检索结果-南通市图书馆

Strengthening of the boreal winter Hadley circulation and its connection with ENSO

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第11期17卷 1327-1333页

作者： Ma Jie1,2.and Li Jianping2.1. College of atmospheric Sciences, Lanzhou University, Lanzhou 730000, china 2. LASG,{2., chinese academy of Sciences, beijing 10002., china) College of atmospheric Sciences Lanzhou University Lanzhou 730000 China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

Empirical orthogonal function (EOF) analysis is carried out for the year-to-year variability of the boreal winter (DJF) mass stream function of the mean meridional circulation (MMC) during the period 1948—2.05. The results demonstrate that it is dominated by the equatorially asymmetric and symmetric modes. Further analysis shows that the former mode is linked with the boreal winter Hadley cell mainly on the decadal time-scale, and the latter on the interannual time-scale. The asymmetric mode index (AMI) with a clear upward trend contributes to the decadal strengthening of the boreal Hadley circulation, and is closely correlated with the tropical SST warming, especially in the region of Indo-west Pacific warm pool (INWP). Furthermore, the AMI also contributes to the abrupt change of the correlation coefficient between the boreal Hadley circulation and ENSO after 1976. The symmetric mode index (SMI) with robust and stable linkage with ENSO shows a significant interannual variability, suggesting that the variability of the Hadley circulation is mainly associated with ENSO on the interannual time-scale.

关键词： the Hadley circulation interannual time-scale decadal time-scale

Persistent anomalous flows over the subtropical western Pacific insummer

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

chinese Science Bulletin 1998年第8期43卷 672-675页

作者： ZHUANG Shiyu\+1 and JI Liren\+2.1. National Meteorological Centre, china Meteorological Administration, beijing 100081, china 2. LASG, institute of atmospheric physics, chinese academy of Sciences, beijing 100080, china National Meteorological Ccntre China Meteomlcgical Administration Beijing China LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing China

The distribution of global persistent anomalies shows that the subtropical western Pacific is a key region with high_frequency occurrence of persistent anomalies. Analyses of streamfunction anomalies, OLR anomalies etc. suggest that the convective heating related to Indian monsoon might be responsible for the development of WPA. The results of numerical experiment by two linear barotropic models support the observation.

关键词： persistent anomalies subtropical high Indian monsoon anomalous forcing.

Numerical simulation of Meiyu front and the diagnosis of moist vorticity vector

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第11期17卷 1341-1347页

作者： Ping Fan1,2.and Luo Zhexian2.1. institute of atmospheric physics, chinese {2. of Sciences, beijing 10002., china 2. Nanjing University of Information Sciences & Technology, Nanjing 2.0044, china) institute of atmospheric {2. Chinese Academy of Sciences Beijing 100029 China Nanjing University of Information Sciences & Technology Nanjing 210044 China

Moist vorticity vector is introduced to study the development and evolution of mesoscale convective vortex (MCV) in the Meiyu front precipitation with the Advanced Regional Predication System (ARPS). In this study, the heavy rainfall is simulated to investigate the genesis, development and dissipation of middle scale convective vortex, which occurred from 0000 UTC 3 July to 12.0 UTC 5 July over the Jianghuai River valley. Moist vorticity vector (MVV) has zonal, radial and vertical components in its 3D spatial distribution. The simulation shows that the vertical component of moist vorticity vector well demonstrates the spatial distribution characteristics of middle scale convective vortex, especially in the process of Meiyu front precipitation. Diagnosis upon zonal, radial averaged and mass-integrated quantities of MVV shows that its vertical component and the surface precipitating ratio are in phase with a correlation coefficient of 0.68, indicating that the vertical component of MVV is closely associated with the Meiyu front precipitation. In addition, the tendency of the vertical component of MVV is mainly determined by the interaction between the vorticity and the zonal and radial gradient of condensational or depositional heating.

关键词： moist vorticity vector mesoscale convective vortex Meiyu front precipitation

Interannual variability of Antarctic Oscillation and its influence on East Asian climate during boreal winter and spring

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第5期49卷 554-560页

作者： FAN Ke1,2.3 & WANG Huijun2.1. Nansen-Zhu International Research Center, institute of atmospheric physics, chinese {2. of Sciences, beijing 10002., china 2. Department of atmospheric Science, Yunnan University, Kunming 650091, china 3. Graduate University of the chinese {2. of Sciences, beijing 100049, china 1. Nansen-Zhu International Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. Department of atmospheric Science Yunnan University Kunming 650091 China 3. Graduate University of the chinese academy of Sciences Beijing 100049 China

The interannual variability of Antarctic Oscillation (AAO) and its influence on East Asian climate during both boreal winter and spring are addressed. The results show that the positive AAO anomaly decreases the cold activity over East Asia during both boreal winter and spring. AAO-related barotropic meridional teleconnection from Antarctic to Arctic is found through analysis of mean me- ridional circulations. This meridional teleconnection is remarkable over Eurasia during boreal winter and over the Pacific Ocean during boreal spring. The results also show that zonal mean zonal wind at high latitudes in Southern Hemisphere has well positive correlation with that of Eurasia during boreal winter and has negative correlation with Pacific North American teleconnection (PNA) during boreal spring, which again display the meridional teleconnection. Thus, local meridional teleconnection is a possible linkage for interaction of circulations at mid-high latitudes between both hemispheres.

关键词： Antarctic Oscillation, Eurasian west wind, meridional teleconnection, mean meridional circulation.

Seasonal variation of global stratosphere-troposphere mass exchange

在线全文

学校读者我要写书评

暂无评论

Progress in Natural Science:Materials International 2007年第12期17卷 1466-1475页

作者： Guo Dong1,2. Lu Daren2.and Sun Zhaobo1(1. institute of atmospheric Sciences, Nanjing University of Information Science and Technology, Nanjing 2.0044,{2. 2. LAGEO, institute of atmospheric physics, chinese academy of Sciences, beijing 10002.,{2.) institute of atmospheric Sciences Nanjing University of Information Science and Technology Nanjing 210044 China LAGEO Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

By Wei formula in pressure coordinate, the stratosphere-troposphere mass exchange (STME) is diagnosed globally for 44 years from 1958 to 2.01 using the European Center for Medium-Range Weather Forecasts (ECMWF) reanalysis datasets. Regions of mass flux into the stratosphere are found over Indonesia, bay of Bangladesh and the mid-west coast of South Africa. Compensating mass outflow from the stratosphere appears mainly over mid-latitudes near large-scale troughs. Upward and downward transport of mass at the middle and high latitudes accompany with each other. Mass flux into troposphere is stronger in autumn and winter than in spring and summer. Strong downward mass flux into the troposphere occurs in eastern Asia the whole year with nearly stable sites. Although the area of eastern Asia accounts for only 5.6% of that of the northern hemisphere (NH), its net mass exchange reaches 15.83% of that of the NH, which means that research on STME of eastern Asia is greatly important to that of the NH and even the global areas. Air across the tropopause enters more from stratosphere to troposphere than that from troposphere to stratosphere, which is possibly related with systematic bias of the assimilated datasets and with persistent rise of the tropopause height. Contributions of the mass exchange and the mass flux exchange in the NH and southern hemisphere (SH) on their latitudes increase from equator to pole, with larger contributions in the NH. Mass exchange and mass flux exchange per areas at high latitudes are larger than that at low latitudes, which means greater mass exchange efficiency at high latitudes.

关键词： stratosphere troposphere mass exchange seasonal variation.

Pattern phenomena in an rf discharge dusty plasma system

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2006年第5期49卷 588-596页

作者： HUANG Feng1,2. YE Maofu2.& WANG Long2.1. College of Science, china Agricultural University, beijing 100083, china 2. institute of physics, chinese academy of Sciences, beijing 100080, china 1. College of Science China Agricultural University Beijing 100083 China 2. institute of physics Chinese Academy of Sciences Beijing 100080 China

Various dust patterns are observed in an rf discharge dusty plasma system. According to the dust growth process from small to large in size, the formation of different dust patterns can be divided into two stages: the small-particle stage (or dust cloud stage), and the large-particle stage (or dust crystal stage). The evolution relations between different dust patterns with gas pressure changing are investigated. Dust voids, dust acoustic waves and strong turbulence modes are presented at the small-particle stage. The self-organized dust lattices and dust clusters are investigated at the large-particle stage. The static structure of a dust lattice is characterized by means of the pair correlation function. Dust clusters formed by particles with different numbers and the regular evolution of the clusters with gas pressure are also investigated. The packing sequences of dust clusters are verified through two-dimensional confined molecular dynamics simulations.

关键词： dusty plasma dust patterns

A subsurface runoff parameterization with water storage and recharge based on the Boussinesq-Storage Equation for a Land Surface Model

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2006年第6期49卷 622-631页

作者： TIAN Xiangjun1,2. XIE Zhenghui1, ZHANG Shenglei1 & LIANG Miaoling1 1. LASG, institute of atmospheric physics, chinese {2. of Sciences, beijing 10002., china 2. Graduate School of the chinese {2. of Sciences, beijing 100039, china 1. LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China 2. Graduate School of the chinese academy of Sciences Beijing 100039 China

Subsurface runoff in a land surface model is usually parameterized as a single-valued function of total storage in a basin aquifer reservoir. This kind of parameterization is often sin-gle-valued function of storage-discharge under a steady or “quasi-steady” state, which cannot rep-resent the influence of aquifer recharge on subsurface runoff generation. In this paper, a new sub-surface runoff parameterization with water storage and recharge based on the Boussinesq-storage equation is developed. This model is validated by a subsurface flow separation algorithm for an ex-ample river basin, which shows that the new model can simulate the subsurface flow reasonably.

关键词： Zsubsurface runoff parameterization Boussinesq-storage equation waterstorage and recharge

Compression behavior of Zr_(41)Ti_(14)Cu_(12.5)Ni_(10)Be_(2..5) bulk metallic glass up to 2. GPa

在线全文

学校读者我要写书评

暂无评论

Science china(physics,Mechanics & Astronomy) 2005年第3期48卷 319-324页

作者： LI Gong 1, 2., ZHAN Zaiji 2., LIU Jing 3 , YUN Jinku 1 , SUN Liling 2., LIU Riping 1 , ZHANG Jun 2.& WANG Wenkui 1, 2.1. Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Qinhuangdao 066004, china 2. Center for Condensed Matter physics, {2. of physics, chinese academy of Sciences, beijing 100080, china 3. BSRF, {2. of High Energy physics, chinese academy of Sciences, beijing 100039, china 1. Key Laboratory of Metastable Materials Science and Technology Yanshan University 066004 Qinhuangdao China 2. Center for Condensed Matter physics Institute of Physics Chinese Academy of Sciences 100080 Beijing China 3. BSRF Institute of High Energy Physics Chinese Academy of Sciences 100039 Beijing China

The compression of a Zr41Ti14Cu12.5Ni10Be2..5 bulk metallic glass (BMG) is investigated at room temperature up to 2. GPa using in-situ high pressure energy dispersive X-ray diffraction with a synchrotron radiation source. The pressure-induced structural relaxation is exhibited. It is found that below about 8 GPa, the existence of excess free volume contributes to the rapid structural relaxation, which gives rise to the rapid volumetric change, and the structural relaxation results in the structural stiffness under higher pressure.

关键词： bulk metallic glass, high pressure, structural relaxation, synchrotron radiation.

Input function and simulated distributions of tritium in the North Pacific

在线全文

学校读者我要写书评

暂无评论

Science china Earth Sciences 2010年第3期53卷 441-453页

作者： BA Qi1,2.& XU YongFu1 1 State Key Laboratory of atmospheric Boundary Layer physics and atmospheric Chemistry, institute of atmospheric physics, chinese academy of Sciences, beijing 10002., china 2.Graduate University of chinese academy of Sciences, beijing 100049, china 1. State Key Laboratory of atmospheric Boundary Layer physics and atmospheric Chemistry Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China2. Graduate University of Chinese Academy of Sciences Beijing 100049 China

An ocean general circulation model (OGCM) of the North Pacific with a southern open boundary condition is used to simulate the distribution and transport of tritium in the North Pacific. First, the observed tritium in precipitation dataset of GNIP/ISOHIS is chosen, and used to develop an input function of tritium for the model domain from 1951 to 1997 in terms of the triangulation for interpolation. Then, the input function is used as an upper flux for the tritium model. The OGCM with tritium is integrated for 47 years with the initial condition of zero tritium concentrations. Compared with the observations from GEOSECS and WOCE, the model generates a meridional gradient of surface tritium concentrations and the high tritium concentrations in the subsurface layer, which is consistent with that indicated in the observations. The simulated time series of total tritium fluxes from the atmosphere to the ocean shows a spike in 1963. The total inventory of tritium in the ocean changes slowly with time after 1975. Tritium enters the higher-latitude region, and then is mainly transported by the subsurface process towards the equatorial region, which is well simulated in the model. However, the difference mainly occurs at 30°N–40°N, which can be seen also in the simulation of CFCs. This difference may partly originate from the insufficient description of physical processes in the OGCM. Nevertheless, some uncertainties exist in the development of the tritium input function, which can also influence the simulated results.

关键词： North Pacific basin-wide ocean general circulation model tritium input function tritium distributions