A Note on Harmonic Analysis of Geophysical Data with Special Reference to the Analysis of Geomagnetic Storms
|dc.description.abstract||Some geophysical characteristics tend to have a fixed distribution relative to the sun. An example is the distribution of air temperature on an ideal earth that is perfectly symmetrical (e.g., in its pattern of land and water) about its axis of rotation. In such a case the geophysical characteristic at any fixed station on the earth undergoes a daily variation that depends only on local time (and latitude and season). This simple pattern of daily change may be modified by intrinsic changes in the solar influences on the earth. The harmonic components of the daily variation at any station may in this case undergo phase changes, in some respects corresponding to Doppler shifts of frequency in optical or sonic phenomena. Care is then needed if the results of harmonic analysis are to be properly interpreted. Such interpretation is discussed with reference to the parts Dst and DS of the magnetic storm variations. Like caution must be observed in cases where the amplitude of a harmonic variation changes,with fixed phase.||en_US|
|dc.description.sponsorship||Scientific Report No. 1 -- Contract No. AF 19(6o4)-2l63 April 18, I960 -- Geophysics Research Directorate Air Force Cambridge Research Center Air Research and Development Command United States Air Force Bedford, Massachusetts||en_US|
|dc.publisher||Geophysical Institute at the University of Alaska||en_US|
|dc.title||A Note on Harmonic Analysis of Geophysical Data with Special Reference to the Analysis of Geomagnetic Storms||en_US|
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