This paper is a statistical survey of Southern Hemisphere cold and hot polar cap patches,in relation to the interplanetary magnetic field(IMF)and ionospheric convection geometry.A total of 11,946 patch events were ide...This paper is a statistical survey of Southern Hemisphere cold and hot polar cap patches,in relation to the interplanetary magnetic field(IMF)and ionospheric convection geometry.A total of 11,946 patch events were identified by Defense Meteorological Satellite Program(DMSP)F16 during the years 2011 to 2022.A temperature ratio of ion/electron temperature(T_(i)/T_(e))<0.68 is recommended to define a hot patch in the Southern Hemisphere,otherwise it is defined as a cold patch.The cold and hot patches have different dependencies on IMF clock angle,while their dependencies on IMF cone angle are similar.Both cold and hot patches appear most often on the duskside,and the distribution of cold patches gradually decreases from the dayside to the nightside,while hot patches have a higher occurrence rate near 14 and 21 magnetic local time(MLT).Moreover,we compared the key plasma characteristics of polar cap cold and hot patches in the Southern and Northern Hemispheres.The intensity of the duskside upward field-aligned current of patches in the Southern Hemisphere(SH)is stronger than that in the Northern Hemisphere(SH),which may be due to the discrepancy in conductivities between the two hemispheres,caused by the tilted dipole.In both hemispheres,the downward soft-electron energy flux of the dawnside patches is significantly greater than that of the duskside patches.展开更多
Geomagnetic substorms release plasma and energy from the magnetotail to the inner magnetosphere and high latitude ionosphere.In this study,we investigate substorms of different time duration,observed during the years ...Geomagnetic substorms release plasma and energy from the magnetotail to the inner magnetosphere and high latitude ionosphere.In this study,we investigate substorms of different time duration,observed during the years 1982 to 2012.We measure substorm duration by a method based on the SME index.Our results demonstrate that longer-duration substorms occur more frequently during solar maximum years,and more frequently between the months of May and July,likely due to the higher polar ionospheric conductivity and more sunward geomagnetic pole directions during summer in the northern hemisphere.Additionally,longer substorms occur more frequently under stronger,longer-lasting southward IMF,and are accompanied by slower solar winds,suggesting that extended magnetic reconnection is required to drive longer substorms.Substorm durations are not significantly related to the minimum SML index,but longer substorms usually have higher SMU and continuously rising PC indices.The SME indices of long-duration substorms show a bimodal MLT distribution located near midnight and dusk after substorm onset,with the peak originally at midnight moving eastward to the morning side during the late recovery phase.Longer duration substorms have a stronger effect on the overall ring current at all MLT sectors except dawnside.Our results provide new insights into the development process and influencing factors of substorms,from the expansion phase to the recovery phase.展开更多
One of the most pressing crises facing the world today is climate change and its impact on the Earth’s ecosystems and human societies.Climate change is currently progressing most rapidly in the polar regions,and its ...One of the most pressing crises facing the world today is climate change and its impact on the Earth’s ecosystems and human societies.Climate change is currently progressing most rapidly in the polar regions,and its effects are already evident,making the polar regions an early indicator of global climate change.Changes in these areas affect sea level rise,ecosystems,weather patterns,and feedback mechanisms that influence global climate.Thus,understanding the polar regions is critical for predicting future changes and developing strategies for mitigation and adaptation(IPCC,2023).The IPCC Special Report on the Ocean and Cryosphere in a Changing Climate also emphasizes the interconnectedness of the polar cryosphere,ocean,and human societies,underscoring that climate action is not just an environmental issue but a matter of human survival(IPCC,2019).Given the urgent need for international collaboration to address the impacts of climate change in the polar regions,it is crucial that scientific findings are effectively shared across borders and disciplines.The International Polar Year 2032-33(Interim IPY Secretariat,2024),currently being planned,underscores this need by encouraging international cooperation and effective knowledge exchange across polar research communities.展开更多
The concept and practice of sustainable development as a guiding institutional principle, as a concrete policy goal, and as a focus of political mobilization remain salient in meeting the multiple challenges in the Ar...The concept and practice of sustainable development as a guiding institutional principle, as a concrete policy goal, and as a focus of political mobilization remain salient in meeting the multiple challenges in the Arctic. How sustainable development is conceptualized and practiced depends very much on how it is embraced by scholars, policy makers and the people in the Arctic. Under the circumstances of climate change and political-economic globalization taking place in the Arctic,展开更多
Advances in Polar Science(APS)was founded in 1990 as a peer-reviewed,English-language journal on multi-disciplinary achievements and advances in Arctic and Antarctic science.It was originally titled Chinese Journal of...Advances in Polar Science(APS)was founded in 1990 as a peer-reviewed,English-language journal on multi-disciplinary achievements and advances in Arctic and Antarctic science.It was originally titled Chinese Journal of Polar Science but,aiming to be more international,it was renamed with the current title in 2011.展开更多
Advances in Polar Science(APS),published since 1990 as a peer-reviewed English-language journal,is dedicated to the presentation of polar research(both Arctic and Antarctic)and of the accomplishments of Arctic and Ant...Advances in Polar Science(APS),published since 1990 as a peer-reviewed English-language journal,is dedicated to the presentation of polar research(both Arctic and Antarctic)and of the accomplishments of Arctic and Antarctic expeditions.The international character of the journal improved greatly over the years from 24%of the published papers with a non-Chinese submitting author in 2015 to 63%in 2020.展开更多
Advances in Polar Science （APS） has been published since 1990 as a peer-reviewed English-language journal dedicated to the presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and rese...Advances in Polar Science （APS） has been published since 1990 as a peer-reviewed English-language journal dedicated to the presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research （until 2011 it was known as the Chinese Journal of Polar Science [English Edition]）. Now, commencing with Vol. 26, No. 3 in 2015, we are moving to make APS more truly international, with two new Co-Editors-in Chief, and a new expert team of disciplinary Editors from China and many other nations involved in polar research （see http：//journal.polar.org.cn/EN/column/column80.shtml）. In the future, Advances in Polar Science will be a completely separate journal from the Chinese-language version of the Chinese Journal of Polar Research.展开更多
This special issue is based on the presentations at the 13th Annual General Meeting of the Asian Forum for Polar Sci- ences （AFoPS-13） in New Delhi on 6-7 August 2012, chaired by Dr. Shri Rasik Ravindra, Director of...This special issue is based on the presentations at the 13th Annual General Meeting of the Asian Forum for Polar Sci- ences （AFoPS-13） in New Delhi on 6-7 August 2012, chaired by Dr. Shri Rasik Ravindra, Director of National Center for Antarctic and Ocean Research of India. To strengthen both scientific and logistic collaboration among Asian countries in- volved in polar research is AFoPS＇s main purpose. During the AFoPS-13, it was decided to publish the AFoPS proceedings annually by each member countries in turn to demonstrate progresses in Polar Science of Asian countries. On the meeting, China was given the great honor to publish the first AFoPS proceedings as a special issue of the Advances in Polar Science （APS）, which is a peer-reviewed journal, published in English. APS is a comprehensive scientific journal dedicated to polar research in all scientific disciplines.展开更多
基金supported by the National Natural Science Foundation of China(Grants 42325404,42120104003,42204164,42474219 and U22A2006)the Chinese Meridian Project,the International Partnership Program of Chinese Academy of Sciences(Grant 183311KYSB20200003)+7 种基金Shandong Provincial Natural Science Foundation(Grants ZR2022QD077,ZR2022MD034)the Stable-Support Scientific Project of China Research Institute of Radiowave Propagation(Grant A132312191)the foundation of the National Key Laboratory of Electromagnetic Environment(Grant 6142403180204)the Chongqing Natural Science Foundation(Grants cstc2021ycjh-bgzxm0072,CSTB2023NSCQ-LZX0082)National Program on Key Basic Research Project(Grant 2022173-SD-1)The work in Norway is supported by the Research Council of Norway Grant 326039Work at UCLA has been supported by NSF grant AGS-2055192This research was supported by the International Space Science Institute(ISSI)in Bern and Beijing,through ISSI International Team project#511(Multi-Scale Magnetosphere-Ionosphere-Thermosphere Interaction).
文摘This paper is a statistical survey of Southern Hemisphere cold and hot polar cap patches,in relation to the interplanetary magnetic field(IMF)and ionospheric convection geometry.A total of 11,946 patch events were identified by Defense Meteorological Satellite Program(DMSP)F16 during the years 2011 to 2022.A temperature ratio of ion/electron temperature(T_(i)/T_(e))<0.68 is recommended to define a hot patch in the Southern Hemisphere,otherwise it is defined as a cold patch.The cold and hot patches have different dependencies on IMF clock angle,while their dependencies on IMF cone angle are similar.Both cold and hot patches appear most often on the duskside,and the distribution of cold patches gradually decreases from the dayside to the nightside,while hot patches have a higher occurrence rate near 14 and 21 magnetic local time(MLT).Moreover,we compared the key plasma characteristics of polar cap cold and hot patches in the Southern and Northern Hemispheres.The intensity of the duskside upward field-aligned current of patches in the Southern Hemisphere(SH)is stronger than that in the Northern Hemisphere(SH),which may be due to the discrepancy in conductivities between the two hemispheres,caused by the tilted dipole.In both hemispheres,the downward soft-electron energy flux of the dawnside patches is significantly greater than that of the duskside patches.
基金supported by NSFC research Grant 42274200National Key R&D Program of China 2023YFC2808900the International Space Science Institute(ISSI)in Bern,through ISSI International Team project#24-628-Precipitation of Energetic Particles from Magnetosphere and Their Effects on the Atmosphere.
文摘Geomagnetic substorms release plasma and energy from the magnetotail to the inner magnetosphere and high latitude ionosphere.In this study,we investigate substorms of different time duration,observed during the years 1982 to 2012.We measure substorm duration by a method based on the SME index.Our results demonstrate that longer-duration substorms occur more frequently during solar maximum years,and more frequently between the months of May and July,likely due to the higher polar ionospheric conductivity and more sunward geomagnetic pole directions during summer in the northern hemisphere.Additionally,longer substorms occur more frequently under stronger,longer-lasting southward IMF,and are accompanied by slower solar winds,suggesting that extended magnetic reconnection is required to drive longer substorms.Substorm durations are not significantly related to the minimum SML index,but longer substorms usually have higher SMU and continuously rising PC indices.The SME indices of long-duration substorms show a bimodal MLT distribution located near midnight and dusk after substorm onset,with the peak originally at midnight moving eastward to the morning side during the late recovery phase.Longer duration substorms have a stronger effect on the overall ring current at all MLT sectors except dawnside.Our results provide new insights into the development process and influencing factors of substorms,from the expansion phase to the recovery phase.
文摘One of the most pressing crises facing the world today is climate change and its impact on the Earth’s ecosystems and human societies.Climate change is currently progressing most rapidly in the polar regions,and its effects are already evident,making the polar regions an early indicator of global climate change.Changes in these areas affect sea level rise,ecosystems,weather patterns,and feedback mechanisms that influence global climate.Thus,understanding the polar regions is critical for predicting future changes and developing strategies for mitigation and adaptation(IPCC,2023).The IPCC Special Report on the Ocean and Cryosphere in a Changing Climate also emphasizes the interconnectedness of the polar cryosphere,ocean,and human societies,underscoring that climate action is not just an environmental issue but a matter of human survival(IPCC,2019).Given the urgent need for international collaboration to address the impacts of climate change in the polar regions,it is crucial that scientific findings are effectively shared across borders and disciplines.The International Polar Year 2032-33(Interim IPY Secretariat,2024),currently being planned,underscores this need by encouraging international cooperation and effective knowledge exchange across polar research communities.
文摘The concept and practice of sustainable development as a guiding institutional principle, as a concrete policy goal, and as a focus of political mobilization remain salient in meeting the multiple challenges in the Arctic. How sustainable development is conceptualized and practiced depends very much on how it is embraced by scholars, policy makers and the people in the Arctic. Under the circumstances of climate change and political-economic globalization taking place in the Arctic,
文摘Advances in Polar Science(APS)was founded in 1990 as a peer-reviewed,English-language journal on multi-disciplinary achievements and advances in Arctic and Antarctic science.It was originally titled Chinese Journal of Polar Science but,aiming to be more international,it was renamed with the current title in 2011.
文摘Advances in Polar Science(APS),published since 1990 as a peer-reviewed English-language journal,is dedicated to the presentation of polar research(both Arctic and Antarctic)and of the accomplishments of Arctic and Antarctic expeditions.The international character of the journal improved greatly over the years from 24%of the published papers with a non-Chinese submitting author in 2015 to 63%in 2020.
文摘Advances in Polar Science （APS） has been published since 1990 as a peer-reviewed English-language journal dedicated to the presentation of multi-disciplinary achievements in Arctic and Antarctic expeditions and research （until 2011 it was known as the Chinese Journal of Polar Science [English Edition]）. Now, commencing with Vol. 26, No. 3 in 2015, we are moving to make APS more truly international, with two new Co-Editors-in Chief, and a new expert team of disciplinary Editors from China and many other nations involved in polar research （see http：//journal.polar.org.cn/EN/column/column80.shtml）. In the future, Advances in Polar Science will be a completely separate journal from the Chinese-language version of the Chinese Journal of Polar Research.
文摘This special issue is based on the presentations at the 13th Annual General Meeting of the Asian Forum for Polar Sci- ences （AFoPS-13） in New Delhi on 6-7 August 2012, chaired by Dr. Shri Rasik Ravindra, Director of National Center for Antarctic and Ocean Research of India. To strengthen both scientific and logistic collaboration among Asian countries in- volved in polar research is AFoPS＇s main purpose. During the AFoPS-13, it was decided to publish the AFoPS proceedings annually by each member countries in turn to demonstrate progresses in Polar Science of Asian countries. On the meeting, China was given the great honor to publish the first AFoPS proceedings as a special issue of the Advances in Polar Science （APS）, which is a peer-reviewed journal, published in English. APS is a comprehensive scientific journal dedicated to polar research in all scientific disciplines.
