与华北干旱相关联的全球尺度气候变化现象   总被引：12，自引：1，他引：11  

黄刚 《气候与环境研究》2006,11(3):270-279

利用ERA-40再分析资料集的风、温度、水汽等再分析资料,分析了华北地区干旱以及北非萨赫勒地区干旱化的气候特征及它们之间的关联,指出在亚非季风区上空存在一个年代际的季风环流异常遥相关波列,正是由于此波列的作用,使得我国华北地区从1965年以后所发生的干旱与北非萨赫勒地区干旱化存在着明显的相关联.并且分析了这两地区的干旱与之相关联的全球气候变化背景,指出由于1965年之后北、南半球气温变化差异的减少导致了亚非季风系统发生了年代际减弱和南撤,从而使得华北和北非萨赫勒地区发生了持续干旱现象.    相似文献   

青藏高原地气温度之间的关系   总被引：20，自引：10，他引：10  

李述训  吴通华 《冰川冻土》2005,27(5):627-632

应用多元线性回归分析方法,对位于40°~25°N,75°~102°E范围内的119个气象观测台站的1991—2000年平均气温和地面温度观测资料进行分析,获得了研究区域的月平均气温、地面温度与纬度、经度和海拔高度间关系的线性统计系数.统计结果和实测资料的比较以及统计分析的相关系数结果表明,高原地区的气温、地面温度和它的年较差与经度、纬度及海拔高度具有很好的相关性.应用曲线拟合方法将所得统计分析系数拟合成时间函数,就可将高原地区的气温和地面温度表示成统一的空间坐标和时间的函数.如果将已验证的1991—2000年平均地面温度与气温差统计结果作为气温与地面温度间关系的实验结果,那么,就可以解决长期困扰多年冻土预报研究中在任意已知时间和空间点上气温条件下,难以确定影响多年冻土温度状况变化上边界条件的变化这一难题.这一结果对于目前正在进行的青藏铁路冻土工程和环境预报研究具有重要意义.  相似文献   

影响青藏铁路冻土区主要工程措施可靠性的气温变化指标分析     

赵世运  张鲁新  吴志坚 《冰川冻土》2005,27(6):926-931

多年冻土是气候条件控制的特殊地质体,气温升高和降水条件变化将对青藏铁路沿线的多年冻土产生深刻影响.从全球气温变化背景和青藏高原气候变化的实际情况出发,分析和论述了气候变化对青藏铁路沿线多年冻土地温特征及冻土区工程建筑物的可靠性产生缓慢而持续影响的气温变化指标.通过对冻土区工程设计原则和工程结构、工程措施可靠性产生重大影响的气温变化特征的分析,提出对目前冻土工程可靠性的看法,并提出应对工程措施.  相似文献   

阿拉斯加德纳里国家公园公路沿线冰椎和融化失稳问题的减灾备选方案   总被引：1，自引：0，他引：1  

TedS.Vinson 《冰川冻土》2005,27(1):17-32

Only one access road leads into Denali Park. The serviceability and safety of this gravel road is obviously of paramount importance to the National Park Service (NPS). Since the late 1950s and mid1960s major icings and a landslide, respectively, have occurred along the Denali Park access road. During the summer of 1990 the landslide activity intensified. The central section of the Park through which the access road traverses is designated as a wilderness area. Consequently, off road field exploration required to quantify the hazards and remediation activities that may be proposed to mitigate icings and stabilize the landslide, are severely restricted and closely scrutinized by the NPS. The results of an evaluation of (1) the current state-of-the-practice to control icings, and (2) thaw stabilization techniques that could be appiled to the northwest corner of the landslide are presented herein. The recommendations which followed, respecting the wilderness area designation for the Park, are also presented.  相似文献   

冻土对沙尘暴的影响研究   总被引：5，自引：1，他引：4  

赵建华  俞亚勋  孙国武 《中国沙漠》2005,25(5):658-662

利用1951-2000年中国大陆685个沙尘暴站、412个冻土深度及706个气温站的观测资料,分析了近50a来沙尘暴与冻土深度的时空分布特征。结果表明:沙尘暴多发中心总与当月的冻深极小值或相对低值区对应,且冻深越小(大),沙尘暴日数越大(小);气温是冻深与沙尘暴反相关关系的纽带。  相似文献   

海洋边界层内风、浪相互作用研究进展   总被引：1，自引：1，他引：0  

李建东  陈希  蒋国荣  刘庭杰 《海洋预报》2005,22(1):58-66

鉴于海洋边界层内风、浪相互作用在海洋、大气研究中的重要意义,本文较详细地回顾、总结了国内外有关海洋边界层风、浪相互作用的研究进展：由最初的关于风应力和空气动力粗糙长度的统计研究发展到后来的利用模式探讨海洋边界层的结构和风、浪耦合机制。最后简单讨论了风、浪耦合研究中存在亟待解决的问题以及未来的研究前景。  相似文献   

The influence of ice marginal setting on early Holocene retreat rates in central West Greenland          下载免费PDF全文

SAMUEL E. KELLEY  JASON P. BRINER  SUSAN R. H. ZIMMERMAN 《第四纪科学杂志》2015,30(3):271-280

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Spatial and temporal variations of stable isotopes in precipitation in midlatitude coastal regions          下载免费PDF全文

Xiaoyang Li  Atsuko Sugimoto  Akihiro Ueta 《水文研究》2017,31(17):3029-3044

Spatial and temporal variations of the isotopic composition of precipitation were investigated to better understand their controlling factors. Precipitation was collected from six locations in Hokkaido, Japan, and event‐based analyses were conducted for a period from March 2010 to February 2013. Relatively low δ values and a high d‐excess for annual averages were observed at three sites located along the Japan Sea compared to the three sites at Pacific Ocean side. Lower δ values in spring and fall and higher d‐excess in winter were observed for the region along the Japan Sea. In total, 264 precipitation events were identified. Precipitation originated predominantly from low‐pressure system (LPS) events, which were classified as northwest (LPS‐NW) and southeast (LPS‐SE) events according to the routes of the low‐pressure center, that passed northwest and southeast of Hokkaido, respectively. LPS‐SE events showed lower δ¹⁸O than LPS‐NW events, which is attributable to the lower δ¹⁸O of water vapor resulting from heavy rainfalls in the upstream region of the LPS air mass trajectories over the Pacific Ocean. This phenomenon observed in Hokkaido can be found in other midlatitude coastal regions and applied for hydrological, atmospheric, and paleoclimate studies. A characteristic spatial pattern was found in LPS‐NW events, in which lower δ¹⁸O was observed on the Japan Sea side than on the Pacific Ocean side in each season. This is likely due to the location of the sampling sites and their distance from the LPS: Precipitation with lower δ¹⁸O in the region along the Japan Sea occurs in a well‐developed cloud system near the low‐pressure center in cold and warm sectors of LPS, whereas precipitation with higher δ¹⁸O on the Pacific side mainly occurs in a warm sector away from the low‐pressure center. Air mass from the north does not always cause low δ in precipitation, and the precipitation process in the upstream region is another important factor controlling the isotopic composition of precipitation, other than the local temperature and precipitation amount.  相似文献   

Late Quaternary glacial history of the Nalati Range,central Tian Shan,China, investigated using 10Be surface exposure dating          下载免费PDF全文

Mei Zhang  Yixin Chen  Yingkui Li  Gengnian Liu 《第四纪科学杂志》2016,31(7):659-670

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Cross‐cutting moraines reveal evidence for North Atlantic influence on glaciers in the tropical Andes     

Jacqueline A. Smith  Donald T. Rodbell 《第四纪科学杂志》2010,25(3):243-248

Surface exposure dating of boulders on an exceptionally well‐preserved sequence of moraines in the Peruvian Andes reveals the most detailed record of glaciation heretofore recognised in the region. The high degree of moraine preservation resulted from dramatic changes in the flow path of piedmont palaeoglaciers at the southern end of the Cordillera Blanca (10° 00′ S, 77° 16′ W), which, in turn, generated a series of cross‐cutting moraines. Sixty ¹⁰Be surface exposure ages indicate at least four episodes of palaeoglacier stabilisation (>65, ca. 65, ca. 32 and ca. 18–15 ka) and several minor advances or stillstands on the western side of the Nevado Jeulla Rajo massif. The absence of ages close to the global Last Glacial Maximum (ca. 21 ka) suggests that if an advance culminated at that time any resulting moraines were subsequently overridden. The timing of expanded ice cover in the central Peruvian Andes correlates broadly with the timing of massive iceberg discharge (Heinrich) events in the North Atlantic Ocean, suggesting a possible causal connection between southward migration of the Intertropical Convergence Zone during Heinrich events and a resultant increase in precipitation in the tropical Andes. Copyright © 2010 John Wiley & Sons, Ltd.  相似文献