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Wavelet Analysis of the Schwabe Cycle Properties in Solar Activity

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chinese Journal of Astronomy and Astrophysics 2004年第6期4卷 578-582页

作者： Gui-Ming LeNational Astronomical Observatories, chinese academy of sciences, Beijing 100012.center for space science and applied research {2., chinese academy of sciences, Beijing 100080 National Astronomical Observatories Chinese Academy of Sciences Beijing 100012 []Center for Space Science and Applied Research Center Chinese Academy of Sciences Beijing 100080

Properties of the Schwabe cycles in solar activity are investigated by using wavelet transform. We study the main range of the Schwabe cycles of the solar activity recorded by relative sunspot numbers, and find that the main range of the Schwabe cycles is the periodic span from 8-year to 14-year. We make the comparison of 11-year’s phase between relative sunspot numbers and sunspot group numbers. The results show that there is some difference between two phases for the interval from 1710 to 1810, while the two phases are almost the same for the interval from 1810 to 1990.

关键词： sun sunspot sun activity method data analysis

The gravity wave instability induced by photochemistry in summer polar mesopause region

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chinese science Bulletin 2000年第3期45卷 267-272页

作者： center for space science and applied research, chinese academy of sciences, Beijing 100080,{2. Laboratory of Numeric Study of Heliospheric Physics, chinese academy of sciences, Beijing 100080,{2. center for space science and applied research Chinese Academy of Sciences Beijing China Laboratory of Numeric Study of Heliospheric Physics Chinese Academy of Sciences Beijing China

The effect of diabatic process due to the photochemical heating and cooling on the gravity wave propagation in middle atmosphere is studied. A linear gravity wave model which considers the diabatic process is established. The unstable region and the growth rate of the gravity wave caused by photochemistry are calculated. And the comparison between the model and the adiabatic gravity wave theory of pure dynamics is made. The results indicate that the photochemical heating process can induce the instability of gravity wave at mesopause. The intensity of the instability becomes stronger as the temperature decreases. The temperature feature and the altitude characteristics of the instability are consistent with the observation. Therefore, the instability of the gravity wave induced by photochemistry may be an important mechanism in polar mesopause region in summer.

关键词： photochemistry instability gravity wave growth rate.

Observation results of relativistic electrons detected by Fengyun-1 satellite and analysis of relativistic electron enhancement (REE) events

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science china(Physics,Mechanics & Astronomy) 2008年第12期51卷 1947-1956页

作者： YANG XiaoChao1,2. & WANG ShiJin1 1 center for space science and applied research, chinese academy of sciences, Beijing 100190,{2. 2.Graduate University of chinese academy of sciences, Beijing 100049,{2. 1. center for space science and applied research Chinese Academy of Sciences Beijing 100190 China 2. Graduate University of chinese academy of sciences Beijing 100049 China

The space particle component detector on Fengyun-1 satellite which works at the sun-synchronous orbit of about 870 km altitude has detected relativistic electrons for a long time. In comparison with the SAMPEX satellite observations during 1999–2.04, the relativistic electron data from Fengyun-1 satellite from June 1999 to 2.05 are used to analyze the relativistic electron enhancement (REE) events at the low earth orbit, and the possible correlation among REE events at the low earth orbit, high-speed solar wind and geomagnetic storms is discussed. The statistical result presents that 45 REE events are found in total during this time period, and the strong REE events with the maximum daily average flux > 400 cm?2.srt-1·s?1 occur mostly during the transition period from solar maximum to solar minimum. Among these 45 REE events, four strong REE events last a longer time period from 2.-to 51-day and correlate closely with high speed solar wind and strong geomagnetic storms. Meanwhile, several strong geomagnetic storms occur continuously before these REE events, and these continuous geomagnetic storms would be an important factor causing these long-lasting strong REE events. The correlation analysis for overall 45 events indicates that the strength of the REE events correlates with the solar wind speed and the strength of the geomagnetic storm, and the correlation for strong REE events is much stronger than that for weak REE events.

关键词： relativistic electron enhancement low earth orbit high-speed solar wind geomagnetic storm

Integrated precise orbit determination of Shenzhou IV unmanned spacecraft

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science china(Technological {2.) 2004年第5期47卷 518-525页

作者： L Congmin1,2. GU Yidong3, LIN Baojun3 & GUO Jiong3 1. center for space science and applied research, chinese academy of sciences, Beijing 100080,{2. 2. Graduate School of the chinese academy of sciences, Beijing 100039,{2. 3. General Establishment of space science and Application, chinese academy of sciences, Beijing 100080,{2. Correspondence should be addressed to L Congmin 1. center for space science and applied research Chinese Academy of Sciences 100080 Beijing China 2. Graduate School of the chinese academy of sciences 100039 Beijing China 3. General Establishment of space science and Application Chinese Academy of Sciences 100080 Beijing China

Considering the characteristic orbit of Shenzhou IV spacecraft and the advantages and disadvantages of several types of domestic orbit measurements, a scheme of IPOD is determined, which uses GPS, SLR and USB observation data jointly plus precise ionosphere corrections to GPS observation data. IPOD system and mathematic models of OD are introduced. The results of different joint OD are analyzed using true observation data, and show that radial accuracy is better than 2.m.

关键词： Shenzhou IV unmanned spacecraft integrated precise orbit determination GPS SLR USB.

Numerical study of successive CMEs during November 4―5, 1998

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science china(Technological {2.) 2008年第10期51卷 1600-1610页

作者： ZHOU YuFen & FENG XueShang SIGMA Weather Group, State Key Laboratory for space Weather, center for space science and applied research,{2., Beijing 100190, china 1. SIGMA Weather Group State Key Laboratory for Space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing 100190 China

We present the solar-terrestrial transit process of three successive coronal mass ejections (CMEs) of November 4―5, 1998 originating from active region 8375 by using a time-dependent three-dimensional magnetohydrodynamics (MHD) simula-tion. These CMEs interacted with each other while they were propagating in inter-planetary space and finally formed a "complex ejecta". A newly developed SIP-CESE MHD model was applied to solve MHD equations numerically. The quiet solar wind was started from Parker-like 1D solar wind solution and the magnetic field map was calculated from the solar photospheric magnetic field data. In our simulation, the ejections were initiated using pulse in the real active region 8375. The interplanetary disturbance parameters, such as speed, direction and angular size of the expanding CME, were determined from the SOHO/LASCO data with the cone-model. We discussed the three-dimensional aspects of the propagation, in-teraction and merging of the three ejections. The simulated interplanetary shocks were compared with the nearby-Earth measurement. The results showed that our simulation could reproduce and explain some of the general features observed by satellite for the "complex ejecta".

关键词： complex ejecta three-dimensional MHD simulation SIP-CESE MHD model

Lunar ~3He estimations and related parameters analyses

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science china Earth {2. 2010年第8期53卷 1103-1114页

作者： LI DiHui, LIU HeGuang, ZHANG WeiGuo, LI Yun & XU ChuanDong center for space science and applied research, chinese academy of sciences, Beijing 100190,{2. 1. center for space science and applied research Chinese Academy of Sciences Beijing 100190 China

As a potential nuclear fuel, 3He element is significant for both the solution of impending human energy crisis and the conservation of natural environment. Lunar regolith contains abundant and easily extracted 3He. Based on the analyses of the impact factors of 3He abundance, here we have compared a few key assessment parameters and approaches used in lunar regolith 3He reserve estimation and some representative estimation results, and discussed the issues concerned in 3He abundance variation and 3He reserve estimation. Our studies suggest that in a range of at least meters deep, 3He abundance in lunar regolith is homogeneously distributed and generally does not depend on the depth; lunar regolith has long been in a saturation state of 3He trapped by minerals through chemical bonds, and the temperature fluctuation on the lunar surface exerts little influence on the lattice 3He abundance. In terms of above conclusions and the newest lunar regolith depth data from the microwave brightness temperature retrieval of the "ChangE-1" Lunar Microwave Sounder, a new 3He reserve estimation has been presented.

关键词： lunar regolith 3He abundance reserve estimation maturity granularity composition solar wind flux CELMS

Effects of gravity waves on the distributions of O_3 and OH in the mesopause region

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chinese science Bulletin 2001年第15期46卷 1265-1268页

作者： XU Jiyao & MA RuipingLaboratory for space Weather, center for space science and applied research,{2., Beijing 100080, china Laboratory of Numeric Study of Heliospheric Physics,{2., Beijing 100080, china Laboratory for space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China Laboratory of Numeric Study of Heliospheric Physics Chinese Academy of Sciences Beijing China

A dynamical-photochemical model of atmospheric gravity waves is used to study the influences of gravity waves on distributions of atmospheric minor species through transportation and photochemical reactions. We mainly study the effect of gravity waves on the distributions of atmospheric trace gases through the nonlinear photochemical reactions. O3 and OH are taken as examples in this note. The calculations indicate that the effect of gravity waves on the distributions of atmospheric trace gases is mainly through the nonlinear photochemical reactions in the mesopause region. The contribution of the nonlinear photochemical reaction caused by gravity waves can exceed the nonlinear transportation and the eddy diffusion.

关键词： gravity wave photochemical reaction coupling between photochemistry and dynamics.

Prediction method for October 2.03 solar storm

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science china(Technological {2.) 2006年第5期49卷 629-640页

作者： XIE Yanqiong1, 2. 3, WEI Fengsi1, FENG Xueshang1 & ZHONG Dingkun1, 2.1. State Key Laboratory of space Weather, center for space science and applied research,{2., Beijing 100080, china 2. Graduate School,{2., Beijing 100039, china 3. Institute of Meteorology, PLA University of science and Technology, Nanjing 2.1101, china State Key Laboratory of space Weather Center for Space Science applied research Chinese Academy of Sciences Beijing 100080 China Graduate School Chinese Academy of Sciences Beijing 100039 China Institute of Meteorology PLA University of Science Technology Nanjing 211101 China

Aiming at two intense shock events on October 2. and 2., 2.03, this paper presents a two-step method, which combines synoptic analysis of space weather ——“observing” and quantitative prediction ——“palpating”, and then uses it to test predictions. In the first step of “observing”, on the basis of observations of the solar source surface magnetic field, interplanetary scintillation (IPS) and ACE spacecraft, we find that the propagation of the shocks is asymmetric relative to the normal direction of their solar sources, and the Earth is located near the direction of the fastest speed and the greatest energy of the shocks. As the two fast ejection shock events, the fast explosion of coronal mass of the extremely high temperature, the strong magnetic field, and the high speed background solar wind are also helpful to their rapid propagation. In the second step of “palpating”, we adopt a new membership function of the fast shock events for the ISF method. The predicted results show that for the onset time of the geomagnetic disturbance, the relative errors between the observational and the predicted results are 1.8% and 6.7%; and for the magnetic disturbance magnitude, the relative errors are 4.1% and 3.1%, re- spectively. Furthermore, the comparison among the predicted results of our two-step method with those of five other prevailing methods shows that the two-step method is advantageous. The results tell us that understanding the physical features of shock propagation thoroughly is of great importance in improving the prediction precision.

关键词： solar storm, interplanetary shock, interplanetary scintillation, two-step method, ISF method.

The variation in the magnetic fluctuation anisotropy across the front boundaries of magnetic clouds and its geomagnetic response

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chinese science Bulletin 2002年第10期47卷 863-867页

作者： LIU Rui & WEI FengsiDepartment of Geophysics, Peking University, Beijing 100871, china Lab for space Weather, {2., chinese academy of sciences, Beijing 100080, china Department of Geophysics Peking University Beijing China Lab for space Weather Center for Space Science and Applied Research Chinese Academy of Sciences Beijing China

A statistical study of magnetic fluctuations near the front boundaries of magnetic clouds is approached with the method of Minimum Variance Analysis, based on the data of ImpS and Wind spacecraft. New discoveries are that (1) fluctuation anisotropy tends to increase across the front boundaries of magnetic clouds; (2. there is a good correlation between the fluctuation anisotropy and the geomagnetic activity indices; and (3) in some cases, although there is southward field component immediately after the front boundary, Kp index descends (or Dst index ascends) with a corresponding decrease of the fluctuation anisotropy; in other cases with no distinct southward field component, Kp index ascends (or Dst index descends) with a corresponding increase of the fluctuation anisotropy. Thus we suggest that the fluctuation anisotropy might be a useful indicator in diagnosing the magnetic activities of magnetic clouds.

关键词： front boundary of magnetic clouds geomagnetic activity fluctuation anisotropy.