On the use of IMAGE FUV for estimating the latitude of the open/closed magnetic field line boundary in the ionosphere
On the use of IMAGE FUV for estimating the latitude of the open/closed magnetic field line boundary in the ionosphere
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DOI：
10.5194/angeo-26-2759-2008
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发表时间：
2008-09
影响因子：
1.9
通讯作者：
P. Boakes;S. Milan;G. Abel;M. Freeman;G. Chisham;B. Hubert;T. Sotirelis
中科院分区：
文献类型：
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作者：
P. Boakes;S. Milan;G. Abel;M. Freeman;G. Chisham;B. Hubert;T. Sotirelis
对IMAGE航天器上的三个远紫外探测器（宽带成像相机WIC和光谱成像仪SI-12和SI-13）估计的开放/封闭磁场线边界（OCB）的纬度进行了统计比较。比较了2000年12月与2001-2002年1月和12月的40多万个OCB估计。三个探测器的FUV OCB代理之间的模态纬度差很小，<1°，除了黎明前和傍晚扇区，其中发现SI-12 OCB代理与SI-13和WIC OCB代理在黎明前扇区向极方向偏移2°，在傍晚扇区向赤道方向偏移2°。比较IMAGE FUV OCB代理与国防气象卫星计划（DMSP）的粒子降水测量结果也显示出系统性差异。发现SI-12 OCB代理位于黎明前地区的较高纬度，与DMSP OCB代理更一致。WIC和SI-13 OCB代理被发现是在更好的协议与DMSP OCB代理在大多数其他磁当地时间。这些系统偏移可用于校正FUV OCB代理，以给出OCB纬度的更准确估计。
A statistical comparison of the latitude of the open/closed magnetic field line boundary (OCB) as estimated from the three far ultraviolet (FUV) detectors onboard the IMAGE spacecraft (the Wideband Imaging camera, WIC, and the Spectrographic Imagers, SI-12 and SI-13) has been carried out over all magnetic local times. A total of over 400 000 OCB estimations were compared from December 2000 and January and December of 2001–2002. The modal latitude difference between the FUV OCB proxies from the three detectors is small, <1°, except in the predawn and evening sectors, where the SI-12 OCB proxy is found to be displaced from both the SI-13 and WIC OCB proxies by up to 2° poleward in the predawn sector and by up to 2° equatorward in the evening sector. Comparing the IMAGE FUV OCB proxies with that determined from particle precipitation measurements by the Defense Meteorological Satellites Program (DMSP) also shows systematic differences. The SI-12 OCB proxy is found to be at higher latitude in the predawn sector, in better agreement with the DMSP OCB proxy. The WIC and SI-13 OCB proxies are found to be in better agreement with the DMSP OCB proxy at most other magnetic local times. These systematic offsets may be used to correct FUV OCB proxies to give a more accurate estimate of the OCB latitude.