Global Distribution of Persistence of Total Electron Content Anomaly

Yang-Yi Sun,Chieh-Hong Chen,Jann-Yenq Liu,Tsung-Yu Wu

doi:10.3390/atmos10060297

Abstract

To better understand the ionospheric morphology response to lithospheric activities, we study the global location preference of the positive and negative total electron content (TEC) anomalies persisting continuously for longer than 24 h at middle and low latitudes (within ±60° N geomagnetic latitudes). The TEC is obtained from the global ionospheric map (GIM) of Center for Orbit Determination in Europe (CODE) under the geomagnetic quiet condition of Kp ≤ 3o during the period of 2005 to 2018. There are a few (less than 4%) TEC anomalies that can persist over 24 h. The conjugate phenomenon is most significant in the eastern Asia to Australia longitudinal sector. The result shows the persistence of the positive TEC anomaly along the ring of fire on the western edge of the Pacific Ocean. The high persistence of the TEC anomalies at midlatitudes suggests that thermospheric neutral wind contributes to the anomaly formation.

Highlights

It has been known that ionospheric structures are highly variable under both geomagnetic disturbed and quiet conditions because the drivers, such as electric field, neutral wind, pressure gradient, and gravity, can transport the ionospheric plasma [1]
Better knowing the global distribution of persistence of total electron content (TEC) anomalies makes the connection between lithospheric activity and ionospheric morphology at different places of the world beneficial
1 and 2 show an event of a TEC anomaly continuously appearing over a certain location for more than 1one

Summary

Introduction

It has been known that ionospheric structures are highly variable under both geomagnetic disturbed and quiet conditions because the drivers, such as electric field, neutral wind, pressure gradient, and gravity, can transport the ionospheric plasma [1]. Solar activity can disturb the ionosphere globally and induce ionospheric weather phenomena that transit rapidly through a large area [2,3]. Lithospheric activities that occurred near the surface can possibly induce the anomaly of ionospheric plasma over a certain location. The TEC anomalies may have a geographical preference if the lithospheric activity is capable of maintaining a TEC anomaly above a certain area. Better knowing the global distribution of persistence of TEC anomalies makes the connection between lithospheric activity and ionospheric morphology at different places of the world beneficial. The above facts motivate us to study the geographical preference of the TEC anomalies. Thenowcasting, above facts and motivate to thestudy rapidly changing ionospheric weather that critically impacts high accuracy positioning, navigation, the geographical preference of the TEC anomalies. The TEC in the GIM derived from the Global Navigation Satellite

Data and Methodology

12 January

The positive

Discussion

Conclusions