The determination of the spatial distribution of auroral luminosity
| dc.contributor.author | Romick, G. J. (Gerald Jerry) | |
| dc.contributor.author | Belon, A. E. (Albert E.) | |
| dc.date.accessioned | 2024-10-29T18:26:53Z | |
| dc.date.available | 2024-10-29T18:26:53Z | |
| dc.date.issued | 1964-05 | |
| dc.identifier.uri | http://hdl.handle.net/11122/15557 | |
| dc.description | UAG R-149; Final Report; Summary excerpt: This investigation concerns the determination of the spatial distribution of auroral luminosity in various emissions. The observational data from which this information is obtained was recorded during the Spring of 1960. Two multi-channel D.C. photometer systems were set up at two stations, College and Fort Yukon, Alaska, which lie on the same geomagnetic meridian, 226 km apart, in the northern auroral zone. Through triangulation techniques, the height of the peak intensity and location of the form can be determined. However, in order to understand the geometrical effect of varying distributions for auroral forms of various latitudinal widths and positions from the stations, a computer program using synthetic model auroras was developed. The results of using four different synthetic auroral forms located at seven different positions with respect to the observing stations shows that path length effects are indeed important. It turns out that in a program using two stations the best position of a form for accurate height and location determination is near either station. Also, the alignment of an auroral form along the field lines can be determined definitely only when the aurora lies between the two stations, the error in determination of alignment becoming worse the farther the form lies from the stations. Previously, height-luminosity profiles have been obtained from observations at a single station, using the assumption of a thin sheet distribution. These present studies indicate that this is a good first order approximation only if the location or height of the form is already known accurately. At best, it is only a first order approximation because of the significant modifications introduced by the actual volume distribution in an auroral form. | en_US |
| dc.description.sponsorship | This investigation was supported through the Atmospheric Sciences Section of the National Science Foundation under grants number 8754 and 15725. | en_US |
| dc.description.tableofcontents | List of tables – List of illustrations (illustrations appear at end of the text) – Chapter I. The assimilation of auroral height and spectral studies – 1.1. Introduction – 1.2. History of the determination of auroral heights and luminosity profiles – 1.3. Observational program – Chapter II. Program of data acquisition – 2.1. Observing stations and basic operation – 2.2. System instrumentation – A. Description – B. Operation – 2.3. Calibration of the photometric system – A. Component analysis – B. Starlight standards – Chapter III. Delineation of the problems of data analysis – 3.1. Introduction – 3.2. Considerations of radiative transfer – A. Discussion – B. Procedure – 3.3. Determination of peak luminosity height and auroral form location – Chapter IV. Synthetic model aurora – 4.1. Introduction – 4.2. Description of photometric observation and synthetic aurora – 4.3. Mathematical formulation of synthetic aurora – 4.4. Synthetic aurora data – 4.5. Discussion of synthetic aurora data – 4.6. Computation of auroral luminosity profiles – A. Power series – B. Fourier expansion – C. Semi-empirical approach – Chapter V. Analysis of auroral luminosity profiles – 5.1. Data – 5.2. Mathematical formulation of the spatial profiles – A. The 3914A and 5577A profiles – B. The 6300A profile – 5.3. Discussion of the 6300A emission region – 5.4. Discussion of the luminosity profiles of 3914A (N₂⁺) and 5577A [OI] – 5.5. Interpretation of the observed luminosity profiles – 5.6. Physical processes in the auroral atmosphere – A. Excitation of the 3914A band of N₂⁺ - B. Excitation of the 5577A line of atomic oxygen – 5.7. Conclusions – Acknowledgements – Appendix I. General aurora (model) – Appendix II. General aurora – References – Illustrations. | en_US |
| dc.language.iso | en_US | en_US |
| dc.publisher | Geophysical Institute at the University of Alaska Fairbanks | en_US |
| dc.subject | Auroras | en_US |
| dc.title | The determination of the spatial distribution of auroral luminosity | en_US |
| dc.type | Report | en_US |
| refterms.dateFOA | 2024-10-29T18:26:54Z |
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