An investigation of ionospheric upper transition height variations at low and equatorial latitudes deduced from combined COSMIC and C/NOFS measurements

Yang, Chunfang; Zhu, Jiang; Yue, Xinan; Wan, Weixing

doi:10.1016/j.asr.2016.11.024

Cited by 5 publications

(2 citation statements)

References 32 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…VSH and Hm at midlatitudes generally have larger values in summer than in winter hemisphere (Ma et al, , Prol et al, , T.‐L. Xu et al, , Yang et al, ). Previous statistical analyses identify that VSH , Hm , Hp , and Hsc increase with solar flux (M.‐L.…”

Section: Introductionmentioning

confidence: 99%

α‐Chapman Scale Height: Longitudinal Variation and Global Modeling

Liu

Jiang

et al. 2019

JGR Space Physics

View full text Add to dashboard Cite

Scale height measures the altitude gradient of the electron density profile and relates with the ionospheric chemistry and dynamics, while its longitudinal variation has not been fully investigated in both statistical analyses and empirical modelings. In this study, 11-year electron density profiles from Constellation Observing System for Meteorology, Ionosphere, and Climate radio occultations are collected to retrieve the α-Chapman scale height (Hm) from the lower topside ionospheric electron density profile (within 200-km altitudes above the peak height of F2 layer [hmF2]) by fitting α-Chapman function with a constant scale height. The Hm shows evident longitudinal variations at midlatitudes, and its zonal structure shows a consistency with that of hmF2 during daytime, which indicates neutral winds change the ionospheric height and shape at the same time. Further, a global modeling of Hm named 2PCAFourier-Hm is built based on a two-layer Principle Component Analysis combined with Fourier regression analysis of its coefficients under low and moderated solar activity. Longitudinal variation is considered in the Hm's modeling, along with the variations of local time, latitude, day of the year, and solar activity. Overall, the model well captures the temporal and spatial variations of Hm with a root-mean-square error of 2.25 km and a correlation coefficient of 0.97 with respect to the Constellation Observing System for Meteorology, Ionosphere, and Climate observations. Plain Language Summary Scale height is the logarithmic altitude gradient of the electron density profile and tightly relates with ionospheric dynamics, plasma thermal structure, and composition. However, longitudinal dependence of scale height has not been fully investigated especially at midlatitudes. Longitudinal variation is such that ionospheric parameters show evident zonal difference at the same local time. Moreover, nearly no empirical models of scale height include the longitude as a variable though Liu et al. (2008, https://doi.org/10.1029/2008JA013490) found equatorial scale height has evident wave-like longitudinal variation.In this study, more than 4,100,000 samples of α-Chapman scale height (Hm) were retrieved from 11-year electron density profiles of Constellation Observing System for Meteorology, Ionosphere, and Climate. We found the midlatitude Hm has evident longitudinal variation, and its zonal structure is tightly relates with neutral winds' dynamics during daytime. Moreover, a five-dimensional (latitude, local time, longitude, day of year, and solar activity) empirical model of Hm is built based on a two-layer Principle Component Analysis combined with Fourier regression analysis of its coefficients. An executable MATLAB live code of this model is also provided in the supporting information.

show abstract

Section: Introductionmentioning

confidence: 99%

α‐Chapman Scale Height: Longitudinal Variation and Global Modeling

Liu

Jiang

et al. 2019

JGR Space Physics

View full text Add to dashboard Cite

show abstract

“…Yang CJ et al (2017) combined topside in situ ion density data from the Communication/Navigation Outage Forecast System (C/NOFS) and the electron density profiles from COSMIC RO measurements to study spatial and temporal variations of the ionospheric upper transition height and the oxygen ion density scale height.…”

Section: Ionospheric Climatology and Modellingmentioning

confidence: 99%

Chinese ionospheric investigations in 2016–2017

Liu

Wan

2018

Earth and Planetary Physics

Self Cite

View full text Add to dashboard Cite

After the release of the previous report to the Committee on Space Research (COSPAR) on progress achieved by Chinese scientists in ionospheric researches (Liu LB and Wan WX, 2016), in the recent two years (2016–2017) many interesting new investigations into various ionospheric related issues have been completed. In this report, about 100 publications are summarized. The topics highlighted are as follows: Ionospheric space weather, ionospheric dynamics, ionospheric climatology and modelling, ionospheric irregularity and scintillation, Global Navigation Satellite System (GNSS) related ionospheric issues and other techniques, and radio wave propagation in the ionosphere. An outstanding feature is that more and more observations from the Meridional Project supported the ionospheric investigations.

show abstract