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Search Results: 1 - 10 of 65958 matches for " YANG Xiu-Qun "
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Numerical modeling of interannual anomalous atmospheric circulation patternsover East Asia during different stages of an El Nino event
El Nino演变不同阶段东亚大气环流年际异常型的数值模拟

SUN Xu-guang,YANG Xiu-Qun,

地球物理学报 , 2005,
Abstract: 给定194 8~1999年逐月变化的全球观测的海表温度分布,使用全球大气环流模式(CCM3 NCAR)模拟了大气对海表温度变化的响应,利用SVD和合成检验方法,分析了ElNino发展阶段夏季、成熟阶段冬季以及衰亡阶段夏季东亚大气环流的年际异常型.结果表明:ElNino发展阶段夏季,中国东北、朝鲜半岛以及日本海附近为高度负异常中心,西太平洋副高偏弱、偏东,东亚夏季风增强;ElNino成熟阶段冬季,东亚大槽加强,东亚北部冬季风加强;ElNino衰亡阶段夏季,西太平洋副高偏强、偏南、西伸,东亚夏季风减弱;ElNino事件在其衰亡阶段夏季与东亚大气环流异常的关系最紧密,其次是成熟阶段冬季,最后是发展阶段夏季.模拟的ElNino演变不同阶段东亚大气环流年际异常型易于解释以往研究中观测分析揭示的由ElNino造成的我国东部气温和降水异常型.
Onset and end of the first rainy season in south China

QIANG Xue-Min,YANG Xiu-Qun,

地球物理学报 , 2008,
Abstract: Onset and end of the First Rainy Season(FRS)in South China are defined in this paper using daily rainfall data and NCEP/NCAR reanalysis daily data for the period 1957~ 2004.After choosing a reasonable area and representative stations in South China,evolutions of variables including rainfall,precipitable water(PW),water vapor flux(WVF),vertical velocity,and potential pseudo-equivalent temperature(PPET)are analyzed.Results show that all these variables have experienced obviously staggered changes around the onset and end.The averaged beginning date of FRS occurs in pentad 19(1st pentad in April),as the precipitation increases outstandingly,in accordance with dramatic increments in PW,WVF and PPET.Meanwhile the WVF changes from divergence to convergence,accompanied by gradually enhanced vertical activities.It rains not too much in April which depicts the features of frontal precipitation.After the East Asian summer monsoon outbreaks in May,South China enters a period with much more precipitation and more vigorous convections.The peak of the rainy season is in June.Not until pentad 34(the 4th pentad of June)that FRS comes to the end when all these variables happen to experience a sudden decrease.According to the above analyses,a timetable of annual onset and ending dates of FRS in South China is given by choosing threshold criteria.Investigations on the potential height and wind fields before and after the beginning(ending)pentads show that the climatological atmospheric circulations are in favor of the increase in temperature and humidity before the beginning and in favor of the southward movement of cold air after the beggining so as consequently to cause remarkable increase in rainfall.As for the ending of the FRS,it is due to the seasonal transition of the general circulation in East Asia,especially due to the first northward shift of the Western Pacific Subtropical High(WPSH).
The possible role of Myosin light chain in myoblast proliferation
Biological Research , 2009, DOI: 10.4067/S0716-97602009000100013
Abstract: skeletal muscles have the potential to regenerate by activation of quiescent satellite cells, however, the molecular signature that governs satellite cells during muscle regeneration is not well defined. myosin light chains (myls) are sarcomere-related proteins as traditional regulator of muscle contraction. in this report, we studied the possible role of myl in the proliferation of skeletal muscle-derived myoblasts. compared to diaphragm-derived myoblasts, the extraocular muscle-derived myoblasts with lower levels of myl proliferated faster, maintained a longer proliferation phase, and formed more final myotubes. it was found that blockading myl with anti-myl antibody or knockdown of myll by sirna targeted against myll could enhance the myoblast proliferation and delay the differentiation of myoblasts. our results suggested that myl, likely myll, can negatively affect myoblast proliferation by facilitating myoblast withdrawal from cell cycle and differentiation.
Interannual Variation of the Tropical Indian Ocean Sea Surface Temperature Pre- and Post-1976/1977

ZHAO Shan-Shan,ZHOU Tian-Jun,YANG Xiu-Qun and,

大气科学 , 2008,
Abstract: Based on 58-year(1948-2005) NCEP/NCAR reanalysis data,interannual variation of the tropical Indian Ocean sea surface temperature pre-and post-1976/1977 is studied.The original data are filtered to retain the variation with periods from 13 months to 8 years.The results show that ENSO could cause a basin-wide warming/cooling mode with the strongest phase in winter in the tropical Indian Ocean which lags ENSO 2-6 months both pre-and post-1977.But the mode pre-1977 is stronger than that post-1977.The former leads the latter two months in phase.Prior to 1977,the dominant mode of the tropical Indian Ocean SSTA(SST anomaly) in autumn appeared as a basin-wide uniform pattern.After 1977,however,the dominant mode appeared as a dipole or zonal gradient pattern.Changes in the response of the Indian Ocean surface wind to ENSO pre-and post-1977 account for the shift of dominant mode.Prior to 1977,the ENSO-related anomalous tropical Indian Ocean surface easterly firstly appeared in summer.After 1977,however,it appeared firstly in spring and a strong anticyclone dominated the southern tropical Indian Ocean throughout the season.
Interdecadal and interannual variation characteristics of rainfall in North China and its relation with the northern hemisphere atmospheric circulations

XU Gui-Yu,YANG Xiu-Qun,SUN Xu-guang,

地球物理学报 , 2005,
Abstract: With the data of monthly precipitation of 26 stations in North China and American NCAR/NCEP monthly reanalysis atmosphere variables, by method of Singular Value Decomposition (SVD), we have investigated the variation features of precipitation in North China at interdecadal and interannual time scales, and also its relation with the atmospheric circulations in the Northern Hemisphere. The results show that it's necessary to do time scale separations to precipitation and atmosphere variables, otherwise, the outcomes of SVD reflect only the characteristics of interannual time scale without interdecadal time scale. Corresponding to interdecadal and interannual time scales of precipitation in North China, there exist significant differences in the anomalies of atmospheric circulations. In connection with the remarkable interdecadal shift of precipitation occurring in the late 1970s in North China, all the atmospheric circulations have the same shift as well, together with a propagation process from ground surface to the upper troposphere.
Storm track variations in the North Pacific in winter season and the coupled pattern with the midlatitude atmosphere-ocean system

REN Xue-Juan,YANG Xiu-Qun,HAN Bo,XU Gui-Yu,

地球物理学报 , 2007,
Abstract: The storm track variations in the North Pacific in winter are investigated by using European ECMWF(ERA40) reanalysis data and the Empirical Orthogonal Function(EOF) method.The coupled patterns of the atmosphere mean flow anomaly and the sea surface temperature(SST) anomaly,related with the storm track variations are studied by the regression method.The results show that there are two main variation modes of the storm track in the North Pacific in winter.The first type is characterized by north(south) shift of the mid-east part of the storm track that connotes a northeastward(southeastward) reorientation of the track.The regression analysis shows that the warmer(colder) SSTA occurs in conjunction with anticyclonic anomalies above that cover the midlatitude North Pacific,companying with the first mode of the storm track.Those are warm ridge(cold trough) pattern in the vertical for the atmosphere-ocean system.Meanwhile,it is Pacific-North American(PNA) negative(positive) phase at the mid and high troposphere.The second type is the intensification(weakening) and northward(southward) shift of the whole storm track.It is associated with warmer(colder) SST in the Kuroshio Current,northward(southward) shift of the Aleutian Low at the low troposphere and westerly jet at the high troposphere,and Western Pacific(WP) negative(positive) phase at the mid-high troposphere.The time coefficients of EOF have significant correlation with Aleutian Low index,PNA index,WP index,Nino-3 index and the Kuroshio Current index,respectively,which demonstrate the existence of the coupling among the three selected fields.
Numerical experiments on interaction between tropical Pacific and tropical Atlantic through the windstress "bridge"

ZHAO Shan-Shan,YANG Xiu-Qun,ZHANG Qiang,ZHANG Yan,

地球物理学报 , 2006,
Abstract: Interaction between the tropical Pacific and the tropical Atlantic through the wind stress bridge was numerically studied with intermediate models of global tropical atmosphere and ocean. In a control experiment, the atmospheric model was run from 1958 to 1998 with observed monthly SST data taken from NCEP reanalysis to generate surface wind stress, and with which the oceanic model was run over the same period with the heat flux taken and/or calculated from NCEP reanalysis data to generate SST. In a parallel experiment, everything is the same as in the control run except that the SST used to force the atmospheric model was fixed to climatological mean in a basin (the tropical Pacific or the tropical Atlantic). The difference between the control and parallel experiments indicates how the SST anomaly (SSTA) in one basin influences the other through the wind stress bridge. The main results are as follows. In general, the warm SSTA in one basin locally produces westerly anomaly in the west and easterly anomaly in the east, and vice versa. For a warm SSTA in the tropical Pacific, the surface easterly anomaly in the east of the basin extends into the tropical Atlantic, inducing a cold SSTA there, and vice versa. For a warm SSTA in the tropical Atlantic, the surface westerly anomaly in the west of the basin extends into tropical Pacific, inducing a warm SSTA there, and vice versa.
Modeling of Natural NOx and VOC Emissions and Their Effects on Tropospheric Photochemistry in China

XIE Min,WANG Ti-jian,JIANG Fei,YANG Xiu-qun,

环境科学 , 2007,
Abstract: An inventory of natural NOx and VOC emissions for China was developed. For the year 2000, it was estimated that the annual soil NOx and vegetation VOC emissions amounted to 225.75 Gg and 13.23 Tg, respectively, in which the total VOC was comprised of 7.77 Tg isoprene, 1.86 Tg monoterpene and 3.60 Tg other VOC. The emissions also showed large seasonal and regional variation. And with the aid of models MM5 and Calgrid, the effects of the emissions on the photochemical formation of O3, NOx, HNO3 and PAN over China were investigated. Countrywide mean concentrations of these pollutants respectively varied 15.3%, 15.7%, 25.5%, 6.5% on account of soil NOx emissions, 5.6%, -4.9%, -19.3%, 142.3% as a result of vegetation VOC emissions, and 26.1%, 8.8%, 4.3%, 177.9% owning to their synthetic effects. The variation was much higher in summer than in any other seasons. In addition, the distribution of the pollutants was affected by the natural emissions because of the different meteorological conditions, pollutant emissions and NMHC/NOx ratios in different regions. The role of natural NOx and VOC emissions on tropospheric photochemistry can not be neglected.
赵珊珊 ZHAO Shan-Shan,周天军 ZHOU Tian-Jun,杨修群 YANG Xiu-Qun,等 et al
大气科学 , 2008, DOI: 10.3878/j.issn.1006-9895.2008.02.15
Abstract: 基于1948~2005年NCEP/NCAR(美国大气研究中心/环境预测中心)再分析资料,讨论了1976/1977年前后的年代际气候变化对热带印度洋海表温度(SST)年际变率特征的影响,结果表明:在气候变化前后,ENSO都能导致热带印度洋SSTA(海表面温度异常)出现全海盆同号的变化,这种模态在冬季最强;气候变化前与变化后相比,该模态对该地区海温年际变率的方差贡献大22.1%,达到最强的时间早2个月。气候变化前,秋季热带印度洋SSTA的主导年际变率模态表现为全海盆同号,变化后则表现为“偶极子模态”(IODM)。导致上述SSTA特征变化的重要原因,是气候变化前后印度洋风场对ENSO的响应不同。在气候变化前,与ENSO相关联的热带印度洋东风异常首先在夏季出现,而变化后则首先在春季出现,并且有一反气旋性环流异常维持在热带东南印度洋。
Spatial-temporal Distribution of Precipitation and Typical Drought or Flood Year over Bole Region in Xinjiang

XIN Yu,ZHANG Guang-xing,YANG Xiu-qun,ZHANG Xin,BO Li-jian,WANG Mei-yu,
辛 渝
,张广兴,杨修群,张 新,博力健,王美玉

中国沙漠 , 2007,
Abstract: 利用新疆博尔塔拉蒙古自治州地区4个气象站1971—2000年的逐日降水资料,用静态统计论观点分析了博州地区降水时空变化特征,并按适应于西北地区的z指数旱涝标准统计出了典型的旱涝年。结果表明:①博州地区降水量西多东少,海拔在1200m以上的地区为半干旱区,其余绝大多数地区为干旱区或重干旱区,多极端降水事件,自然灾害以旱灾为主洪灾其次,自然生态环境极其脆弱;②年(月)降水量以少于30a的年(月)平均值为多;③12月至次年2月降水量极小,空间分布呈东多西少型,其他月份则反之;④多雨期出现在夏半年4~9月。其中5—7月大面积干旱与局地洪灾往往并存;⑤山区有两个雨季共5个旬次,平均降水量的月际分布为双峰型,主峰在7月,次峰在5月;其他地区仅1个雨季共两个旬次,平均降水量的月际分布为单峰型,峰值出现在5月;⑥同一气候背景中,博州各个地貌单元的旱涝程度不一,降水空间分布极其复杂。
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