Plasmaspheric Electron Content Inferred from Residuals between GNSS-Derived and TOPEX/JASON Vertical TEC Data

Lei Liu,Jian Kong,Lulu Shan,Yibin Yao

doi:10.3390/rs10040621

Lei Liu, Jian Kong + Show 2 more

Open Access

https://doi.org/10.3390/rs10040621

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Abstract

The plasmasphere, which is located above the ionosphere, is a significant component of Earth’s atmosphere, and the plasmasphere electron content (PEC) distribution is determined by different physical mechanisms to those of the ionosphere electron content (IEC). However, the observation for the PEC is very limited. In this study, we introduced a methodology (called zero assumption method, which is based on the assumption that PEC can reach zero) to extract the PEC over TOPEX/JASON (T/J) and global navigation satellite system (GNSS) overlapping areas. Results show that the daily systematic bias (T/J vertical TEC > GNSS-derived vertical TEC) for both low (2009) and high (2011) solar activity condition is consistent, and the systematic bias for JASON2 and JASON1 is different. We suggest that systematic biases predominantly arise from the sea state bias (SSB), especially the tracker bias. After removing the systematic bias, we extracted reliable PEC inferred from differences between GNSS-derived vertical TEC and T/J vertical TEC data. Finally, the characteristics of the plasmaspheric component distribution for different local times, latitudes, and seasons were investigated.

Highlights

The plasmasphere is located where the ionosphere and magnetosphere meet and contains relatively dense and low energy plasma
Results show that the daily systematic bias (T/J vertical TEC (vTEC) > global navigation satellite system (GNSS)-derived vTEC) for both low (2009) and high (2011) solar activity condition is consistent, and the systematic bias for JASON2 and JASON1 is different
We suggest that systematic biases predominantly arise from the sea state bias (SSB), especially the tracker bias

Summary

Introduction

The plasmasphere is located where the ionosphere and magnetosphere meet and contains relatively dense and low energy plasma. The plasmasphere density distribution is determined by different physical mechanisms to those of the ionosphere, and the existence of the plasmasphere makes it difficult to interpret data from ionospheric measurements [3] Despite these difficulties, many efforts and approaches have been proposed to estimate PEC and identify the plasmaspheric contribution to the ionosphere total electron content (TEC). Belehaki et al [13] extracted PEC from residuals between GPS-derived TEC and ground-based ionosonde IEC at Athens, showing that PEC exhibits a diurnal variation with a morning minimum and an evening maximum, and that PEC contribution describes the significance of the plasmasphere to the ionosphere, especially during the night. The characteristics of the plasmasphere component for different local times, latitudes, and seasons were investigated

GNSS-Derived vTEC Data and JASON vTEC Data

Data Processing and Analysis

Characteristics of the Plasmasphere

Findings

Discussion

Conclusions