Comprehensive Studies On Interplanetary Meso-and Micro-scale Structures

Interplanetary meso- and micro-scale structures and magnetic reconnection are twoimportant phenomina in space physics, they play key roles in space weather. To furtherstudy the two phenomina will be helpful to improve the prediction of space weather,and to understand the magnetic reconnection which is import process in plasma physics.On the basis of the observations of the interplanetary meso- and micro-scale structures,such as magnetic decreased region in magnetic cloud, boundary layers of magnetic cluds,and the interaction region formed by multiple magnetic clouds, the characteristics ofmagneticΔeld and plasma in these structures are studied. Some interplanetary magneticreconnection events related to these structures are also analyzed.(1) Based on the WIND observational data for the plasma waves from thermal noisereceptor (TNR), plasma and the magneticΔelds, we analyze the plasma wave activitiesin the 60 magnetic cloud's boundary layers (BLs) andΔnd that there are often variousplasma wave activities in the BLs, which are diΔerent from those in the adjacent solar wind(SW) and the magnetic clouds (MC). The basic characteristics are that: the enhancementof the Langmuir wave near the electronic plasma frequency (fpe) is a dominant waveactivity in 75% investigated samples; the events enhanced both in the langmuir and ionacoustic waves(f < fpe) are about 60% investigated samples; broadband, continuousenhancement in the plasma wave activities were observed in the whole frequency band ofTNR in about 30% of the 60 samples.(2) By analyzing the WIND data of an interplanetary magnetic cloud(MC) on 2November 2001, new evidences for magnetic reconnection in the rear part of this MC isfound. In the rear part of MC, the largely dip and the large change of the orientation ofthe magneticΔeld occurred simultaneously,θ≈45°, andφchanged from 90°to 320°. Correspondingly, the number density of ions increased, and the superthermal electronswere heated and accelerated, however, its number density decreased. Meanwhile, inversejets and Hall term were observed. The pitch angle's distributions of the electrons withlower energy and higher energy showed strong turbulence and bi-directionΔow, respec-tively; the plasma wave activity enhanced near the electron plasma frequency, fpe and2fpe.(3) By analyzing the ACE plasma and magnticΔeld data, the interaction regionsformed by multiple magnetic clouds are studied. Two kinds of these interaction regionare found with the characteristics of decreased and increased magneticΔeld strength, re-spectively. The magnetic reconnection signals are also found in the interaction region withdecreased magneticΔle and a boundary layer of magnetic cloud. The basic characteristicsare that the magnitude of magneticΔeld,—B—, drops, whith change in the latitudialangle,Δθ≈135°, and abrupt variation in the azimuth angle,Δφ≈180°; however, thedensity, temperature and parameterβof plasma increase. These interaction regions areformed in the range of 0.4AU–0.8AU away from the sun according to the SOHO observa-tions of CMEs. These characters could be interpreted as a possible observational evidenceof interplanetary magnetic reconnections with high magnetic-Raynold-number, which arealso supported by the preliminary numerical simulation.The design of hardware and security system of the Data and Communication Systemin Meridian Projectis also introduced. The Data and Communication System is to collect,storage, manage the data produced by the instruments of Meridian Project, and to providethe data service for various users. High availability and hogh performance hardwaresystem is designed to support the data center. An security system is also planed to securethe whole system. We adopt the Storage Area Network(SAN) and tape library to providethe huge data storage; use the hot standby cluster, two-core-switch Gigabit Ethernet tobuild a high performance and high availability system; useΔrewall and security gateway to secure the network and system; and design a data disaster recovery system to evade datadisaster. The concept of Virtual Space Weather Observatory(VSWO) is also proposed tointegrate the various distributed space weather resource.