共查询到20条相似文献，搜索用时 62 毫秒
1.
Summary Solar and lunar geomagnetic tides inH at Alibag have been determined by spectral analysis of discrete Fourier transforms following the method of Black and the well-known Chapman-Miller method. The seasonal variation inL
2(H) is opposite to that inL
2(D) with maximum in thed season and minimum in thej season. In bothH andD the enhancement due to sunspot activity is larger in lunar tide than in solar tide. Surprisingly, the enhancement due to magnetic activity is greater inL
2(H) than inS
1(H), while the contrary is true for declination. It is inferred that there is a local time component of the storm time variation contrary to the view expressed by Green and Malin. The enhancements in amplitudesL
2 andS
1 inH andD, due to sunspot activity and due to magnetic activity, have been separated. The results show that the amplitude at zero sunspot number increases with magnetic activity in all the four parameters, while the enhancement due to sunspot activity at different levels of magnetic activity decreases with increase ofK
p. But if bothK
p andR are increasing, whenK
p increases enhancement due toR decreases and whenR increases enhancement due toK
p decreases. 相似文献
2.
A. Mete Isikara 《Pure and Applied Geophysics》1973,104(1):544-552
Summary The sunspot cycle variation of the amplitude of the solar magnetic variation has been investigated for magnetically moderate, quiet and disturbed days at Istanbul for the period 1949–1968, and fairly good linear relationship has been found forZ andD components of the earth's magnetic field. In some cases, it is rather difficult to say that there is any linear relationship between sunspot number and the amplitude of theH component of the earth's magnetic field. Meanwhile,K indices has also been considered with sunspot number by means of multiple regression analysis to overcome some uncertainties in this investigation. 相似文献
3.
D. R. K. Rao 《Pure and Applied Geophysics》1972,95(1):131-140
Summary Lunar and luni-solar geomagnetic components have been computed upto four harmonics for low latitude station Alibag, outside equatorial electrojet belt, and the equatorial electrojet stations Annamalainagar, Kodaikanal and Trivandrum in the south Indian region. The computations are confined to data of very high solar activity period 1958–61. Amplitudes of lunar semidiurnal component (L
2), in the horizontal intensity (H), undergo an equatorial enhancement. Phase difference of 2 hrs is noticed inL
2
(H) between nonelectrojet and electrojet stations. In the vertical intensity (Z), L
2 is maximum ine andj-seasons at Trivandrum, close to the magnetic equator. Ind-season, however, maximumL
2
(Z) occurs at Annamalainagar (dip 5°.4N). The phase difference between the electrojet and nonelectrojet stations observed inL
2
(H) is not noticed inL
2
(Z). The differential vertical upward drift motion of charged particles may explain the observed phase difference inL
2
(H). Seasonal variations in amplitudes and times of maxima are noticed at all the stations inL
2
(H) andL
2
(Z). Similar variation is also noticed at Alibag inL
2 of declination (D). 相似文献
4.
Summary The lunar daily (L) and lunar monthly (M) variations in horizontal magnetic field (H), maximum electron density (N
max
), height of peak ionisation (h
max
), semi-thickness (y
m
) of theF
2 layer and total electron content (N
t
) at Huancayo for the period January 1960 to December 1961 are described. The lunar tidal variations inh
max
follow sympathetically the variations inH such that an increase of magnetic field causes the raising of height of peak ionisation. Lunar tides inN
max
are opposite in phase to that ofh
max
with a delay of about 1–2 hours, suggesting that an increase of height causes a decrease in maximum electron density. The lunar tides in semi-thickness are very similar in phase to that inh
max
. The lunar tidal effects in any of the parameters are largest inD-months and least inJ-months. The amplitude of lunar tides in maximum electron density seems to increase with increasing height whereas the phase seems to be constant with height. It is concluded that lunar tides in the ionospheric parameters at magnetic equator are greatly controlled by the corresponding geomagnetic variations.Presented at the Third International Symposium on Equatorial Aeronomy, Ahmedabad, 3–10 February 1969. 相似文献
5.
S. Jeevananda Reddy 《Pure and Applied Geophysics》1976,114(1):29-38
Summary A modified method of computing theS
q
-range in terms ofR
x
inH, D andZ has been suggested. Mean quiet-day daily rangesR
x
, have been computed for five Indian stations usingH, D andZ data for selected years. The seasonal and latitudinal variation ofR
x
(H), R
x
(Z) andR
x
(D) are discusses. Thee-season maximum inR
x
(H) andR
x
(Z) is attributed to the decrease in the distance between the foci during equinoxes; the electrojet and theS
q
-foci movement with seasons have little influence onS
q
(D). It is inferred that the electrojet current is independent of the worldwideS
q
current system and stands with its own return currents.The variation of lunar semi-diurnal tide inH[L
2
(H)] with the dip latitude in Indian region shows a secondary peak at 9° N dip latitude. This secondary peak in theL
2
(H) is termed as Lunar secondary electrojet, and it is suggested that this is possibly produced by magneto-acoustic oscillations due to the drift motion of the charged particles that produce the primary jet in a direct transverse to itself. 相似文献
6.
D. R. K. Rao 《Pure and Applied Geophysics》1972,98(1):146-152
Summary Results of sunspot cycle influence on solar and lunar ranges at a low latitude station, Alibag, outside the equatorial electrojet belt, show that the sunspot cycle association in solar ranges is three times that of the lunar ranges in thed- andj-seasons. This is in general agreement with the earlier results for non-polar latitude stations. The association with sunspot number of individual lunar amplitudes is greatest for lunar semidiurnal harmonic in thej-season. During this season, the sunspot cycle influence on lunar variations is more than that on solar variations, thereby indicating that the lunar current is situated at a level more favourable for sunspot cycle influence than the level of the current associated with solar variations. With the increase in solar activity a shift appears in the times of maxima of semidiurnal lunar variation towards a later lunar hour ine- andj-seasons and in the year. 相似文献
7.
Geomagnetic solar and lunar daily variationsS andL, at Alibag, India are derived, by the well-known Chapman-Miller method, from the series of homogeneous mean hourly magnetic data of the years 1932 to 1972. The data for all the three elements — declinationD and horizontal and vertical intensitiesH andZ — are analysed, by dividing the data suitably for a study of the seasonal variations, the effect of the changes in the solar and magnetic activities onS andL, the oceanic dynamo contribution toL, and their interactions with each other. The main results are as follows.
- ForS the daily pattern and its seasonal progression conform to the type expected from a northern-hemisphere station. On the other hand, the amplitudes of all the four harmonics ofL systematically have higher values in winter, and inD andZ the harmonics show large phase differences between summer and winter. The pattern ofL in winter suggests that the lunar current system consists of a single set of vortices in the summer hemisphere rather than the conventional vortices, one set in each of the hemispheres.
- Solar-cycle modulation on the solar ranges as well as on the amplitudes of the first three harmonics ofS is greater than that expected solely from the increase in E-region conductivity, whereas the corresponding modulation onL is comparable to that on the E-region conductivity.
- With increasing magnetic activity the first harmonic ofS shows an increase, and the first three harmonics ofL indicate a general decrease, in amplitude.
- Of the variability inS 96%, but inL only 32%, is found to be accounted for by the combined effect of the variations in the solar and magnetic activities.
8.
J. Podsklan 《Surveys in Geophysics》1984,6(3-4):261-267
130 sites were occupied in a magnetic survey of Slovakia. About half of those occupied in previous surveys (1952.5, 1958.5, and 1967.5) were unsuitable because of increased man made noises. New stations were substituted. A combination of classical magnetometers (forH andD) and a proton magnetometer (forF) was used.Z was computed fromH andF. Instruments were calibrated at Hurbanovo magnetic observatory before the survey and at regular size intervals during it.Reduction to epoch was made on the assumption that the scale variation is everywhere the same and equal to that at Hurbanovo. Preliminary maps are hand drawn, but the data have been transferred to computer tape and computer plotted maps are being prepared. 相似文献
9.
The system consists of three magnetic variometers with electrical output signals for theH, D, andZ components, a proton magnetometer for the total field, a data acquisition system, two cassette recorders, an analogue chart recorder, a calendar clock, and a telex. The analogue and digital input data are sampled at 10 sec intervals, averaged over a minute, and recorded on a magnetic tape cassette. The computed hourly and daily mean values and the daily minimum and maximum values are recorded together with the occurrence times on a second cassette, at the operator's request. Rapid run recording of the 10 sec values of each measured component is initiated automatically during magnetic storms.DIMARS incorporates several test functions as ROM test, A/D converter test, recorder test, telexline test and checking the memory content. The test functions can be activated by the equipment keyboard, or via the telex. The telex can also be operated as an output printer. 相似文献
10.
E. Kring Lauridsen 《Surveys in Geophysics》1984,6(3-4):223-232
In a large coil with vertical axis the current is adjusted so thatZ=0. A smaller coil of a new type with four sets of cylindrical turns is placed with its axis horizontal. ThisD-coil is provided with a telescope pointing at a mark nearly in the magnetic meridian. A proton magnetometer sensor is placed in the common centre of the coils. Two series of readings are taken with theD-coil in the erect and inverted position respectively. Variations ofD, H, F, andD-coil current are recorded. A simple formula gives the mean value ofD. 相似文献
11.
Ebun Oni 《Pure and Applied Geophysics》1972,94(1):198-211
Summary The author proposes a new technique of magnetic interpretation in the case of a two-dimensional model, whereby six analytical expressions are deduced and computed forDH, DZ, PHB, PZB, AHB andAZB. These expressions denote the induced part of magnetic anomaly inH component, the induced part of anomaly inZ component, the permanent magnetization part ofH anomaly, the permanent magnetization part ofZ anomaly, the sum (DH+PHB), and the sum (DZ+PZB), respectively. The use of a series of these six curves taken together instead of the single profile curve, will improve the existing method of magnetic interpretation, reduce the uncertainties of the inverse problem, and provide a valuable tool for paleomagnetic studies of in situ older rocks commonly found in equatorial Africa. The resulting advantages outweigh the apparent increase in computation. This technique was applied to a field profile obtained across a subsurface dolerite vein, and the results agree with the theoretical predictions outlined. 相似文献
12.
Dr. K. Burkhart 《Pure and Applied Geophysics》1953,24(1):54-56
Zusammenfassung Die magnetischen Bais werden in zwei Klassen (I und II) eingeteilt, je nachdem sie positive oder negative Ausschlagsrichtung inH zeigen. Wie die Analysen der charakteristischen Hauptstromvektoren ergeben, kann man aus dem Verhalten derH-Variationen allein nichts über den tatsächlichen Verlauf des ionosphärischen Strombandes aussagen. Da dieD-Variationen größenordnungsmäßig denH-Variationen entsprechen, gewinnt man erst nach Berücksichtigung beider Elemente ein sicheres Bild der Stromverhältnisse. So können bei ähnlichenD-Schwankungen aber entgegengesetzten Ausschlägen inH fast gleiche Stromverhältnisse in der Ionosphäre existieren. — Bemerkenswert ist bei sehr vielen Bais das Einsetzen desD-Maximums vor dem desH-Maximums. Das entspricht einer anfänglich meridionalen Strömung, die allmählich in eine zonale einbiegt.
Summary The magnetic bays are divided into two classes according to their positive or negative directions ofH. As results from the analysis the characteristic main-current-vectors nothing definitive can be concluded from the behavior of theH-variations alone concerning the actual course of the ionospheric ribbon-current. Since theD-variations in their sizes correspond with theH-variations a correct picture of the positions can be only won after considerations of eather element. Thus almost similar current situations may exist in the ionosphere provided similarD-fluctuations showing different directions inH are effective. — Particularly to be mentioned is the fact that in many bays the maximum appears before that of theH-maximum and this is corresponding to the initial meridional-current which slowly turns into a zonalcurrent.相似文献
13.
Mario Bossolasco 《Pure and Applied Geophysics》1951,20(1):46-49
Summary The comparison of the geomagneticK-indices for Mogadiscio with the correspondingK
p
for the whole earth, during the 2.nd Intern. Polar Year 1932–33, allows to deduce some features of the equatorial geomagnetic activity. Furthermore, evidence is adduced indicating that the geomagnetic disturbance at Mogadiscio is normal inH andD, while it appears slightly abnormal inZ.
Communication presentée à l'Association Internationale de Magnétisme et Electricité Terrestres, IXe Assemblée Générale de l'UGGI, Bruxelles, Séance du 28 Août 1951. 相似文献
Communication presentée à l'Association Internationale de Magnétisme et Electricité Terrestres, IXe Assemblée Générale de l'UGGI, Bruxelles, Séance du 28 Août 1951. 相似文献
14.
The diurnal variations in the amplitude and parameters of polarization ellipses of the first Schumann resonance according
to three magnetic field components, observed on December 1–10, 2007, at the Barentsburg and Lovozero observatories, have been
studied. Ellipses have been constructed in the (H, D) and (H, Z) planes. The value of the minor axis, inclination of the major axis, ellipticity, and the rotation direction have been estimated.
The vertical magnetic component of the Schumann resonance is three to four times as small as the horizontal component. The
difference in the diurnal variations in the ellipse parameters between both observatories has been found. The effect can be
caused by a difference in the Earth’s conductivity in the vicinity of the observatories and by conductivity anisotropy. The
major axis inclination and ellipticity have semidiurnal components. The polarization vector mostly rotates from D to H in the horizontal plane and from Z to H in the vertical plane at both stations. 相似文献
15.
Using the minute data of the H component of geomagnetic field from the 20°E magnetic meridian chain and the 30°N magnetic latitudinal chain, the temporal evolution characteristics of the equatorial ring current during the storm on November 7-10, 2004 are studied. It is indicated that the UT-MLT and UT-MLAT graphics extremely exhibit the local time distribution, latitudinal variation and temporal evo- lution of the H component. The results show: (1) The UT-MLT contour clearly shows the increasing of the H component mostly around noon during the initial phase, representing the geomagnetic effect from the magnetopause current system. During the main phase, most negative values of the H com- ponent appear around the dusk-side, indicating the dawn-dusk asymmetric distribution of the ring cur- rent. (2) The contour of UT-MLAT suggests the latitudinal variation of the H component decreasing with the enhancement of the latitudes during geomagnetic storm, which is in good agreement with the Dst index. The latitudinal variations provide a new sight for describing the temporal characteristics of the intensity of the storm-time ring current. (3) Both the contours of UT-MLT and UT-MLAT are useful to monitor the space-time distribution of the equatorial ring current. 相似文献
16.
Prof. Sydney Chapman 《Pure and Applied Geophysics》1951,19(3-4):151-158
Summary Evidence is adduced indicating that geomagnetic disturbance at Huancayo isnormal, that is, comparable with that shown elsewhere in similar latitudes —as contrasted with the remarkable Huancayoabnormality, in the horizontal magnetic force, of the quiet-day solar and lunar daily variations, and in theS
q augmentation (solar flare effect). the normality of magnetic disturbance at Huancayo is manifested by the disturbance daily variationS
D, and by the storm-effectD
st and its associated changes of daily mean (D
m) and the non-cyclic variation; it is not stated whether or not the irregular part,D
i, is normal. The normality ofD
st seems natural according to theChapman-Ferraro theory of magnetic storms, but the normality ofS
D is less easy to explain.Prof.Sydney Chapman, Research Associate, California Institute of Technology, under Signal Corps Project No. 24-172 B; on leave (from April 1950 to March 1951) from Oxford University, Queen's College,Oxford, England. 相似文献
17.
Summary The lunar semidiurnal variation of ionospheric absorption at Freiburg and of thef
0
F2 at, Genova, Freiburg and Léopoldville has been deduced. The results are compared with those obtained by other Authors. Magnetic dip, rather than geomagnetic latitude, is found to be a parameter controlling the morphology of the lunar semidiurnal variation of theF2 layer. Finally, a graphical representation of the amplitude of lunar semidiurnal variation off
0
F2 as function of the magnetic dip is also given.
This research was supported by a grant from the Committee on Lunar Variation (IAGA). The paper has been presented at the XII-Assembly of the I.G.G.U. in Helsinki (July–August 1960). 相似文献
Riassunto Viene determinata la variazione lunare semidiurna dell'assorbimento ionosferico per Friburgo e della frequenza critica dello stratoF2 per Genova, Friburgo, Léopoldville. I risultati sono confrontati con quelli ottenuti da altri Autori per varie stazioni situate in diverse parti del globo. In particolare si trova che la inclinazione magnetica, meglio della latitudine geomagnetica, è il parametro che regola la morfologia della variazione lunare inF2. Infine si dà una rappresentazione grafica dell'ampiezza della variazione lunare dellaf 0 F2 come funzione dell'inclinazione magnetica.
This research was supported by a grant from the Committee on Lunar Variation (IAGA). The paper has been presented at the XII-Assembly of the I.G.G.U. in Helsinki (July–August 1960). 相似文献
18.
J. Bitterly J. M. Cantin R. Schlich J. Folques D. Gilbert 《Surveys in Geophysics》1984,6(3-4):233-239
A new portable magnetometer theodolite with fluxgate sensor has been developed for measuring the components of the earth's magnetic field. With this instrument, used as a null detector, it is possible to make absolute measurements of declination (D) and inclination (I). The compensation of the main magnetic field allows direct intensity measurements (H, X, Y, Z components); in this case the calibration is made by reference to a proton magnetometer.The observation procedure is particularly easy and quick. The accuracy is better than 5 sec of arc forD andI and better than 1 nT for direct intensity measurements. 相似文献
19.
利用2019年度大华北秋季复测156个测点的流动地磁矢量资料,获得河北及周边地区岩石圈磁场半年变化图,分析归纳河北及周边地区岩石圈磁场的总体变化特征,并研究测区内2019年12月3日河北怀安MS3.4地震和2019年12月5日河北丰南MS4.5地震前岩石圈磁场局部变化和异常特征。结果表明：丰南MS4.5地震发生在H矢量的转向区,总强度F负异常的高值区,D要素负异常的高梯度带和Z值变化的高值区;怀安MS3.4地震则发生在H矢量幅值弱化且转向区,D要素零值线附近的正值区和Z值变化的低值区。 相似文献
20.
A digital recording system has been operated at the U.K. observatories since 1979. The magnetic elementsH, D, andZ are monitored continuously by a triaxial fluxgate magnetometer operating in the variometer mode. Ordinate values are recorded at 30-sec intervals. Total field and the temperature of the variometer chamber are measured at the start of each 10-min data block.Fluxgate magnetometer baseline values are derived from absolute measurements made by proton vector magnetometer and Kew declinometer in the conventional manner.In this paper the data handling procedures are described and the quality of the data over a period of two years is discussed. 相似文献