UARS particle environment monitor observations during the November 1993 storm: Auroral morphology, spectral characterization, and energy deposition
UARS particle environment monitor observations during the November 1993 storm: Auroral morphology, spectral characterization, and energy deposition
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1993 年 11 月风暴期间 UARS 粒子环境监测观测：极光形态、光谱特征和能量沉积
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
C. Gurgiolo
中科院分区：
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作者：
J. Sharber;R. Frahm;R. Link;G. Crowley;J. Winningham;E. Gaines;R. Nightingale;D. Chenette;B. Anderson;C. Gurgiolo
在1993年11月3日至11日的大风暴期间，UARS粒子环境监测器（PEM）在57°倾角、585公里的圆形轨道上，对北方半球当地时间午夜至黎明磁区和南半球中午至傍晚磁区的高能粒子、X射线和磁场扰动进行了测量。X射线图像每90分钟的轨道提供两次电子沉淀区的全球图像（20分钟分辨率），用于研究风暴主要和恢复阶段的形态。在5 eV和5 MeV之间测量的沉淀电子的详细检查表明，在几百eV到几MeV的能量范围内，光谱通常可以由kappa分布表示，其在keV范围内具有热特性，在较高能量下具有幂律分布。选定的光谱测量用于计算电离产生率作为高度的函数。剖面的峰值在95至120公里之间，每个剖面在较低的高度处都有一个由韧致辐射X射线产生的次级边缘。我们表明，由此产生的电离可以是显着的高度低至平流层上部。由于这种电离在全球产生的时间很长，预计将对大气化学产生重大影响。全球功率输入到极光区由于沉淀粒子已计算出的风暴使用PEM X射线和粒子观测的每一天。1993年11月4日，风暴的主要和早期恢复阶段，由现场测量的电子通量计算的北方半球功率为56.8 GW;通过使用X射线图像确定的是47.4GW，这些值可以与使用PEM磁力计和电子通量计算的同一天北方半球焦耳加热率290 GW进行比较测量.
During the major storm of November 3–11, 1993, the UARS particle environment monitor (PEM), in a 57° inclination, 585-km circular orbit, made measurements of energetic particles, X rays, and magnetic field perturbations in the midnight-dawn magnetic local time sector of the northern hemisphere and in the noon-evening sector of the southern hemisphere. X-ray images provide a global picture (∼20-min resolution) of the electron precipitation regions twice per 90-min orbit, which were used to study morphology during the main and recovery phases of the storm. Detailed examination of the precipitating electrons measured between 5 eV and 5 MeV show that in the several hundred eV to several MeV energy range the spectra may often be represented by the kappa distribution, which has a thermal character in the keV range and a power law distribution at higher energies. Selected spectral measurements were used to calculate ionization production rates as functions of altitude. The profiles peak between 95 and 120 km, each having a secondary ledge at lower altitudes produced by the bremsstrahlung X rays. We show that the ionization thus produced can be significant at altitudes as low as the upper stratosphere. Because of the length of time over which this ionization is produced globally, it is expected to have a substantial impact on atmospheric chemistry. Global power inputs to the auroral regions due to precipitating particles have been computed for each day of the storm using PEM X-ray and particle observations. On November 4, 1993, the day that includes the main and early recovery phases of the storm, the northern hemispheric power calculated by in situ measurement of the electron fluxes was 56.8 GW; that determined by using the X-ray images was 47.4 GW, These values may be compared with the northern hemisphere Joule heating rate of 290 GW on the same day computed using the PEM magnetometer and electron flux measurements.