Late Miocene–Quaternary rapid stepwise uplift of the NE Tibetan Plateau and its effects on climatic and environmental changes     

《Quaternary Research》2014,81(3):400-423

The way in which the NE Tibetan Plateau uplifted and its impact on climatic change are crucial to understanding the evolution of the Tibetan Plateau and the development of the present geomorphology and climate of Central and East Asia. This paper is not a comprehensive review of current thinking but instead synthesises our past decades of work together with a number of new findings. The dating of Late Cenozoic basin sediments and the tectonic geomorphology of the NE Tibetan Plateau demonstrates that the rapid persistent rise of this plateau began ~ 8 ± 1 Ma followed by stepwise accelerated rise at ~ 3.6 Ma, 2.6 Ma, 1.8–1.7 Ma, 1.2–0.6 Ma and 0.15 Ma. The Yellow River basin developed at ~ 1.7 Ma and evolved to its present pattern through stepwise backward-expansion toward its source area in response to the stepwise uplift of the plateau. High-resolution multi-climatic proxy records from the basins and terrace sediments indicate a persistent stepwise accelerated enhancement of the East Asian winter monsoon and drying of the Asian interior coupled with the episodic tectonic uplift since ~ 8 Ma and later also with the global cooling since ~ 3.2 Ma, suggesting a major role for tectonic forcing of the cooling.  相似文献   

Recent Progresses in Comparative Planetology——Summary of the Session of Comparative Planetology at the 3rd Conference of Earth System Sciences     

Yongyun Hu  Feng Tian  Shijie Zhong  Long Xiao 《地球科学进展》2014,29(11):1298-1302

Comparative planetology is an interdisciplinary science between Earth sciences and astronomy. It studies physical, chemical and dynamical properties of planets and satellites and their surface characteristics, interior structures and chemistry, magnetic field, climate and possible existence of life. Although the study of comparative planetary science is at its infancy stage in China, it is very encouraging to see that 25 papers were received by the session, which is much more than what we expected. It indicates that more and more scientists are interested in this research field. These papers can be classified into three categories: solar planets, extra-solar planets, and moon explorations. Scientists from both China and oversea reported their recent results.  相似文献   

中国大陆降水时空变异规律——I.气候学特征   总被引：2，自引：0，他引：2       下载免费PDF全文

任国玉  战云健  任玉玉  陈峪  王涛  柳艳菊  孙秀宝 《水科学进展》2015,26(3):299-310

为系统了解大尺度降水气候特征,利用2 300多个国家级气象站逐日观测资料,分析了中国大陆1956—2013年多年平均降水的空间分布和季节性变化规律。主要新认识有:① 暴雨量、暴雨日数和暴雨强度最高的站点在华南沿海,而小雨量、小雨日数最多的站点主要在江南内陆山区、丘陵;东部季风区山地、丘陵多出现低强度降水,平原和沿海易出现高强度降水;② 四季降水量均由西北内陆向东南沿海递增,南方秋季降水量明显小于春季,但华西和江南沿海秋季降水量较多,冬季降水在东南丘陵出现高值中心;③ 珠江和东南诸河流域降水量年内存在2个峰值,其中珠江流域有6月主峰值和8月次峰值,东南诸河流域主峰在6月中下旬,次峰在8月末,长江流域总体表现为单峰型,出现在6月下旬和7月初,西南诸河流域和北方所有流域降水均表现为夏季单峰型;④ 南方各大河流域从2月末到6月中下旬陆续进入雨季,北方各大河流域进入雨季时间集中在6月末、7月初;南、北方雨季结束时间比雨季开始时间集中,从南到北进入雨季时间持续120 d以上,而从北到南退出雨季时间则仅持续不到45 d;⑤ 丰雨期的持续时间,珠江流域从5月初到9月上旬后期,东南诸河从5月上旬到7月上旬,8月末到9月初再度短暂出现,长江流域从6月中下旬到7月中旬,西南诸河从7月中旬到 8月下旬,淮河流域从7月上旬至7月底、8月初,辽河流域在8月初出现极短丰雨期;⑥ 降水年际变异性最高的站点在青藏高原西南、塔里木盆地、阿拉善高原、华北平原北部和汾河谷地,海河流域年降水具有最大的变异系数。  相似文献   

Study of the climatological behaviors of Euro-Atlantic and West Asia blockings in the period of 1959–2018     

《Dynamics of Atmospheres and Oceans》2020

In this study, comparison of blocking climatological behaviors is presented for the two periods of 1959–1988 and 1989–2018 in a part of the Northern Hemisphere including the Atlantic Ocean, Europe and West Asia regions. Blocking events were detected using a modified blocking index that is based on vertically integrated potential vorticity. By applying this index, the characteristics of detected blocking events such as frequency, duration, intensity and area were determined and compared for both the periods.According to the results, on average, 16 and 15 blocking events per year were identified in the first and second periods, respectively. The trend analysis shows that the number of blocking events in the period 1959–1988 was significantly decreased, while it was slightly increased in the period 1989–2018. Blocking activity was most prevalent from the eastern Atlantic through Europe to West Asia, but this longitude band exhibits a relatively eastward shift in the second period. In addition, the seasonal distributions are similar to those found in previous studies with the higher occurrence of blocking events during winter and autumn seasons and the lowest frequency in summer, as well as long-lasting events and greater intensity and extension in winter than the summer time, especially in the second period. These seasonal variations of blocking frequency may be due to synoptic scale eddies and planetary waves which are more active and stronger in the colder seasons than the other seasons. On the other hand, a comparison between the two periods shows that the blocking events tend to be more frequent over West Asia especially during summer in recent years. Although discrepancies between the two periods are not significant, they could be partly due to the impacts of climate change in recent decades.  相似文献   

中国热带海-气相互作用与ENSO动力学及预测研究进展     

任宏利  郑飞  罗京佳  王润  刘明竑  张文君  周天军  周广庆 《气象学报》2020,78(3):351-369

国际上针对海洋-大气系统的观测、理论和模拟方面已经开展了广泛而深入的研究,为短期气候预测水平的不断提升奠定了坚实基础,这其中中国学者做出了许多重要贡献。文中简要回顾了中国学者70年来在热带海-气相互作用与ENSO动力学及预测方面的研究进展。其中,热带海-气相互作用部分主要涉及4个方面的内容:热带太平洋气候特征与ENSO现象、热带印度洋海温主要模态及其与太平洋相互作用、热带大西洋海温主要模态及与海盆的相互作用、中高纬度海-气系统对ENSO的影响;ENSO动力学包括7个方面的内容:基本理论的相关研究、ENSO相关的诊断与模拟研究、两类ENSO相关研究、ENSO触发机制相关研究、ENSO与其他现象的相互作用、外部强迫与大气遥相关、气候变化与ENSO响应;ENSO预测主要包括2个方面的内容:动力-统计ENSO预测方法、ENSO预测系统与应用。最后,还讨论了上述相关方面亟待解决的问题。   相似文献   

Midlatitude unstable air-sea interaction with atmospheric transient eddy dynamical forcing in an analytical coupled model     

Chen  Lilan  Fang  Jiabei  Yang  Xiu-Qun 《Climate Dynamics》2020,55(9-10):2557-2577

While recent observational studies have shown the critical role of atmospheric transient eddy (TE) activities in midlatitude unstable air-sea interaction, there is still a lack of a theoretical framework characterizing such an interaction. In this study, an analytical coupled air-sea model with inclusion of the TE dynamical forcing is developed to investigate the role of such a forcing in midlatitude unstable air-sea interaction. In this model, the atmosphere is governed by a barotropic quasi-geostrophic potential vorticity equation forced by surface diabatic heating and TE vorticity forcing. The ocean is governed by a baroclinic Rossby wave equation driven by wind stress. Sea surface temperature (SST) is determined by mixing layer physics. Based on detailed observational analyses, a parameterized linear relationship between TE vorticity forcing and meridional second-order derivative of SST is proposed to close the equations. Analytical solutions of the coupled model show that the midlatitude air-sea interaction with atmospheric TE dynamical forcing can destabilize the oceanic Rossby wave within a wide range of wavelengths. For the most unstable growing mode, characteristic atmospheric streamfunction anomalies are nearly in phase with their oceanic counterparts and both have a northeastward phase shift relative to SST anomalies, as the observed. Although both surface diabatic heating and TE vorticity forcing can lead to unstable air-sea interaction, the latter has a dominant contribution to the unstable growth. Sensitivity analyses further show that the growth rate of the unstable coupled mode is also influenced by the background zonal wind and the air–sea coupling strength. Such an unstable air-sea interaction provides a key positive feedback mechanism for midlatitude coupled climate variabilities.

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从FY-4A卫星遥感数据和GFS资料估算全天空状况下的地表长波辐射通量     

闵敏  吴晓 《气象》2020,46(3):336-345

本文介绍一种利用FY-4A成像仪遥感数据和全球预报系统(GFS)资料估算全天空地表长波辐射通量的反演方法。该方法通过辐射传输模拟和统计回归计算建立云天地表下行长波辐射通量的反演模式,并基于GFS资料处理云覆盖地区的地表上、下行长波辐射通量。这种全天空状况下两种通量的反演结合了FY-4A晴空地表长波辐射业务产品和本文反演模式处理的云天地表上、下行长波辐射通量。2018年9月1日的处理结果与Aqua/CERES同类产品相对比,精度为:RMSE=20.52 W·m^-2,R=0.9481,Bias=3.3 W·m^-2(夜间地表下行辐射通量对比);RMSE=25.58 W·m^-2,R=0.9096,Bias=5.4 W·m^-2(白天地表下行辐射通量对比);RMSE=10.97 W·m^-2,R=0.9762,Bias=-3.3 W·m^-2(夜间地表上行辐射通量对比);RMSE=19.97 W·m^-2,R=0.9283,Bias=5.0 W·m^-2(白天地表上行辐射通量对比)。这些结果表明本文发展的方法能够反演出精度较好的云天上下行长波辐射通量资料,为今后利用FY-4后续星处理生成全天空状况下的地表长波辐射通量产品奠定了理论基础。  相似文献   

西北太平洋热带气旋频数及生成位置的气候变化研究进展          下载免费PDF全文

吴泽铭  张冬娜  胡春迪  杨崧 《山东气象》2020,40(4):1-10

自20世纪70年代末期以来,西北太平洋的热带气旋在全球变暖的背景下主要发生了两种宏观的气候变化：一个是热带气旋生成频数呈现年代际减少,尤其是在东南部海域;另一个则是其生成与活动位置等总体特征有向西北偏移的趋势。本文对这两个方面的研究进展进行了概述。近些年的研究表明,垂直风切变的增强可能是夏秋季热带气旋频数减少的最主要原因,这与太平洋-印度洋海面温度变化导致的大尺度环境变化有密切联系。同样有研究认为北大西洋海面温度的多年代际振荡对近期西北太平洋热带气旋生成频数的减少也非常重要。但西北太平洋西部强热带气旋的频数呈现出增加的趋势,这可能与东亚近海海面温度的显著升高有关,尽管这种变化是否可信仍有争议。近20年来,西北太平洋热带气旋活动普遍出现西北移倾向,包括生成位置和路径位置,这种变化可能受到了ENSO变异及20世纪90年代末期太平洋气候突变的调控。同时,热带环流的极向扩张又导致了热带气旋的有利环境向北扩张,因此西北太平洋热带气旋活动也出现极向迁移的趋势。  相似文献   

Diurnal Variation of Tropical Cyclone Rainfall in the Western North Pacific in 2008-2010   总被引：1，自引：0，他引：1       下载免费PDF全文

SHU Hai-Long  ZHANG Qing-Hong  XU Bin 《大气和海洋科学快报》2013,6(2)

Diurnal variation of tropical cyclone (TC) rainfall in the western North Pacific (WNP) is investigated using the high-resolution Climate Prediction Center's morphing technique (CMORPH) products obtained from the National Oceanic and Atmospheric Administration (NOAA). From January 2008 to October 2010, 72 TCs and 389 TC rainfall days were reported by the Joint Typhoon Warning Center's (JTWC) best-track record. The TC rain rate was partitioned using the Objective Synoptic Analysis Technique (OSAT) and interpolated into Local Standard Time (LST). Harmonic analysis was applied to analyze the diurnal variation of the precipitation. Obvious diurnal cycles were seen in approximately 70% of the TC rainfall days. The harmonic amplitude and phase of the mean TC rainfall rate vary with TC intensity, life stage, season, and spatial distribution. On the basis of intensity, tropical depressions (TDs) exhibit the highest precipitation variation amplitude (PVA), at approximately 30%, while super typhoons (STs) contain the lowest PVA, at less than 22%. On the basis of lifetime stage, the PVA in the decaying stage (more than 37%) is stronger than that in the developing (less than 20%) and sustaining (28%) stages. On the basis of location, the PVA of more than 35% (less than 18%) is the highest (lowest) over the high-latitude oceanic areas (the eastern ocean of the Philippine Islands). In addition, a sub-diurnal cycle of TC rainfall occurs over the high-latitude oceans. On the basis of season, the diurnal variation is more pronounced during summer and winter, at approximately 30% and 32%, respectively, and is weaker in spring and autumn, at approximately 22% and 24%, respectively.  相似文献   

Trend and Interannual Variability of Chinese Air Pollution since 2000 in Association with Socioeconomic Development: A brief Overview          下载免费PDF全文

LIN Jin-Tai  PAN D  ZHANG Rui-Xiong 《大气和海洋科学快报》2013,6(2):84-89

air pollution, trend and variability, socioeconomic development, satellite measurements, bottom-up emission inventories, top-down constraints  相似文献