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ULF Waves Associated with Solar Wind Deceleration in the Earth＇s Foreshock

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Chinese Physics Letters 2009年第11期26卷 258-261页

作者：符慧山曹晋滨杨彪 Lucek E Reme H dandouras i State Key Laboratory of Space Weather Center for Space Science and Applied Research Beijing 100190 Graduate University of Chinese Academy of Sciences Beijing 100049 Beijing University of Aeronautics and Astronautics Beijing 100190 institute of Space Physics and Applied Technology Peking University Beijing 100871 Blackett Laboratory Imperial College Prince Consort Road London SW7 2BZ UK Centre d'Etude Spatiale des Rayonnements 31028 Toulouse France

Characteristics of ULF waves associated with the solar wind deceleration in the Earth＇s foreshock on 6-7 April 2003 is studied using the wave telescope technique. in the satellite frame, the ULF waves are the left-handed polarized and quasi anti-parallel propagating mode, with a power peak at about 18.63mHz. The wave vector in the GSE coordinates is estimated to be k = （-4.29, 2.28, 1.21）×10^-4 km^-1, in the solar wind frame, the frequency of waves becomes - 9.39 mHz after the Doppler shift correction. The propagation direction of the waves is thus reversed and correspondingly the polarization of the waves becomes right-handed. The above-mentioned characteristics of the ULF waves in the solar wind frame indicate that the ULF waves associated with the solar wind deceleration are the Alfven-whistler waves, which have been frequently reported in both the observations and computer simulations.

关键词： Plasma physics Environmental and Earth science Astrophysics and astroparticles

Shrinkage of magnetosphere observed by TC-1 satellite during the high-speed solar wind stream

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Science China(Technological Sciences) 2008年第10期51卷 1695-1703页

作者： H. RME i. dandouras C. M. CARR Centre d'Etude Spatiale des Rayonnements BP 4346 31028 Toulouse cedex 4 France The Blackett Laboratory Imperial College London SW7 2BZ UK

During the interval 06:14―07:30 UT on August 24, 2005, since the Earth’s magneto- pause was suddenly compressed by the persistent high-speed solar wind stream with the southward component of the interplanetary magnetic field (iMF), the magnetopause moved inward for about 3.1 RE. Meanwhile, TC-1 satellite shifted from northern plasma sheet to the northern lobe/mantle region, although it kept inward flying during the interval 06:00―07:30UT. The shift of TC-1 from the plasma sheet to the lobe/mantle is caused by the simultaneous inward displacements of the plasma sheet and near-Earth lobe/mantle region, and their inward movement velocity is larger than the inward motion velocity of TC-1. The joint inward dis-placements of the magnetopause, the lobe/mantle region and the plasma sheet indicate that the whole magnetosphere shrinks inward due to the magnetospheric compression by the high-speed solar wind stream, and the magnetospheric ions are attached to the magnetic field lines (i.e. ‘frozen’ in magnetic field) and move inward in the shrinking process of magnetosphere. The large shrinkage of magne-tosphere indicates that the near-Earth magnetotail compression caused by the strong solar wind dynamic pressure is much larger than its thickening caused by the southward component of the iMF, and the locations of magnetospheric regions with different plasmas vary remarkably with the variation of the solar wind dynamic pressure.

关键词： solar wind dynamic pressure shrinkage of magnetosphere storm sudden commencement substorm

MHD and kinetic analysis of flow bursts in the Earth's plasma sheet

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Science China(Technological Sciences) 2014年第1期57卷 55-66页

作者： MA YuDuan CAO JinBin FU HuiShan REME H. dandouras i. YANG JunYing WANG ZhiQiang TAO Dan YANG Jian School of Astronautics Beihang University SOA Key Laboratory for Polar Science Polar Research Institute of China University of Toulouse UPS-OMP IRAP Toulouse 31028 France The French National Centre for Scientific Research The Research Institute in Astrophysics and Planetology BP 44346F-31028 Toulouse cedex 4 France Nanjing University of Aeronautics and Astronautics

in an attempt to study the flow bursts in the Earth＇s plasma sheet we select an event that took place on August 7, 2004 in the expansion phase of a substorm, using data from the geomagnetic index, solar wind data, plasma and magnetic field observa- tions from C1 Cluster satellite （the Cluster mission has 4 satellites） and from Double Star TC-1 satellite. in MHD approach, TC-1 firstly observed the tailward flow, then the earthward, and finally the flow altemated in two directions. C1 firstly ob- served the earthward plasma flow, and then the tailward plasma flow. Before flow bursts are observed by TC-1 and C1, there are disturbances in local entropy with their tailward local entropy larger than those of the earthward. The kinetic features of the plasma flow observed by C1 are similar to those in MHD. However, kinetic characteristics of the plasma flow observed by TC-1 are far more than the description in MHD. The inadequacy mainly exists in two cases：（i） the firstly enhanced tailward flows given in MHD are found without significant increase of the energetic tailward flux; （ii） the almost stagnant flow in MHD is composed of the enhanced energetic ion flux in both earthward and tailward directions. The earthward flow burst observed by TC-1 might be multiple overshoots and rebounds. The earthward flow burst observed by C1 might be simply rebounded in the near-Earth. The pulsation observed by C1 is earlier than that observed by TC-1 with the former intensity less than that of the latter. After the energetic ion flux in the tailward direction is significantly enhanced, the power spectrum intensity of the ULF wave commences to increase obviously, which may suggest that the stream instability is closely correlated with ULF pulsations.

关键词： MHD kinetic flux entropy

The correlations of ions density with geomagnetic activity and solar dynamic pressure in cusp region

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Chinese Science Bulletin 2007年第7期52卷 967-971页

作者： GUO JianGuang SHi JianKui ZHANG TieLong LiU ZhenXing A. FAZAKERLEY H. REME i. dandouras E. LUOEK State Key Laboratory of Space Weather CSSAR Chinese Academy of Sciences Beijing 100080 China Graduate University of the Chinese Academy of Sciences Beijing 100049 China Space Research institute Austrian Academy of Sciences Graz A-8010 Austria MSSL University College London Holmbury St. Mary Dorking RH5 6NT UK CESR Toulouse 31028 France imperial College London SW7 2BZ UK

A statistical study of the properties of ions (O+, He+ and H+) measured by the Cluster-ii in cusp region as a function of the solar wind dynamic pressure and geomagnetic index Kp respectively was made dur-ing the summer and fall of 2001-2003. The main results are that: (1) O+ ion density responds in a sig-nificant way to geomagnetic index Kp, and He+ ion density is not correlated with geomagnetic index Kp, both of them have a significant positive correlation with solar wind dynamic pressure; (2) H+ ion density is also observed to increase with solar wind dynamic pressure, and not correlated with geomagnetic index Kp.

关键词：极隙区地磁活动离子密度太阳风动压相关性

Surveys on magnetospheric plasmas based on the Double Star Project (DSP) exploration

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Science China(Technological Sciences) 2008年第10期51卷 1639-1647页

作者： C. P. ESCOUBET C. M. CARR H. RME A. FAZAKERLEY H. LAAKSO i. dandouras M. DUNLOP ESA/ESTEC SCI-SH Keplerlaan 1 2200 AG Noordwijk The Netherlands imperial College of Science Technology and Medicine London SW7 2BZ United Kingdom CESR BP4346 31028 Toulouse Cedex 4 France Mullard Space Science Laboratory Univ. College London Dorking Surrey RH5 6NT United Kingdom imperial College of Science Technology and Medicine London SW7 2BZ United Kingdom Rutherford Appleton Laboratory Didcot Oxon OX11 0QX United Kingdom

The equatorial and polar satellites of the Double Star Project (DSP) were launched successfully on December 29, 2003 and July 25, 2004, respectively, and both of them are operating smoothly. The DSP provides a good opportunity for investigat-ing the structure of the magnetosphere. Based on the DSP data collected during 2004, we have surveyed the distribution of the magnetic fields and plasmas in the magnetosphere. it is found that: (1) Near the Earth’s equatorial plane within geo-centric distances of less than 7 RE, the Earth’s magnetic field is dipolar. in the vi-cinity of the magnetopause, the magnetic field is enhanced by a factor of about 1.5, and on the nightside, the magnetic field can vary significantly from the Earth’s di-pole field, likely caused by the presence of the near-Earth tail current sheet. (2) in the day-side magnetosheath, the electron and ion densities are usually both in the range of 10―30 cm?3; the ion and electron temperatures are usually about 200 and 50 eV, respectively. The flow pattern is usually smooth, with a low velocity in the subsolar region and with significantly higher velocities in the dawn and dusk flanks. (3) in the region between the magnetopause and plasmasphere the density is low, approximately 0.5―5 cm?3, and the temperature is high, about 1―10 keV for ions and 0.1―5 keV for electrons. The ion temperature has an apparent anisotropy, with the ratio of the perpendicular and parallel temperatures being about 1.0―1.3 for the night- and dusk-side magnetosphere and about 1.3―2.0 for the day- and dawn-side magnetosphere. There is an evident sunward convection of about 50 km/s in the magnetosphere. On the dawn side, the flow becomes somewhat turbulent, and in the vicinity of the night-noon meridian plane, the convection is rather slow. (4) The high-energy electrons with energies higher than 2 MeV are mainly located in the regions with 3 ize of the high-energy electrons area varies with time, it may expand and shrink

关键词： Earth’s magnetosphere space exploration geomagnetic field space plasmas

磁宁静期磁尾爆发性整体流持续时间多点卫星研究

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地球物理学报 2005年第2期48卷 252-258页

作者：马玉端曹晋滨周国成刘振兴 H.Reme i.dandouras 中国科学院空间科学与应用研究中心 Centre d'Etude Spatiale des Rayonnements 31028 Toulouse France

本文利用星簇CLUSTER的三颗卫星数据分析了磁宁静期磁尾爆发性整体流(BBFs,BurstyBulkFlows)的时间尺度,并与单个卫星的结果做了比较.事例研究表明,利用三颗卫星观测数据判断的BBFs的时间尺度比单个卫星的大一倍左右.对于三颗卫星观测... 详细信息

本文利用星簇CLUSTER的三颗卫星数据分析了磁宁静期磁尾爆发性整体流(BBFs,BurstyBulkFlows)的时间尺度,并与单个卫星的结果做了比较.事例研究表明,利用三颗卫星观测数据判断的BBFs的时间尺度比单个卫星的大一倍左右.对于三颗卫星观测到的同一个BBFs ,BBFs在晨昏方向上的摆动决定了CLUSTER的三个卫星观测到BBFs的先后次序.三颗卫星的观测也显示了BBFs的高度局域化特征.磁宁静期磁尾BBFs寿命的增大,使得BBFs携带的质量和能量的地向输运增加.这种地向输运增加的结果是:磁尾储存的能量得到较为平稳的释放,改变了亚暴起始产生的时间,为解决磁层压力平衡矛盾(PBi,PressureBalanceinconsistency)问题提供了新的思路.

关键词： BBFs 局域化输运摆动时间尺度

A Theoretic interpretation of Movement of the Cusp Equatorward Boundary

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空间科学学报 2005年第5期25卷 412-418页

作者： J. B. Cao A. Leonovich G. C. Zhou Z. X. Liu H. Reme i. dandouras Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100080 China China-Russia Joint Research Center on Space Weather Beijing 100080 China Centre d＇Etude Spatiale des Rayonnements 31028 Toulouse France

A preliminary model is proposed to describe quantitatively the position and movement of cusp equatorward boundary. This integrated model, consisting of an empirical model of the magnetopause and a compressed dipolar model of Open/Closed field line, connects quantitatively the solar wind conditions, subsolar magnetopause and cusp equatorward boundary. it is shown that the increasing solar wind dynamic pressure and the increasing southward interplanetary Magnetic Field (iMF) component drive the magnetopause to move inward and the cusp equatorward. This model is adopted to interpret quantitatively the cusp movement of August 14, 2001 observed by Cluster. The results show that the subsolar magnetopause moved earthward from 10.7 Re to 9.0Re during the period of 002300-002800 UT, and correspondingly the cusp equatorward boundary shifted equatorward. The observations of Cluster C1 and C4 show the cusp equatorward boundary that Cluster C1 and C4 were crossing during same interval moved equatorward by 4.6°. The cusp equatorward boundary velocity computed in the theoretical model (10.7 km/s) is in good agreement with the observed value(9.4km/s) calculated from the data of CiS of Cluster C4 and C1.

关键词：太阳风赤道边界线磁场

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磁层快速对流事件的多点卫星联合观测

地球物理学报 2007年第5期50卷 1277-1282页

作者：马玉端曹晋滨周国成刘振兴 H. Reme i. dandouras E. Lucek 中国科学院空间天气学重点实验室北京100080 Centre d'Etude Spatiale des Rayonnements imperial College London

本文利用星簇Cluster的三颗卫星(C1,C3和C4)在2001年和2002年的数据,研究了快速对流事件(RCE,Rapid Convection Event)及其与亚暴的关系.结果显示单点卫星对RCE的观测,不能反映磁尾RCE的真实情况.在2002年7月25日发生的一次RCE事件,C1... 详细信息

本文利用星簇Cluster的三颗卫星(C1,C3和C4)在2001年和2002年的数据,研究了快速对流事件(RCE,Rapid Convection Event)及其与亚暴的关系.结果显示单点卫星对RCE的观测,不能反映磁尾RCE的真实情况.在2002年7月25日发生的一次RCE事件,C1和C3观测到这次RCE,C4却没有观测到.在三颗卫星联合观测到的306次RCE中,C1观测到215次,C3观测到266次,C4观测到227次.统计研究表明,单点卫星观测到的RCE的平均时间也不能准确反映磁层内的RCE.由此推论在整个中心等离子体片内,快速对流事件所承担的能量和磁通量的输运量,可能远大于单点卫星观测给出的结果.用速度来定义的磁尾爆发性整体流(BBF,Bursty Bulk Flow)与亚暴的关系,比用磁通量定义的RCE与亚暴的关系要更加紧密.

关键词： RCE 磁通量持续时间输运

pTC-1 observation of ion high-speed flow reversal in the near-Earth plasma sheet during substorm

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Science China(Technological Sciences) 2008年第10期51卷 1721-1730页

作者： H. RME i. dandouras C. M. CARR Centre d'Etude Spatiale des Rayonnements CEDEX 4 F-31028 Toulouse France The Blackett Laboratory Imperial College London SW7 2BW UK

Based on measurements of FGM and HiA on board TC-1 at its apogee on Septem-ber 14, 2004, we analyzed the ion high-speed flows in the near-Earth plasma sheet observed during the substorm expansion phase. Strong tailward high-speed flows (Vx ～ -350 km/s) were first seen at about X ～ -13.2 RE in near-Earth magnetotail, one minute later the flows reversed from tailward to earthward. The reversal process occurred quickly after the substorm expansion onset. The near-Earth magnetotail plasma sheet was one of key regions for substorm onset. Our analysis showed that the ion flow reversal from tailward to earthward was likely to be in close relation with the substorm expansion initiation and might play an important role in trigger-ing the substorm expansion onset.

关键词： near-Earth magnetotail magnetospheric substorm plasma sheet ion high speed flow