- Open Access
Special issue “Coupling of the high and mid latitude ionosphere and its relation to geospace dynamics”
Earth, Planets and Space volume 68, Article number: 168 (2016)
The EPS special issue, Coupling of the High and Mid Latitude Ionosphere and Its Relation to Geospace Dynamics, originated from a session held during the Asia Oceania Geosciences Society (AOGS) 2014 meeting in Sapporo (Japan). In addition to the papers presented at the conference, others of common scientific interest have been included. In the end, 12 papers have been published, covering a wide variety of scientific topics.
The focus of this special issue is on the coupling of the high and mid latitude ionosphere, which plays an important role in geospace dynamics. Recently, the coverage offered by ground-based observation networks, such as magnetometers, high-frequency (HF) radars, Global Positioning System (GPS) receivers and others, has increased dramatically, improving our understanding of the coupling between the high and mid latitude ionosphere. In addition, several satellites in geospace provide essential in situ data, yielding numerous new findings, as well as posing new questions. The papers in this issue contribute to our understanding of the high/mid (and low/equatorial) latitude ionosphere and geospace coupling, as well as geospace dynamics.
Sudden changes in the dynamic pressure of solar wind, known as sudden impulses (SI), have a major influence on the magnetosphere and ionosphere. Specifically, the SI have a significant effect on ionospheric convection at high and mid latitudes, as observed by the Super Dual Auroral Radar Network (SuperDARN) HF radars (Hori et al. 2015), as well as on auroral emissions (Liu et al. 2015). In addition, the interaction between solar wind and the magnetosphere leads to substorms, which are manifestations of the explosive energy release processes. The inductive effects of the magnetosphere during the course of a substorm have been studied by Mishin et al. (2015).
Magnetosphere–ionosphere interaction, equatorward of the auroral emission region (subauroral latitudes), often generates subauroral polarization streams (SAPS). Nagano et al. (2015) have identified the slowest speed limit of SAPS and have suggested that the ionospheric feedback mechanism does not play a significant role in the slower part of the SAPS.
The ionosphere is formed as a result of solar emission, magnetosphere–ionosphere coupling, and ionosphere–thermosphere coupling processes. It is important to know the distribution of ionospheric plasma densities in order to understand the formation processes of the ionosphere. The characteristics of the distribution of ionospheric plasma density were studied by employing FORMOSAT-3/COSMIC satellite data (Chang et al. 2015), GPS TEC data (Kumar et al. 2015), and SuperDARN HF radar data (Oinats et al. 2016a). The results of the analysis of the observation data were compared with HWM93 simulation or International Reference Ionosphere (IRI)-2012 model.
Additionally, the ionosphere is disturbed by ionospheric plasma instability processes and ionospheric–thermosphere coupling processes. The characteristics of traveling ionospheric disturbances of various origins were studied by employing SuperDARN HF radar data (Oinats et al. 2016b). Tsunami-driven traveling ionospheric disturbances were studied by employing GPS TEC data (Tang et al. 2015). Seif et al. (2015) have studied the detailed characteristics of daytime ionospheric scintillation near the magnetic equator and have discussed the role of gradient-drift instability in generating ionospheric plasma irregularities.
In addition, in order to study ionospheric characteristics, it is important to develop techniques to enhance the precision of analyzing observational data. Ponomarenko et al. (2015) have developed an algorithm for calibrating the elevation angle parameter of the SuperDARN radars, which is important in identifying echo locations. Furthermore, it is important to model the ionospheric parameters to extract the main characteristics of ionospheric disturbances. Mandrikova et al. (2015) have developed an algorithm for modeling ionospheric parameter FoF2 and extracting the main characteristics of ionospheric perturbations during different seasons and geomagnetic activities.
With the advance of observational techniques and the expansion of the field of view of the existing observation network, as well as the development of modeling/numerical simulation algorithms, we hope to enhance the understanding of the ionosphere, ranging from the high to mid/low latitude, and its relation to the dynamics of the geospace and upper atmosphere.
Chang FY, Liu JY, Chang LC, Lin CH, Chen CH (2015) Three-dimensional electron density along the WSA and MSNA latitudes probed by FORMOSAT-3/COSMIC. Earth Planets Space 67:156
Hori T, Shinbori A, Fujita S, Nishitani N (2015) IMF-By dependence of transient ionospheric flow perturbation associated with sudden impulses: superDARN observations. Earth Planets Space 67:190
Kumar S, Tan EL, Murti DS (2015) Impacts of solar activity on performance of the IRI-2012 model predictions from low to mid latitudes. Earth Planets Space 67:42
Liu J, Hu H, Han D, Yang H, Lester M (2015) Simultaneous ground-based optical and SuperDARN observations of the shock aurora at MLT noon. Earth Planets Space 67:120
Mandrikova OV, Fetisova NV, Polozov YA, Solovev IS, Kupriyanov MS (2015) Method for modeling of the components of ionospheric parameter time variations and detection of anomalies in the ionosphere. Earth Planets Space 67:131
Mishin VV, Mishin VM, Lunyushkin SB, Pu Z, Wang C (2015) Strong induction effects during the substorm on 27 August 2001. Earth Planets Space 67:162
Nagano H, Nishitani N, Hori T (2015) Occurrence characteristics and lowest speed limit of subauroral polarization stream (SAPS) observed by the SuperDARN Hokkaido East radar. Earth Planets Space 67:126
Oinats AV, Nishitani N, Ponomarenko P, Ratovsky KG (2016a) Diurnal and seasonal behavior of the Hokkaido East SuperDARN ground backscatter: simulation and observation. Earth Planets Space 68:18
Oinats AV, Nishitani N, Ponomarenko P, Berngardt OI, Ratovsky KG (2016b) Statistical characteristics of medium-scale traveling ionospheric disturbances revealed from the Hokkaido East and Ekaterinburg HF radar data. Earth Planets Space 68:8
Ponomarenko P, Nishitani N, Oinats AV, Tsuya T, St.-Maurice J-P (2015) Application of ground scatter returns for calibration of HF interferometry data. Earth Planets Space 67:138
Seif A, Tsunoda RT, Abdullah M, Hasbi AM (2015) Daytime gigahertz scintillations near magnetic equator: relationship to blanketing sporadic E and gradient-drift instability. Earth Planets Space 67:177
Tang L, Zhang X, Li Z (2015) Observation of ionospheric disturbances induced by the 2011 Tohoku tsunami using far-field GPS data in Hawaii. Earth Planets Space 67:88