MEAN YEARLY VALUES OF THE EARTH'S MAGNETIC FIELD AT THE MAGNETIC OBSERVATORY, CAPE TOWN

1942 ◽  
Vol 29 (3) ◽  
pp. 129-132
Author(s):  
A. Ogg
Keyword(s):  
Magnetic Field ◽  
Cape Town ◽  
Magnetic Observatory ◽  
Earth’S Magnetic Field ◽  
Earth's Magnetic Field

The Earth's magnetic field variations at the Algerian magnetic observatory of Tamanrasset from 1932 to 2020.

2021 ◽  
Author(s):  
Lemgharbi Abdenaceur ◽  
Hamoudi Mohamed ◽  
Abtout Abdeslam ◽  
Abdelhamid Bendekken ◽  
Ener Aganou ◽  
...  
Keyword(s):  
Magnetic Field ◽  
International Association ◽  
Sampling Rate ◽  
Magnetic Data ◽  
Magnetic Observatory ◽  
Earth’S Magnetic Field ◽  
Data Set ◽  
Secular Variations ◽  
The World ◽  
Earth's Magnetic Field

<p>In order to understand the spatial and temporal behavior of the Earth's magnetic field, scientists, following C.F. Gauss initiative in 1838 have established observatories around the world. More than 200 observatories aiming to continuously record, the time variations of the magnetic field vector and to maintain the best standard of the accuracy and resolution of the measurements.</p><p>This study focused on the acquisition and analysis of the magnetic data provided by the Algerian magnetic observatory of Tamanrasset (labelled TAM by the International Association of Geomagnetism and Aeronomy). This observatory is located in southern Algeria at 5.53°E longitude, 22.79°N Latitude. Its altitude is 1373 meters above msl. TAM is continuously running since 1932, using old brand variometers, like Mascart and La Cour with photographic recording at the very beginning. Nowadays modern electronic equipment are used in the framework of INTERMAGNET project. Very large geomagnetic database collected over a century is available. We will describe the history and the various improvement of the methods and instrumentation.</p><p>Preliminary analysis of time series of the observatory data allowed to distinguish two kinds of data: the first type, with low resolution, collected between 1932 and 1992. This data set comes from the annual, monthly, daily and hourly means. The second one with high resolution is represented by minutes and seconds sampling rate since 1993 when TAM was integrated to the world observatory network, INTERMAGNET. Part of the second dataset contains many gaps. We try to fill these gaps thanks to mathematical methods. Absolute measurements and repeat station data allow better accuracy in the secular variations and an improved regional model.</p><p>Keywords: TAM observatory, temporal variation, terrestrial magnetic field, secular variations, INTERMAGNET.</p>

On the possibility of an intra-Earth source of Sq-variations of the Earth's magnetic field

2021 ◽  
Author(s):  
Beibit Zhumabayev ◽  
Ivan Vassilyev
Keyword(s):  
Magnetic Field ◽  
Coordinate System ◽  
Local Coordinate System ◽  
Spherical Body ◽  
Time Of Day ◽  
Magnetic Observatory ◽  
Earth’S Magnetic Field ◽  
The Earth ◽  
Earth's Magnetic Field ◽  
Variation Vector

<p>Analysis of the direction of motion of the vector of Sq-variations of the Earth's magnetic field, depending on the time of day and season of the year, shows that the observed Sq-variation is similar to the magnetic field created by a negatively charged spherical body moving in space. Transformations of the Sq-variation vector from the local coordinate system of the magnetic observatory to the ecliptic coordinate system are performed. A possible connection between the origin of the Sq-variation and the electric dipole moment of quartz molecules oriented towards the center of the Earth during the crystallization of the mineral and causing the electric and dipole magnetic fields of the Earth is considered. A scheme for conducting an experiment that allows us to separate the effects of extraterrestrial and extraterrestrial sources of Sq-variations is proposed.</p>

scholarly journals Space weather effects on drilling accuracy in the North Sea

2005 ◽  
Vol 23 (9) ◽  
pp. 3081-3088 ◽  
Author(s):  
S. J. Reay ◽  
W. Allen ◽  
O. Baillie ◽  
J. Bowe ◽  
E. Clarke ◽  
...  
Keyword(s):  
Magnetic Field ◽  
External Field ◽  
North Sea ◽  
Survey Method ◽  
Magnetic Observatory ◽  
Magnetic Survey ◽  
Earth’S Magnetic Field ◽  
The North ◽  
Earth's Magnetic Field ◽  
The North Sea

Abstract. The oil industry uses geomagnetic field information to aid directional drilling operations when drilling for oil and gas offshore. These operations involve continuous monitoring of the azimuth and inclination of the well path to ensure the target is reached and, for safety reasons, to avoid collisions with existing wells. Although the most accurate method of achieving this is through a gyroscopic survey, this can be time consuming and expensive. An alternative method is a magnetic survey, where measurements while drilling (MWD) are made along the well by magnetometers housed in a tool within the drill string. These MWD magnetic surveys require estimates of the Earth's magnetic field at the drilling location to correct the downhole magnetometer readings. The most accurate corrections are obtained if all sources of the Earth's magnetic field are considered. Estimates of the main field generated in the core and the local crustal field can be obtained using mathematical models derived from suitable data sets. In order to quantify the external field, an analysis of UK observatory data from 1983 to 2004 has been carried out. By accounting for the external field, the directional error associated with estimated field values at a mid-latitude oil well (55° N) in the North Sea is shown to be reduced by the order of 20%. This improvement varies with latitude, local time, season and phase of the geomagnetic activity cycle. By accounting for all sources of the field, using a technique called Interpolation In-Field Referencing (IIFR), directional drillers have access to data from a "virtual" magnetic observatory at the drill site. This leads to an error reduction in positional accuracy that is close to matching that of the gyroscopic survey method and provides a valuable independent technique for quality control purposes.

scholarly journals RESPONSE OF BIOLOGICAL SYSTEMS TO GEOMAGNETIC STORMS

2018 ◽  
Vol 3 (5) ◽  
pp. 126-131
Author(s):  
A. A. Bazhenov ◽  
M. V. Prikop ◽  
A. S. Averina ◽  
V. V. Sukhovskaya ◽  
A. V. Ukhova
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Activity ◽  
Geomagnetic Storms ◽  
Biological Systems ◽  
Magnetic Storms ◽  
Magnetic Observatory ◽  
Earth’S Magnetic Field ◽  
Motion Activity ◽  
Earth's Magnetic Field ◽  
The City

At present, influence of weak magnetic fields associated with solar and geomagnetic activity on biological systems is gaining more interest. Taking into account the accumulated data on the influence of geomagnetic storms on different biological levels, it is obvious that the mechanism of influence is universal. One of the approaches in this search may be the study of patterns and differences in the response to geomagnetic storms of various biological objects. As a research material served: data on the number of ambulance calls in the city of Irkutsk for acute myocardial infarction, cerebral infarction; results of retrospective analysis of the number of spontaneous parturition of the city of Irkutsk; data on the motion activity of fruit fly Drosophyla melanogaster, obtained by automated monitoring. The investigated indicators were compared with the parameters of geomagnetic activity at different time scales. As indicators of geomagnetic storms, three-hour (ap) and daily (Ap) equal to the average amplitude of variation of the geomagnetic field of the Earth. In the case of comparing the motion activity of fruit flies with magnetic storms, the local companions of the Earth’s magnetic field were additionally considered according to the data of the Irkutsk magnetic observatory. As a result of the conducted studies it was established that the detected response of biological systems depends on the characteristics of the state of the Earth’s magnetic field, which falls on the period of passage of magnetic storms. The obtained data also indicate possible gender differences in the response to the effects of the geomagnetic factor by organisms of different levels.

The Atlas of the Earth's Magnetic Field

2012 ◽  
Author(s):  
A. Soloviev ◽  
A. Khokhlov ◽  
E. Jalkovsky ◽  
A. Berezko ◽  
A. Lebedev ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Earth’S Magnetic Field ◽  
Earth's Magnetic Field

Atlas of Earth's magnetic field

2011 ◽  
Vol 12 (2) ◽  
pp. 1-9
Author(s):  
A. E. Berezko ◽  
A. V. Khokhlov ◽  
A. A. Soloviev ◽  
A. D. Gvishiani ◽  
E. A. Zhalkovsky ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Earth’S Magnetic Field ◽  
Earth's Magnetic Field

scholarly journals Night-time Sferic Propagation at Frequencies Below 10 KHz

1967 ◽  
Vol 20 (1) ◽  
pp. 101 ◽  
Author(s):  
KJW Lynn ◽  
J Crouchley
Keyword(s):  
Magnetic Field ◽  
Geographic Distribution ◽  
Angle Of Incidence ◽  
European Studies ◽  
Earth’S Magnetic Field ◽  
Night Time ◽  
The West ◽  
Earth's Magnetic Field ◽  
Effective Angle

Results of a study at Brisbane of individual night-time sferics of known origin are described. A propagation attenuation minimum was observed in the 3-6 kHz range. The geographic distribution of sferic types was also examined. Apparent propagation asynunetries were observed, since sferics were detected at greater ranges to the west than to the east at 10 kHz, whilst the number of tweek-sferics arising from the east was about four times that arising from the west. Comparison with European studies suggest that these asymmetries are general. These results are then " interpreted in terms of an ionospheric reflection cgefficient which is a function of the effective angle of incidence of the wave on the ionosphere and of orientation with respect to the Earth's magnetic field within the ionosphere.

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