A global picture of ionospheric slab thickness derived from GIM TEC and COSMIC radio occultation observations. Issue 1 (30th January 2016)

• Record Type: Journal Article
• Authors: Huang, He; Liu, Libo; Chen, Yiding; Le, Huijun; Wan, Weixing
• Is Part Of: Journal of geophysical research. Volume 121:Issue 1(2016:Jan.)
• Page Start: 867
• Page End: 880
• Publication Date: 2016-01-30
• Subjects: global feature -- slab thickness -- profile shape; Magnetospheric physics -- Periodicals; Space environment -- Periodicals; Cosmic physics -- Periodicals; Planets -- Atmospheres -- Periodicals; Heliosphere (Astrophysics) -- Periodicals; Geophysics -- Periodicals; 523.01
• DOI: 10.1002/2015JA021964
• Languages: English
• ISSNs: 2169-9380

Abstract

Abstract: The ionospheric equivalent slab thickness (EST), defined as the ratio of total electron content (TEC) to F 2 layer peak electron density ( Nm F 2 ), describes the thickness of the ionospheric profile. In this study, we retrieve EST from TEC data obtained from Global Ionospheric Map (GIM) and Nm F 2 retrieved from Constellation Observing System for Meteorology, Ionosphere and Climate (COSMIC) ionospheric radio occultation data. The diurnal, seasonal, and solar activity variations of global EST are analyzed as the excellent spatial coverage of GIM and COSMIC data. During solstices, daytime EST in the summer hemisphere is larger than that in the winter hemisphere, except in some high‐latitude regions, and the reverse is true for the nighttime EST. The peaks of EST often appear at 0400 local time. The presunrise enhancement in EST appears in all seasons, while the postsunset enhancement in EST is not readily observed in equinox. Both enhancements are attributed to the more remarkable electron density decay of Nm F 2 compared to that of TEC. The dependence of EST on solar activity is related to the inconsistent solar activity dependences of electron density at different altitudes. Furthermore, it is interesting that EST is enhanced from 0° to 120°E in longitude and 30° to 75°S in latitude during nighttime, just to the east of Weddell Sea Anomaly, during equinox and the Southern Hemisphere summer. This phenomenon is supposed to be related to the effects of geomagnetic declination‐related plasma vertical drifts. Key Points: Spatial and temporal features of global ionospheric slab thickness Presunrise and postsunset enhancements in slab thickness Higher slab thickness exists to the east of WSA