The persistence and symmetry of cyclones around the poles of Jupiter are unknown.In the present investigation,inspired by cyclones at the South Pole of the Earth,we propose a mechanism that provides an explanation for...The persistence and symmetry of cyclones around the poles of Jupiter are unknown.In the present investigation,inspired by cyclones at the South Pole of the Earth,we propose a mechanism that provides an explanation for this problem.The negative temperature gradient with respect to latitude may play an important role here.This temperature gradient is induced by solar radiation because of the small axial inclination of Jupiter.Our numerical simulations suggest that cyclones in the polar regions of Jupiter may be modulated or controlled by the radially directional Rayleigh–Taylor instability,driven by centrifugal force and the negative temperature gradient along the latitude.展开更多
Lunar dust is one of the most threatening problems confronting the return of human beings to the moon.In this work we studied the spatial distribution behavior of charged lunar dust in the solar wind plasma environmen...Lunar dust is one of the most threatening problems confronting the return of human beings to the moon.In this work we studied the spatial distribution behavior of charged lunar dust in the solar wind plasma environment in the south polar region of the moon and considered the influence of a mini-crater using Spacecraft Plasma Interactions Software.The distribution of dust and plasma at low solar altitude angles of 20°and 0°was studied,and the spatial density of lunar dust was~10^(10.4)m^(-3)and~10^(11.5)m^(-3),respectively.This is because a higher surface potential will result in transportation of small dust particles and photoelectrons can also neutralize positively charged lunar dust.The dust density in the plasma void region created by a mini-crater with a 5 m high wall was studied.We obtained a quasi-neutral electric environment in the plasma void region of the mini-crater,and the dust density was about a magnitude lower than that in other regions.The dust risk to a spacesuit is much lower on the nightside than on the dayside,but there is severe charged lunar dust transport in the region between light and shade,which is dominated by the difference in surface and plasma potential caused by photoelectrons.展开更多
The remote sensing technique is widely used in Polar Regions,and Moderate Resolution Imaging Spectroradiomete(MODIS) is one of the most important satellite sensors in the domain of remote sensing.In this article,MOD...The remote sensing technique is widely used in Polar Regions,and Moderate Resolution Imaging Spectroradiomete(MODIS) is one of the most important satellite sensors in the domain of remote sensing.In this article,MODIS sensor,including the information of its satellites,its system constitutes,its hardware characteristic,its large spectra and usual applications are briefly introduced first.Then,there is a particular introduction of MODIS's use in Polar Regions,which refers to the polar physiognomy,polar atmosphere and polar ocean,with citing many examples.At last,views about the development of MODIS and its series sensors in the future,including the improved applications in Polar Regions are given.展开更多
Because of the decrease in sea ice coverage,maritime activities in the polar regions have increased steadily over the years and several issues related to maritime activities have arisen.It is essential to understand t...Because of the decrease in sea ice coverage,maritime activities in the polar regions have increased steadily over the years and several issues related to maritime activities have arisen.It is essential to understand these challenges because they could have serious political,environmental,and economic consequences.Although there are significant geographical and legal differences and differences in the types of activities between the Arctic and the Antarctic,a single International Maritime Organization Polar Code covers both regions.In this analysis,changes in polar regions are introduced,and the differences between the Arctic and Antarctic are discussed.The differences in maritime activities in the two polar regions are then discussed,and the Polar Code is evaluated in terms of these differences.展开更多
Dear Colleagues, We would like to invite you to submit manuscripts to a special issue entitled "Current Research on Atmospheric Aerosols and Trace Gases over the Polar Regions" of the Journal Advances in Polar Scie...Dear Colleagues, We would like to invite you to submit manuscripts to a special issue entitled "Current Research on Atmospheric Aerosols and Trace Gases over the Polar Regions" of the Journal Advances in Polar Science (APS). APS is an international, peer-reviewed journal jointly sponsored by the Polar Research Institute of China (PRIC) and the Chinese Arctic and Antarctic Administration (CAA). It is a quarterly journal published in March, June, September and December by Science Press of China and circulated internationally (ISSN 1674-9928, CN 31-2050/P). Articles published in APS are free of charge with generous funding from PRIC. For more details, please visit the APS's websites. Thank you in advance for your consideration to submit manuscripts to this special issue, and we encourage you to share this announcement broadly with interested colleagues.展开更多
A polar version of mesoseale model, Polar MM5 is introduced in the paper. The modifications for the polar MM5 dynamics and physics compared with standard MM5 are described. Additionally, parallel simulations of the Po...A polar version of mesoseale model, Polar MM5 is introduced in the paper. The modifications for the polar MM5 dynamics and physics compared with standard MM5 are described. Additionally, parallel simulations of the Polar MM5 and original MM5 reveal that the Polar MM5 reproduces better near-surface variables forecasts than the original MM5 over the North American Arctic regions. The well predicted near surface temperature and mixing ratio by the Polar MM5 confirm the modified physical parameterization schemes in the Polar MM5 are appropriate for the research region.展开更多
Evolution of remote sensing sensors technologies is presented, with emphasis on its suitability in observing the polar regions. The extent of influence of polar regions on the global climate and vice versa is the spea...Evolution of remote sensing sensors technologies is presented, with emphasis on its suitability in observing the polar regions. The extent of influence of polar regions on the global climate and vice versa is the spearhead of climate change research. The extensive cover of sea ice has major impacts on the atmosphere, oceans, and terrestrial and marine ecosystems of the polar regions in particular and teleconnection on other processes elsewhere. Sea ice covers vast areas of the polar oceans, ranging from ~18 × 106 km2 to ~23 × 106 km2, combined for the Northern and Southern Hemispheres. However, both polar regions are witnessing contrasting rather contradicting effects of climate change. The Arctic sea ice extent is declining at a rate of 0.53 × 106 km2·decade–1, whereasAntarcticaexhibits a positive trend at the rate of 0.167 × 106 km2·decade–1. This work reviews literature published in the field of sea ice remote sensing, to evaluate and access success and failures of different sensors to observe physical features of sea ice. The chronological development series of different sensors on different satellite systems, sensor specifications and datasets are examined and how they have evolved to meet the growing needs of users is outlined. Different remote sensing technology and observational methods and their suitability to observe specific sea ice property are also discussed. A pattern has emerged, which shows that microwave sensors are inherently superior to visible and infrared in monitoring seasonal and annual changes in sea ice. Degree of successes achieved through remote sensing techniques by various investigators has been compared. Some technologies appear to work better under certain conditions than others, and it is now well accepted that there is no algorithm that is ideal globally. Contribution of Indian remote sensing satellites is also reviewed in the context of polar research. This review suggests different primary datasets for further research on sea ice features (sea ice extent, ice type, sea ice thickness, etc.). This work also examines past achievements and how far these capabilities have evolved and tap into current state of art/direction of sensor technologies. Effective monitoring and syntheses of past few decades of research pinpoint useful datasets for sea ice monitoring, thereby avoiding wastage of resources to find practical datasets to monitor these physically inaccessible regions.展开更多
HF (high frequency) radar sounder technology has been developed for several missions of Mars surface/subsurface exploration. This paper presents a model of rough surface and stratified sub-surfaces to describe the mul...HF (high frequency) radar sounder technology has been developed for several missions of Mars surface/subsurface exploration. This paper presents a model of rough surface and stratified sub-surfaces to describe the multi-layer structure of Mars polar deposits. Based on numerical simulation of radar echoes from rough surface/stratified interfaces, an inversion approach is developed to obtain the parameters of Polar Layered Deposits, i.e. layers thickness and dielectric constants. As a validation example, the SHARAD radar sounder data of the Promethei Lingula of Mars South Polar region is adopted for parameters inversion. The result of stratification is also analyzed and compared with the optical photo of the deep cliff of Chasma Australe canyon. Dielectric inversions show that the deposit media are not uniform, and the dielectric constants of the Promethei Lingula surfaces are large, and become reduced around the depth of 20 m - 30 m, below where most of the deposits are nearly pure ice, except a few thin layers with a lot of dust.展开更多
Using data from the Cluster spacecraft from January 2003 to December 2004, we perform a statistical study on some properties of the field-aligned electron(FAE) events and interplanetary magnetic field(IMF) By dependen...Using data from the Cluster spacecraft from January 2003 to December 2004, we perform a statistical study on some properties of the field-aligned electron(FAE) events and interplanetary magnetic field(IMF) By dependence of FAE events with different durations in high-altitude polar regions. A total of 1335 FAE events were observed by the C3 spacecraft. More down-flowing events were observed in the Southern Hemisphere, and more up-flowing events were observed in the Northern Hemisphere. It proves that down-flowing events mainly originate from magnetosphere or solar wind and up-flowing events are mainly derived from ionosphere. Short-lifetime events showed a morning concentration in the magnetic local time distribution, and long-lifetime events were concentrated both before and after noon. For the IMF By dependence of the FAE events, short-lifetime events were much affected by IMF By and resulted in a morning concentration, while the long-lifetime events were almost unaffected by IMF By. With further analysis, we determined that the short-lifetime and long-lifetime events had different sources.展开更多
The European Centre for Medium-Range Weather Forecasts Reanalysis ERA40,National Centers for Environmental Prediction(NCEP) 20th-century reanalysis,and three station observations along an Antarctic traverse from Zhong...The European Centre for Medium-Range Weather Forecasts Reanalysis ERA40,National Centers for Environmental Prediction(NCEP) 20th-century reanalysis,and three station observations along an Antarctic traverse from Zhongshan to Dome-A stations are used to assess 2-m temperature simulation skill of a regional climate model.This model(HIRHAM) is from the Alfred Wegener Institute for Polar and Marine Research in Germany.Results show:(1) The simulated multiyear averaged 2-m temperature field pattern is close to that of ERA40 and NCEP;(2) the cold bias relative to ERA40 over all of Antarctic regions is 1.8℃,and that to NCEP reaches 5.1℃;(3) bias of HIRHAM relative to ERA40 has seasonal variation,with a cold bias mainly in the summer,as much as 3.4℃.There is a small inland warm bias in autumn of 0.3℃.Further analysis reveals that the reason for the cold bias of 2-m temperature is that physical conditions of the near-surface boundary layer simulated by HIRHAM are different from observations:(1) During the summer,observations show that near-surface atmospheric stability conditions have both inversions and non-inversions,which is due to the existence of both positive and negative sensible heat fluxes,but HIRHAM almost always simulates a situation of inversion and negative sensible heat flux;(2) during autumn and winter,observed near-surface stability is almost always that of inversions,consistent with HIRHAM simulations.This partially explains the small bias during autumn and winter.展开更多
基金supported by the National Nature Science Foundation of China(Grant No.NSFC41974204).
文摘The persistence and symmetry of cyclones around the poles of Jupiter are unknown.In the present investigation,inspired by cyclones at the South Pole of the Earth,we propose a mechanism that provides an explanation for this problem.The negative temperature gradient with respect to latitude may play an important role here.This temperature gradient is induced by solar radiation because of the small axial inclination of Jupiter.Our numerical simulations suggest that cyclones in the polar regions of Jupiter may be modulated or controlled by the radially directional Rayleigh–Taylor instability,driven by centrifugal force and the negative temperature gradient along the latitude.
基金Project supported by the National Key Research and Development Program of China(Grant No.2020YFC2201300)the Strategic Priority Research Program of Chinese Academy of Sciences(Grant No.XDA17010301)the Technical Basic Scientific Research Project(Grant No.JSZL2019903B001)。
文摘Lunar dust is one of the most threatening problems confronting the return of human beings to the moon.In this work we studied the spatial distribution behavior of charged lunar dust in the solar wind plasma environment in the south polar region of the moon and considered the influence of a mini-crater using Spacecraft Plasma Interactions Software.The distribution of dust and plasma at low solar altitude angles of 20°and 0°was studied,and the spatial density of lunar dust was~10^(10.4)m^(-3)and~10^(11.5)m^(-3),respectively.This is because a higher surface potential will result in transportation of small dust particles and photoelectrons can also neutralize positively charged lunar dust.The dust density in the plasma void region created by a mini-crater with a 5 m high wall was studied.We obtained a quasi-neutral electric environment in the plasma void region of the mini-crater,and the dust density was about a magnitude lower than that in other regions.The dust risk to a spacesuit is much lower on the nightside than on the dayside,but there is severe charged lunar dust transport in the region between light and shade,which is dominated by the difference in surface and plasma potential caused by photoelectrons.
文摘The remote sensing technique is widely used in Polar Regions,and Moderate Resolution Imaging Spectroradiomete(MODIS) is one of the most important satellite sensors in the domain of remote sensing.In this article,MODIS sensor,including the information of its satellites,its system constitutes,its hardware characteristic,its large spectra and usual applications are briefly introduced first.Then,there is a particular introduction of MODIS's use in Polar Regions,which refers to the polar physiognomy,polar atmosphere and polar ocean,with citing many examples.At last,views about the development of MODIS and its series sensors in the future,including the improved applications in Polar Regions are given.
文摘Because of the decrease in sea ice coverage,maritime activities in the polar regions have increased steadily over the years and several issues related to maritime activities have arisen.It is essential to understand these challenges because they could have serious political,environmental,and economic consequences.Although there are significant geographical and legal differences and differences in the types of activities between the Arctic and the Antarctic,a single International Maritime Organization Polar Code covers both regions.In this analysis,changes in polar regions are introduced,and the differences between the Arctic and Antarctic are discussed.The differences in maritime activities in the two polar regions are then discussed,and the Polar Code is evaluated in terms of these differences.
文摘Dear Colleagues, We would like to invite you to submit manuscripts to a special issue entitled "Current Research on Atmospheric Aerosols and Trace Gases over the Polar Regions" of the Journal Advances in Polar Science (APS). APS is an international, peer-reviewed journal jointly sponsored by the Polar Research Institute of China (PRIC) and the Chinese Arctic and Antarctic Administration (CAA). It is a quarterly journal published in March, June, September and December by Science Press of China and circulated internationally (ISSN 1674-9928, CN 31-2050/P). Articles published in APS are free of charge with generous funding from PRIC. For more details, please visit the APS's websites. Thank you in advance for your consideration to submit manuscripts to this special issue, and we encourage you to share this announcement broadly with interested colleagues.
文摘A polar version of mesoseale model, Polar MM5 is introduced in the paper. The modifications for the polar MM5 dynamics and physics compared with standard MM5 are described. Additionally, parallel simulations of the Polar MM5 and original MM5 reveal that the Polar MM5 reproduces better near-surface variables forecasts than the original MM5 over the North American Arctic regions. The well predicted near surface temperature and mixing ratio by the Polar MM5 confirm the modified physical parameterization schemes in the Polar MM5 are appropriate for the research region.
文摘Evolution of remote sensing sensors technologies is presented, with emphasis on its suitability in observing the polar regions. The extent of influence of polar regions on the global climate and vice versa is the spearhead of climate change research. The extensive cover of sea ice has major impacts on the atmosphere, oceans, and terrestrial and marine ecosystems of the polar regions in particular and teleconnection on other processes elsewhere. Sea ice covers vast areas of the polar oceans, ranging from ~18 × 106 km2 to ~23 × 106 km2, combined for the Northern and Southern Hemispheres. However, both polar regions are witnessing contrasting rather contradicting effects of climate change. The Arctic sea ice extent is declining at a rate of 0.53 × 106 km2·decade–1, whereasAntarcticaexhibits a positive trend at the rate of 0.167 × 106 km2·decade–1. This work reviews literature published in the field of sea ice remote sensing, to evaluate and access success and failures of different sensors to observe physical features of sea ice. The chronological development series of different sensors on different satellite systems, sensor specifications and datasets are examined and how they have evolved to meet the growing needs of users is outlined. Different remote sensing technology and observational methods and their suitability to observe specific sea ice property are also discussed. A pattern has emerged, which shows that microwave sensors are inherently superior to visible and infrared in monitoring seasonal and annual changes in sea ice. Degree of successes achieved through remote sensing techniques by various investigators has been compared. Some technologies appear to work better under certain conditions than others, and it is now well accepted that there is no algorithm that is ideal globally. Contribution of Indian remote sensing satellites is also reviewed in the context of polar research. This review suggests different primary datasets for further research on sea ice features (sea ice extent, ice type, sea ice thickness, etc.). This work also examines past achievements and how far these capabilities have evolved and tap into current state of art/direction of sensor technologies. Effective monitoring and syntheses of past few decades of research pinpoint useful datasets for sea ice monitoring, thereby avoiding wastage of resources to find practical datasets to monitor these physically inaccessible regions.
文摘HF (high frequency) radar sounder technology has been developed for several missions of Mars surface/subsurface exploration. This paper presents a model of rough surface and stratified sub-surfaces to describe the multi-layer structure of Mars polar deposits. Based on numerical simulation of radar echoes from rough surface/stratified interfaces, an inversion approach is developed to obtain the parameters of Polar Layered Deposits, i.e. layers thickness and dielectric constants. As a validation example, the SHARAD radar sounder data of the Promethei Lingula of Mars South Polar region is adopted for parameters inversion. The result of stratification is also analyzed and compared with the optical photo of the deep cliff of Chasma Australe canyon. Dielectric inversions show that the deposit media are not uniform, and the dielectric constants of the Promethei Lingula surfaces are large, and become reduced around the depth of 20 m - 30 m, below where most of the deposits are nearly pure ice, except a few thin layers with a lot of dust.
基金supported by the National Natural Science Foundation of China(Grant Nos.4127414641474137 and 41374169)the Specialized Research Fund for State Key Laboratory in China
文摘Using data from the Cluster spacecraft from January 2003 to December 2004, we perform a statistical study on some properties of the field-aligned electron(FAE) events and interplanetary magnetic field(IMF) By dependence of FAE events with different durations in high-altitude polar regions. A total of 1335 FAE events were observed by the C3 spacecraft. More down-flowing events were observed in the Southern Hemisphere, and more up-flowing events were observed in the Northern Hemisphere. It proves that down-flowing events mainly originate from magnetosphere or solar wind and up-flowing events are mainly derived from ionosphere. Short-lifetime events showed a morning concentration in the magnetic local time distribution, and long-lifetime events were concentrated both before and after noon. For the IMF By dependence of the FAE events, short-lifetime events were much affected by IMF By and resulted in a morning concentration, while the long-lifetime events were almost unaffected by IMF By. With further analysis, we determined that the short-lifetime and long-lifetime events had different sources.
基金supported by the Program of China Polar Environment Investigation and Assessment(2011–2015)the Basic Scientific Special Project "Climate System Model" of Chinese Academy of Meteorological Science(Grant No.2012Z001)the National Natural Science Foundation of China(Grant Nos.41005045 and 41206179)
文摘The European Centre for Medium-Range Weather Forecasts Reanalysis ERA40,National Centers for Environmental Prediction(NCEP) 20th-century reanalysis,and three station observations along an Antarctic traverse from Zhongshan to Dome-A stations are used to assess 2-m temperature simulation skill of a regional climate model.This model(HIRHAM) is from the Alfred Wegener Institute for Polar and Marine Research in Germany.Results show:(1) The simulated multiyear averaged 2-m temperature field pattern is close to that of ERA40 and NCEP;(2) the cold bias relative to ERA40 over all of Antarctic regions is 1.8℃,and that to NCEP reaches 5.1℃;(3) bias of HIRHAM relative to ERA40 has seasonal variation,with a cold bias mainly in the summer,as much as 3.4℃.There is a small inland warm bias in autumn of 0.3℃.Further analysis reveals that the reason for the cold bias of 2-m temperature is that physical conditions of the near-surface boundary layer simulated by HIRHAM are different from observations:(1) During the summer,observations show that near-surface atmospheric stability conditions have both inversions and non-inversions,which is due to the existence of both positive and negative sensible heat fluxes,but HIRHAM almost always simulates a situation of inversion and negative sensible heat flux;(2) during autumn and winter,observed near-surface stability is almost always that of inversions,consistent with HIRHAM simulations.This partially explains the small bias during autumn and winter.