The O+ 834‐Å dayglow: Satellite observations and interpretation with a radiation transfer model
The O+ 834‐Å dayglow: Satellite observations and interpretation with a radiation transfer model
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O+ 834-Å 日光：利用辐射传输模型进行卫星观测和解释
DOI：
10.1029/ja088ia11p09271
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发表时间：
1983
影响因子：
--
通讯作者：
S. Bowyer
中科院分区：
文献类型：
--
作者：
Shailendra Kumar;S. Chakrabarti;F. Paresce;S. Bowyer
用辐射传输模式解释了空军卫星STP-78-1上EUV光谱仪观测到的O+834-A白天辉光。在600公里高度，观测到近天顶方向(θ=40°)白辉强度随磁纬度变化，近天顶方向(θ=40°)为400R~500R，近天顶与近低谷强度之比相对较大，约为0.30-0.65.这表明，即使在这样高的高度，电离层顶部的O+离子也构成了834A气辉辐射共振散射的光学厚度介质.对位于赤道附近460公里高度的AE-E航天器的O+密度进行了同步测量，以归一化STP 78-1气辉数据。在零光学厚度下，氧原子的电离激发产生4P态的O+原子所需的g值为1.1×10−8 S−1。由834-A气辉资料得到的O+密度的纬向分布表明，在1000公里以下的赤道槽周围有一个双峰(±13°纬度)，这是赤道异常的特征，在1000公里以上的磁赤道上有一个单峰。在高纬度(>；20°)，夏半球的O+密度明显低于冬半球。
The O+ 834-A dayglow observations made with the EUV spectrometer on the Air Force satellite STP-78-1 are interpreted with the use of a radiation transfer model. At 600-km altitude the dayglow intensity was observed to vary with magnetic latitude from 30 R to 300 R in the near zenith direction (θ = 40°) and from 400 R to 500 R in the near nadir direction (θ = 140°); the correspondingly large near zenith to near nadir intensity ratio of 0.3–0.65 over much of the dayside indicates that the O+ ions in the topside ionosphere constitute an optically thick medium for resonance scattering of 834-A airglow emission even at this high altitude. Simultaneous measurements of the O+ density from the AE-E spacecraft at 460-km altitude near the equator are used to normalize the STP 78-1 airglow data. A g value of 1.1×10−8 s−1 at zero optical depth is required for the ionization excitation of atomic oxygen leading to the production of O+ atoms in 4P state. The latitudinal distribution of O+ density derived from the 834-A airglow data shows a double peak (at ±13° latitude) surrounding an equatorial trough, characteristic of the equatorial anomaly, at altitudes below 1000 km and a single peak at the magnetic equator above 1000 km. At high latitudes (>20°) the O+ densities in the summer hemisphere are substantially lower than those in the winter hemisphere.