 The case sensitivity function approach to diagnostic and robust computation: a relaxation strategy; Schyns, Michael  ; Haesbroeck, Gentiane et alin Antoch, Jaromir (Ed.) COMPSTAT 2004: Proceedings in Computational Statistics (2004) Detailed reference viewed: 7 (1 ULg) Properties of localized, high latitude, dayside aurora; ; et al Conference (2003, February 19) [1] The FUV instrument on the IMAGE spacecraft frequently observes intense ultraviolet (UV) emission from a localized dayside region poleward of the general auroral oval location. One type of these ... [more ▼] [1] The FUV instrument on the IMAGE spacecraft frequently observes intense ultraviolet (UV) emission from a localized dayside region poleward of the general auroral oval location. One type of these emissions has been described as the signature of direct proton precipitation into the cusp after lobe reconnection during northward interplanetary magnetic field (IMF) and high solar wind dynamic pressure periods [Frey et al., 2002]. Here we describe a completely different type of high latitude aurora, which does not show any signature of precipitating protons. It also occurs during northward IMF conditions however, only during periods of very low solar wind dynamic pressure. It occurs at a much higher geomagnetic latitude than the normal cusp location and only during periods of positive IMF By. The intensity of the UV emission is somewhat anti-correlated with the solar wind dynamic pressure, much in contrast to the cusp emission. The brightness of the localized emission changes rapidly on time scales between 30 and 70 minutes without corresponding changes in solar wind properties. Coincident measurements by the FAST spacecraft verify that this is not the cusp, that ion precipitation is absent in these regions, and that strong precipitation of field-aligned accelerated electrons causes the aurora. We interpret this aurora as the optical signature of electron precipitation in the upward leg of a current system which closes the downward leg of the current system into the cusp in the ionosphere. [less ▲] Detailed reference viewed: 8 (1 ULg)Characteristics and Cause of Localized Auroral Uv Emission At High Latitude; ; et al in EGS XXVII General Assembly, Nice, 21-26 April 2002 (2002) The FUV instrument on IMAGE frequently observes localized ultraviolet emission at high latitudes, poleward of the general auroral oval. These localized emissions occur during northward IMF conditions and ... [more ▼] The FUV instrument on IMAGE frequently observes localized ultraviolet emission at high latitudes, poleward of the general auroral oval. These localized emissions occur during northward IMF conditions and there are two different types of them. One type is especially distinct in the observations of Doppler shifted Lyman alpha emission from proton precipitation. This type occurs during high solar wind dynamic pressure. We interpret this emission as the optical signature of proton precipitation into the cusp after lobe reconnection at the magnetopause. The second type of localized emission is distinct in the wide-band (WIC) and oxygen (SI13) images, but is absent in the proton images. This emission occurs during positive IMF By, but very low solar wind density and dynamic pressure. We interpret this emission as the optical signature of electron acceleration in the upward part of a field aligned current circuit after reconnection. [less ▲] Detailed reference viewed: 5 (1 ULg) |
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