Changes in the global cryosphere and their impacts: A review and new perspective     

ShiYin Liu  TongHua Wu  Xin Wang  XiaoDong Wu  XiaoJun Yao  Qiao Liu  Yong Zhang  JunFeng Wei  XiaoFan Zhu 《寒旱区科学》2020,12(6):343-354

As one of the five components of Earth's climatic system, the cryosphere has been undergoing rapid shrinking due to global warming. Studies on the formation, evolution, distribution and dynamics of cryospheric components and their interactions with the human system are of increasing importance to society. In recent decades, the mass loss of glaciers, including the Greenland and Antarctic ice sheets, has accelerated. The extent of sea ice and snow cover has been shrinking, and permafrost has been degrading. The main sustainable development goals in cryospheric regions have been impacted. The shrinking of the cryosphere results in sea-level rise, which is currently affecting, or is soon expected to affect, 17 coastal megacities and some small island countries. In East Asia, South Asia and North America, climate anomalies are closely related to the extent of Arctic sea ice and snow cover in the Northern Hemisphere. Increasing freshwater melting from the ice sheets and sea ice may be one reason for the slowdown in Atlantic meridional overturning circulation in the Arctic and Southern Oceans. The foundations of ports and infrastructure in the circum-Arctic permafrost regions suffer from the consequences of permafrost degradation. In high plateaus and mountainous regions, the cryosphere's shrinking has led to fluctuations in river runoff, caused water shortages and increased flooding risks in certain areas. These changes in cryospheric components have shown significant heterogeneity at different temporal and spatial scales. Our results suggest that the quantitative evaluation of future changes in the cryosphere still needs to be improved by enhancing existing observations and model simulations. Theoretical and methodological innovations are required to strengthen social economies' resilience to the impact of cryospheric change.  相似文献   

浙江省新型冠状病毒感染肺炎疫情时空分布特征     

白雪  乔观民  李加林  梅思雨  马仁锋 《地理科学》2020,40(12):2010-2018

以浙江省新型冠状病毒感染的肺炎确诊案例数据库为基础,运用SPSS24.0进行数据挖掘和ArcGIS10.2进行空间分析,发现：① 浙江省病例新增人数时间变化符合泛泊松分布函数,男女易感染率差异不大,典型症状为发热、咳嗽和肺部影像学病变。② 病例感染率具有明显的空间聚集性,总体呈现为“一带四心”格局,“一带”为台?温沿海铁路带的县级地域单元,“四心”为宁波海曙区（11.02/10万）,湖州秀洲区（4.29/10万）,杭州上城区（4.06/10万）和江干区（4.80/10万）,杭州桐庐县（5.78/10万）。③ 核密度集聚中心呈现北?南?北转移的态势,整体呈现“多核多心”“主核固定,多心演化”“单一主核,多心消退”和“疫情消退”4个阶段的空间演化特征。④ 浙江省的扩散率总体呈现先上升后下降态势,空间差异明显,风险管控视角分为5类地区。⑤ 根据疫情演化与传染特征,提出疫情4阶段治理策略,解决公共卫生问题的根本是推动生活圈建设,打造健康城市。  相似文献   

How can FAST improve study of the pulsar emission mechanism and magnetospheric dynamics?     

Hong-Guang Wang  Guo-Jun Qiao  Yuan-Jie Du  Ji-Guang Lu  Ren-Xin Xu  Ke-Jia Lee  Xiong-Wei Liu 《天文和天体物理学研究(英文版)》2019,(2)

The Five-hundred-meter Aperture Spherical radio Telescope(FAST) has the potential to discover many new pulsars and new phenomena. In this paper we mainly concentrate on how FAST can impact study of the pulsar emission mechanism and magnetospheric dynamics. Several observational programs heading to this direction are reviewed. To make full use of the superior performance of FAST and maximize the scientific outcome, these programs can be arranged in different phases of FAST according to their demands for observational conditions. We suggest that programs can be performed following the test phase, which are observations of multifrequency mean pulse profiles, anomalous X-ray pulsars(AXPs)/soft gamma-ray repeaters(SGRs), mode changing, drifting subpulse and nulling. The long-term monitoring can be carried out for mode changing, AXPs/SGRs and precessional pulsars. Others programs, including polarization observations of radio and γ-ray pulsars, searching for weak pulse components, and multifrequency observations of subpulse drifting, microstructure and giant pulses, can be conducted in all the normal operating phases(the first and second phases). These programs will push forward the frontier in this field in different respects. The search for sub-millisecond pulsars and follow-up observations of their emission properties are very important projects for FAST, but they may be covered by other papers in this mini-volume; therefore,they are not discussed here.  相似文献   

受扰动海域大型底栖动物群落特征及基于AMBI和M-AMBI指数的生态健康评价：以山东烟台辛安河口为例     

周政权  李晓静  陈琳琳  李宝泉  刘甜甜  艾冰花  杨陆飞  刘博  陈桥 《海洋学报(英文版)》2018,37(5):77-86

To understand the ecological status and macrobenthic assemblages of the Xin'an River Estuary and its adjacent waters, a survey was conducted for environmental variables and macrobenthic assemblage structure in September 2012(Yantai, China). Several methods are adopted in the data analysis process: dominance index,diversity indices, cluster analysis, non-metric multi-dimentional scaling ordination, AMBI and M-AMBI. The dissolved inorganic nitrogen and soluble reactive phosphorus of six out of eight sampling stations were in a good condition with low concentration. The average value of DO((2.89±0.60) mg/L) and p H(4.28±0.43) indicated that the research area faced with the risk of ocean acidification and underlying hypoxia. A total of 62 species were identified, of which the dominant species group was polychaetes. The average abundance and biomass was577.50 ind./m2 and 6.01 g/m2, respectively. Compared with historical data, the macrobenthic assemblage structure at waters around the Xin'an River Estuary was in a relatively stable status from 2009 to 2012.Contaminant indicator species Capitella capitata appeared at Sta. Y1, indicating the animals here suffered from hypoxia and acidification. AMBI and M-AMBI results showed that most sampling stations were slightly disturbed,which were coincided with the abiotic measurement on evaluating the health conditions. Macrobenthic communities suffered pressures from ocean acidification and hypoxia at the research waters, particularly those at Stas Y1, Y2 and Y5, which displays negative results in benthic health evaluation.  相似文献   

The response of the upper ocean to tropical cyclone Viyaru over the Bay of Bengal     

Kashem Mir  Ahmed Md Kawser  Qiao Fangli  Akhter M A E  Chowdhury K M Azam 《海洋学报(英文版)》2019,38(1):61-70

Better forecast of tropical cyclone(TC) can help to reduce risk and enhance management. The TC forecast depends on the scientific understanding of oceanic processes, air-sea interaction and finally, the atmospheric process. The TC Viyaru is taken as an example, which is formed at the end of 11 May 2013 and sustains up to 17 May 2013 during pre-monsoon season. Argo data are used to investigate ocean response processes by comparing pre-and post-conditions of the TC. Eight oceanic parameters including the sea surface temperature(SST), the sea surface salinity(SSS), and the barrier layer thickness(BLT), the 26°C isotherm depth in the ocean(D26), the isothermal layer depth(ILD), the mixed layer depth(MLD), the tropical cyclone heat potential(TCHP) and the effective oceanic layer for cyclogenesis(EOLC) are chosen to evaluate the pre-and post-conditions of the TC along the track of Viyaru. The values of the SST, D26, BLT, TCHP and EOLC in the pre-cyclonic condition are higher than the post-cyclonic condition, while the SSS, ILD and MLD in the post-cyclonic condition are higher than the pre-cyclonic condition of the ocean due to strong cyclonic winds and subsurface upwelling. It is interesting that the strong intensity of the TC reduces less SST and vice versa. The satisfied real time Argo data is not available in the northern Bay of Bengal especially in the coastal region. A weather research and forecasting model is employed to hindcast the track of Viyaru, and the satellite data from the National Center Environmental Prediction are used to assess the hindcast.  相似文献   

沉底试验水雷打捞回收辅助系统方案研究          下载免费PDF全文

乔晓君  张宏欣 《数字海洋与水下攻防》2019,2(3):60-63

为进一步提高水中兵器试验实施的实效性和安全性,针对多年来沉底水雷打捞中出现的若干问题,在回顾分析实际案例的基础上,设计了由吊车、绞盘、绞盘控制台、张力检测系统、自动缓冲系统、支架、钢索及超载报警系统等单元构成的打捞回收辅助系统,并阐述了海上使用方法和异常情况处置预案。  相似文献   

Sedimentary Characteristics of the Second Marine Layer During the Late Marine Isotope Stage 3 in Southern Yellow Sea and Their Response to the East Asian Monsoon     

Yang Zhang  Guangxue Li  Hongzhou Guo  Yong Liu  Haoyin Wang  Jishang Xu  Dong Ding  Lulu Qiao  Yanyan Ma  Liyan Wang  Qian Li 《中国海洋大学学报(英文版)》2018,17(5):1103-1113

We use the particle size of sediments in core YS01 A to study the sedimentary environment of the mud deposit in the central South Yellow Sea of China during late Marine Isotope Stages 3(MIS3;40.5 kyr–31.3 kyr).In addition,the East Asian Monsoon and its relationship with the North Atlantic Ocean climate change are discussed based on the sensitive grain-size calculation and the spectrum analysis.The results show that during late MIS3,the muddy area in the central South Yellow Sea experienced the evolution of coastal facies,shallow marine facies,coastal facies,and continental facies,with weak hydrodynamic conditions.Compared with other climate indicators,we found that there were many century to millennium-scale climate signals documented in the muddy area sediments in the central South Yellow Sea.According to our particle size results,three strong winter monsoon events occurred at 37.6 kyr,35.6 kyr and 32.2 kyr.The East Asian Winter Monsoon records in core YS01 A are consistent with the Greenland ice core and the Hulu cave stalagmite δ~(18)O.The millennial and centennial scale cycles,which are 55 yr,72 yr,115 yr,262 yr respectively,correspond to solar activity cycles,while the 1049 yr and 2941 yr cycles correspond to the Dansgaard-Oeschger cycles.These cycles indicate that the paleoclimate evolution of the area was controlled by the solar activities,with the high-latitude driving thermohaline circulation as the main energy conveyor belt,followed by the sea-air-land amplification of the winter monsoon variation in the central Yellow Sea in the late MIS3.  相似文献   

栅格地图数据的现势性检查     

何乔  赵泳  郭海涛 《海洋测绘》2006,26(1):57-59

鉴于全自动的栅格地图数据现势性检查受到自动特征提取技术的可靠性和准确性不高以及提取速度较慢等因素的限制,使得不能满足生产作业的需求。采用像素数的变化比率的方法来实现半自动栅格地图数据的现势性检查。实验证明该方法是可行的。  相似文献   

西藏高原汛期旱涝年水汽输送差异特征     

林志强  乔钰  唐叔乙 《气象科技》2014,42(1):110-117

利用西藏高原39个气象站自1961年或建站开始至2010年汛期(5—9月)的逐月降水资料,根据Z指数和区域旱涝指数分析了近50年西藏高原汛期旱涝的变化特征。在此基础上,选取了典型旱、涝年,采用NCEP/NCAR再分析月平均资料,通过合成分析方法分析了旱、涝年的水汽输送特征的差异。结果表明:近50年以来,西藏高原以旱为主,涝灾较少,干湿状况具有明显年代际变化;西藏高原汛期旱涝与水汽输送异常联系紧密,典型旱(涝)年北印度洋、西北太平洋和亚洲中纬度地区的整层水汽通量经向、纬向及整层水汽通量和水汽通量散度均存在显著差异,呈反位相分布。越赤道急流区的差异最为显著,索马里越赤道气流区的水汽输送差异主要表现在经向上,而菲律宾越赤道气流区的水汽输送差异主要表现在纬向上。  相似文献   

剑河县近45a降水变化特征   总被引：2，自引：0，他引：2  

邓学军  刘建粤  白慧  梁平 《贵州气象》2006,30(3):9-12

利用剑河县1960年12月～2005年逐月降水资料,统计分析该县年、季降水距平百分率的年际和年代际变化特征以及旱涝的演变趋势。结果得出：剑河县年降水呈“少→多→少→多→少”的规律变化;冬季呈准20a周期变化;春季呈“正常→多→持续偏少→多”的变化趋势;夏季呈“正常→少→多→少”的变化趋势;秋季呈多→持续偏少的趋势变化,与贵州和黔东南地区变化趋势相反。年、季降水距平百分率与旱涝变化趋势相一致。  相似文献