The three‐dimensional solar wind around solar maximum
The three‐dimensional solar wind around solar maximum
复制标题
DOI：
10.1029/2003gl017136
复制
发表时间：
2003-05
影响因子：
5.2
通讯作者：
D. McComas;H. Elliott;N. Schwadron;J. Gosling;R. Skoug;Bruce E. Goldstein
中科院分区：
文献类型：
--
作者：
D. McComas;H. Elliott;N. Schwadron;J. Gosling;R. Skoug;Bruce E. Goldstein
尤利西斯号现在正在完成它的第二个太阳极轨道，随着太阳经过太阳活动周期的后极大期，它在纬度上下降了。在北半球太阳极大期前后形成的一个中等大小的环极日冕洞持续存在，并产生了一个高度倾斜的CIR，观测范围从~ 70°N下降到~ 30°N。我们发现高速流中的速度最大值遵循着在太阳极小期附近的大极日冕洞中观测到的速度随纬度降低而缓慢下降的相同规律。这些结果表明太阳风的加速效应与太阳经度或太阳自转有关。我们还发现，在这个太阳周期的极大期后阶段，太阳风动压明显低于前一个太阳周期，这表明虽然太阳层比太阳极小期附近大，但它应该比前一个极大期期间或之后小。
Ulysses is now completing its second solar polar orbit, dropping back down in latitude as the Sun passes through its post‐maximum phase of the solar cycle. A mid‐sized circumpolar coronal hole that formed around solar maximum in the northern hemisphere has persisted and produced a highly inclined CIR, which was observed from ∼70°N down to ∼30°N. We find that the speed maxima in the high‐speed streams follow the same slow drop in speed with decreasing latitude observed in the large polar coronal holes around solar minimum. These results suggest a solar wind acceleration effect that is related to heliolatitude or solar rotation. We also find that the solar wind dynamic pressure is significantly lower in the post‐maximum phase of this solar cycle than during the previous one, indicating that while the heliosphere is larger than near solar minimum, it should be smaller than during or after the previous maximum.