With the approaching of the 24th solar cycle peak year （2012-2014）, the impacts of super solar storms on the geospace envi- ronment have drawn attentions. Based on the geomagnetic field observations during Carringto...With the approaching of the 24th solar cycle peak year （2012-2014）, the impacts of super solar storms on the geospace envi- ronment have drawn attentions. Based on the geomagnetic field observations during Carrington event in 1859, we estimate the interplanetary solar wind conditions at that time, and investigate the response of the magnetosphere-ionosphere system to this extreme solar wind conditions using global 3D MHD simulations. The main findings include： l） The day-side magnetopause and bow shock are compressed to 4.3 and 6.0 Re （Earth radius）, and their flanks are also strongly compressed. The magneto- pause shifts inside the geosynchronous orbit, exposing geosynchronous satellites in the solar wind in the magnetosheath. 2） During the storm, the region-1 current increases by about 60 times, and the cross polar potential drop increases by about 80 times; the reconnection voltage is about 5 to 6 times larger than the average storms, which means a larger amount of the solar wind energy enters the magnetosphere, resulting in strong space weather phenomena.展开更多
The joint European Space Agency and Chinese Academy of Sciences Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will explore global dynamics of the magnetosphere under varying solar wind and interplane...The joint European Space Agency and Chinese Academy of Sciences Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will explore global dynamics of the magnetosphere under varying solar wind and interplanetary magnetic field conditions,and simultaneously monitor the auroral response of the Northern Hemisphere ionosphere.Combining these large-scale responses with medium and fine-scale measurements at a variety of cadences by additional ground-based and space-based instruments will enable a much greater scientific impact beyond the original goals of the SMILE mission.Here,we describe current community efforts to prepare for SMILE,and the benefits and context various experiments that have explicitly expressed support for SMILE can offer.A dedicated group of international scientists representing many different experiment types and geographical locations,the Ground-based and Additional Science Working Group,is facilitating these efforts.Preparations include constructing an online SMILE Data Fusion Facility,the discussion of particular or special modes for experiments such as coherent and incoherent scatter radar,and the consideration of particular observing strategies and spacecraft conjunctions.We anticipate growing interest and community engagement with the SMILE mission,and we welcome novel ideas and insights from the solar-terrestrial community.展开更多
Frequently observed throat auroras have been suggested to be correspondent to indentations on the subsolar magnetopause,but how these indentations can be generated is unknown yet.Based on analyzing the detailed observ...Frequently observed throat auroras have been suggested to be correspondent to indentations on the subsolar magnetopause,but how these indentations can be generated is unknown yet.Based on analyzing the detailed observational features of throat aurora,a conceptual model for generation of throat aurora is proposed.This model suggests that precipitation of a north-south aligned stripy diffuse aurora can lead to an ionospheric conductivity enhancement and thus produce a polarization electric field in dusk-to-dawn direction in the ionosphere.After mapping to the magnetosphere along closed field lines,this electric field can guide a magnetopause reconnection to develop inward the magnetosphere and result in a throat aurora.Because this model can comprehensively explain all the observational results that have been presented up to now,we argue that the assumption of ionospheric polarization electric field affecting magnetopause reconnection should be true and be worthy of further investigations.展开更多
基金supported by National Natural Science Foundation of China (Grant Nos. 40921063, 40974106,40831060)the special fund for State Key Laboratory of Ministry of Science and Technology
文摘With the approaching of the 24th solar cycle peak year （2012-2014）, the impacts of super solar storms on the geospace envi- ronment have drawn attentions. Based on the geomagnetic field observations during Carrington event in 1859, we estimate the interplanetary solar wind conditions at that time, and investigate the response of the magnetosphere-ionosphere system to this extreme solar wind conditions using global 3D MHD simulations. The main findings include： l） The day-side magnetopause and bow shock are compressed to 4.3 and 6.0 Re （Earth radius）, and their flanks are also strongly compressed. The magneto- pause shifts inside the geosynchronous orbit, exposing geosynchronous satellites in the solar wind in the magnetosheath. 2） During the storm, the region-1 current increases by about 60 times, and the cross polar potential drop increases by about 80 times; the reconnection voltage is about 5 to 6 times larger than the average storms, which means a larger amount of the solar wind energy enters the magnetosphere, resulting in strong space weather phenomena.
基金supported by Royal Society grant DHFR1211068funded by UKSA+14 种基金STFCSTFC grant ST/M001083/1funded by STFC grant ST/W00089X/1supported by NERC grant NE/W003309/1(E3d)funded by NERC grant NE/V000748/1support from NERC grants NE/V015133/1,NE/R016038/1(BAS magnetometers),and grants NE/R01700X/1 and NE/R015848/1(EISCAT)supported by NERC grant NE/T000937/1NSFC grants 42174208 and 41821003supported by the Research Council of Norway grant 223252PRODEX arrangement 4000123238 from the European Space Agencysupport of the AUTUMN East-West magnetometer network by the Canadian Space Agencysupported by NASA’s Heliophysics U.S.Participating Investigator Programsupport from grant NSF AGS 2027210supported by grant Dnr:2020-00106 from the Swedish National Space Agencysupported by the German Research Foundation(DFG)under number KR 4375/2-1 within SPP"Dynamic Earth"。
文摘The joint European Space Agency and Chinese Academy of Sciences Solar wind Magnetosphere Ionosphere Link Explorer(SMILE)mission will explore global dynamics of the magnetosphere under varying solar wind and interplanetary magnetic field conditions,and simultaneously monitor the auroral response of the Northern Hemisphere ionosphere.Combining these large-scale responses with medium and fine-scale measurements at a variety of cadences by additional ground-based and space-based instruments will enable a much greater scientific impact beyond the original goals of the SMILE mission.Here,we describe current community efforts to prepare for SMILE,and the benefits and context various experiments that have explicitly expressed support for SMILE can offer.A dedicated group of international scientists representing many different experiment types and geographical locations,the Ground-based and Additional Science Working Group,is facilitating these efforts.Preparations include constructing an online SMILE Data Fusion Facility,the discussion of particular or special modes for experiments such as coherent and incoherent scatter radar,and the consideration of particular observing strategies and spacecraft conjunctions.We anticipate growing interest and community engagement with the SMILE mission,and we welcome novel ideas and insights from the solar-terrestrial community.
基金supported by the National Key R & D Program of China (Grant No. 2018YFC1407303)the National Natural Science Foundation of China (Grant Nos. 41774174, 41704159, 41831072 & 41431072)
文摘Frequently observed throat auroras have been suggested to be correspondent to indentations on the subsolar magnetopause,but how these indentations can be generated is unknown yet.Based on analyzing the detailed observational features of throat aurora,a conceptual model for generation of throat aurora is proposed.This model suggests that precipitation of a north-south aligned stripy diffuse aurora can lead to an ionospheric conductivity enhancement and thus produce a polarization electric field in dusk-to-dawn direction in the ionosphere.After mapping to the magnetosphere along closed field lines,this electric field can guide a magnetopause reconnection to develop inward the magnetosphere and result in a throat aurora.Because this model can comprehensively explain all the observational results that have been presented up to now,we argue that the assumption of ionospheric polarization electric field affecting magnetopause reconnection should be true and be worthy of further investigations.
