Annales Geophysicae
SCOPUS (1983-1985,1988-1990,1994-2023)SCIE-ISI
1432-0576
0992-7689
Cơ quản chủ quản: Copernicus Gesellschaft mbH , European Geosciences Union
Lĩnh vực:
Atmospheric ScienceGeologyEarth and Planetary Sciences (miscellaneous)Space and Planetary ScienceAstronomy and Astrophysics
Các bài báo tiêu biểu
<i>Introduction</i>The Cluster missionAbstract. The Cluster mission, ESA’s first cornerstone project, together with the SOHO mission, dating back to the first proposals in 1982, was finally launched in the summer of 2000. On 16 July and 9 August, respectively, two Russian Soyuz rockets blasted off from the Russian cosmodrome in Baikonour to deliver two Cluster spacecraft, each into their proper orbit. By the end of August 2000... ...
Tập 19 Số 10/12 - Trang 1197-1200
Temporal and spatial variations in TEC using simultaneous measurements from the Indian GPS network of receivers during the low solar activity period of 2004–2005Abstract. With the recent increase in the satellite-based navigation applications, the ionospheric total electron content (TEC) and the L-band scintillation measurements have gained significant importance. In this paper we present the temporal and spatial variations in TEC derived from the simultaneous and continuous measurements made, for the first time, using the Indian GPS network of 18... ...
Tập 24 Số 12 - Trang 3279-3292
Properties and geoeffectiveness of magnetic clouds in the rising, maximum and early declining phases of solar cycle 23Abstract. The magnetic structure and geomagnetic response of 73 magnetic clouds (MC) observed by the WIND and ACE satellites in solar cycle 23 are examined. The results have been compared with the surveys from the previous solar cycles. The preselected candidate MC events were investigated using the minimum variance analysis to determine if they have a flux-rope structure and to obtain the... ...
Tập 23 Số 2 - Trang 625-641
Cluster observations of reconnection due to the Kelvin-Helmholtz instability at the dawnside magnetospheric flankAbstract. On 3 July 2001, the four Cluster satellites traversed along the dawnside magnetospheric flank and observed large variations in all plasma parameters. The estimated magnetopause boundary normals were oscillating in the z-direction and the normal component of the magnetic field showed systematic 2–3 min bipolar variations for 1 h when the IMF had a small positive bz-component and ... ...
Tập 24 Số 10 - Trang 2619-2643
Spatio-temporal patterns of seasonal rainfall in Spain (1912-2000) using cluster and principal component analysis: comparisonAbstract. In this work, cluster and principal component analysis are used to divide Spain in a limited number of climatically homogeneous zones, based on seasonal rainfall for 32 Spanish localities for the period 1912–2000. Using the hierarchical technique of clustering Ward's method, three clusters have been obtained in winter and spring, and four clusters have been obtained in summer and... ...
Tập 22 Số 5 - Trang 1435-1448
GPS radio occultation with CHAMP and GRACE: A first look at a new and promising satellite configuration for global atmospheric soundingAbstract. CHAMP (CHAllenging Minisatellite Payload) and GRACE (Gravity Recovery And Climate Experiment) formed a satellite configuration for precise atmospheric sounding during the first activation of the GPS (Global Positioning System) radio occultation experiment aboard GRACE on 28 and 29 July 2004. 338 occultations were recorded aboard both satellites, providing globally distributed ver... ...
Tập 23 Số 3 - Trang 653-658
Resonant enhancement of relativistic electron fluxes during geomagnetically active periods Abstract. The strong increase in the flux of relativistic electrons during the recovery phase of magnetic storms and during other active periods is investigated with the help of Hamiltonian formalism and simulations of test electrons which interact with whistler waves. The intensity of the whistler waves is enhanced significantly due to injection of 10-100 keV electrons during the substorm... ...
Yearly variations in the low-latitude topside ionosphere
Tập 18 Số 7 - Trang 789-798 - 2000
Observations made by the Hinotori satellite have been analysed to determine the yearly variations of the electron density and electron temperature in the low-latitude topside ionosphere. The observations reveal the existence of an equinoctial asymmetry in the topside electron density at low latitudes, i.e. the density is higher at one equinox than at the other. The asymmetry is hemisphere-dependen......
Quantitative modeling of the ionospheric response to geomagnetic activityAbstract. A physical model of the coupled thermosphere and ionosphere has been used to determine the accuracy of model predictions of the ionospheric response to geomagnetic activity, and assess our understanding of the physical processes. The physical model is driven by empirical descriptions of the high-latitude electric field and auroral precipitation, as measures of the strength of the... ...
Tập 18 Số 7 - Trang 766-781
Predicting geomagnetic storms from solar-wind data using time-delay neural networksAbstract. We have used time-delay feed-forward neural networks to compute the geomagnetic-activity index Dst one hour ahead from a temporal sequence of solar-wind data. The input data include solar-wind density n, velocity V and the southward component Bz of the interplanetary magnetic field. Dst is not included in the input data. The networks implement an explicit functional relationship ... ...
Tập 14 Số 7 - Trang 679-686