RING CURRENT DEVELOPMENT DURING THE GREAT GEOMAGNETIC STORM OF FEBRUARY 1986
RING CURRENT DEVELOPMENT DURING THE GREAT GEOMAGNETIC STORM OF FEBRUARY 1986
复制标题
DOI：
10.1029/ja093ia12p14343
复制
发表时间：
1988-12-01
影响因子：
2.8
通讯作者：
KREMSER, G
中科院分区：
文献类型：
--
作者：
HAMILTON, DC;GLOECKLER, G;KREMSER, G
这场近几十年来最大的磁暴于1986年2月6日突然开始，在接下来的两天里缓慢发展，并在2月8日晚些时候迅速增强，在2月9日的第一个小时达到最小值Dst-312 nT。最初恢复很快，但完全恢复需要一个多月。在本文中，我们遵循环电流的发展，在风暴中使用粒子测量的电荷-能量-质量（CHEM）仪器上的主动磁层粒子示踪剂探索者（AMPTE）CCE航天器。我们比较了环电流离子的能量含量与预期的利用几乎完整的环电流能量范围（1-310千电子伏/电子）的第一次组合物覆盖范围从davedDst值。环电流的组成，从风暴前的安静时间到早期恢复阶段，为期五天。太阳风和电离层源的离子都是暴时环电流的重要组成部分。虽然H+在风暴的大部分时间里携带着大部分的能量，但O+在风暴的最大阶段附近占主导地位，其能量密度为47%，而H+为36%。这与1984年至1985年期间发生的所有较温和的风暴形成对比，其中H+离子包含了风暴最大值附近的大部分能量密度。在这场风暴中，非常快速的初始Dst恢复（τ = 9.3小时）主要是由于环电流内部（L= 2.5-3.0）通过电荷交换快速损失75 - 100-keV O+。由于人们长期以来观察到大风暴中初始Dst恢复比中等风暴快得多，我们认为在大风暴的最大相附近一般存在一个主要的（>50%）O++ N+环电流分量。
The largest geomagnetic storm in recent decades began with a sudden commencement on February 6, 1986, developed slowly over the next two days, and, with a rapid intensification late on February 8, reached a minimumDstof −312 nT during the first hour of February 9. Initial recovery was rapid, but full recovery took more than a month. In this paper we follow the ring current development during the storm using particle measurements from the charge‐energy‐mass (CHEM) instrument on the Active Magnetospheric Particle Tracer Explorers (AMPTE) CCE spacecraft. We compare the energy content of the ring current ions with that expected from observedDstvalues utilizing for the first time composition coverage over nearly the complete ring current energy range (1–310 keV/e). The ring current composition is followed for five days from prestorm quiet time to early recovery phase. Ions of both solar wind and ionospheric origin are important constituents of the storm time ring current. Although H+carries the majority of the energy during most of the storm, O+dominates near the storm's maximum phase, with 47% of the energy density compared with 36% in H+. This is in contrast with all of the more moderate storms which occurred during 1984–1985 in which H+ions contained most of the energy density near storm maximum. The very rapid initialDstrecovery (τ ∼ 9.3 hours) in this storm results largely from the rapid loss of 75‐ to 100‐keV O+via charge exchange in the inner portion of the ring current (L= 2.5–3.0). Since it has been long observed that initialDstrecovery is much more rapid in great storms than in moderate storms, we suggest that a major (>50%) O++ N+ring current component generally exists near the maximum phase of great storms.