scattering is strongly coherent across the LOFAR bandwidth used here (25-64 MHz). The size of these structures distinguishes them from previously identified ionospheric scintillation with LOFAR in Fallows et al. (2020), https://doi.org/10.1051/swsc /2020010, where the scale sizes of the plasma structure varied from \ensuremath\sim500 m to 5 km. |
| Year of Publication | 2023 |
| Journal | Space Weather |
| Volume | 21 |
| Number of Pages | e2022SW003198 |
| Section | |
| Date Published | jan |
| ISBN | |
| URL | |
| DOI | 10.1029/2022SW003198 |
