Asymmetric Relationship between the Meridional Displacement of the Asian Westerly Jet and the Silk Road Pattern

In previous work, a significant relationship was identified between the meridional displacement of the Asian westerly jet （JMD） and the Silk Road Pattern （SRP） in summer. The present study reveals that this relationship is robust in northward JMD years but absent in southward JMD years. In other words, the amplitude of the SRP increases with northward displacement of the jet but shows little change with southward displacement. Further analysis indicates that, in northward JMD years, the Rossby wave source （RWS） anomalies, which are primarily contributed by the planetary vortex stretching, are significantly stronger around the entrance of the Asian jet, i.e., the Mediterranean Sea-Caspian Sea area, with the spatial distribution being consistent with that related to the SRP. By contrast, in southward JMD years, the RWS anomalies are much weaker. Therefore, this study suggests that the RWS plays a crucial role in inducing the asymmetry of the JMD-SRP relationship. The results imply that climate anomalies may be stronger in strongly northward-displaced JMD years due to the concurrence of the JMD and SRP, and thus more attention should be paid to these years.

Two Modes of the Silk Road Pattern and Their Interannual Variability Simulated by LASG/IAP AGCM SAMIL2.0

In this study, two modes of the Silk Road pattern were investigated using NCEP2 reanalysis data and the simulation produced by Spectral Atmospheric Circulation Model of IAP LASG, Version 2 （SAMIL2.0） that was forced by SST observation data. The horizontal distribution of both modes were reasonably reproduced by the simulation, with a pattern correlation coefficient of 0.63 for the first mode and 0.62 for the second mode. The wave train was maintained by barotropic energy conversion （denoted as CK） and baroclinic energy conversion （denoted as CP） from the mean flow. The distribution of CK was dominated by its meridional component （CKy） in both modes. When integrated spatially, CKx was more efficient than its zonal component （CKx） in the first mode but less in the second mode. The distribution and efficiency of CK were not captured well by SAMIL2.0. However, the model performed reasonably well at reproducing the distribution and efficiency of CP in both modes. Because CP is more efficient than CK, the spatial patterns of the Silk Road pattern were well reproduced. Interestingly, the temporal phase of the second mode was well captured by a single-member simulation. However, further analysis of other ensemble runs demonstrated that the successful reproduction of the temporal phase was a result of internal variability rather than a signal of SST forcing. The analysis shows that the observed temporal variations of both CP and CK were poorly reproduced, leading to the low accuracy of the temporal phase of the Silk Road pattern in the simulation.

Comparison between the interannual and decadal components of the Silk Road pattern

The Silk Road pattern（SRP）, which is a teleconnection pattern along the Asian upper-tropospheric westerly jet in summer, exhibits both interannual and decadal variabilities. Through the nineyear Gaussian filtering method and regression analyses, this study compares the interannual and decadal components of the SRP. The results indicate that the interannual SRP corresponds to a well-organized wave train of alternate cyclonic and anticyclonic anomalies across the Eurasian continent along the Asian westerly jet, resulting in a similar wave-like pattern of cold and warm surface temperature anomalies. This pattern of temperature anomalies differs from that associated with the original SRP, which is characterized by warmer or cooler temperatures mainly over Europe–West Asia and Northeast Asia, depending on the phase of the SRP. On the other hand, the decadal SRP shows a similar pattern to the interannual one from Europe to Central Asia, but the meridional wind anomalies tend to be weak over East Asia. These circulation anomalies are responsible for the significant temperature anomalies over Europe–West Asia and Northeast Asia but weak anomalies between these two domains.

Teleconnection between Sea Ice in the Barents Sea in June and the Silk Road,Pacific–Japan and East Asian Rainfall Patterns in August

In contrast to previous studies that have tended to focus on the influence of the total Arctic sea-ice cover on the East Asian summer tripole rainfall pattern, the present study identifies the Barents Sea as the key region where the June sea-ice variability exerts the most significant impacts on the East Asian August tripole rainfall pattern, and explores the teleconnection mechanisms involved. The results reveal that a reduction in June sea ice excites anomalous upward air motion due to strong near-surface thermal forcing, which further triggers a meridional overturning wave-like pattern extending to midlatitudes.Anomalous downward motion therefore forms over the Caspian Sea, which in turn induces zonally oriented overturning circulation along the subtropical jet stream, exhibiting the east–west Rossby wave train known as the Silk Road pattern. It is suggested that the Bonin high, a subtropical anticyclone predominant near South Korea, shows a significant anomaly due to the eastward extension of the Silk Road pattern to East Asia. As a possible descending branch of the Hadley cell, the Bonin high anomaly ultimately triggers a meridional overturning, establishing the Pacific–Japan pattern. This in turn induces an anomalous anticyclone and cyclone pair over East Asia, and a tripole vertical convection anomaly meridionally oriented over East Asia. Consequently, a tripole rainfall anomaly pattern is observed over East Asia. Results from numerical experiments using version 5 of the Community Atmosphere Model support the interpretation of this chain of events.

Connection between the Silk Road Pattern in July and the Following January Temperature over East Asia

This study investigates a cross-seasonal influence of the Silk Road Pattern（SRP）in July and discusses the related mechanism.Both the reanalysis and observational datasets indicate that the July SRP is closely related to the following January temperature over East Asia during 1958/59–2001/02.Linear regression results reveal that,following a higher-than-normal SRP index in July,the Siberian high,Aleutian low,Urals high,East Asian trough,and meridional shear of the East Asian jet intensify significantly in January.Such atmospheric circulation anomalies are favorable for northerly wind anomalies over East Asia,leading to more southward advection of cold air and causing a decrease in temperature.Further analysis indicates that the North Pacific sea surface temperature anomalies（SSTAs）might play a critical role in storing the anomalous signal of the July SRP.The significant SSTAs related to the July SRP weaken in October and November,re-emerge in December,and strengthen in the following January.Such an SSTA pattern in January can induce a surface anomalous cyclone over North Pacific and lead to dominant convergence anomalies over northwestern Pacific.Correspondingly,significant divergence anomalies appear,collocated in the upper-level troposphere in situ.Due to the advection of vorticity by divergent wind,which can be regarded as a wave source,a stationary Rossby wave originates from North Pacific and propagates eastward to East Asia,leading to temperature anomalies through its influence on the large-scale atmospheric circulation.

江、河、海交融影响下的扬州古城格局演进研究

扬州位于运河和长江交汇处,长江岸线、运河水系的变迁及海上贸易的影响,对扬州古城格局演进产生了重大作用。运河水系和长江岸线的变迁,推动扬州古城从闾里制度格局下的“单城”,发展为坊市制度及其后的“多城”。随着古代扬州的水环境变迁及工商业贸易的繁荣,扬州古城形态历经从秦至隋时期的“口”字形、唐至元时期的“吕”字形至明清时期的“明”字形的格局变化,以及自唐元时期的“南北纵向”至明清时期的“东西横向”生长方向变化;城市功能也从封闭型防御功能为主逐步演进为开放型商贸功能为主,并呈现“江、河、海共生型”扬州古城空间格局演进特点。

丝绸之路视域下唐代纺织品中鸟衔花纹样的起源与形式流变

文章以唐代纺织品中的鸟衔花纹样为研究对象,通过历史文献与考古实物等资料对其溯源。梳理丝绸之路打通后西方鸟衔花纹样的传播,并分析其传入唐代后的形式演变。研究表明,唐代纺织品中的鸟衔花纹样因受到了西方含绶鸟纹样题材、纬线显花织造技术等因素影响而形成。并经历了模仿、改造、定型三个发展阶段,完成从呆板程式向传神自由转变的本土化进程,该纹样在唐代的演变可进一步细分为“团窠对鸟”和“足踏花台”的双线发展模式。

近几十年丝绸之路遥相关对中国夏季气温的影响

为分析近几十年丝绸之路遥相关对中国夏季气温的影响及可能机理,基于1961-2020年CN05.1高分辨格点气温资料和ERA5大气再分析资料,采用经验正交分解、回归分析和相关分析等统计诊断方法分析丝绸之路遥相关对中国夏季气温的影响及可能机理,结果表明:(1)丝绸之路遥相关主要沿亚洲急流自西向东传播,呈显著的“-+-+”分布,其活动中心主要位于里海、巴尔喀什湖和中国北方地区,并存在明显的年际变化和年代际变化。中国夏季气温整体上呈一致的变化趋势,其中20世纪60-80年代由暖到冷,90年代后又明显升温。(2)除新疆西部和西藏西部、东北地区西部及江淮地区为负相关分布外,夏季丝绸之路遥相关与同期中国大部分地区气温之间为显著的正相关关系。(3)丝绸之路遥相关可通过影响北半球对流层中高层位势高度、垂直速度和涡度平流等环流因子导致中国夏季气温异常。具体表现为受丝绸之路遥相关影响产生的位势高度正异常有利于晴好天气的维持,同时对流层中高层受负涡度平流控制,以下沉运动为主,导致中国夏季气温异常升高。

唐代织绣品中石榴纹样的艺术特征与文化意蕴

织绣品上的石榴纹样初见于东汉,直至唐代才开始繁荣,并对后世的吉祥纹样创作产生了重要影响。本文以唐代织绣品中石榴纹样为研究对象,以考古出土的石榴纹织绣品为载体,结合文献、史料和古籍图像资料,从题材组合、造型表达及构图形式三个方面对石榴纹样的艺术特征进行分析与整理,进而揭示其文化意蕴。研究认为,石榴纹样的题材多为植物组合,呈现“花叶相伴”的多元性,果实造型表达圆润生动,构图形式匀称且稳定。在唐代丝路文化交流背景下,石榴纹样受到了西亚祆教和印度佛教文化的影响,体现了对生息不止的追求。在纹样本土化的过程中,石榴纹样融入了人们对丰产丰育的世俗祈盼,逐渐成为喜闻乐见的吉祥纹样。

丝绸之路甘肃段遗址保护与展示研究

丝绸之路甘肃段沿线有着丰厚的文化遗产,以丝绸之路甘肃段两汉到元时期的221个遗址点为研究对象,对丝绸之路沿线遗址形成的背景进行梳理,同时利用最邻近分析、不平衡指数、地理集中指数、核密度分析等方法对其空间分布特征进行研究分析,得出丝绸之路甘肃段遗址主要分布于陇东和河西走廊地区。分析了丝绸之路甘肃沿线遗址保护与展示过程中存在的问题,并利用遗址空间分布特征提出了点-线-面的保护体系及遗址主题阐释体系。

The Concurrent Record-breaking Rainfall over Northwest India and North China in September 2021

Extremely heavy rainfall occurred over both Northwest India and North China in September 2021.The precipitation anomalies were 4.1 and 6.2 times interannual standard deviation over the two regions,respectively,and broke the record since the observational data were available,i.e.,1901 for India and 1951 for China.In this month,the Asian uppertropospheric westerly jet was greatly displaced poleward over West Asia,and correspondingly,an anomalous cyclone appeared over India.The anomalous cyclone transported abundant water vapor into Northwest India,leading to the heavy rainfall there.In addition,the Silk Road pattern,a teleconnection pattern of upper-level meridional wind over the Eurasian continent and fueled by the heavy rainfall in Northwest India,contributed to the heavy rainfall in North China.Our study emphasizes the roles of atmospheric teleconnection patterns in concurrent rainfall extremes in the two regions far away from each other,and the occurrence of rainfall extremes during the post-or pre-monsoon period in the northern margins of monsoon regions.

SR型与EAP型遥相关“结合模态”对2020年江淮入梅初期强降水的影响

利用ERA5逐日再分析资料和中国气象局提供的逐日站点降水资料,分析了丝绸之路型(Silk-Road,SR)与东亚—太平洋型(East Asia–Pacific,EAP)遥相关的“结合模态”对2020年江淮梅雨入梅的影响,结果表明“结合模态”可以触发江淮流域的持续性降水。2020年6月初,负SR型(Silk-Road)和正EAP型(East Asia–Pacific)同时出现,并且位相差达到6月份最大值,二者协同作用下导致2020年入梅时间异常偏早。主要表现为:(1)负SR型引起西风急流加速,促使急流入口区南侧的江淮流域上空出现强的高层辐散。(2)负SR型有利于南亚高压东移,正EAP型有利于西太平洋副热带高压西移,二者相向而行。负SR型和正EAP型于6月9日位相差达最大,此时南亚高压和西太平洋副热带高压重叠于120°E左右,有利于江淮流域持续性降水。(3)低层东亚中、低纬度有一对与正EAP型相关的异常“气旋—反气旋”环流,使低空(20°~35°N,100°~125°E)盛行强西南气流,中纬度的偏北气流有利于干冷空气向南输送,与西南暖湿气流汇合于江淮流域上空,带来强烈的水汽辐合,也使得大气的局地上升运动更为强烈。

多元文化交融视角下中国古代织物莲纹造型研究

莲纹作为中国传统纹饰突出的代表之一,在古代染织纹样史研究中,较少从多角度解读其映照的跨文化交流。文章结合现存实物考证,梳理莲纹造型流变,分析其所见丝绸之路多元文化交融及对外国纺织品的影响。研究认为:早期莲纹基于“十”字形结构发展为“四叶式”,具有本土自身的发展体系。北朝至唐代织物中“莲座”图式受到古希腊罗马建筑和犍陀罗艺术的影响,“莲花化生”图式映射出佛教生命思想及世俗吉祥寓意;由“宝相莲花”图式管窥中日纺织艺术交流,“滴珠窠”图式是蒙元时期中国与伊朗纺织文化交流的例证,文艺复兴时期欧洲纺织品中石榴形莲纹反映了中国莲花原型的跨文化传播。

丝绸之路背景下唐代纹样的风格特征分析

纹样作为民族文化融合下形成的特有视觉符号,展现了丰富的物质文化和灿烂的精神文明。围绕陆上丝绸之路的展开,通过对唐代具有代表性的联珠纹、团花纹、卷草纹、宝相花纹和朵云纹的风格特征分析,发现唐代纹样具有对称美、曲线美、有象征意义的整体特点,探寻唐代图案纹样在西域文化、中原汉文化与西方外来文化交流与融合下所产生的流变,从侧面映射出唐代民族的交融进程,凸显中华民族在民族交融中的人文成就。

吐蕃丝织品纹样研究文献综述

吐蕃丝织品纹样研究文献综述的研究目的为对前人所作研究进行了一个清晰分类,相关吐蕃时期丝织品图案纹样研究现状将何为吐蕃系统做了解释,对东西方现存雷同的吐蕃系统丝织品纹样进行了跨国界的分析比对,以图像学的方法证明学术猜想;本文的研究方法采用文献研究法,形成对研究对象的总体印象,并得到较为详实的比较资料;据前人研究,提取总结出的该时期独特规律性质,成为判别丝织品是否为吐蕃系统丝织品的主要依据。在丝织品内在组织结构判断上,中原系统为夹经S捻,中亚系统为加强Z捻,已在学界达成共识。对吐蕃系统丝织品纹样源流研究现状中,对丝绸的具体源流进行了分析与质疑。国外相关吐蕃系统丝织品研究,思路条理清晰,针对丝织品上出现的具体形象分析其背后的内涵与形象来源地,旁征博引,其研究具备时间线上的脉络延续性特点。

从伊尔汗王朝到帖木儿时代中国纹样对波斯艺术的影响

伊朗和中国有着长期的商业交往和政治联系。两国之间的大部分联系受益于中国商品外销到伊朗。贸易往来触发了两个古老文明之间的文化艺术交流,特别是在1221年,蒙古人控制了伊朗之后,两者间的艺术交流,尤其是中国对伊朗视觉艺术的影响更加快速和广泛。本文回顾了从伊尔汗王朝开始到帖木儿时代(1370-1507),在中国和伊朗的商贸往来影响下,两国艺术纹样之间的关联性。

Spatial pattern of location advantages of ports along the Maritime Silk Road

Location advantages of ports refer to the current developments of ports based on their conditions, such as geographic location, traffic accessibility and hinterland economy, etc., and the spatial pattern of ports’ location advantages reflects the spatial distributions, the regularities and the correlations among their conditions for development. A good understanding of the spatial patterns of ports’ location advantages can help to better identify the relative advantages of ports, position ports’ functions and make strategic plans for development. This paper selected 1259 ports from 63 countries along the Maritime Silk Road as research objects and builds an accessing model to analyze their location advantages on the bases of six factors: the influence of strategic shipping pivot, the competitiveness of port location potential, port network status, the influence of city, the influence of traffic trunk, and road network density in hinterland. The study has the following three findings. Firstly, the location advantages of ports show a 'high-low-high' distribution pattern from the west to the east, displaying an obvious 'core-periphery' regionalized distribution. Secondly, most ports have high location advantages, mainly located in Strait of Malacca, the United Arab Emirates, northern Mediterranean coastal region and China-Japan region, the top 10 ports are mainly located in Singapore, China, Malaysia and Japan, indicating that the shipping industry in Asia-Pacific region has stepped to the far front of the global competition;slow economic growths, wars, far away from the Belt and Road countries or bad climate have low location advantages, mainly located in African coastal areas, Oceania, Northeast Europe and Russia. Thirdly, compared with the landward location advantages, the seaward location advantages have a higher influence, and different indicators of location advantages have different influences on the evaluation results, the competitiveness of port location potential being the core indicator.

新疆克里雅女性民族服饰源流探寻

文章基于维吾尔族克里雅女性民族服饰实物研究,结合现有文献和研究成果,以陆路丝绸之路为视角,从服饰面料、形制、纹样三方面探寻服饰源流。研究结果表明:服饰面料的选择受南疆地区至晚于公元3世纪就存在并延续的桑蚕历史主导,面料纹样以明清时期缠枝花和具几何特征的伊斯兰纹样为主,色彩兼具宗教性和民族性,黑白为主色的宗教色彩中加入了天蓝色、紫色彰显民族身份;服饰形制的主要源头可上溯到五千年之前的西北游牧民族袷袢及欧亚贯头衣形制;装饰纹样体现多信仰、多文明交流的背景,弧形纹样的原形或为随文明交流而来的双翼纹。探寻所得对促进维吾尔族民族历史文化研究具有重要意义,也或能为了解丝绸之路上的世界史打开一隅。

Why Was the Strengthening of Rainfall in Summer over the Yangtze River Valley in 2016 Less Pronounced than that in 1998 under Similar Preceding El Nino Events？Role of Midlatitude Circulation in August

It is widely recognized that rainfall over the Yangtze River valley （YRV） strengthens considerably during the decaying summer of E1 Nifio, as demonstrated by the catastrophic flooding suffered in the summer of 1998. Nevertheless, the rainfall over the YRV in the summer of 2016 was much weaker than that in 1998, despite the intensity of the 2016 E1 Nifio having been as strong as that in 1998. A thorough comparison of the YRV summer rainfall anomaly between 2016 and 1998 suggests that the difference was caused by the sub-seasonal variation in the YRV rainfall anomaly between these two years, principally in August. The precipitation anomaly was negative in August 2016--different to the positive anomaly of 1998.

华南前汛期盛期中国东部降水异常模态的环流特征及成因分析

根据1958-2011年中国东部（105°E以东）316站逐日降水观测资料及环流逐日再分析资料,利用统计分析、物理量诊断等方法,探讨华南前汛期盛期（5月21日至6月10日）中国东部降水异常模态及对应大气环流特征和可能成因。分析发现,华南前汛期盛期中国东部降水异常表现为两个相互独立的降水模态：第一模态为华南全区一致型,当其时间系数为正（负）时,整个华南降水偏多（少）,黄河中游降水偏少（多）;第二模态为华南沿海东部型,当其时间系数为正（负）时,华南沿海东部降水偏多（少）,而长江中下游降水偏少（多）。研究发现,造成华南前汛期盛期两个降水型的环流特征有明显差异：全区一致型降水主要受东亚高空西风急流南北偏移、副热带高压脊东西偏移及低层南海北部异常风场影响;沿海东部型降水主要由东亚高空西风急流强弱及位置异常、副热带高压强弱变化、低层日本以南西太平洋异常风场导致。此外,两个降水型对应环流异常的成因也各不相同。第一模态中高层环流异常由丝绸之路遥相关型导致,低层风场异常在5月下旬由阿拉伯海向下游传播的风场异常波列引起,在6月上旬则由西太平洋西移的异常反气旋（气旋）造成。第二模态的中高层环流异常先后由极地—欧亚遥相关型、环球遥相关型引起,低层风场异常由高层环流异常的动力作用造成。两降水型均存在整层深厚的垂直运动,但第一模态的垂直运动在高层闭合且对应显著的辐合辐散异常,第二模态则不具有上述特征。