中国热带第四纪动物群与气候波动   总被引：1，自引：0，他引：1  

黄镇国  张伟强 《地理学报(英文版)》2003,13(4):488-497

About 70 examples of Quaternary fauna in China‘s tropics are enumerated in this paper. Of which about 40% of the examples can be found even in cooling stages, showing the smaller amplitude of climatic fluctuation during Quaternary. According to the temporal and spatial distribution of tropical faunas, the following characters of climate variation can be evidenced: two main cycles in Early Pleistocene, three main cycles in Middle Pleistocene, two main cycles in Late Pleistocene and Holocene Megathermal. The drop in temperature during the Latest Glacial Period and Neoglaciation has not endangered the existence of tropical faunas. With influence of cooling fluctuation during historical period, some faunas have removed southwards progressively, but disappearance of these animals in China‘s tropics was mainly the result of artificial factors.  相似文献   

中纬度和热带地区的中尺度对流系统     

Rutl.  SA 陈伯民 《大气情报》1991,(26):86-98

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Sensitivity of the Simulated Tropical Intraseasonal Oscillation to Cumulus Parameterizations          下载免费PDF全文

JIA Xiaolong  LI Chongyin 《Acta Meteorologica Sinica》2008,22(3):257-276

The sensitivity of the simulated tropical intraseasonal oscillation or MJO （Madden and Julian oscillation） to different cumulus parameterizations is studied by using an atmospheric general circulation model （GCM）--SAMIL （Spectral Atmospheric Model of IAP LASG）. Results show that performance of the model in simulating the MJO alters widely when using two different cumulus parameterization schemes-the moist convective adjustment scheme （MCA） and the Zhang-McFarlane （ZM） scheme. MJO simulated by the MCA scheme was found to be more realistic than that simulated by the ZM scheme. MJO produced by the ZM scheme is too weak and shows little propagation characteristics. Weak moisture convergence at low levels simulated by the ZM scheme is not enough to maintain the structure and the eastward propagation of the oscillation. These two cumulus schemes produced different vertical structures of the heating profile. The heating profile produced by the ZM scheme is nearly uniform with height and the heating is too weak compared to that produced by the MCA, which maybe contributes greatly to the failure of simulating a reasonable MJO. Comparing the simulated MJO by these two schemes indicate that the MJO simulated by the GCM is highly sensitive to cumulus parameterizations implanted in. The diabatic heating profile plays an important role in the performance of the GCM. Three sensitivity experiments with different heating profiles are designed in which modified heating profiles peak respectively in the upper troposphere （UH）, middle troposphere （MH）, and lower troposphere （LH）. Both the LH run and the MH run produce eastward propagating signals on the intraseasonal timescale, while it is interesting that the intraseasonal timescale signals produced by the UH run propagate westward. It indicates that a realistic intraseasonal oscillation is more prone to be excited when the maximum heating concentrates in the middle-low levels, especially in the middle levels, while westward propagating disturbances  相似文献   

基于SSA-AR方法的MJO指数预报模型试验   总被引：7，自引：0，他引：7  

朱红蕊  江志红  张勤  鞠晓慧 《热带气象学报》2010,26(3):371-378

采用奇异谱分析(SSA)与自回归向量(AR)预报模型相结合的方法,对热带地区大气季节内振荡(MJO)指数向量作自适应滤波意义下的预报试验。结果表明,通过对MJO原始序列进行SSA的分解重建,无论采用对重建的分量序列进行AR(P)建模的方案,还是利用对重建合成序列进行AR(P)建模的方案,均可得到两周以上的MJO指数预报能力,其提前20天指数预报值与实况之间平均相关系数达到0.5,与直接对MJO原始序列进行AR建模相比较,该方法有较高的预报技巧和超前预报能力,预报效果也较稳定,故将SSA-AR方案进一步完善,可望作为MJO指数业务预报的有效模型。  相似文献   

The Effect of Regional Ocean-Atmosphere Coupling on the Long-term Variability in the Pacific Ocean     

FENG Lin  WU Dexing  LIN Xiaopei  MENG Xiangfeng 《大气科学进展》2010,27(2):393-402

A fully coupled ocean-atmosphere model is applied to highlight the mechanism of the long-term variability (including decadal and longer time scales) in the Pacific Ocean. We are interested in the effect of ocean-atmosphere coupling of different regions during these processes. The control run successfully simulates the Pacific long-term variability, whose leading modes are the Pacific (inter) Decadal Oscillation (PDO) and the North Pacific mode (NPM). Furthermore, three numerical experiments are conducted, s...  相似文献   

1948-2003年热带地区降水气候特征与变化   总被引：5，自引：0，他引：5  

刘锦绣  施能 《南京气象学院学报》2006,29(5):627-634

使用1948—2003年全球陆地和海洋的月降水资料,研究了热带地区年降水量场的趋势变化,同时还研究了ENSO事件与热带地区年降水量的关系。结果表明,在1948—2003年,热带地区年降水量场以负趋势为主要变化特征。给出了降水趋势明显的13个区域,指出热带海洋降水趋势明显的地区比陆地的范围广而且强度大,正趋势区基本都在南半球的海洋上,且北半球降水趋势明显的海洋区域都呈负趋势。研究结果还表明,ENSO事件可能是热带地区年降水量减少的一个重要原因;同时给出了ENSO事件发生时热带地区的明显旱涝区,并与以往的研究进行了比较。  相似文献   

Intraseasonal Oscillation in the Tropical Indian Ocean   总被引：1，自引：1，他引：1  

LI Chongyin  HU Ruijin  YANG Hui 《大气科学进展》2005,22(5):617-624

1. Introduction The intraseasonal oscillation (ISO or Madden- Julian Oscillation, MJO) in the tropical atmosphere has been studied extensively, including its existence, structure, evolution and propagation (Madden and Ju- lian, 1971; Murakami, et al., 198…  相似文献   

白垩纪末全球变冷时期北大西洋增温现象     

徐明芝 《海洋地质前沿》2005,21(12):14-16

受低纬度环境影响的范围和低纬度环境受到暂时性气候影响的范围是气候和古气候研究中的新问题。气候模式预测：如果在温室效应下高纬度地区像数据中所说的那样变暖,则热带地区的温度要高于数据中描述的温度（如Huber等,2000）。这种不一致现象表明古温度估计中有误差和对温室气候动力学缺乏了解。有研究得出温室热带冷于现代热带的结论,  相似文献   

Distribution and Variation of Carbon Monoxide in the Tropical Troposphere and Lower Stratosphere          下载免费PDF全文

LI Qian  SHI Hua-Feng  SHAO Ai-Mei  BIAN Jian-Chun  Lü Da-Ren 《大气和海洋科学快报》2014,(3):218-223

The authors examine the distribution and varia- tion of carbon monoxide （CO） in the tropics from the sur- face to the lower stratosphere. By analyzing space-borne microwave limb sounder （MLS） measurements, measure- ments of pollution in the troposphere （MOPITT） and mod- em-era retrospective analysis for research and applications （MERRA） meteorological products, and atmospheric chemistry and climate model intercomparison project （ACCMIP） surface emission inventories, the influences of atmospheric dynamics and surface emissions are investi- gated. The results show that there are four centers of highly concentrated CO mixing ratio over tropical areas in differ- ent seasons： two in the Northern Hemisphere and another two in the Southern Hemisphere. All of these centers cor- respond to local deep convective systems and mon- soons/anticyclones. The authors suggest that both deep convections and anticyclones affect CO in the tropical tro- posphere and lower stratosphere--the former helping to transport CO from the lower to the middle troposphere （or even higher）, and the dynamical uplift and isolation effects of the latter helping to build up highly concentrated CO in the upper troposphere and lower stratosphere （UTLS）. Similarly, there are two annual surface emission peaks in- duced by biomass burning emissions： one from the North- ern Hemisphere and the other from the Southern Hemi- sphere. Both contribute to the highly concentrated CO mixing ratio and control the seasonal variabilities of CO in the UTLS, combining the effects of deep convections and monsoons. Results also show a relatively steady emission rate from anthropogenic sources, with a small increase mainly coming from Southeast Asia and lndia. These emis- sions can be transported to the UTLS over Tibet by the joint effort of surface horizontal winds, deep convections, and the Asian summer monsoon system.  相似文献   

Spatial and Temporal Variations of Atmospheric Angular Momentum and Its Relation to the Earth Length of Day          下载免费PDF全文

YANG Ping  SHI Wenjing  XIAO Ziniu  DONG Shi  REN Juzhang 《Acta Meteorologica Sinica》2014,28(1):150-161

The characteristics of atmospheric-angular-momentum （AAM） and length-of-day （LOD） on different timescales are investigated in this paper, on the basis of the NECP/NCAR reanalysis data and an LOD dataset for 1962-2010. The variation and overall trend of the AAM anomaly （AAMA） at different latitudes are presented, and the relationship between AAMA and LOD is discussed. The AAMAs in different latitude regions exhibit different patterns of variation, and the AAMA in the tropics makes a dominant contribution to the global AAMA. In the tropics, the AAMA propagates poleward to the extratropical regions. It is confirmed that a downward propagation of the AAMA occurs in the lower stratosphere. Correlation analysis shows that the relationship between AAMA and LOD varies significantly on different timescales. Specifically, the tropical AAMA is positively correlated with LOD on short timescales, but they are not obviously correlated on long timescales. This indicates that the interaction between AAM and the earth＇s angular momentum follows the conservative restriction on short timescales, but the influence of the earth angular momentum on that of the atmosphere depends on the interaction process on long timescales.  相似文献