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

丝绸之路遥相关是夏季对流层高层沿亚洲急流波导东传的准定常波列,它能显著影响欧亚大陆的气候异常。最近的研究表明丝绸之路遥相关具有明显的年际和年代际变化分量。本文比较了这两种时间尺度的异同。结果表明:丝绸之路遥相关在年际时间尺度上对应横跨欧亚大陆上空清晰的波列状环流异常,并导致下垫面类似的波列状冷暖温度异常;而其年代际变化对应的环流异常在欧洲到中亚与年际相似,但在东亚明显减弱,而且对应的温度异常也北移到俄罗斯远东地区。我们认为年代际的这些特点可能受到其他气候要素的影响,并认为去除年代际可以更加突出丝绸之路遥相关的物理本质及其气候影响。

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。

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。

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。

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。

“一带一路”对我国城镇化发展格局的影响

2013年9月和10月,习近平主席先后提出共建"丝绸之路经济带"和"21世纪海上丝绸之路"的重大倡议,得到国际社会高度关注。这是中国为推动经济全球化深入发展而提出的国际区域经济合作新模式,旨在促进经济要素有序自由流动、资源高效配置和市场深度融合,推动沿线各国实现经济政策协调,开展更大范围、更高水平、更深层次的区域合作。2014年3月,中共中央、国务院联合发布了《国家新型城镇化规划(2014—2020年)》,是今后一个时期指导全国城镇化健康发展的宏观性、基础性规划。"一带一路"与"新型城镇化"这两个新时期国家战略如何对接融合发展成为重要命题。本文分析了我国近年来城镇化发展格局的主要特征,中西部地区城镇化总体上动力不足;探讨了我国周边地区城镇化发展特点,以及六大国际走廊的城镇化发展态势与格局;提出了一带一路对我国城镇化发展格局的可能影响,会给沿边地区和中西部地区城镇化带来重大机遇,促进我国城镇化更加全面均衡发展。

丝绸之路经济带中国段经济发展时空演化特征

以丝绸之路经济带中国段各县域(市、旗、区)单元为基本单元,以1980年、1990年、2000年和2013年统计年鉴的相关县域数据为数据源,结合钱纳里经济发展理论、空间相关分析和地理加权回归模型,系统分析丝绸之路经济带中国段县域经济发展时空格局演化特征及其成因。结果表明:(1)丝绸之路经济带经济发展整体上经历了"均衡→不均衡→逐步均衡"的发展趋势,其中区域性中心城市和资源富集性县域单元发展速度明显快于偏远和资源贫乏区域,对周边县域有较明显的辐射和联动效应。(2)丝绸之路经济带经济发展的冷点和热点集聚区经历了从无到有和从少到多的过程,形成了资源富集区域和区域性中心城市集聚区。(3)县域经济增长以空间正关联为主,HH类型有减小趋势,LL类型较为稳定,HL和LH类型则较少且分布零散。(4)通过因子加权回归发现,全社会固定资产投资、3次产业总值和地方政府财政支出对经济增长贡献最大,其它3个因子对其经济发展和空间格局分布亦有显著相关性,各因子对县域经济的影响的显著性随时间推移而不断增强。

丝绸之路打通前后联珠纹的起源与流变

联珠纹在丝绸之路文化传播交流中有着相当特殊的地位,对联珠纹样的研究无疑是丝绸之路装饰艺术的重要着力点。联珠纹的起源问题一直以来颇受关注,然而相关讨论却并不多见。文章试图以丝绸之路为节点对联珠纹的起源与形式流变问题进行探讨,借助现有文献及彩陶、金银器皿和织物等实物载体,分别从丝绸之路打通之前联珠纹在中国的发展,以及丝绸之路打通之后联珠纹在中国的发展这两条发展脉络为线索来进行析解探源,从而解析联珠纹样在中国发展变化的来龙去脉。