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边界层动力过程在Madden-Julian振荡发展中的作用 被引量:2
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作者 巢纪平 林永辉 王斌 《气象学报》 CSCD 北大核心 1996年第1期18-32,共15页
利用包括边界层爱克曼辐合-降水加热过程在内的短期气候变化模式[1],研究了Madden-Julian振荡[11,12]形成的机制。当经圈方向用抛物圆柱函数展开,并对赤道偶对称解取n=0,2,4三个截断模时,在长波近似... 利用包括边界层爱克曼辐合-降水加热过程在内的短期气候变化模式[1],研究了Madden-Julian振荡[11,12]形成的机制。当经圈方向用抛物圆柱函数展开,并对赤道偶对称解取n=0,2,4三个截断模时,在长波近似下的自由波解,一为向东的Kelvin波,另外两支为向西的Rossby波。当考虑边界层动力影响后,修正后的Kelvin波,其向东传播的速度约为10ms-1,且在长波波段是不稳定的,最不稳定的波出现在纬向一波附近,不稳定增长率的量级约为O(10m-6s-1),理论结果和Madden-Julian振荡在赤道附近主体环流东传的观测事实接近。另外两支修正后的Rossby波,其中经圈尺度较小的那支波,除波长极长的波外,波是阻尼的;但另一支经圈尺度较大的波,在短的波段是不稳定增长的,这似乎可以用来解释Madden-Julian振荡中大尺度超级云团的西传过程。这些结果表明边界层动力过程在Madden-Julian振荡的形成中是一种重要的机制。 展开更多
关键词 Madden-julian 振荡 边界层辐合 大气 动力过程
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德尔格JULIAN麻醉机维修实例 被引量:1
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作者 张忆 《医疗装备》 2012年第5期87-87,共1页
本文通过维修JULIAN麻醉机实例的分析,总结了一些这一型号麻醉机维修思路,提供一点维修经验。
关键词 julian麻醉机 自检controller PCB
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海表温度异常对Madden-Julian振荡的影响 被引量:7
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作者 巢纪平 林永辉 王斌 《气象学报》 CSCD 北大核心 1996年第3期257-271,共15页
在前文[1]的基础上,进一步研究当海表温度存在经圈方向不均匀分布或偏离气候状态(距平)时,改变水分收支平衡及边界层的湿度辐合这一物理过程对Madden-Julian振荡的可能影响。结果表明,它对修正的Kelvin波和... 在前文[1]的基础上,进一步研究当海表温度存在经圈方向不均匀分布或偏离气候状态(距平)时,改变水分收支平衡及边界层的湿度辐合这一物理过程对Madden-Julian振荡的可能影响。结果表明,它对修正的Kelvin波和Rossby波的传播性质影响不大。但当海表温度为正距平时,修正后东传Kelvin波振幅不稳定增长到e倍的时间约减小了14.5%,其不稳定增长率随着热源特征宽度的增加而增加,当特征宽度为2倍Rossby变形半径时,不稳定增长率达极大,但当特征宽度继续增大时,其不稳定增长率又将减小。当海表温度为负距平时,修正后东传Kelvin波振幅不稳定增长到e倍的时间约增加20%,其不稳定增长率随着冷源特征宽度的增加而减小,当特征宽度为2倍Rossby变形半径时,其不稳定增长率达极小,此后;随着特征宽度的增加其不稳定增长率随之增加,但始终小于无海表温度异常的情形。经圈尺度较小的那支修正的Rossby波除波长极长的波段外,波仍是阻尼的;而经圈尺度较大的那支修正的Rossby波,在短的波段内仍是不稳定增长的。 展开更多
关键词 振荡 海表温度异常 色散性 不稳定性 大气
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Impacts of Sea Surface Temperature in the Tropical Pacific on Interannual Variability of Madden-Julian Oscillation in Precipitation 被引量:4
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作者 李薇 宇如聪 张学洪 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2001年第3期429-444,共16页
The Madden-Julian Oscillation (MJO) is investigated in two sets of 11-year records of observed precipitation, the daily mean Microwave Sounding Units (MSU) oceanic rainfall (Spencer, 1993) data and the pentad Climate ... The Madden-Julian Oscillation (MJO) is investigated in two sets of 11-year records of observed precipitation, the daily mean Microwave Sounding Units (MSU) oceanic rainfall (Spencer, 1993) data and the pentad Climate Prediction Center Merged Analysis of Precipitation (CMAP) data (Xie and Arkin, 1997). Obvious interannual variability is found in the MJO in the tropical Pacific. MJO is limited to the west of dateline in normal years while extends more east during the year of warm sea surface temperature (SST) appeared in the eastern Pacific (i.e., El Ni?o years of 1982–1983, 1986–1988, 1991–1992) and manifested in the central-eastern Pacific for several months. The most significant correlation between interannual variability of MJO in the central-eastern Pacific and SST was found in the vicinity of the Ni?o3 region. Forced by observed SST, CCM3 presents a realistic trend of interannual variability to MJO in the 11 years, with a smaller magnitude than that from the observation. Comparison between the two realizations of the CCM3 simulation, which are forced by weekly and monthly mean SST respectively, showed that the MJO activities resemble each other in central-eastern Pacific while there is discrepancy in the western Pacific. It is suggested that the interannual variability of MJO is controlled, to certain extent bythe powerful interannual variability of SST in the central-eastern Pacific. In the western Pacific, however, there were remarkable impacts of the intraseasonal oscillation of SST on the MJO, where there was active MJO around the year. The notable disagreement between simulated and observed MJO in the western Pacific may come from the lack of high frequency variation of SST force, or from the shortage of air sea interaction for the intraseasonal time scale. It might be of importance to the MJO which is unable to be represented in the atmospheric model. Key words Madden-Julian Oscillation - Precipitation - Sea surface temperature - Interannual variability This study was sponsored by Chinese Academy of Sciences under grant “Hundred Talents” for “Validation of Coupled Climate Models”, the National Natural Science Foundation of China (Grant No. 49823002), and Project G1999043808. 展开更多
关键词 Madden-julian Oscillation PRECIPITATION Sea surface temperature Interannual variability
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Satellite Measurements of the Madden–Julian Oscillation in Wintertime Stratospheric Ozone over the Tibetan Plateau and East Asia 被引量:3
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作者 ZHANG Yuli LIU Yi +1 位作者 LIU Chuanxi V.F.SOFIEVA 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2015年第11期1481-1492,共12页
We investigate the Madden-Julian Oscillation (MJO) signal in wintertime stratospheric ozone over the Tibetan Plateau and East Asia using the harmonized dataset of satellite ozone profiles. Two different MJO indices ... We investigate the Madden-Julian Oscillation (MJO) signal in wintertime stratospheric ozone over the Tibetan Plateau and East Asia using the harmonized dataset of satellite ozone profiles. Two different MJO indices -- the all-season Real-Time multivariate MJO index (RMM) and outgoing longwave radiation-based MJO index (OMI) -- are used to compare the MJO- related ozone anomalies. The results show that there are pronounced eastward-propagating MJO-related stratospheric ozone anomalies (mainly within 20-200 hPa) over the subtropics, The negative stratospheric ozone anomalies are over the Tibetan Plateau and East Asia in MJO phases 4-7, when MJO-related tropical deep convective anomalies move from the equatorial Indian Ocean towards the western Pacific Ocean. Compared with the results based on RMM, the MJO-related stratospheric column ozone anomalies based on OM1 are stronger and one phase ahead. Further analysis suggests that different sampling errors, observation principles and retrieval algorithms may be responsible for the discrepancies among different satellite measurements. The MJO-related stratospheric ozone anomalies can be attributed to the MJO-related circulation anomalies, i.e., the uplifted tropopanse and the northward shifted westerly jet in the upper troposphere. Compared to the result based on RMM, the upper tropospheric westerly jet may play a less important role in generating the stratospheric column ozone anomalies based on OMI. Our study indicates that the circulation-based MJO index (RMM) can better characterize the MJO- related anomalies in tropopause pressure and thus the MJO influence on atmospheric trace gases in the upper troposphere and lower stratosphere, especially over subtropical East Asia. 展开更多
关键词 Madden-julian Oscillation stratospheric ozone TROPOPAUSE subtropical jet stream
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Simulation of the Madden-Julian Oscillation in Wintertime Stratospheric Ozone over the Tibetan Plateau and East Asia: Results from the Specified Dynamics Version of the Whole Atmosphere Community Climate Model 被引量:2
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作者 LIU Chuan-Xi LIU Yi ZHANG Yu-Li 《Atmospheric and Oceanic Science Letters》 CSCD 2015年第5期264-270,共7页
The authors examined the Madden-Julian Oscillation(MJO) in stratospheric ozone during boreal winter using a simulation from the Specified Dynamics version of the Whole Atmosphere Community Climate Model(SD-WACCM) in 2... The authors examined the Madden-Julian Oscillation(MJO) in stratospheric ozone during boreal winter using a simulation from the Specified Dynamics version of the Whole Atmosphere Community Climate Model(SD-WACCM) in 2004 and 2010. Comparison with European Centre for Medium-Range Weather Forecasts Interim Reanalysis(ERA-Interim) data suggested that the model simulation represented well the three-dimensional structure of the MJO-related ozone anomalies in the upper troposphere and stratosphere(i.e., between 200 and 20 h Pa). The negative ozone anomalies were over the Tibetan Plateau and East Asia in MJO phases 3–7, when the MJO convective anomalies travelled from the equatorial Indian Ocean towards the equatorial western Pacific Ocean. Due to the different vertical structures of the MJO-related circulation anomalies, the MJO-related stratospheric ozone anomalies showed different vertical structure over the Tibetan Plateau(25–40°N, 75–105°E) and East Asia(25–40°N, 105–135°E). As a result of the positive bias in the model-calculated ozone in the upper troposphere and lower stratosphere, the amplitude of MJO-related stratospheric ozone column anomalies(10–16 Dobson Units(DU)) in the SD-WACCM simulation was slightly larger than that(8–14 DU) in the ERA-Interim reanalysis. 展开更多
关键词 Madden-julian OSCILLATION STRATOSPHERIC OZONE trop
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翻译批评研究的名与实——尤莉安娜·豪斯(Juliane House)教授访谈及启示 被引量:4
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作者 张汨 《燕山大学学报(哲学社会科学版)》 2021年第3期91-96,共6页
作为翻译研究图谱中的重要部分,翻译批评持续受到国内外研究者的关注,同时研究考虑的因素也从语言转换逐渐过渡到社会历史文化以及认知等宏观和微观因素。尤莉安娜·豪斯(Juliane House)教授是翻译批评研究界的执牛耳者,自1977年以... 作为翻译研究图谱中的重要部分,翻译批评持续受到国内外研究者的关注,同时研究考虑的因素也从语言转换逐渐过渡到社会历史文化以及认知等宏观和微观因素。尤莉安娜·豪斯(Juliane House)教授是翻译批评研究界的执牛耳者,自1977年以来持续关注翻译批评研究,访谈中豪斯教授详细论述了翻译批评研究的名与实,前者包括目前对该领域研究的不同指称,后者则包括研究开展的视角、内容和方法等。最后,访谈人进而对推动翻译批评研究提出几点思考和展望。 展开更多
关键词 翻译批评 名与实 尤莉安娜·豪斯 研究展望
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Julian麻醉机软故障检修两例 被引量:1
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作者 朱胜军 《中国医疗器械杂志》 CAS 2002年第2期155-155,共1页
关键词 julian麻醉机 软故障检修 多功能麻醉机 故障现象 故障分析
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Madden Julian Oscillations in Total Column Ozone, Air Temperature and Surface Pressure Measured over Cochin during Summer Monsoon 2015 被引量:1
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作者 Vazhathottathil Madhu 《Open Journal of Marine Science》 2016年第2期270-282,共13页
The intra-seasonal variability plays a major role in the inter-annual variability of weather parameters such as rainfall, temperature and pressure which lead to extreme weather events in certain years. The active (mor... The intra-seasonal variability plays a major role in the inter-annual variability of weather parameters such as rainfall, temperature and pressure which lead to extreme weather events in certain years. The active (more rainy days) and break (less rainy days) periods of Indian summer monsoon heavily depend on the intra-seasonal variability of weather parameters such as wind, pressure and temperature oscillations during the monsoon season. In the present analysis daily total column ozone, surface temperature and surface pressure measured over Cochin using Microtop II Ozonometer (sun Photometer) were used to study the Intra-Seasonal Variations (ISV) of the above parameters during the monsoon season, 2015. The dominant and significant intra-seasonal oscillations (ISOs) were identified using an advanced statistical method called the Discrete Mayer’s Wavelet (DMW) analysis. Two major ISOs such as Madden Julian Oscillations (MJO, 30 - 60 days) and quasi-bi weekly (12 - 16 days) oscillations were found in TCO, surface temperature and pressure. In TCO an additional mode of ISO with quasi tri-weekly periodicity was also found (16 - 22 day). It is observed that MJO mode is the dominant among all other modes and its positive and negative phases correlate with positive and negative anomalies of the above parameters. The ISO mode in the surface pressure shows an out of phase relation with the Indian summer monsoon rainfall which indicates the active and break periods of Indian summer monsoon. The contribution of MJO mode is dominant in the tropical atmosphere, which modulates the intra-seasonal variability. It is found that for the year 2015 total column ozone, surface pressure and surface temperature show an annual range of 30 DU, 4 hPa and 1°C, respectively. 展开更多
关键词 Intra-Seasonal Oscillations Total Column Ozone (TCO) Madden julian Oscillation Wavelet Analysis
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Evaluation of the Madden-Julian oscillation in HiRAM
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作者 Jie Jiang Lu Wang +1 位作者 Jiuwei Zhao Tim Li 《Atmospheric and Oceanic Science Letters》 CSCD 2022年第4期19-26,共8页
The aim of this study was to understand the cause of Madden–Julian oscillation(MJO)bias in the High Resolution AtmosphericModel(HiRAM)driven by observed SST through process-oriented diagnosis.Wavenumber-frequency pow... The aim of this study was to understand the cause of Madden–Julian oscillation(MJO)bias in the High Resolution AtmosphericModel(HiRAM)driven by observed SST through process-oriented diagnosis.Wavenumber-frequency power spectrum and composite analyses indicate that HiRAM underestimates the spectral amplitude over theMJO band and mainly produces non-propagating rather than eastward-propagating intraseasonal rainfall anomalies,as observed.Column-integrated moist static energy(MSE)budget analysis is conducted to understand the MJO propagation bias in the simulation.It is found that the bias is due to the lack of a zonally asymmetric distribution of the MSE tendency anomaly in respect to the MJO convective center,which is mainly attributable to the bias in vertical MSE advection and surface turbulent flux.Further analysis suggests that it is the unrealistic simulation of MJO vertical circulation anomalies in the upper troposphere as well as overestimation of the Rossby wave response that results in the bias. 展开更多
关键词 Madden–julian oscillation Moist static energy Eastward propagation HiRAM
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Julian Corbett:广告的魔力是提供“欢乐时光”
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作者 徐铱璟 《新营销》 2016年第10期18-21,共4页
每一年,快消品巨头们在广告营销上花费高昂,而更高的营销效率是他们一直寻求的。在新的市场变化下,如何能与消费者进行更有效的沟通是关键。在线上,品牌可以通过丰富有趣的数字化手段与消费者互动,但是到了线下似乎有些困难,是否能打通... 每一年,快消品巨头们在广告营销上花费高昂,而更高的营销效率是他们一直寻求的。在新的市场变化下,如何能与消费者进行更有效的沟通是关键。在线上,品牌可以通过丰富有趣的数字化手段与消费者互动,但是到了线下似乎有些困难,是否能打通线上到线下的互动体验?2013年,Julian Corbett与哥哥Giles共同创建了Ksubaka(促巴卡),通过游戏应用的数字化手段帮助品牌在线下零售渠道以一种新的形式接触消费者。 展开更多
关键词 julian 广告营销 线下 数字化手段 营销效率 零售渠道 快消品 游戏化 互动体验 中国电影市场
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旅行摄影师Julian Love
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《影像视觉》 2008年第4期74-79,共6页
Julian Love是英国最引人注目的旅行摄影师之一,也是去年"英国年度旅行摄影师大奖"的获得者。从作为学生单纯地迷恋旅行摄影到步入职业摄影师的行列,仅仅两年的时间。而如今,他的作品已大量出现在各种旅行刊物上并通过网上书... Julian Love是英国最引人注目的旅行摄影师之一,也是去年"英国年度旅行摄影师大奖"的获得者。从作为学生单纯地迷恋旅行摄影到步入职业摄影师的行列,仅仅两年的时间。而如今,他的作品已大量出现在各种旅行刊物上并通过网上书店销往全世界。Love特别钟爱中东地区。不过,他下一步的拍摄目的地是印度和巴西。 展开更多
关键词 摄影师 julian Love 三脚架
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朱利安·巴恩斯小说中的历史记忆与身份认同
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作者 李婧璇 《湘潭大学学报(哲学社会科学版)》 CSSCI 北大核心 2024年第1期157-162,共6页
朱利安·巴恩斯是英国当代著名小说家,2011年荣获布克奖,历史记忆是其小说的重要主题。巴恩斯通过多样的艺术形式深刻展现了历史记忆对型塑身份认同的重要意义。在其小说中,个体的记忆困惑与遗忘导致了身份认同危机,而记忆重拾则参... 朱利安·巴恩斯是英国当代著名小说家,2011年荣获布克奖,历史记忆是其小说的重要主题。巴恩斯通过多样的艺术形式深刻展现了历史记忆对型塑身份认同的重要意义。在其小说中,个体的记忆困惑与遗忘导致了身份认同危机,而记忆重拾则参与了身份认同的建构,此外国家也运用历史记忆型塑国民的国家认同,而超国家政治共同体则同样借用历史记忆维护其成员的认同感,巩固其政治地位。 展开更多
关键词 朱利安·巴恩斯 历史记忆 身份认同
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MJO对2020年夏季中国东部持续性降水的维持作用
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作者 赵起帆 周洋 《大气科学》 CSCD 北大核心 2024年第3期1157-1172,共16页
本文利用美国NOAA的CMORPH降水和NCEP的CFSv2再分析资料、欧洲中心ERA-5再分析数据、Wheeler和Hendon的MJO指数等资料和敏感性数值试验分析了MJO对2020年夏季中国东部持续性降水的影响机制。通过相关、回归、波源分析等方法发现:(1)与... 本文利用美国NOAA的CMORPH降水和NCEP的CFSv2再分析资料、欧洲中心ERA-5再分析数据、Wheeler和Hendon的MJO指数等资料和敏感性数值试验分析了MJO对2020年夏季中国东部持续性降水的影响机制。通过相关、回归、波源分析等方法发现:(1)与往年相比,2020年夏季风雨带在我国华南和长江中下游地区长时间维持,使得该地区季风降水具有明显的极端性特征;(2)同时,我国东部大气中高层位势高度出现负异常,伴随着水汽辐合和低层大气不稳定,均有利于2020年夏季强降水的维持;(3)2020年夏季MJO活跃于1、2位相,其振幅在10~30天具有显著的周期。MJO在非洲和印度洋产生显著的Rossby波源,该波源激发的波列沿急流传播,造成了我国东部位势高度负异常的维持,同时也有利于我国东部夏季降水的维持;(4)通过敏感性试验进一步验证,MJO的在10~30天的信号有利于在我国东部500 hPa上空形成负的位势高度异常,有利于该区域降水增加。 展开更多
关键词 Madden-julian振荡(MJO) Rossby波源 季风降水 中国东部
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海温和MJO对2023年西南春旱的协同影响 被引量:1
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作者 陆晓娟 王芝兰 +6 位作者 张金玉 王昀 王丽娟 胡蝶 沙莎 王素萍 李忆平 《干旱气象》 2024年第2期166-179,共14页
2023年春季,我国西南地区发生了严重的气象干旱,对当地社会经济造成严重影响。为深入认识这次干旱事件的成因、并为未来西南地区春旱的预测提供科学依据,本文利用站点观测数据、美国国家环境预测中心和国家大气研究中心(National Center... 2023年春季,我国西南地区发生了严重的气象干旱,对当地社会经济造成严重影响。为深入认识这次干旱事件的成因、并为未来西南地区春旱的预测提供科学依据,本文利用站点观测数据、美国国家环境预测中心和国家大气研究中心(National Centers for Environmental Prediction/National Center for Atmospheric Research,NCEP/NCAR)再分析数据、美国国家海洋和大气管理局(National Oceanic and Atmospheric Administration,NOAA)的海表温度等,采用T-N波作用通量和合成分析等方法,从海温和热带大气季节内振荡(Madden-Julian Oscillation,MJO)的角度深入探讨此次春旱成因。结果表明:(1)2023年我国西南春旱是高温干旱复合事件,3月干旱发生在中部,4月干旱加剧并向西扩展,5月干旱持续。(2)3月北太平洋的马蹄形海温异常导致西风急流偏南偏西,抑制了西南地区的降水。(3)4月印度洋暖海温通过Kelvin波导致孟加拉湾附近的反气旋式环流异常,西北太平洋暖海温通过Rossby波导致南海至菲律宾的气旋式环流异常,造成西南地区南部出现偏北风,导致水汽辐散,加剧干旱。(4)5月MJO长时间维持在西太平洋,通过Gill响应引发南海至菲律宾对流层低层的气旋异常,减少偏南水汽的输送,从而使得西南干旱持续。 展开更多
关键词 海表温度 热带大气季节内振荡 西南春旱 成因
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Madden–Julian Oscillation: Its Discovery, Dynamics, and Impact on East Asia 被引量:14
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作者 Tim LI Jian LING Pang-Chi HSU 《Journal of Meteorological Research》 SCIE CSCD 2020年第1期20-42,共23页
In this review article,we pay primary attention to innovative works in the Madden–Julian Oscillation(MJO)field done by Chinese scientists.The historical aspect of discovery of the MJO and earlier studies of its dynam... In this review article,we pay primary attention to innovative works in the Madden–Julian Oscillation(MJO)field done by Chinese scientists.The historical aspect of discovery of the MJO and earlier studies of its dynamics by Chinese scientists are first described.It is followed by the description of recent advances in MJO propagation and initiation dynamics.For MJO eastward propagation,two types of the moisture mode theory are introduced.The first one emphasizes the effect of zonal asymmetry of perturbation moisture in the atmospheric boundary layer and the second one emphasizes the zonal asymmetry of column integrated moisture static energy(MSE)tendency.The mechanisms for MJO initiation over the western Indian Ocean include three distinctive processes:lower tropospheric moistening due to horizontal advection caused by preceding suppressed-phase MJO,midlatitude Rossby wave activity flux convergence in the upper troposphere originated from the Southern Hemisphere,and a delayed sea surface temperature feedback in association with a preceding opposite-phase MJO.The impacts of MJO on low-frequency variability of precipitation and temperature and associated extreme events in East Asia are also discussed. 展开更多
关键词 Madden–julian Oscillation(MJO) propagation and INITIATION lower TROPOSPHERIC moistening ROSSBY wave activity flux delayed sea surface temperature feedback
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Recent Advance in Understanding the Dynamics of the Madden-Julian Oscillation 被引量:43
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作者 李天明 《Journal of Meteorological Research》 SCIE 2014年第1期1-33,共33页
The Madden-Julian oscillation (MJO) is a dominant atmospheric low-frequency mode in the tropics. In this review article, recent progress in understanding the MJO dynamics is described. Firstly, the fundamental physi... The Madden-Julian oscillation (MJO) is a dominant atmospheric low-frequency mode in the tropics. In this review article, recent progress in understanding the MJO dynamics is described. Firstly, the fundamental physical processes responsible for MJO eastward phase propagation are discussed. Next, a recent modeling result to address why MJO prefers a planetary zonal scale is presented. The effect of the seasonal mean state on distinctive propagation characteristics between northern winter and summer is discussed in a theoretical framework. Then, the observed precursor signals and the physical mechanism of MJO initiation in the western equatorial Indian Ocean are further discussed. Finally, scale interactions between MJO and higher- frequency eddies are delineated. 展开更多
关键词 Madden-julian oscillation (MJO) eastward phase propagation physical mechanism of MJOinitiation scale interaction
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基于BDS的田野文物信息化系统设计与应用
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作者 王如意 卢小平 +2 位作者 侯岳 冯志立 苏莹莹 《信息技术》 2024年第11期120-124,131,共6页
针对河南省田野文物保护信息化程度低、保护难度大等现状,设计了一种集移动端和Web管理端为一体的田野文物保护信息化服务系统。系统依托北斗位置服务、WebGIS、高精度定位便携设备等技术,采用MD5和儒略日结合的加密登录方法,保证系统... 针对河南省田野文物保护信息化程度低、保护难度大等现状,设计了一种集移动端和Web管理端为一体的田野文物保护信息化服务系统。系统依托北斗位置服务、WebGIS、高精度定位便携设备等技术,采用MD5和儒略日结合的加密登录方法,保证系统安全性;具有精准定位、多源数据融合、动态可视化等功能,通过高精度定位便携设备,利用HNCORS获取差分数据进行定位解算,从而获得高精度位置信息。该系统已成功应用于河南省田野文物信息化工作中,有效解决了田野文物信息化程度低问题,为切实做好文物保护工作,提供了基础性的技术支撑。 展开更多
关键词 北斗位置服务 WEBGIS MD5 儒略日 田野文物
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Different Impacts of Madden–Julian Oscillation on Winter Rainfall over Southern China 被引量:2
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作者 Xiong CHEN Jian LING +2 位作者 Chongyin LI Lifeng LI Minghao YANG 《Journal of Meteorological Research》 SCIE CSCD 2021年第2期271-281,共11页
Winter rainfall over southern China is usually enhanced when Madden–Julian oscillation(MJO) is active over the Indian Ocean, but it can be weakened under certain conditions. Here, the diversity of MJO impacts on wint... Winter rainfall over southern China is usually enhanced when Madden–Julian oscillation(MJO) is active over the Indian Ocean, but it can be weakened under certain conditions. Here, the diversity of MJO impacts on winter rainfall and its mechanisms are explored by using scenarios of enhanced and suppressed rainfall anomalies over southern China when MJO is active over the Indian Ocean. The combined effects of low-frequency background moisture and intraseasonal winds are the major contributors to the different rainfall anomalies. Anomalous circulation in mid–high latitudes, especially on intraseasonal timescales, is almost opposite in the two scenarios, which can modulate the response of extratropical atmosphere to MJO heating and then induces the different circulations over southern China. In the enhanced scenario, mid–high latitudes of Eurasia and southern China are dominated by positive and negative sea level pressure anomalies, respectively. The southerly over southern China and the South China Sea induced by MJO heating promotes the anomalous moisture convergence and ascending motion over southern China, resulting in the enhanced rainfall. In the suppressed scenario, however, the circulation in mid–high latitudes does not favor rainfall over southern China and leads to the northerly response to MJO heating over southern China, which enhances moisture divergence and weakens rainfall over southern China. 展开更多
关键词 Madden–julian oscillation(MJO) winter rainfall southern China moisture diagnoses
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Influence of Springtime Atlantic SST on ENSO:Role of the Madden-Julian Oscillation 被引量:1
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作者 Xin YAN Juzhang REN +1 位作者 Jianhua JU Song YANG 《Journal of Meteorological Research》 SCIE CSCD 2018年第3期380-393,共14页
Increased evidence has shown the important role of Atlantic sea surface temperature(SST) in modulating the El Nio-Southern Oscillation(ENSO). Persistent anomalies of summer Madden-Julian Oscillation(MJO) act to link t... Increased evidence has shown the important role of Atlantic sea surface temperature(SST) in modulating the El Nio-Southern Oscillation(ENSO). Persistent anomalies of summer Madden-Julian Oscillation(MJO) act to link the Atlantic SST anomalies(SSTAs) to ENSO. The Atlantic SSTAs are strongly correlated with the persistent anomalies of summer MJO, and possibly affect MJO in two major ways. One is that an anomalous cyclonic(anticyclonic) circulation appears over the tropical Atlantic Ocean associated with positive(negative) SSTA in spring, and it intensifies(weakens) the Walker circulation. Equatorial updraft anomaly then appears over the Indian Ocean and the eastern Pacific Ocean, intensifying MJO activity over these regions. The other involves a high pressure(low pressure) anomaly associated with the North Atlantic SSTA tripole pattern that is transmitted to the mid-and low-latitudes by a circumglobal teleconnection pattern, leading to strong(weak) convective activity of MJO over the Indian Ocean. The above results offer new viewpoints about the process from springtime Atlantic SSTA signals to summertime atmospheric oscillation, and then to the MJO of tropical atmosphere affecting wintertime Pacific ENSO events, which connects different oceans. 展开更多
关键词 Madden-julian Oscillation(MJO) ATLANTIC sea surface temperature anomaly(SSTA) Walker circulation TELECONNECTION El Nio-Southern Oscillation(ENSO)
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