Ionospheric slab thickness and its seasonal variations observed by GPS

Abstract

The ionospheric slab thickness, the ratio of the total electron content (TEC) to the F2-layer peak electron density (NmF2), is closely related to the shape of the ionospheric electron density profile Ne (h) and the TEC. Therefore, the ionospheric slab thickness is a significant parameter representative of the ionosphere. In this paper, the continuous GPS observations in South Korea are firstly used to study the equivalent slab thickness (EST) and its seasonal variability. The averaged diurnal medians of December-January-February (DJF), March-April-May (MAM), June-July-August (JJA) and September-October-November (SON) in 2003 have been considered to represent the winter, spring, summer and autumn seasons, respectively. The results show that the systematic diurnal changes of TEC, NmF2 and EST significantly appeared in each season and the higher values of TEC and NmF2 are observed during the equinoxes (semiannual anomaly) as well as in the mid-daytime of each season. The EST is significantly smaller in winter than in summer, but with a consistent variation pattern. During 14-16 LT in daytime, the larger EST values are observed in spring and autumn, while the smaller ones are in summer and winter. The peaks of EST diurnal variation are around 10-18 LT which are probably caused by the action of the thermospheric wind and the plasmapheric flow into the F2-region. r

Assessment of BeiDou differential code bias variations from multi-GNSS network observations

“…As we know, the slant TEC (STEC) along the LOS can be expressed as the following equation, ignoring the high-order effect of the ionosphere (Jin et al, 2008):…”

“…The multi-GNSS observations with multiple frequencies and multiple systems provide us more chances to monitor Earth's ionospheric variations and behaviors. The ionospheric total electron content (TEC) and electron density profile from ground-based and spaceborne multi-frequency GNSS observations can be used for ionospheric delay correction and related scientific research (Jin et al, 2006(Jin et al, , 2007(Jin et al, , 2013Hernández-Pajares et al, 2011), including monitoring of Earth's ionosphere, modeling, and prediction, as well as disturbances and anomalous variations following the solar flare, geomagnetic storms, anthropogenic activities (e.g., rocket lunching and explosion), and natural hazards (e.g., earthquakes, tsunamis, and volcanic eruptions) (Calais et al, 1998;Afraimovich et al, 2010Afraimovich et al, , 2013Steiner et al, 2011;Mukhtarov et al, 2013;Occhipinti et al, 2013;Jin et al, 2010Jin et al, , 2014Jin et al, , 2015. The increasing number of onorbit GNSS satellites and operating stations have improved the temporal-spatial resolution of GNSS observations, but some biases in GNSS observables cannot be removed.…”

Climatology of the ionospheric slab thickness along the longitude of 120° E in China and its adjacent region during the solar minimum years of 2007–2009

“…Bhonsle et al, 1965;Titheridge, 1973;Huang, 1983). Based on most of the available and reliable observations of ionospheric TEC and NmF2, numerous analyses for recording the climatology of the slab thickness have been conducted over the past few decades (Jayachandran et al, 2004;Chuo, 2007;Jin et al, 2007;Stankov and Warnant, 2009;Guo et al, 2011;Kenpankho et al, 2011;Weng et al, 2012). Jayachandran et al (2004) investigated the variation in the slab thickness during the solar maximum and minimum phases of an intense solar cycle by using the hourly values of TEC and NmF2 at Hawaii (low latitude), Boulder (mid-latitude) and Goosebay (high latitude).…”

High-order ionospheric effects on electron density estimation from Fengyun-3C GPS radio occultation

“…When the signal transmitted by GPS satellites propagates through the Earth's ionosphere and lower atmosphere, it will be delayed due to the atmosphere refraction (Jin et al, 2004(Jin et al, , 2007(Jin et al, , 2009). Nowadays, GPS can monitor the atmosphere and ionosphere with lots of advantages such as low cost, high precision, high temporal and spatial resolution, and all-weather and all-time observations (Afraimovich et al, 2010;Jin et al, 2011Jin et al, , 2015Jin et al, , 2016; this particularly applies to space-borne GPS radio occultation (RO) (Jin et al, 2014a).…”