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A new technique for deriving the quiet day curve from imaging riometer data at Zhongshan Station, Antarctic

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Science China(Technological Sciences) 2014年第10期57卷 1967-1976页

作者： HE Fang hu hongqiao hu ZeJun LIU RuiYuan SOA Key Laboratory for Polar Science Polar Research Institute of China Key Laboratory of Ionospheric Environment Institute of Geology and Geophysics Chinese Academy of Sciences

A new technique for estimating quiet day curve(QDC)was *** validate the new approach,QDCs were derived from data acquired by the imaging riometer installed at the Chinese Zhongshan Station in *** evaluation was performed by comparing the difference between QDC derived by the new technique and those derived by Tanaka’s *** results were discussed in terms of the diurnal variation and ***,cosmic noise absorption(CNA)images were built using both techniques in order to evaluate the implications of the changes when obtaining them using different methods of the QDC *** influence of the multiplicative factor value on the QDC determination in Tanaka’s technique was evaluated.

关键词： riometer absorption technique

A case study based on ground observations of the conjugate ionospheric response to interplanetary shock in polar regions

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Advances in Polar Science 2021年第2期32卷 141-160页

作者： HE Fang hu Zejun hu hongqiao huANG Dehong YU Yao MNR Key Laboratory for Polar Science Polar Research Institute of ChinaShanghai200136China

Data acquired by imaging relative ionospheric opacity meters(riometers),ionospheric total electron content(TEC)monitors,and three-wavelength auroral imagers at the conjugate Zhongshan station(ZHS)in Antarctica and Yellow River station(YRS)in the Arctic were analyzed to investigate the response of the polar ionosphere to an interplanetary shock event induced by solar flare activity on July 12,*** the arrival of the interplanetary shock wave at the magnetosphere at approximately 18:10 UT,significantly enhanced auroral activity was observed by the auroral imagers at the ***,the polar conjugate observation stations in both hemispheres recorded notable evolution in the two-dimensional movement of cosmic noise *** of the ionospheric TEC data acquired by the conjugate pair showed that the TEC at both sites increased considerably after the interplanetaryshock wave arrived,although the two stations featured different sunlight conditions(polar night in July in the Antarctic region and polar day in the Arctic region).However,the high-frequency(HF)coherent radar data demonstrated that different sourcesmight be responsible for the electron density enhancement in the *** the Arctic polar day period in July,the increased electron density over YRS might have been caused by anti-sunward convection of the plasma irregularity,whereas in Antarctica during the polar night,the increased electron density over ZHS might have been caused by energetic particle precipitation from the *** different physical processes might be responsible for the different responses of the ionosphere at the two conjugate stations in response to the same interplanetary shock event.

关键词： polar ionosphere conjugate interplanetary shock response irregularity

An introduction to the riometer system deployed at China-Iceland joint Arctic observatory and its beam-forming correction method based on the preliminary data

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Advances in Polar Science 2021年第3期32卷 248-260页

作者： HE Fang hu Zejun hu hongqiao huANG Dehong YU Yao MNR Key laboratory for Polar Science Polar Research Institute of ChinaShanghai 200136China

The China-Iceland joint Arctic observatory(CIAO)has formally been operating since October 18,2018,and an imaging riometer system was deployed at CIAO in August 2019 for the conjunction observation purpose with the co-located ground-based all sky imager auroral observation *** features of the riometer and antenna system are *** riometer’s beam-forming performance were evaluated with the analysis method introduced in *** analysis results showed that the mapping of beams was incorrectly ordered,and the correction has been *** revised ordering result was reasonably verified and the analysis method was proved to be effective.

关键词： imaging riometer beam forming analysis method mapping

Effect of interplanetary shock on an ongoing substorm:Simultaneous satellite-ground auroral observations

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Science China(Technological Sciences) 2023年第3期66卷 654-662页

作者： LIU JianJun CHEN XiangCai WANG ZhiQiang hu ZeJun ZHAO XingXin hu hongqiao HAN DeSheng LUI A.T.Y Ministry of Natural Resources(MNR) Key Laboratory for Polar SciencePolar Research Institute of ChinaShanghai 200136China Antarctic Zhongshan National Field Observation and Research Station for Snow and Ice Space Special Environment and DisastersPolar Research Institute of ChinaShanghai 200136China College of Astronautics Nanjing University of Aeronautics and AstronauticsNanjing 211106China Institute of Space Physics and Applied Technology Peking UniversityBeijing 100871China State Key Laboratory of Marine Geology School of Ocean and Earth ScienceTongji UniversityShanghai 200092China Applied Physics Laboratory Johns Hopkins UniversityLaurelMarylandUSA

Substorm processes have been studied in detail,and it is well known that interplanetary(IP)shock encountering the terrestrial magnetosphere causes global ***,how IP shock compression to the magnetosphere affects the development of an ongoing substorm remains ***,the simultaneous satellite and ground-based auroral evolutions associated with an IP shock impact on the magnetopause during an ongoing substorm on May 7th,2005,were *** IMAGE satellite over the Southern Hemisphere captured the global development substorm,which was initiated at 17:38:47 *** poleward branch of the nightside auroral oval was fortuitously monitored by an all-sky camera at the Zhongshan Station(-74.5°magnetic latitude,ZHO)in *** satellite imager observed continuous brightening and broadening of the nightside auroral oval after the IP shock *** simultaneous ground-based optical aurora measurement displayed the intensification and expansion of a preexisting auroral surge poleward of the aurora *** geomagnetic field variations and the instantly increased PC indices indicated an elevated merging rate and enhanced the convection-related DP-2 ***,this IP shock transient impact did not significantly change the ongoing development of the substorm,although it meets the magnetospheric precondition hypothesis.

关键词： interplanetary shock substorm global auroral images all-sky camera Zhongshan Station

Interplanetary shock-associated aurora

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Advances in Polar Science 2019年第1期30卷 11-23页

作者： LIU Jianjun hu hongqiao HAN Desheng YANG huigen SOA Key Laboratory for Polar Science Polar Research Institute of China State Key Laboratory of Marine Geology School of Ocean and Earth Science Tongji University

Interplanetary shocks or solar wind pressure pulses have prompted impacts on Earth's magnetospheric and ionospheric environment, especially in causing dynamic changes to the bright aurora in the polar ionosphere. The auroral phenomenon associated with shock impingements, referred to as shock aurora, exhibits distinct signatures differing from other geophysical features on the dayside polar ionosphere. Shock aurora provides a direct manifestation of the solar wind–magnetosphere–ionosphere interaction. Imagers onboard satellites can obtain the associated large-scale auroral characteristics during shock impingement on the magnetopause. Therefore, auroral data from satellites are very useful for surveying the comprehensive features of shock aurora and their general evolution. Nonetheless, the ground-based high temporal-spatial resolution all-sky imagers installed at scientific stations play an essential role in revealing medium-and small-scale characteristics of shock aurora. Here, we focus on shock aurora imaging signatures measured by imagers onboard satellites and ground-based all-sky imagers.

关键词： interplanetary shock sudden impulse shock aurora wave-particle interaction field-aligned current

Dayside poleward moving auroral forms and ionospheric convection under stable interplanetary magnetic field (IMF) conditions

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Science China(Technological Sciences) 2013年第4期56卷 910-916页

作者： XING ZanYang YANG huiGen HAN DeSheng WU ZhenSen LIU JunMing hu ZeJun ZHANG QingHe hu hongqiao LIU Yonghua School of Science Xidian University SOA Key Laboratory for Polar Science Polar Research Institute of China

Using high temporal resolution optical data obtained from three-wavelength all-sky imagers over six winters continuously at Yellow River Station （78.92°N,11.93°E） in Arctic,we statistically investigated the dependence of location of poleward moving auroral forms （PMAFs） on the interplanetary magnetic field （IMF） B z and B y components as a function of MLT and MLAT under stable IMF *** is found that more PMAFs occurred in lower latitude for Bz＆lt;0 and there was less evident IMF B y-related prenoon-postnoon asymmetry for Bz＆lt;0 than for Bz＆gt;*** found that the PMAFs were distributed over a wide range of MLT when Bz＆lt;0,which indicates that the reconnection X-line might spread like an ’S’ ***,during northward IMF,PMAFs were observed predominantly prenoon for IMF By＆gt;0 and postnoon for IMF By＆lt;0 associating with the effect of the high-latitude reconnection,which is largely consistent with the theoretical model of the convection flow.

关键词： poleward moving auroral forms (PMAFs) reconnection prenoon-postnoon asymmetry

Application of autocorrelation method on ionospheric short--term forecasting in China

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Chinese Science Bulletin 2006年第3期51卷 352-357页

作者： LIU Ruiyuan LIU Shunlin XU Zhonghua WU Jian WANG Xianyi ZHANG Beichen hu hongqiao School of Electronic Information of Wuhan University Wuhan 430072 China Polar Research Institute of China Shanghai 200136 China China Research Institute of Radiowave Propagation Xinxiang 453003 China

Adopting the autocorrelation method in the ionospheric short-term forecasting, we put for- ward a simple and practical forecasting method― the sectional autocorrelation method, that is, for pre- dictions of one hour to four hours ahead the auto- correlation coefficient of RDF with the “iteration” method is selected, for prediction of more than four hours ahead, the autocorrelation coefficient of f0F2 with the “at once” method is used. The prediction precisions have been quantitatively estimated based on the data from Chongqing and Guangzhou Ionos- onde Stations. It is shown that the method is much improved for the predictions of one hour to four hours ahead. For the predictions of more than four hours ahead the prediction error reaches a saturation value, which is still lower than that of the “median” method. This new method could also be applied to the short-term forecasting of other ionospheric parame- ters.

关键词：电离层电离层预报自相关法短期预报中国

SuperDARN CUTLASS Finland radar observations of high-latitude magnetic reconnections under northward interplanetary magnetic field (IMF) conditions

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Science China(Technological Sciences) 2012年第5期55卷 1207-1216页

作者： ZHANG QingHe LIU RuiYuan YANG huiGen hu hongqiao ZHANG BeiChen DUNLOP Malcolm LESTER Mark BOGDANOVA Yulia WALSH Andrew SOA Key Laboratoryfor Polar Science Polar Research Institute of ChinaShanghai 200136China Space Science Department Rutherford-Appleton LaboratoryChiltonDidcotUK Department of Physics and Astronomy University of LeicesterLeicesterUK Mullard Space Science Laboratory University College LondonDorkingSurreyUK

A number of backscatter power enhancement events with ＂equatorward-moving radar auroral forms＂ in the high-latitude ionosphere were observed by SuperDARN CUTLASS Finland radar when the IMF was northward during 09：00 -10：00 UT on 26 March 2004. These events were also associated with sunward flow enhancements at each location in the Northern Hemisphere which were shown in ionospheric convections measured by the SuperDARN radars. These are typical features of high-latitude （lobe） magnetic reconnections. The durations of the velocity enhancements imply that the evolution time of the lobe reconnec- tions is about 8-16 rain from their origin at the reconnection site to their addition to the magnetotall lobe again. In additional, the Double Star TC-1 spacecraft was moving from magnetosheath into magnetosphere, and crossing the magnetopause near the subsolar region during this interval, and observed typical low-latitude magnetic reconnection signatures. This infers that the dayside high- and low-latitude reconnections may occur simultaneously.

关键词： high-latitude magnetic reconnection equatorward-moving radar auroral form evolution time of the lobe reconnections

Extraction of auroral oval boundaries from UVI images: A new FLICM clustering-based method and its evaluation

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Advances in Polar Science 2011年第3期22卷 184-191页

作者： WANG Qian MENG Qinghu hu ZeJun XING ZanYang LIANG JiMin hu hongqiao School of Life Sciences and Technology Xidian University Xi＇an 710071 China SOA Key Laboratory for Polar Science Polar Research Institute of China Shanghai 200136 China School of Science Xidian University Xi＇an 710071 China

Based on the fuzzy local information c-means （FLICM） clustering algorithm, a new method is developed for extracting the equatorward and poleward boundaries of the auroral oval from images acquired by the Ultraviolet Imager （UVI） aboard the POLAR satellite. First, the method iteratively segments the UVI image with the FLICM clustering algorithm, according to an integrity criterion for the segmented auroral oval. Then, possible gaps in the extracted auroral oval are filled, based on prior knowledge of its shape. To evaluate the method objectively, the extracted boundaries are compared with the precipitating electron boundaries determined from DMSP satellite precipitation particle data. The evaluation results demonstrate that the proposed method generates more accurate auroral boundaries than traditional methods.

关键词： Auroral boundary UVI image segmentation evaluation