Electric field variability associated with the Millstone Hill electric field model
| Autor: | Tim Fuller-Rowell, Mihail Codrescu, J. M. Holt, S. J. Cariglia, John C. Foster |
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| Rok vydání: | 2000 |
| Předmět: |
Physics
Atmospheric Science Millstone Hill Ionospheric dynamo region Ecology Meteorology Field (physics) Joule effect Paleontology Soil Science Forestry Aquatic Science Oceanography Atmospheric sciences Geophysics Earth's magnetic field Space and Planetary Science Geochemistry and Petrology Electric field Physics::Space Physics Earth and Planetary Sciences (miscellaneous) Electric potential Joule heating Earth-Surface Processes Water Science and Technology |
| Zdroj: | Journal of Geophysical Research: Space Physics. 105:5265-5273 |
| ISSN: | 0148-0227 |
| DOI: | 10.1029/1999ja900463 |
| Popis: | Joule heating that is generated at high latitudes in the thermosphere because of the magnetospherically imposed electric potential is proportional to the average of the square of the electric field (E field). Most theoretical Joule heating computations use only average electric fields, resulting in heating that is proportional to the square of the average E field. The computation of the average of the square of the E field requires knowledge about the statistical characteristics of E field variability associated with the average electric field model. In this paper we present the variability associated with the Millstone Hill bin-averaged empirical E field model [Foster et al. 1986] and discuss the implications of variability as an upper atmosphere energy source. We rebinned the radar plasma drift measurements from Millstone Hill, Massachusetts, in magnetic latitude and local time as a function of auroral activity and calculated the average electric fields and the variability associated with them as reflected in the bin standard deviations. We present the E field patterns and the associated variability for both quiet and disturbed geomagnetic conditions for the four seasons. We show that for an electric field model with a Gaussian distribution of small-scale variability around the mean, the average field and the variability have equal contributions to Joule heating generation. |
| Databáze: | OpenAIRE |
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