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Candidi, Maurizio
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- PublicationOpen AccessGround based observations of Pc3-Pc5 geomagnetic pulsation power at Antarctic McMurdo station(1998-06)
; ; ; ; ;Ballatore, P.; Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974, U.S.A ;Engebretson, M. J.; Department of Physics, Augsburg College, Minneapolis, MN 55454, U.S.A ;Maclennan, C. G.; Bell Laboratories, Lucent Technologies, Murray Hill, NJ 07974, U.S.A ;Candidi, M.; IFSI/CNR, Roma, Italy; ; ; The two horizontal geomagnetic components and, measured by a fluxgate magnetometer at Antarctic McMurdo station (corrected geomagnetic coordinates 80.0° S, 327.5° E), are analyzed for the period May-June 1994; the spectral powers are calculated and integrated over three frequency intervals corresponding to the nominal ranges. The time dependence of those integrated powers and their correlations with northern auroral indices and solar wind speed are considered. The observations are compared with previous results reported from Terra Nova Bay station (located near McMurdo at the same corrected geomagnetic latitude) during Antarctic summer intervals. The differences found between the two stations are discussed in terms of the seasonal dependence of geomagnetic field line configurations in the near cusp region.138 172 - PublicationOpen AccessEffects on SuperDARN HF radar echoes of sudden impulses of solar wind dynamic pressure(2005)
; ; ; ; ; ; ; ; ; ; ; ; ;In this work we perform a statistical analysis of the ionospheric echo response observed by six radars of the SuperDARN network in the Northern Hemisphere, over 236 Sudden Impulses (SI) of solar wind dynamic pressure events (from 1997 through 2000). For that purpose, we make use of MRS, the Mean Rate of Scattering, as a function of time during the SI event. We classify the events in sudden increases (I events, 144 cases) and decreases (D events, 92 cases) of the solar wind dynamic pressure. Moreover, we make use of the AE index to define two distinct conditions of the ionosphere under which each event may take place: Quiet and Disturbed. Regarding Quiet conditions, for both I and D events, we find that MRS displays an increase related to the SI time. On the contrary, for Disturbed conditions, D events display an increase in MRS, while I events show a clear dip. The similarity of response for I and D events under Quiet conditions is briefly discussed, but the smaller number of D events does not allow one to further analyse them. As for the I events, a latitudinal analysis shows that the MRS increase for Quiet conditions is seen both at low latitudes (60 −70 3) and at high latitudes (70 −80 3); for Disturbed Is the MRS decrease is stronger at high latitudes. We suggest that the MRS increase for Quiet Is can be due to two different mechanisms: 1) a soft electron precipitation induced by Field Line Resonances (FLR) or loss cone instability at lower latitudes; 2) an enlargement of the cusp at higher latitudes, which in turn may induce enhanced particle precipitation. For what concerns Disturbed Is, the MRS decrease can be produced by a higher energy electron precipitation (>1 keV), that enhances the electron density in the E and D regions. This provokes a strong absorbtion of the radio waves in the D region and a higher refraction in the E region, leading to a decrease in MRS, especially at higher latitudes.130 27 - PublicationOpen AccessInterazioni magnetosfera-ionosfera(1993)
; ;Candidi, M.; CNR, Istituto di Fisica Spazio Interplanetario, Frascati, Italia124 1011 - PublicationRestrictedElectric field computation analysis for the Electric Field Detector (EFD) on board the China Seismic-Electromagnetic Satellite (CSES)(2017-09)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; The floating potential variability of the Electric Field Detector (EFD) probes, on board the Chinese Seismo-Electromagnetic Satellite (CSES), has been modeled, and the effects of several structural and environmental elements have been determined. The expected floating potentials of the probes are computed considering the ambient ionospheric plasma parameter variations. In addition, the ion collection variability, due to the different probe attitudes along the orbit, and its effect on each floating potential, are considered. Particular attention is given to the analysis of the shadow produced by the stubs, in order to determine the artificial electric field introduced by instrumental effects which has to be subtracted from the real measurements. The modulation of the altered electric field, due to the effect on shadowing of the ion drift, as measured by the ESA satellite Swarm A in a similar orbit, is also modeled. Such simulations are made in preparation of real EFD data analysis performed during the upcoming flight of CSES.135 7