High-latitude ion temperature climatology during the International Polar Year 2007–2008

Yamazaki, Yosuke; Kosch, M. J.; Ogawa, Y.; Themens, David R.

doi:10.1051/swsc/2016029

Cited by 3 publications

(3 citation statements)

References 54 publications

(63 reference statements)

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“…Yamazaki et al. (2016) used ESR data from the solar minimum years 2007–2008 and found a pattern of ion temperature variations that is, similar to the pattern shown in Figure 6. Using TIE‐GCM model simulations, they showed that the observed ion temperature enhancements are mainly caused by ion frictional heating.…”

Section: Discussionmentioning

confidence: 62%

“…This might suggest that the formation of the depletion region observed in the ESR data is connected to frictional heating Vanhamäki et al (2016). andVoiculescu et al (2016) observe an increase in the ion temperature colocated with a high-latitude post-midnight trough, and they suggest that ion frictional heating might play a part in the formation of the observed trough Yamazaki et al (2016). used ESR data from the…”

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confidence: 99%

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Electron Density Depletion Region Observed in the Polar Cap Ionosphere

et al. 2021

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This paper presents and discusses electron density depletion regions observed with the incoherent scatter EISCAT Svalbard Radar (ESR) located at 75.43°N geomagnetic latitude. The data include several decades of measurements, which make them suitable for studying statistical features and characteristics of the ionospheric parameters. Here we focus on the electron density depletions and their dependence on diurnal and seasonal variations and solar activity. An electron density depletion region is identified in the ESR data in the early morning sector. This depletion region seems to be clearest during equinox and winter and moderate/high solar activity. An enhancement in the ion temperature is often co‐located with the electron density depletion region. The ion temperature enhancement could indicate that ion frictional heating is related to the electron density depletion region. However, during summer when the solar activity is low, the electron density depletion is not observed although the ion temperature is enhanced, suggesting that formation of the electron density depletion regions due to ion frictional heating may depend on the background effective temperature and O/N2 ratio. In addition, seasonal changes in the solar zenith angle could also contribute to the formation of the depletion region.

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Section: Discussionmentioning

confidence: 62%

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confidence: 99%

Electron Density Depletion Region Observed in the Polar Cap Ionosphere

et al. 2021

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“…AE index has previously been assessed as a driver index of F region ionospheric storm variability in the works of Wu and Wilkinson () and Perrone et al (), demonstrating comparable performance to other common geomagnetic indices, such as Dst and Ap . At high latitudes, with the dominant ionospheric storm time response being driven by Joule heating in the vicinity of the auroral electrojets (Yamazaki et al, ), AE , as an auroral electrojet index, acts as a convenient proxy of this heating. For a potential global reparameterization of the NeQuick, other indices may be necessary to reflect the different physical processes governing the ionospheric response to storms in different regions of the globe.…”

Section: A Refitted and Parameterized Nequick Topsidementioning

confidence: 99%

Topside Electron Density Representations for Middle and High Latitudes: A Topside Parameterization for E‐CHAIM Based On the NeQuick

et al. 2018

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In this study, we present a topside model representation to be used by the Empirical Canadian High Arctic Ionospheric Model (E‐CHAIM). In the process of this, we also present a comprehensive evaluation of the NeQuick's, and by extension the International Reference Ionosphere's, topside electron density model for middle and high latitudes in the Northern Hemisphere. Using data gathered from all available incoherent scatter radars, topside sounders, and Global Navigation Satellite System Radio Occultation satellites, we show that the current NeQuick parameterization suboptimally represents the shape of the topside electron density profile at these latitudes and performs poorly in the representation of seasonal and solar cycle variations of the topside scale thickness. Despite this, the simple, one variable, NeQuick model is a powerful tool for modeling the topside ionosphere. By refitting the parameters that define the maximum topside scale thickness and the rate of increase of the scale height within the NeQuick topside model function, r and g, respectively, and refitting the model's parameterization of the scale height at the F region peak, H0, we find considerable improvement in the NeQuick's ability to represent the topside shape and behavior. Building on these results, we present a new topside model extension of the E‐CHAIM based on the revised NeQuick function. Overall, root‐mean‐square errors in topside electron density are improved over the traditional International Reference Ionosphere/NeQuick topside by 31% for a new NeQuick parameterization and by 36% for a newly proposed topside for E‐CHAIM.

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