Find in Library

<p>In this work, the results of the analysis on total electron content (TEC) data before, during and after the geomagnetic storm of 8 September 2017 are reported. One of the responses to geomagnetic storms due to the southern vertical interplanetary magnetic field (<span class="inline-formula"><i>B</i>_<i>z</i></span>) is the enhancement of the electron density in the ionosphere. Vertical TEC (VTEC) from the Center for Orbit determination in Europe (CODE) along with a statistical method were used to identify positive and/or negative ionospheric storms in response to the geomagnetic storm of 8 September 2017. When analyzing the response to the storm of 8 September 2017 it was indeed possible to observe an enhancement of the equatorial ionization anomaly (EIA); however, what was unexpected was the identification of a local TEC enhancement (LTE) to the south of the EIA (<span class="inline-formula">∼40</span><span class="inline-formula">^∘</span>&thinsp;S, right over New Zealand and extending towards the southeastern coast of Australia and also eastward towards the Pacific). This was a very transitory LTE that lasted approximately 4&thinsp;h, starting at <span class="inline-formula">∼</span>&thinsp;02:00&thinsp;UT on 8 September where its maximum VTEC increase was of 241.2&thinsp;%. Using the same statistical method, comparable LTEs in a similar category geomagnetic storm, the 2015 St. Patrick's Day storm, were looked for. However, for the aforementioned storm no LTEs were identified. As also indicated in a past recent study for a LTE detected during the 15 August 2015 geomagnetic storm, an association between the LTE and the excursion of <span class="inline-formula"><i>B</i>_<i>z</i></span> seen during the 8 September 2017 storm was observed as well. Furthermore, it is very likely that a direct impact of the super-fountain effect along with traveling ionospheric disturbances may be playing an important role in the production of this LTE. Finally, it is indicated that the 8 September 2017 LTE is the second one to be detected since the year 2016.</p>