Distribution of charged lunar dust in the south polar region of the moon

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.

Are cyclones in Jupiter's polar regions modulated by the radially directional Rayleigh–Taylor instability?

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.

Progress in application of MODIS for remote sensing in Polar Regions

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.

Evaluation of the Polar Code in different environments and for different maritime activities in the two polar regions

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.

Soliciting Contributions to a Special Issue of "Current Research on Atmospheric Aerosols and Trace Gases over the Polar Regions" in Advances in Polar Science

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.

A mesoscale model used in the Polar regions:modification and verification

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.

Sea Ice Observations in Polar Regions: Evolution of Technologies in Remote Sensing

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.

Parameter Inversions of Multi-Layer Media of Mars Polar Region with Validation of SHARAD Data

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.

Some properties of field-aligned electron events in high-altitude polar regions

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.

Simulation and evaluation of 2-m temperature over Antarctica in polar regional climate model

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.

用于极地的中尺度大气模式Polar MM5的改进和检验

介绍了一个用于极地研究的中尺度大气模式———Polar MM5,阐述了该模式区别于标准的中尺度大气模式MM5的动力学和物理特征。利用Polar MM5获得了10 d的模拟结果表明,Polar MM5能较好地模拟高纬度地区近地面气象变量特征,尤其是对近地面温度和水汽混合比可得到高精度模拟结果,证实了在高纬度地区对标准MM5所进行的物理参数化方案的改进是切实有效的。

Progress in polar upper atmospheric physics research in China

The Chinese Antarctic Great Wall, Zhongshan, Kunlun and Arctic Yellow River stations have unique geographical locations, well suited to carry out polar upper atmospheric observations. This paper reviews the tremendous history of nearly 30 years of Chinese polar expeditions and major progress in polar upper atmospheric physics research. This includes the polar upper atmospheric physics conjugate observation system at Zhongshan Station in the Antarctic and Yellow River Station in the Arctic, and original research achievements in polar ionospheric fields, aurora and particle precipitation, the polar current system, polar plasma convection, geomagnetic pulsations and space plasma waves, inter-hemispheric comparisons of the space environment, space weather in polar regions, power spectrum of the incoherent scatter radar, ionospheric heating experiments and polar meso- spheric summer echoes, polar ionosphere-magnetosphere numerical simulation and others. Finally, prospects for Chinese polar upper atmospheric physics research are outlined.

Simulated perturbation in the sea-to-air flux of dimethylsulfi de and the impact on polar climate

Marine biogenic emission of dimethylsulfi de(DMS)has been well recognized as the main natural source of reduced sulfur to the remote marine atmosphere and has the potential to aff ect climate,especially in the polar regions.We used a global climate model(GCM)to investigate the impact on atmospheric chemistry from a change to the contemporary DMS fl ux to that which has been projected for the late 21 st century.The perturbed simulation corresponded to conditions that pertained to a tripling of equivalent CO 2,which was estimated to occur by year 2090 based on current worst-case greenhouse gas emission scenarios.The changes in zonal mean DMS fl ux were applied to 50°S–70°S Antarctic(ANT)and 65°N–80°N Arctic(ARC)regions.The results indicate that there are clearly diff erent impacts after perturbation in the southern and northern polar regions.Most quantities related to the sulfur cycle show a higher increase in ANT.However,most sulfur compounds have higher peaks in ARC.The perturbation in DMS fl ux leads to an increase of atmospheric DMS of about 45%in ANT and 33.6%in ARC.The sulfur dioxide(SO 2)vertical integral increases around 43%in ANT and 7.5%in ARC.Sulfate(SO 4)vertical integral increases by 17%in ANT and increases around 6%in ARC.Sulfur emissions increases by 21%in ANT and increases by 9.7%in ARC.However,oxidation of DMS by OH increases by 38.2%in ARC and by 15.17%in ANT.Aerosol optical depth(AOD)increases by 4%in the ARC and by 17.5%in the ANT,and increases by 22.8%in austral summer.The importance of the perturbation of the biogenic source to future aerosol burden in polar regions leads to a cooling in surface temperature of 1 K in the ANT and 0.8 K in the ARC.Generally,polar regions in the Antarctic Ocean will have a higher off setting eff ect on warming after DMS fl ux perturbation.

The research of Polar sea ice and its role in climate change

As an important part of global climate system, the Polar sea ice is effccting on global climate changes through ocean surface radiation balance, mass balance, energy balance as well as the circulating of sea water temperature and salinity. Sea ice research has a centuries - old history. The many correlative sea ice projects were established through the extensive international cooperation during the period from the primary research of intensity and the boaring capacity of sea ice to the development of sea/ice/air coupled model. Based on these reseamhes, the sea ice variety was combined with the global climate change. All research about sea ice includes： the physical properties and processes of sea ice and its snow cover, the ecosystem of sea ice regions, sea ice and upper snow albedo, mass balance of sea ice regions, sea ice and climate coupled model. The simulation suggests that the both of the area and volume of polar sea ice would be reduced in next century. With the developing of the sea ice research, more scientific issues are mentioned. Such as the interaction between sea ice and the other factors of global climate system, the seasonal and regional distribution of polar sea ice thickness, polar sea ice boundary and area variety trends, the growth and melt as well as their influencing factors, the role of the polynya and the sea/air interactions. We should give the best solutions to all of the issues in future sea ice studying.

Cryoseismologic Studies for Polar Environment—Recent Progress of Japanese Contribution

Majority areas of Antarctica and Greenland are under the thick ice sheet and characterized by evolving cryosphere surroundings. In the polar region, associated with the recent trend on climate change such as global warming, glacier relating earthquakes are increasing during this 21st century. In this paper, a decade of progress in “Cryoseismology” at bi-polar regions is re-viewed by focusing on the contribution from Japanese researchers. In particular, the specific cryoseismic events are treated, which occurred in the coastal area of East Antarctica, around the Lützow-Holm Bay, together with the coast and whole inland area of Greenland. As the major scientific results, frequency-overtone signals in the harmonic cryoseismic tremors were analyzed by assuming constant sources, suggesting inter-glacial asperities that generate characteristic tremors. Infrasound source locations were also determined by using the array deployment at the coastal regions in the Antarctic. In contrast, characteristics of glacial earthquakes and seismic interferometry approach have been conducted so as to achieve the fine structure of the Greenland Ice Sheet (GrIS) in particular the basal condition beneath the ice sheet.

A comparative study on the ionospheric current systems in the Antarctic and Arctic regions

The current systems representing the solar and lunar daily variations (S and L) of the gcomagnetic field have been calculated on the basis of the date obtained from the global network Of gcornagnetic observatories. The characteristics of these current.systems in the Antarctic and Arctic regions have been analysed comparatively. The results show that: (1) There are certain differences in the current systems of these two regions, that implies definite differences in the ionospheric dynamo process, responsible for both S and L, and the field-aligned current, responsible for S. The differences of the magnetic field structure in these two polar regions may be the basic reason of the above-mentioned differences. (2) There are remarkable differences in the internal current systems of these two polar regions, that is attributed to both the inducing field (current) and the underground conductivity. In general, the conductivity of the Antarctic region is higher than that of the Arctic region.

Feature Extraction to Polar Image

Some algorithms of feature extraction in existing literature studied for image processing was the gray image with one-dimensional parameter. However, some feature points’ extraction for three-dimensional color of polar image, such as the color edge extraction, inflection points, and so on, was urgently to be solved a polar color problem. For achieving quickly and accurately the color feature extraction to polar image, this paper proposed a similar region of color algorithm. The algorithm was compared to polar image, and the effect to color extraction was also described by the combination of the proposed and existing algorithms. Moreover, this paper gave the comparison of the proposed algorithm and an existing classical algorithm to extraction of color feature. These researches in this paper provided a powerful tool for polar image classification, color feature segmentation, precise recognition, and so on.

Imbalance and Polarization of Spatial Distribution of China's Swine Production

Based on annual pork yield of each province in 1996-2014,using Gini coefficient and spatial polarization index model,empirical analysis was carried out for spatial imbalance and polarization degree of swine production distribution. Results indicate that there is high imbalance in spatial distribution of swine production. The imbalance takes on first rise then declines with fluctuation,largely because of inter-group gap. From the perspective of regions,the regions with balanced grain production have the highest imbalance in swine production,followed by main sales regions,and the main grain production regions have the lowest imbalance. The polarization index indicates that the overall polarization degree of the spatial distribution of swine production takes on a growing trend,and that of each functional region of grain production is also growing.

湖冰作为极地海冰技术中试基地的探讨

极地海冰技术验证需在不同环境中开展测试,渤海海冰的不稳定性无法保障反复的长期试验时间,寻求利用国内寒区湖泊作为中试基地,解决室内缺少接近极地条件的中试难题。为此,在含章湖、青海湖、乌梁素海和呼和诺尔湖开展湖冰生消、物理性质、力学性质等调查研究,并与南、北极海冰的物理和力学性质进行对比评估。结果表明,含章湖、青海湖、乌梁素海湖和呼和诺尔湖均有时间充裕的冰封期。呼和诺尔湖冰厚最大,超过1 m;乌梁素海冰厚超过50 cm;含章湖和青海湖冰厚相似,最大冰厚超过30 cm。含章湖、青海湖和乌梁素海冰晶体均以柱状冰为主,与极地一年冰晶体结构相似。含章湖和青海湖冰的盐度及密度与北极夏季海冰相似。含章湖冰的单轴压缩强度比极地夏季海冰强度高;乌梁素海湖冰强度与南极普里兹湾固定冰强度相似。研究结果表明国内一些湖泊可作为极地海冰技术验证的中试基地。

中国极地海洋微生物研究进展

极地海洋环境蕴含丰富的微生物资源,其独特的生命特征、特殊的极端环境适应及生态效应机制,都有着重要的科学研究意义及应用开发前景。回顾我国近10年来在极地海洋微生物领域的研究,所取得的主要进展包括:(1)揭示了南北极海洋微生物群落特有的结构和功能、二甲基硫/二甲基巯基丙酸内盐(DMS/DMSP)循环相关基因及可培养细菌基因组的独特生物地理学特征;(2)发现了极地海洋细菌通过代谢DMSP抵御原生动物捕食的新生态功能、温度响应新机制及新的几丁质氧化降解利用通路;(3)揭示了噬菌体对极地海洋细菌种群的调控作用;(4)阐明了极地海洋细菌产生的系列新型有机质降解酶的催化机制及其应用潜力;(5)建立了极地海洋细菌胞外多糖的制备工艺,评估了其在医学及食品等领域的应用潜力;(6)分离鉴定了系列极地海洋微生物新物种。以上研究成果先后发表在Nature Microbiology,Nature Communica-tions,Microbiome,ISME Journal等国际知名期刊上,提升了我国极地海洋微生物研究的水平、影响力和话语权。未来加强多学科交叉研究及前沿技术应用研发将进一步促进我国极地海洋微生物学研究的发展。