The areal distribution of geomagnetic activity as an aeromagnetic survey problem near the auroral zone

1953 ◽  
Vol 34 (6) ◽  
pp. 836 ◽  
Author(s):  
L. W. Morley
Keyword(s):  
Geomagnetic Activity ◽  
Auroral Zone ◽  
Aeromagnetic Survey ◽  
Areal Distribution

scholarly journals Scintillations of Radio Sources and Geomagnetic Activity

1962 ◽  
Vol 15 (4) ◽  
pp. 568 ◽  
Author(s):  
OB Slee
Keyword(s):  
Magnetic Field ◽  
Radio Source ◽  
Geomagnetic Activity ◽  
Auroral Zone ◽  
Radio Sources ◽  
Present Communication ◽  
Earth’S Magnetic Field ◽  
K Index ◽  
Northern Latitudes ◽  
The Relationship

The relationship between variations in the Earth's magnetic field and radio source scintillation has been somewhat obscure since the first observation by Little and Maxwell (1952) that, for sources observed through the Northern Auroral Zone, the scintillation rate, but not the amplitude, was closely correlated with the planetary K index. Since then a number of observers, mainly situated in high northern latitudes, also found no relation between the scintillation amplitude and geomagnetic activity. It is the purpose of the present communication to show that at southern temperate latitudes a relationship does exist between these quantities.

scholarly journals Analysis of geomagnetic disturbances dynamics during increased solar activity and magnetic storms (according to the measurements of INTERMAGNET station network)

2019 ◽  
Vol 127 ◽  
pp. 02003
Author(s):  
Oksana Mandrikova ◽  
Anastasia Rodomanskay ◽  
Alexander Zaitsev
Keyword(s):  
Geomagnetic Activity ◽  
Geomagnetic Field ◽  
Auroral Zone ◽  
Magnetic Storms ◽  
Magnetic Data ◽  
Field Variation ◽  
Geomagnetic Disturbances ◽  
Station Network ◽  
Ground Station ◽  
Automated Method

We present and describe an automated method for analysis of magnetic data and for detection of geomagnetic disturbances based on wavelet transformation. The parameters of the computational algorithms allow us to estimate the characteristics of non-uniformly scaled peculiar properties in the variations of geomagnetic field that arise during increasing geomagnetic activity. The analysis of geomagnetic data before and during magnetic storms was carried out on the basis of the method according to ground station network. Periods of increasing geomagnetic activity, which precede and accompany magnetic storms, are highlighted. The dynamic of geomagnetic field variation in the auroral zone is considered in detail.

IRREGULAR MAGNETIC ACTIVITY IN NORTHERN CANADA WITH SPECIAL REFERENCE TO AEROMAGNETIC SURVEY PROBLEMS

Geophysics ◽  
1957 ◽  
Vol 22 (3) ◽  
pp. 646-659 ◽  
Author(s):  
K. Whitham ◽  
E. I. Loomer
Keyword(s):  
Magnetic Activity ◽  
Auroral Zone ◽  
Maximum Activity ◽  
High Latitudes ◽  
Aeromagnetic Survey ◽  
Northern Canada ◽  
K Index ◽  
Seasonal Characteristics ◽  
Short Period ◽  
Two Peaks

An investigation of the diurnal and seasonal characteristics of irregular magnetic activity in northern Canada, using two indices of disturbance, shows that in general the K index provides a reliable but smoothed measure of short period activity. Two peaks of activity are evident, a day‐time peak, dominant inside the polar cap, and a night peak, dominant south of the auroral zone. The latter occurs within one hour of local geomagnetic midnight at four Canadian observatories, whereas the day‐time peak occurs progressively later at higher latitudes. The maximum activity occurs in the equinoxes at latitudes near the auroral zone, and during the summer solstice at very high latitudes. Measurements of range at the most disturbed observatory suggest that aeromagnetic surveying in high latitudes is in general feasible, but that for accurate reconnaissance work it is very advantageous to plan operations, so far as conditions permit, taking account of the systematic diurnal variation of disturbance. It is shown that errors of about one half the assumed diurnal change between base lines will occur and sufficient data is given to allow approximate predictions of the optimum length of flight lines.

A discussion on D and E region winds over Europe - Winds and temperatures in the auroral zone and their relations to geomagnetic activity

1972 ◽  
Vol 271 (1217) ◽  
pp. 563-575 ◽  
Keyword(s):  
Electric Fields ◽  
Geomagnetic Activity ◽  
Atmospheric Temperature ◽  
Global Scale ◽  
Auroral Zone ◽  
Neutral Wind ◽  
Wind Speeds ◽  
A Value ◽  
Neutral Temperature ◽  
E Region

Measurements of neutral wind velocity and neutral atmospheric temperature above 90 km in the auroral zone have shown distinct correlations with local and global geomagnetic activity respectively. Individual magnetic substorms have been observed to produce neutral wind speeds of over 500 m -s at 130 to 150 km. Ion-neutral particle drag is a likely accelerating mechanism with enhanced meridional electric fields and electron density. These wind disturbances can theoretically propagate to mid-latitudes in the night hemisphere and produce anomalously high neutral wind speeds on a global scale especia y during geomagnetic storm conditions. Such anomalously high wind speeds have been observed on several occasions at mid-latitude sites during disturbed conditions. Neutral temperature values in the auroral zone show a positive correlation with geomagnetic activity with a relatively slow decay following heating. The temperature dependence upon the G9 index (which is representative of jQ) is altitude dependent, increasing from a value near to the global mean (25 K per unit C9) at 140 km to an enhanced value of 50 K per unit G9 at 165 km. Auroral zone measurements are only possible during the period September to April inclusive; however, in this period, during quiet geomagnetic conditions and between 130 and 200 km, there is a decrease of neutral temperature of 150±50K between mid-latitudes (30° N) and the aurora zone (70° N) which is significantly greater than the polewards decrease of temperature predicted from satellite drag density data.

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