scholarly journals IV. The diurnal variation of terrestrial magnetism

1908 ◽  
Vol 208 (427-440) ◽  
pp. 163-204 ◽  
Keyword(s):  
Diurnal Variation ◽  
Barometric Pressure ◽  
Diurnal Changes ◽  
Electric Currents ◽  
Terrestrial Magnetism ◽  
Previous Communication ◽  
Unknown Amplitude ◽  
Order Of Magnitude ◽  
Probable Origin ◽  
Magnetic Oscillations

1. In a previous communication I proved that the Diurnal Variation of Terrestrial Magnetism has its origin outside the earth’s surface and drew the natural conclusion that it was caused by electric currents circulating in the upper regions of the atmosphere. If we endeavour to carry the investigation a step further and enquire into the probable origin of these currents, we have at present no alternative to the theory first proposed by Balfour Stewart that the necessary electromotive forces are supplied by the permanent forces of terrestrial magnetism acting on the bodily motion of masses of conducting air which cut through its lines of force. In the language of modern electrodynamics the periodic magnetic disturbance is due to Foucault currents induced in an oscillating atmosphere by the vertical magnetic force. The problem to he solved in the first instance is the specification of the internal motion of a conducting shell of air, which shall, under the action of given magnetic forces, determine the electric currents producing known electromagnetic effects. Treating the diurnal and semidiurnal variations separately, the calculation leads to the interesting results that each of them is caused by an oscillation of the atmosphere which is of the same nature as that which causes the diurnal changes of barometric pressure. The phases of the barometric and magnetic oscillations agree to about 1¾ hours, and it is doubtful whether this difference may not be due to uncertainties in the experimental data. In the previous communication referred to I already tentatively suggested a connexion between the barometric and magnetic changes, but it is only recently that I have examined the matter more closely. In the investigation which follows I begin by considering the possibility that both variations are due to one and the same general oscillation of the atmosphere. The problem is then absolutely determined if the barometric change is known, and we may calculate within certain limits the conducting power of the air which is sufficient and necessary to produce the observed magnetic effects ; this conducting power is found to be considerable. It is to be observed, however, that the electric currents producing the magnetic variations circulate only in the upper layers of the atmosphere, where the pressure is too small to affect the barometer; the two variations have their origin therefore in different layers, which may to some extent oscillate independently. Though we shall find that the facts may be reconciled with the simpler supposition of one united oscillation of the whole shell of air, there are certain difficulties which are most easily explained by assuming possible differences in phase and amplitude between the upper and lower layers. If the two oscillations are quite independent, the conducting power depending on the now unknown amplitude of the periodic motion cannot be calculated, but must still be large, unless the amplitude reaches a higher order of magnitude than we have any reason to assume.

scholarly journals The diurnal variation of terrestrial magnetism

1907 ◽  
Vol 80 (535) ◽  
pp. 80-82 ◽  
Keyword(s):  
Diurnal Variation ◽  
Barometric Pressure ◽  
Diurnal Changes ◽  
Electric Currents ◽  
Terrestrial Magnetism ◽  
Previous Communication ◽  
Unknown Amplitude ◽  
Order Of Magnitude ◽  
Probable Origin ◽  
Magnetic Oscillations

1. In a previous communication I proved that the diurnal variation of terrestrial magnetism had its origin outside the Earth’s surface, and drew the natural conclusion that it was caused by electric currents circulating in the upper regions of the atmosphere. If we endeavour to carry the investigation a step further, and consider the probable origin of these currents, we have at present no alternative to the theory, first proposed by Balfour Stewart, that the necessary electromotive forces are supplied by the permanent forces of terrestrial magnetism acting on the bodily motion of masses of conducting air which cut through its lines of force. In the language of modern electro-dynamics, the periodic magnetic disturbance is due to Foucault currents induced in an oscillating atmosphere by the vertical magnetic force. The problem to be solved in the first instance is the specification of the internal motion of a conducting shell of air, which shall, under the action of given magnetic forces, determine the electric currents producing known electro­magnetic effects. Treating the diurnal and semi-diurnal variations separately, the calculation leads to the interesting results that each of them is caused by an oscillation of the atmosphere which is of the same nature as that which causes the diurnal changes of barometric pressure. The phases of the barometric and magnetic oscillations agree to about 1 3/4 hours, and it is doubtful whether this difference may not be due to uncertainties in the experimental data. In the previous communication referred to, I already tentatively suggested a connection between the barometric and magnetic changes, but it is only recently that I have examined the matter more closely. In the investigation which follows, I begin by considering the possibility that both variations are due to one and the same general oscillation of the atmosphere. The problem is then absolutely determined if the barometric change is known, and we may calculate within certain limits the conducting power of the air which is sufficient and necessary to produce the observed magnetic effects. This conducting power is found to be considerable. It is to be observed, however, that the electric currents producing the magnetic variations circulate only in the upper layers of the atmosphere, where the pressure is too small to affect the barometer; the two variations have their origin, therefore, in different layers, which may to some extent oscillate independently. Though we shall find that the facts may be reconciled with the simpler supposition of one united oscillation of the whole shell of air, there are certain difficulties which are most easily explained by assuming possible differences in phase and amplitude between the upper and lower layers. If the two oscillations are quite independent, the conducting power depending on the now unknown amplitude of the periodic motion cannot be calculated, but must still be large unless the amplitude reaches a higher order of magnitude than we have any reason to assume.

scholarly journals V. Atmospheric electricity potential gradient at Kew Observatory, 1898 to 1912

1915 ◽  
Vol 215 (523-537) ◽  
pp. 133-159 ◽  
Keyword(s):  
Diurnal Variation ◽  
Atmospheric Electricity ◽  
Potential Gradient ◽  
Barometric Pressure ◽  
One Year ◽  
Meteorological Elements

In a previous paper, called E 1 for brevity, I discussed the results obtained for the diurnal variation of the potential gradient of atmospheric electricity at Kew Observatory from 1898 to 1904. The present paper deals with the same subject, but employs data from the fifteen years 1898 to 1912. The earlier period of seven years, though longer than that available at most observatories, was too short to give a satisfactorily representative presentation of some of the phenomena. To obtain results fairly characteristic of the locality many years data are required of some of the meteorological elements, especially barometric pressure and rainfall. For the latter element, in fact, a considerably longer period is desirable than that available even now for potential gradient at Kew. The same may be true of potential gradient itself, but various reasons exist for not waiting longer. Owing to building operations, the electrograph results for 1913 were exposed to special uncertainties. Also the transfer of the electrograph from the position it has occupied since 1898 is now in contemplation. Thus 1912 may be regarded as ending an epoch. Another reason requires fuller explanation. The Kew water-dropper—the earliest it is believed in regular operation—was erected in 1861 under Lord Kelvin’s personal supervision. The original electrometer and batteries as they decayed were replaced by others, but the instrument remained essentially unchanged in its original site until 1896. Of the records obtained prior to that date those of only three years had been discussed, two years, 1862 to 1864, by Prof. J. D. Everett, and one year, 1880, by Mr. G. M Whipple. In both cases the results were expressed in what were really arbitrary units. The relation between the voltage shown by the instrument and the true potential gradient in the open was altogether unknown.

scholarly journals Shotgun Lipidomics Discovered Diurnal Regulation of Lipid Metabolism Linked to Insulin Sensitivity in Nondiabetic Men

2019 ◽  
Vol 105 (5) ◽  
pp. 1501-1514 ◽  
Author(s):  
Katharina Kessler ◽  
Mathias J Gerl ◽  
Silke Hornemann ◽  
Markus Damm ◽  
Christian Klose ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Insulin Sensitivity ◽  
Diurnal Variation ◽  
Saturated Fatty Acids ◽  
Insulin Response ◽  
Time Of Day ◽  
Diurnal Changes ◽  
High Fat ◽  
Shotgun Lipidomics ◽  
Meal Timing

Abstract Context Meal timing affects metabolic homeostasis and body weight, but how composition and timing of meals affect plasma lipidomics in humans is not well studied. Objective We used high throughput shotgun plasma lipidomics to investigate effects of timing of carbohydrate and fat intake on lipid metabolism and its relation to glycemic control. Design 29 nondiabetic men consumed (1) a high-carb test meal (MTT-HC) at 09.00 and a high-fat meal (MTT-HF) at 15.40; or (2) MTT-HF at 09.00 and MTT-HC at 15.40. Blood was sampled before and 180 minutes after completion of each MTT. Subcutaneous adipose tissue (SAT) was collected after overnight fast and both MTTs. Prior to each investigation day, participants consumed a 4-week isocaloric diet of the same composition: (1) high-carb meals until 13.30 and high-fat meals between 16.30 and 22:00 or (2) the inverse order. Results 12 hour daily lipid patterns showed a complex regulation by both the time of day (67.8%) and meal composition (55.4%). A third of lipids showed a diurnal variation in postprandial responses to the same meal with mostly higher responses in the morning than in the afternoon. Triacylglycerols containing shorter and more saturated fatty acids were enriched in the morning. SAT transcripts involved in fatty acid synthesis and desaturation showed no diurnal variation. Diurnal changes of 7 lipid classes were negatively associated with insulin sensitivity, but not with glucose and insulin response or insulin secretion. Conclusions This study identified postprandial plasma lipid profiles as being strongly affected by meal timing and associated with insulin sensitivity.

scholarly journals II. The diurnal variations of the wind and barometric pressure

1877 ◽  
Vol 25 (171-178) ◽  
pp. 402-411
Keyword(s):  
Diurnal Variation ◽  
Royal Society ◽  
Barometric Pressure ◽  
Diurnal Variations ◽  
The Self ◽  
Diurnal Wind ◽  
Wind Currents ◽  
Remarkable Manner

In a paper which was read before the Royal Society in 1873, and which was honoured with a place in the 'Philosophical Transactions' of that year, I discussed the diurnal variations of the wind and barometric pressure at Bombay, and deduced therefrom the fact that a system of diurnal wind-currents moves synchronally with the diurnal variation of barometric pressure. Reasons, were given for believing that that system of diurnal wind-currents is a universal phenomenon; and on that hypothesis I showed how the diurnal variations of the barometer could be explained as a result of those currents. I have lately examined closely the “Discussion of the Anemometrical Results furnished by the self-recording Anemometer at Bermuda,” which forms Appendix II. of the ‘Quarterly Weather-Report of the Meteorological Office, London,’ July to September 1872. Those results support the conclusions arrived at in my former paper in such a remarkable manner as to justify the readvancement of some of them in a form which will prominently exhibit their relation to the diurnal variation of the barometer.

The solar semidiurnal variation of cosmic-ray intensity 70 m.w.e. underground

1968 ◽  
Vol 46 (10) ◽  
pp. S839-S843 ◽  
Author(s):  
G. Cini-Castagnoli ◽  
M. A. Dodero ◽  
L. Andreis
Keyword(s):  
Diurnal Variation ◽  
Cosmic Ray ◽  
Fermi Acceleration ◽  
Sidereal Time ◽  
Cosmic Ray Intensity ◽  
Intensity Measurements ◽  
Hourly Data ◽  
Semidiurnal Variation ◽  
Order Of Magnitude ◽  
Different Depths

Cosmic-ray intensity measurements have been carried out during the last year at a depth of 70 m.w.e. in the Monte dei Cappuccini laboratory in Torino, using solid vertical semicubical scintillator telescopes with a total area of 2 m2. Hourly data for 245 days corrected for barometric changes have been analyzed for the solar, apparent sidereal, and antisidereal daily variations whose harmonics are as follows:[Formula: see text]The true sidereal diurnal variation is estimated to have an amplitude of 0.019% with a time of maximum at 1720 h local sidereal time. The solar diurnal variation at different depths underground follows the energy dependence calculated with Axford's theory. The solar semidiurnal variation shows instead a fairly constant value at different μ energies. Its order of magnitude agrees with that expected as a result of Fermi acceleration in collisions of primaries moving in roughly solar and antisolar directions with solar wind inhomogeneities.

scholarly journals XIX. Results of the magnetic observations at the Kew Observatory.— No. III

1866 ◽  
Vol 156 ◽  
pp. 441-451
Keyword(s):  
Diurnal Variation ◽  
Present Communication ◽  
Terrestrial Magnetism ◽  
Magnetic Elements ◽  
Rigorous Description ◽  
Magnetic Investigation ◽  
Magnetic Observatories ◽  
At Home

T h e recognition of a cosmical origin of some of the variations of terrestrial magnetism has made it desirable to employ in magnetic observatories apparatus of a more exact and dependable character, and methods of dealing with the results thus obtained of a more close and rigorous description, than were previously thought requisite. The present communication is directed to the discussion of the Lunar-diurnal Variation of the three magnetic elements shown by the instrum ents and methods adopted at the Kew Observatory, commencing in 1858, and continued as far as the reductions have at present proceeded, viz. to the close of 1864. I t has the double purpose, first, of making known the systematic and highly satisfactory character of the results which have been already obtained; and, second, of acting in some measure as a guide, and certainly as an encouragement, to the several establishments at home and abroad which have adopted the Kew System of magnetic investigation.

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