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Cluster and TC-1 observation of magnetic holes in the plasma sheet

第十一届全国日地空间物理学术讨论会

作者： M.W.Dunlop C.M.Carr K.H.Glassmeier H.Reme a.fazakerley Space Sciences Division RAL Oxford UK Max-Planck-Institute for Solar System Research Germany IGM TU Braunschweig Germany CNSR France MSSL UK

＜正＞At about 0330UT on February 23, 2005, Cluster was located at about （9.0,1.6,7.0）Re（GSM）;the GSM locations of Double Star TC-1 and TC2 at 0430UT were about （10.4,0.4,2.1）Re and about （0.5,0.1,-1.4）Re in the low-altitude cusp, respectively. Inside the dayside magnetosheath close to the magnetopause, Bxabout 0, Bz was positive with the maximum being less than 20nT, and By≈-50nT. During 0320-0340 Cluster four spacecraft were traversing through the magnetopause and observed pronounced plasma flow in the magnetospheric boundary layer. The flow speed was over 370 km/s, much higher than the background magnetosheath flow and directed poleward and duskward. Preliminary analysis shows that this high-speed flow may possibly manifest a reconnection event. In the meantime, TC-1 at the low-latitude also observed high-speed flow when the satellite entered the LLBL for a short time interval. The flow was basically along the +y-direction and much higher than the background magnetosheath flow. Interesting enough, just within the time period of Cluster measurement of high-speed flow, the IMAGE FUV observed both proton and electron aurora brightening on the duskside of polar ionosphere. One hour later around 0440UT, TC-1 was crossing the magnetopause from the magnetosphere toward the magnetosheath. The spacecraft encountered with high-speed flow in the LLBL and an FTE in the magnetosheath. Of particular interest are the facts that just in the time period of TC-1 observation of high-speed flow, TC-2 detected sharp energetic electron enhancements and the IMAGE FUV also saw both proton and electron aurora brightening on the duskside of polar ionosphere. In addition, TC-2 also detected an energetic electron burst at the time when TC-1 encountered the FTE. Implications of this multi-spacecraft observation of a high-speed flow event are discussed in this paper. The possible global reconnection pattern at the dayside magnetopause is also contemplated.

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Cluster and TC-1 observation of magnetic holes in the plasma...

极尖区电离层离子与地磁活动及太阳风的相关分析

第十四届全国日地空间物理学术研讨会

作者： M.W.Dunlop A.P.Walsh H.Reme C.Carr E.Lucek a.fazakerley Rutherford Appleton Laboratory Didcot OX11 0QX UK Mullard Space Science Laboratory University College London Holmbury St.Mary Dorking Surrey RH5 6NT UK Université de Toulouse

Magnetic holes with relatively small scale sizes, detected by Cluster and TC-1 in the magnetotail plasma sheet, are studied in this paper. It is found that these magnetic holes are spatial structures and they are not magnetic depressions generated by the flapping movement of the magnetotail current sheet. Most of the magnetic holes (93%) were observed during intervals with B z larger than B x, i.e., they are more likely to occur in a dipolarized magnetic field topology. For the randomly selected plasma sheet crossing events there are only 31% of the cases have the magnetic field with Bz larger than Bx, suggesting that the occurrence of magnetic holes might have a close relationship with the dipolarization process and/or a perturbed magnetosphere. The magnetic holes typically have a scale size comparable to the local proton Larmor radius and are accompanied by an electron flux enhancement at 90°pitch angle. It is also shown that most of the magnetic holes occur in the marginally mirror-stable environments;however, whether the plasma sheet magnetic holes are generated by the mirror instability related to ions or not is unknown. Comparison of ratios, scale sizes and propagation direction of magnetic holes detected by Cluster and TC-1 suggests that magnetic holes observed in the vicinity of TC-1 orbit (-12Re) are likely further developed than those observed by Cluster (-18Re).

关键词： magnetic holes mirror mode structures plasma sheet dipolarization

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科学通报 2007年第3期52卷 339-343页

作者：郭建广史建魁 T.L.Zhang 刘振兴 a.fazakerley H.Rème I.Dandouras E.Lucek 中国科学院空间天气学国家重点实验室 Space Research Institute Aus-trian Academy of SciencesGrazA-8010 Austria Mullard Space Science Laboratory University College LondonHolmbury St.MaryDorking RH5 6NTUK Centred'Etude Spatiale des Rayonnements Toulouse 31028France Imperial College LondonS 272B2UK

对2001～2003年间Cluster星簇穿越极尖区期间观测到的电离层起源的离子(O+离子,He+离子和H+离子)特性进行了统计分析,主要研究了这些离子的数密度与地磁活动以及太阳风动压之间的关系.结果表明:O+离子数密度和地磁活动指数Kp之间存在着... 详细信息

对2001～2003年间Cluster星簇穿越极尖区期间观测到的电离层起源的离子(O+离子,He+离子和H+离子)特性进行了统计分析,主要研究了这些离子的数密度与地磁活动以及太阳风动压之间的关系.结果表明:O+离子数密度和地磁活动指数Kp之间存在着正相关关系,He+离子数密度和地磁活动指数Kp不相关,O+离子和He+离子数密度都和太阳风动压之间存在着显著的正相关关系;H+离子数密度与太阳风动压之间存在着正相关关系,而和地磁活动指数Kp不相关.最后,对这些离子的特性与太阳风动压及地磁活动之间的关系进行了讨论.

关键词：极尖区离子 Kp指数太阳风动压

Field-Aligned Electrons in Polar Region Observed by Cluster on 30 September 2001

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Chinese Physics Letters 2012年第9期29卷 244-247页

作者： ZHANG Zi-Ying SHI Jian-Kui CHENG Zheng-Wei Andrew fazakerley State Key Laboratory of Space Weather National Space Science CenterChinese Academy of SciencesBeijing 100190 MSSL University College LondonUK

The physical process in the Earth's polar region is very complex and still needs to be further *** the data from Cluster satellite measurement,an analysis on field-aligned electrons in the mid-latitude cusp on 30 September 2001 has been *** satellite observed a down-flowing electron event in the low-latitude boundary and a sequential up-flowing electron event in the high-latitude boundary of the cusp *** down-flowing electron had a velocity as high as 500 km/s and a flux of 2.0×10^(9) cm^(-2)-s^(-1).The up-flowing electron had a velocity up to 1200 km/s and a flux of 4.9×10^(9) cm^(-2)-s^(-1).Both the velocity and the flux observed in this event are the maximum values of the up-flowing electrons observed by all satellites to *** electron is the main contributor for the field-aligned current in this *** physical mechanism is also *** down-flowing electron in the low-latitude boundary of the cusp region may result from solar wind injecting during the southward IMF,and the up-flowing electrons in the high-latitude boundary of cusp may result from mirroring of the solar wind,or from the ionospheric up-flowing electrons which have been accelerated.

关键词： latitude Earth flowing

Solar wind entry via flux tube into magnetosphere observed by Cluster measurements at dayside magnetopause during southward IMF

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Science China(Technological Sciences) 2009年第7期52卷 2104-2111页

作者： M. Dunlop A. Balogh H. Rème Y. V. Bogdanova A. fazakerley Rutherford Appleton Laboratory Didcot United Kingdom Imperial College of Science Technology and Medicine London United Kingdom CESR BP4346 31028 Toulouse Cedex 4 France Mullard Space Science Laboratory Dorkink United Kingdom Department of Physics La Trobe University Victoria 3086 Australia

By analyzing hot ion and electron parameters together with magnetic field measurements from Cluster, an event of magnetopause crossing of the spacecraft has been investigated. At the latitude of about 40° and magnetic local time (MLT) of 13:20 during the southward interplanetary magnetic field (IMF), a transition layer was observed, with the magnetospheric field configuration and cold dense plasma features of the magnetosheath. The particle energy-time spectrograms inside the layer were similar to but still a little different from those in the magnetosheath, obviously indicating the solar wind entry into the magnetosphere. The direction and magnitude of the accelerated ion flow implied that reconnection might possibly cause such a solar wind entry phenomenon. The bipolar signature of the normal magnetic component BN in magnetopause coordinates further supported happening of reconnection there. The solar wind plasma flowed toward the magnetopause and entered the magnetosphere along the reconnected flux tube. The magnetospheric branch of the reconnected flux tube was still inside the magnetosphere after reconnection and supplied the path for the solar wind entry into the dayside magnetosphere. The case analysis gives observational evidence and more details of how the reconnection process at the dayside low latitude magnetopause caused the solar wind entry into the magnetosphere.

关键词： transport process magnetic reconnection solar wind-magnetosphere interactions

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

Magnetospheric Boundary Layer Structure and Dynamics as Seen From Cluster and Double Star Measurements

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空间科学学报 2013年第6期33卷 577-603页

作者： Y V Bogdanova C J Owen M W Dunlop M G G T Taylor A N fazakerley Space Science and Technology Department RALChiltonDidcotOxfordshireOX11 0QXUK Mullard Space Science Laboratory University College LondonHolmbury St.MaryDorkingSurreyRH5 6NTUK Science and Robotic Exploration Directorate ESA/ESTECNoordwijkThe Netherlands

In this review,we discuss the structure and dynamics of the magnetospheric LowLatitude Boundary Layer(LLBL)based on recent results from multi-satellite missions Cluster and Double *** boundary layer,adjacent to the magnetopause on the magnetospheric side,usually consists of a mixture of plasma of magnetospheric and magnetosheath origins,and plays an important role in the transfer of mass and energy from the solar wind into the magnetosphere and subsequent magnetospheric *** southward Interplanetary Magnetic Field(IMF)conditions,this boundary layer is generally considered to be formed as a result of the reconnection process between the IMF and magnetospheric magnetic field lines at the dayside magnetopause,and the structure and plasma properties inside the LLBL can be understood in terms of the time history since the reconnection *** northward IMF conditions,the LLBL is usually thicker,and has more complex structure and *** observations confirm that the LLBL observed at the dayside can be formed by single lobe reconnection,dual lobe reconnection,or by sequential dual lobe reconnection,as well as partially by localized cross-field *** LLBL magnetic topology and plasma signatures inside the different sub-layers formed by these processes are discussed in this *** role of the Kelvin-Helmholtz instability in the formation of the LLBL at the flank magnetopause is also ***,we conclude that the LLBL observed at the flanks can be formed by the combination of processes,(dual)lobe reconnection and plasma mixing due to non-linear Kelvin-Helmholtz waves.

关键词：边界层结构磁层顶双星群集国际货币基金组织等离子体特性测量拓扑结构

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 < L < 4.5; the size 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

Tourism Waste Management in the European Union: Lessons Learned from Four Popular EU Tourist Destinations

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American Journal of Climate Change 2015年第5期4卷 431-445页

作者： Chukwunonye Ezeah Jak fazakerley Timothy Byrne Faculty of Sciences and Engineering University of Wolverhampton City Campus-South Wolverhampton UK Royal Haskoning DHV UK Ltd. Honey Comb Liverpool UK School of Sciences and Technology The University of Northampton Northampton UK

From a sustainability perspective, achieving greater efficiencies in environmental waste management is at the heart of current academic discussion on climate change science. Over the last few decades the tourism industry has developed exponentially and is now considered one of the most dynamic economic activities worldwide. Solid waste is a commonly identified and ever increasing aspect of tourism;the improper management of which can lead to substantial and irreversible direct and indirect environmental, economic and social impacts. However, the management of solid waste in tourism dominated island communities is particularly problematic due to climatic conditions, topography, financial restraints, planning issues, changing consumption patterns, transient population, and seasonal variations in solid waste quantity and composition. In addition, there is often a lack of momentum to implement new initiatives and programs as stakeholders involved in the design, construction and operation of tourist resorts have conflicts of interest. Using information gathered from key informant interviews, participation observations and literature reviews, this article appraises current waste management practices in four European tourist destinations, namely: Mallorca, Tenerife, Kefalonia and Rhodes. Findings indicate that, although there are signs of compliance with global best practice, a variety of locally-based measures need to be implemented to enhance sustainability.

关键词： Waste Management Tourist Destination Island Communities European Union Greenhouse Gas Emission