Physics of the Earth’s Space Environment

Prölss, Gerd W.

doi:10.1007/978-3-642-97123-5

Cited by 240 publications

(247 citation statements)

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“…Positive storm effect is mostly related to thermospheric winds rather than neutral composition changes (Prölss 2004). For this reason the relative ion composition is close to the standard model.…”

Section: Discussionsupporting

confidence: 68%

Retrieval of thermospheric parameters from routine ionospheric observations: assessment of method’s performance at mid-latitudes daytime hours

Mikhailov

Belehaki

Perrone

et al. 2012

J. Space Weather Space Clim.

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A new method has been developed to retrieve neutral temperature T n and composition [O], [N 2 ], [O 2 ] from electron density profiles in the daytime mid-latitude F 2 -region under both quiet and disturbed conditions. A comparison with CHAMP neutral gas density observations in the vicinity of Millstone Hill Incoherent Scatter Radar (ISR) has shown that the retrieved neutral gas densities coincide with the observed ones within the announced accuracy of CHAMP observations, provided that accurate N e (h) ISR profiles are used for the retrieval. The performance of the method has also been tested ingesting Digisonde N e (h) profiles. In this case the agreement with CHAMP neutral gas density observations is less successful. Possible factors that can influence the performance accuracy are investigated. These are mostly related to limitations due to the ionogram scaling and inversion methods, including performance limitations of the sounding technique itself, like for instance during G-conditions. Several tests presented here demonstrate that discrepancies in the hmF2 values provided by the Digisondes could have an important impact on the performance of the method. It should be noted that in all tests performed here using Digisonde N e (h) profiles, the topside part is approximated with the NeQuick model and any assessment concerning the impact of the topside profiler on the accuracy of the method is beyond the scope of this investigation. Despite the limitations related to the use of Digisonde profiles, the proposed method has the potential to monitor the thermosphere at least with ISR N e (h) profiles. Digisonde electron density profiles can also be used if quality improvements are made concerning the ionogram inversion methods.

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Section: Discussionsupporting

confidence: 68%

Retrieval of thermospheric parameters from routine ionospheric observations: assessment of method’s performance at mid-latitudes daytime hours

Mikhailov

Belehaki

Perrone

et al. 2012

J. Space Weather Space Clim.

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“…The neutral species are assumed to have a common drift velocity v n and temperature T n . The transport equations for the neutral moments were obtained from Prölss (2004).…”

Section: Ionospheric Species and Their Momentsmentioning

confidence: 99%

The effects of mesoscale regions of precipitation on the ionospheric dynamics, electrodynamics and electron density in the presence of strong ambient electric fields

2010

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Abstract.We have developed a new high resolution twodimensional model of the high latitude ionosphere in which nonlinear advection terms are closely coupled with the electrodynamics. The model provides a self-consistent description of the ionospheric feedback on the electrodynamical perturbations produced by auroral arc-related particle precipitation in regions with strong ambient electric fields. We find in particular that a heretofore neglected ion Pedersen advection term can introduce considerable changes in the electron density profile, the current density distribution, the conductivities and the electron temperatures. We find that the convective effects can carry the ionisation more than 150 km outside the precipitation region in a few minutes, with attendant large changes in the current distribution and E-region densities that become enhanced outside the region of particle precipitation. The production of a tongue of ionisation that slowly decays outside the auroral boundaries contrasts with the sharp geometric cut-off and associated stronger current densities found in previous studies.

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“…ac.jp/dstdir/, and http://wdc.kugi.kyoto-u.ac.jp/ dstae/index.html, respectively. For more detailed information about the indices, we refer to Prolss (2004) and Verbanac et al (2011aVerbanac et al ( , 2010. Among the available geomagnetic indices, these three indices have been chosen for the evaluation of the geomagnetic activity since their variations can be physically interpreted and related to the specific current system, for example, the ring current and polar electrojet.…”

Section: Data Sets and Methodsmentioning

confidence: 99%

“…However, the interaction of the HSS and the slow wind forms a corotating interaction region (CIR), containing regions of compressed plasma (e.g., Gosling 1996, and references therein) indicated by enhanced plasma density and magnetic field intensity. In HSS/CIRs the B s is associated with these compressions and/or Alfvénic waves in the HSS itself (e.g., Burlaga & Lepping 1977;Schwenn 1983;Tsurutani et al 2004;Prolss 2004). The occurrence rate of ICMEs peaks during the solar cycle maximum (e.g., Richardson & Cane 2010, and references therein), and then their geomagnetic effects dominate.…”

Section: Introductionmentioning

confidence: 99%

Comparison of geoeffectiveness of coronal mass ejections and corotating interaction regions

Verbanac

Živković

Vršnak

et al. 2013

A&A

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Context. A detailed comparison of the geomagnetic responses to interplanetary coronal mass ejection (ICMEs) and corotating interaction regions (CIRs) during solar cycle 23 was performed using geomagnetic indices Dst, Ap, and AE. Aims. We aim to find out if there are relative differences in the response of various magnetospheric current systems to the impact of ICMEs and CIRs. In addition, we are exploring the possibility of forecasting geomagnetic activity using the coronagraphic observations of the ICME take-off. Methods. The peak values of the plasma characteristics of ICMEs and CIRs (velocity V, magnetic field B, and BV related to the electric field), and geomagnetic indices were investigated by applying the linear and power-law cross correlation analysis. The influence of the time-resolution on the results was performed for two time resolutions obtained by one-hour (three-hour for Ap) and six-hour data averaging. Results. For ICMEs the power-law fits are found to be important only for the relationships between BV and geomagnetic indices. For Ap and Dst, there is no difference between the one-hour (three-hour for Ap) and six-hour option. For AE, the one-hour data distribution shows more clearly the non-linear dependence on BV. Our data set shows that below BV ∼ 5 mV m −1 ICMEs have practically no geomagnetic effect at low and mid latitudes, but at high latitudes at least some geomagnetic activity will be triggered. For all HSS/CIRs dependencies, a power law is found to better describe the data than the linear fit. The data distributions show that BV has to reach ∼4 mV m −1 in order to drive at least some geomagnetic activity at all latitudes. We observed that there are fast CMEs that have almost no geomagnetic effect at low and mid latitudes. On the other hand, at high latitudes, fast CMEs always trigger some geomagnetic activity. This might be have implications for space weather forecasting. Conclusions. Magnetospheric response to both solar drivers (ICMEs and CIRs) is different at various latitudes, thus results in different development of various current systems within the Earth's magnetosphere and ionosphere. Furthermore, we show that ICMEs and CIRs cause different geomagnetic activity. In the case of ICMEs equatorial current system responses in a linear manner, while the response of the polar-current system is likely to be non-linear. For HSS/CIRs, apparently all current systems respond in a non-linear way, especially the polar current system.

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Physics of the Earth’s Space Environment

Abstract: Cover picture: Dayglow and aurora imaged from the DEI satellite at an altitude of about 20,000 km. Further information may be found in Sections 3.3.8 and 7.4 (L.A. Frank, University ofIowa).

Cited by 240 publications

References 0 publications

Retrieval of thermospheric parameters from routine ionospheric observations: assessment of method’s performance at mid-latitudes daytime hours

Retrieval of thermospheric parameters from routine ionospheric observations: assessment of method’s performance at mid-latitudes daytime hours

The effects of mesoscale regions of precipitation on the ionospheric dynamics, electrodynamics and electron density in the presence of strong ambient electric fields

Comparison of geoeffectiveness of coronal mass ejections and corotating interaction regions

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