Momentum balance of dayside E region neutral winds during geomagnetically quiet summer days
Momentum balance of dayside E region neutral winds during geomagnetically quiet summer days
复制标题
地磁安静夏季白天E区中性风动量平衡
DOI：
10.1029/1999ja900224
复制
发表时间：
1999
影响因子：
--
通讯作者：
S. Nozawa
中科院分区：
文献类型：
--
作者：
S. Maeda;H. Fujiwara;S. Nozawa
本文的目的是研究极光电离层中的白天安静时间E区中性动量平衡。利用欧洲非相干散射(EISCAT)共同程序2(CP-2)资料，获得了1993年6月15日和16日1100到1300UT(1200到1400LT和1400到1600MLT)98到119公里高度的中性风矢量。中性动量方程中的各个强迫项是由MSISE-90模式得到的中性风确定的。为了计算速度随时间的变化，包括与时间相关的平流项和中性动量方程中的粘性力，采用多项式拟合法对得到的中性风进行了垂直和时间的微分。在106公里高度以下，除98公里高度的经向分量外，其余随时间项均大于气压梯度力。在110~116公里高度，气压梯度力与科里奥利力具有相同的量级，而随时间变化的项小于两者。中性风流与气压梯度力基本垂直。在119公里高度，粘性阻力与压力梯度和科里奥利力的粘性阻力处于相同的数量级，并且大于Pedersen和Hall阻力。在这个高度，离子阻力的大小是科里奥利力的∼7%。
An intent of this paper is to study dayside quiet time E region neutral momentum balance in the auroral ionosphere. Neutral wind vectors were obtained by using the European Incoherent Scatter (EISCAT) Common Program 2 (CP-2) data between 98 and 119 km height from 1100 to 1300 UT (from 1200 to 1400 LT and from 1400 to 1600 MLT) on June 15 and 16, 1993. Individual forcing terms in the neutral momentum equation were determined from the derived neutral winds with the MSISE-90 model. In order to calculate the velocity change with time including advection, designated as the time-dependent term, and the viscous force in the neutral momentum equation, a polynomial fitting procedure was applied to perform the vertical and time differentiation of the derived neutral winds. Below 106 km height, the time-dependent term was greater than the pressure gradient force except for the meridional component at 98 km height on June 15. Between 110 and 116 km height, the pressure gradient force was in the same order of magnitude as that of the Coriolis force and the time-dependent term was smaller than these two. The neutral wind flow was nearly perpendicular to the pressure gradient force. At 119 km height, the viscous drag was in the same order of magnitude as those of the pressure gradient and Coriolis forces and greater than the Pedersen and Hall drags. The magnitude of ion drag was ∼7% of the Coriolis force at this height level.
影响因子：
25.2
作者：
J. Forbes;H. Garrett
通讯作者：
J. Forbes;H. Garrett