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211.
Relationships between Interannual and Intraseasonal Variations of the Asian-Western Pacific Summer Monsoon Hindcasted by BCC_CSM1.1(m) 总被引:4,自引:0,他引:4
LIU Xiangwen ;WU Tongwen ;YANG Song ;LI Qiaoping ;CHENG Yanjie ;LIANG Xiaoyun ;FANG Yongjie ;JIE Weihua ;NIE Suping 《大气科学进展》2014,31(5):1051-1064
Using hindcasts of the Beijing Climate Center Climate System Model, the relationships between interannual variability (IAV) and intraseasonal variability (ISV) of the Asian-western Pacific summer monsoon are diagnosed. Predictions show reasonable skill with respect to some basic characteristics of the ISV and IAV of the western North Pacific summer monsoon (WNPSM) and the Indian summer monsoon (ISM). However, the links between the seasonally averaged ISV (SAISV) and seasonal mean of ISM are overestimated by the model. This deficiency may be partially attributable to the overestimated frequency of long breaks and underestimated frequency of long active spells of ISV in normal ISM years, although the model is capable of capturing the impact of ISV on the seasonal mean by its shift in the probability of phases. Furthermore, the interannual relationships of seasonal mean, SAISV, and seasonally averaged long-wave variability (SALWV; i.e., the part with periods longer than the intraseasonal scale) of the WNPSM and ISM with SST and low-level circulation are examined. The observed seasonal mean, SAISV, and SALWV show similar correlation patterns with SST and atmospheric circulation, but with different details. However, the model presents these correlation distributions with unrealistically small differences among different scales, and it somewhat overestimates the teleconnection between monsoon and tropical central-eastern Pacific SST for the ISM, but underestimates it for the WNPSM, the latter of which is partially related to the too-rapid decrease in the impact of E1 Nifio-Southern Oscillation with forecast time in the model. 相似文献
212.
The nonlinear association between ENSO and the Euro-Atlantic winter sea level pressure 总被引:1,自引:0,他引:1
A nonlinear projection of the tropical Pacific sea surface temperature anomalies (SSTA) onto the Northern Hemisphere winter sea level pressure (SLP) anomalies by neural networks (NN) was performed to investigate the nonlinear association between El Niño-Southern Oscillation (ENSO) and the Euro-Atlantic winter climate. While the linear impact of ENSO on the Euro-Atlantic winter SLP is weak, the NN projection reveals statistically significant SLP anomalies over the Euro-Atlantic sector during both extreme cold and warm ENSO episodes, suggesting that the Euro-Atlantic climate mainly responds to ENSO nonlinearly. The nonlinear response, mainly a quadratic response to the SSTA, reveals that regardless of the sign of the SSTA, positive SLP anomalies are found over the North Atlantic, stretching from eastern Canada to Europe (with anomaly center located just northwestward of Portugal), and negative anomalies centered over Scandinavia and Norwegian Sea, consistent with the excitation of the positive North Atlantic Oscillation pattern. 相似文献
213.
NASA/GEWEX (National Aeronautics and Space Administration/Global Energy and Water Cycle Experiment) Surface Radiation Budget (SRB) has released its latest radiation dataset, version 3.0. We examine the accuracy of the monthly mean global radiation in China using surface-observed radiation (SOR) data at 42 stations during the period 1984?C2004. Overall comparison shows a general overestimation of satellite retrieval radiation data with a bias of 14.6?W?m?2 and a root mean square error of 25.9?W?m?2. Differences at individual stations suggested satellite data are consistently higher than surface measurements over eastern China (110°E), but occasional underestimation occurs in Western China, especially Southwest China. Intra-annual variation analysis indicates that SRB satellite radiation can capture the annual cycle well. For trend of global radiations, there are evident discrepancies between satellite retrievals and surface measurements for both the entire period and segmental terms. For the entire period from 1984 to 2004, most stations show a positive trend based on surface measurements, while the majority of collocated pixels show a negative trend. Segmental trends demonstrated that the principal difference occurred during the first period of 1981?C1994. After 1994, the two datasets change similarly. Therefore, trend analysis in terms of detecting global dimming/brightening remains very difficult as surface measurements and satellite products do not agree yet. In addition, some proposals are made towards better understanding of the bias of satellite products and to improve further the satellite retrieval algorithm with better representation of both cloud and aerosol properties. 相似文献
214.
CINRAD/SA雷达频综故障检修方法 总被引:2,自引:1,他引:2
频综是多普勒全相参天气雷达的核心部件,其组件工艺水平高且价格昂贵,它提供了整个雷达工作所需的基准信号,共有5路输出,它们分别是9.6MHz主时钟信号、COHO信号、RF DRIVE信号、STALO信号、RF TEST SIGNAL信号.由于不同地区雷达发射机工作频率不同,因此频综不能通用,在台站,备份频综组件不太现实.由于厂家没有提供频综图纸,使得故障判别难度加大.因此通过剖析频综内部结构,给出频综的内部原理简图.针对十多个CINRAD/SA雷达频综出现的故障,划分出三种故障类型,并提出具体维修方法,在此基础上,归纳出该型号雷达在使用过程中频综出现故障时,雷达操作、维护人员应掌握的故障排查方法及技巧,以提高台站的保障能力. 相似文献
215.
风云三号降水测量雷达技术性能分析 总被引:1,自引:0,他引:1
风云三号降水测量卫星主要用于台风等灾害性天气系统强降水的监测,并提供全球中低纬度地区降水的结构信息。降水三维结构的准确测量是通过风云三号降水测量卫星的核心载荷——双频降水测量雷达实现的。首先介绍了风云三号降水测量雷达的主要任务与探测能力要求,然后通过仿真技术对降水测量雷达距离分辨率、水平分辨率、扫描角度、天线旁瓣电平、测量精度、波束匹配精度等主要技术性能指标进行了详细的分析。最后,利用于2010年开展的降水测量雷达样机航空校飞试验评估验证了降水测量雷达的各项功能和主要性能参数。结果表明,风云三号降水测量雷达整体降水探测性能与全球降水测量卫星的双频降水雷达相当。 相似文献
216.
中酸性侵入岩氧化钾平面分布规律及其与地壳厚度的关系 总被引:1,自引:0,他引:1
燕山地区中生代陆内造山作用强烈,形成数百个中生代中酸性侵入体。本区侵入岩的氧化钾分布具有南北分区、东西分带的特征。燕山北区中酸性侵入岩K2O含量普遍较高,平均为5.0%,而燕山南区中酸性侵性岩K2O含量平均为4.0%,统计分析表明,燕山陆内造山带中生代中酸性侵入岩氧化钾与地壳厚度呈线性相关,;地壳厚度是决定燕山地区中生代侵入岩氧化钾空间分布的主要因素,与板块边缘岛弧带火山岩氧化钾空间分布的主要制药 相似文献
217.
218.
且干布拉克早寒武世硅质岩岩石学、地球化学特征及地质意义 总被引:1,自引:0,他引:1
通过对西山布拉克组第一岩性段硅质岩岩石学、地球化学特征研究,探讨其沉积环境和成因,推测其与库鲁克塔格早古生代地壳演化关系。研究区硅质岩夹泥质硅岩、流纹质晶屑凝灰岩的岩石组合,硅质岩的Al/(Al+Fe)值(~0.6)、Ce/Ce*值(~0.57)、(La/Yb)n值(~0.66)等特征指示为欠补偿、缺氧的深水盆地沉积环境。其Fe/Ti值(~29.2),Al/(Al+Fe+Mn)值(~0.54),(Fe+Mn)/Ti值(~31.3),富集Ag,As,Sb,Ba元素等特征,表明该区硅质岩为热水和海水混合成因,形成过程中海水有较高的生产力。硅质岩∑REE在剖面底部为14.9×10-6,向上减小为8.6×10-6,至顶部增加到105.6×10-6,表明剖面底部到顶部热水活动强度呈减弱趋势。早寒武世硅质岩岩石学、地球化学特征表明,硅质岩形成于裂陷槽盆地中,是上升洋流将海底热水物质带至沉积地点与海水发生不同程度混合的产物,为库鲁克塔格早寒武世早期处于拉张裂解环境提供了岩石学和地球化学证据。 相似文献
219.
中国北方农牧交错带人类生存环境的过去,现在和未来 总被引:1,自引:0,他引:1
中国北方农牧业交错带是我国生产最不稳定的地带,风、旱、冻、雪等灾害频繁出现,具有敏感而脆弱的人地关系。文章在研究了该地带人类生存环境的演化及其规律的基础上,对未来百年人类的生存环境作了预测。 相似文献
220.
吴素珍 《中国地球化学学报》1989,8(1):72-83
The metasedimentary-volcanic series of the Wutai and Hutuo groups experienced regional metamorphism and thus turned into moderate-to low-grade metamorphic rocks.REE abundances and REE distribution patterns in the Shizui and Taihuai Subgroup metasedimentary-volcanic rocks are typical of the Archean,whereas the Gaofan Subgroup and the Hutuo Group show post-Archean REE geochemical char-acteristics.Five types of REE distribution pattern are distinguished:(1)rightward inclined smooth curves with little REE anomaly(Eu/Eu*=0.73-0.95) and heavy REE depletion (e.g.the Late Archean metasedimentary rocks);(2)rightward inclined V-shaped curves with sharp Eu anoma-ly (Eu/Eu*=0.48-0.76) and slightly higher ∑REE (e.g.the post-Archean metasedimentary rocks);(3) rightward inclined steep curves with negative Eu anomaly(Eu/Eu*=0.73-0.76) and the lowest ∑REE (e.g.the post-Archean dolomites);(4)rightward inclined,nearly smooth curves with both positive Eu anomaly and unremarkable positive Eu anomaly(Eu/Eu*=0.95-1.25)(e.g.the meta-basic volcanic rocks);and (5) rightward inclined curves with Eu anomaly(Eu/Eu*=1.09-1.19)and heavy REE depletion(e.g.the meta-acid volcanic rocks).Strata of the two groups are considered to have been formed in an island-arc belt-an instable continental petrogenetic environment. 相似文献