A simple oblique dip model for geomagnetic micropulsations
نویسندگان
چکیده
It is pointed out that simple models adopted so far have tended to neglect the obliquity of the magnetic ®eld lines entering the Earth's surface. A simple alternative model is presented, in which the ambient ®eld lines are straight, but enter wedge shaped boundaries at half a right-angle. The model is illustrated by assuming an axially symmetric, compressional, impulse type disturbance at the outer boundary, all other boundaries being assumed to be perfectly conducting. The numerical method used is checked from the instant the excitation ceases, by an analytical method. The ®rst harmonic along ®eld lines is found to be of noticeable size, but appears to be mainly due to coupling with the fundamental, and with the ®rst harmonic across ®eld lines.
منابع مشابه
Experimental and numerical crashworthiness investigation of hybrid composite aluminum tubes under dynamic axial and oblique loadings
This research deals with axial and oblique impact crash tests on simple and hybrid composite tubes. Axial and oblique impact tests have been generated on simple and hybrid composite tubes with one, two and three layers. A drop test rig was used to conduct the experiments. Furthermore, in order to gain more detailed knowledge about the crash process, finite element simulations of the experim...
متن کاملLongitudinal dependence of the daily geomagnetic variation during quiet time
[1] The daily variation of the geomagnetic field during quiet time at equinox features a longitudinal dependence, which is observed in the dip-latitude/longitude frame. Two explanations are considered: (1) the longitudinal changes of the geomagnetic latitude at constant dip-latitude and (2) the longitudinal variations of the main field, which modulates the ionospheric dynamo e.m.f. and determin...
متن کاملOblique Ionograms Automatic Scaling Algorithm OIASA application to the ionograms recorded by Ebro observatory ionosonde
This is anOp Abstract – The oblique ionograms automatic scaling algorithm (OIASA), developed at the INGV for the identification of trace of oblique ionograms, allows the determination of the maximum usable frequency (MUF) for communication between the transmitter and receiver, automatically rejecting poor quality ionograms. A test of the algorithm using data from a campaign of oblique soundings...
متن کاملGeomagnetic field variations at dip equatorial latitudes of West Africa
A comprehensive study of geomagnetic field variations has been carried out at the dip equatorial latitudes of West Africa. The data obtained during the 1993 French participation in the International Equatorial Electrojet Year experiment in Africa was used for the analysis. Only the quiet condition was examined. Variation in the three geomagnetic field elements (H, D, and Z) showed more variabil...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
دوره شماره
صفحات -
تاریخ انتشار 1998