The present study explores the center‐of‐mass (Hc) of the ionosphere as the effective ionospheric varying shell height (VSH). We presents global ionospheric maps GIM‐Hc produced with IRI‐Plas model by assimilating the instant GIM‐TEC maps provided by JPL from 1994 to present which allows obtaining global maps of the F2 layer critical frequency, GIM‐foF2 (or NmF2) and peak height, GIM‐hmF2. Ratio TEC/NmF2 represents the slab‐thickness model of the ionosphere, GIM‐τ, fitted to foF2, hmF2 peak at each cell of a map. The slab‐thickness τ is for the first time tied to hmF2 peak height with its components τbot below hmF2 and topside τtop. Equations for evaluating Hc with IRI‐Plas and NeQuick models are derived from Ne(h) profile complemented with the total electron content—height profile TEC(h) from the bottom boundary of the ionosphere (65–80 km over the Earth) to varying altitude h up to 20,200 km (GPS orbit). The position of Hc depends on the altitude range selected at the ionosphere and plasmasphere. We determine Hc from Ne(h) and TEC(h) profile within the borders of τ from the bottom side (hmF2 − τbot) to topside (hmF2 + τtop). Regression linear model of Hc variation with hmF2 is derived which allows estimate of Hc from the F2 layer peak height hmF2. Statistical characteristics of GIM‐Hc maps can serve for validation and updating the effective shell height with Hc parameter varying over the globe for improved vertical TEC evaluation from the slant TEC observations.

中文翻译：

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从平板厚度模拟电离层质量中心

本研究探索了电离层的质心（Hc），作为有效的电离层变化的壳高（VSH）。我们通过吸收JPL从1994年至今提供的GIM-TEC即时图，介绍了用IRI-Plas模型制作的全球电离层图GIM-Hc，该图可以获取F2层临界频率，GIM-foF2（或NmF2）和峰值的全局图高度，GIM-hmF2。比率TEC / NmF2表示电离层的平板厚度模型GIM-τ，它适合于图的每个像元上的foF2，hmF2峰。平板厚度τ首次与hmF2峰高相关，其分量τbot在hmF2以下且在顶部τtop以下。使用IRI-Plas和NeQuick模型评估Hc的方程式是从Ne（h）轮廓与总电子含量（从电离层底部边界（地球上65-80 km）到变化的高度轮廓TEC（h））相补充得出的高度h可达20,200公里（GPS轨道）。Hc的位置取决于在电离层和等离子层选择的高度范围。我们从底部（hmF2-τbot）到顶部（hmF2 +τtop）的τ边界内的Ne（h）和TEC（h）轮廓确定Hc。推导了Hc随hmF2变化的回归线性模型，该模型允许根据F2层峰高hmF2估算Hc。GIM-Hc图的统计特征可用于验证和更新有效的壳高，其中Hc参数在全球范围内有所变化，从而可以根据倾斜的TEC观测值改善垂直TEC评估。