检索结果-南通市图书馆

Diagnostic Study on Seasonality and Interannual Variability of Wind Field

在线全文

学校读者我要写书评

暂无评论

Advances in atmospheric sciences 1999年第4期16卷 537-543页

作者：薛峰曾庆存 LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing

Based on NCEP/ NCAR reanalysis data during 1980-1994, seasonally and interannual variability of the horizontal wind field are studied. It is shown that: (1) In the lower troposphere, there exist regions with maximum of seasonally in the tropics, the subtropics and high latitudes, which is called the tropical, subtropical and temperate-frigid monsoon region respectively. In the upper troposphere, the subtropical monsoon combines with the tropical monsoon as a nonseparably planetary monsoon system. In the stratosphere, there is a belt with very large seasonality in each hemisphere caused by the inversely seasonal circulation and by the establishment and collapse of the night jet. (2) Seasonal variation of the large-scale monsoon may generally be attributed to that of the zonal wind, however, seasonal variation of the meridional wind is of great importance in East Asian monsoon region. (3) In monsoon region, interannual variability of the atmospheric general circulation is closely related to seasonal variation of monsoon, while in the tropical Pacific, it may considerably be influenced by the external factors such as sea surface temperature (SST) anomalies associated with El Nino or La Nina event. Moreover, interannual variability undergoes a pronounced annual cycle.

关键词： atmospheric general circulation Seasonality Interannual variability Monsoon

Estimating open boundary conditions from coastal tidal observations by adjoint approach

在线全文

学校读者我要写书评

暂无评论

Science China Earth sciences 1998年第3期41卷 330-336页

作者：朱江曾庆存郭冬建刘卓 institute of atmospheric physics Chinese Academy of Sciences Beijing China

A numerical study for estimating the tidal open boundary conditions of a shelf current modrl from tb coastal tidal observations is presented. The method is based on the optimal control/adjoint method. A lrast square fitting of the model state to simulated data is used. Two ideal domains and coastlines are considered. Using the IAP shallow. water model and its adjoint model, some identical twin experiments are carried out to test efficiency and lirnilsd of the method. The results show that the adjoint method can efficiently estimate the open boundary conditions well for gulf/bay like domains. The adjoint method seems to have great potential to improve the accuracy of tide and shelf current modeling in coastal regions.

关键词： adjoint method open boundary conditions shelf current model.

An Unsaturated Soil Water Flow Problemand Its Numerical Simulation

在线全文

学校读者我要写书评

暂无评论

Advances in atmospheric sciences 1999年第2期16卷 183-196页

作者：谢正辉戴永久曾庆存 LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing

A numerical model for the unsaturated flow equation with moisture content as prognostic variable is established in order to simulate liquid moisture flow in an unsaturated zone with homogeneous soil, and different initial and boundary conditions. For an infiltration or evaporation problem, its numerical solution by using a finite difference method is very sensitive to its upper boundary condition and the related soil parameters, and using a traditional finite element method usually yields oscillatory non-physics profiles. However, we obtain a nonoscillatory solution and evade a non-physics solution for the problem by using the mass-lumped finite element method. This kind of boundary conditions is handled very well. Numerical simulations for certain soils show that the numerical scheme can be used in simulation of liquid moisture flow for infiltration, evaporation, re-distribution and their alternate appearances. It can be also applied to a high-resolution land surface model.

关键词： Unsaturated flow Finite element Mass lumping Numerical simulation

The NPO/ NAO and Interdecadal Climate Variation in China

在线全文

学校读者我要写书评

暂无评论

Advances in atmospheric sciences 2000年第4期17卷 555-561页

作者：李崇银李桂龙 LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing

This article discusses the interannual variation of the North Atlantic Oscillation (NAO) and North Pacific Oscillation (NPO), its relationship with the interdecadal climate variation in China which is associated with the climate jump in the Northern Hemisphere in the 1960’s, using the data analyses. It is clearly shown that both the amplitudes of the NAO and NPO increase obviously in the 1960’s and the main period of the oscillations changes from 3-4 years before the 1960’s to 8–15 years after the 1960’s. Therefore, interdecadal climate variation in China or the climate jump in the 1960’s is closely related to the anomalies of the NAO and NPO. Key words North Atlantic Oscillation (NAO) - North Pacific Oscillation (NPO) - Climate Jump - Interdecadal climate variation This work was supported by National Key Basic Science Program in China (G1998040903), chinese academy of Science and the National Natural Science Fundation of China (Grant No.49823002).The authors are also grateful to Ms. Wang Xuan for typing the manuscript.

关键词： North Atlantic Oscillation (NAO) North Pacific Oscillation (NPO) Climate Jump Interdecadal climate variation

A new model on bidirectional reflectance surface-atmospheric coupled radiation

在线全文

学校读者我要写书评

暂无评论

Science China Earth sciences 2001年第4期44卷 298-306页

作者：邱金桓 institute of atmospheric physics Chinese Academy of Sciences Beijing China

An exact and available model on bidirectional reflectance surface-atmospheric coupled radiation is of great significance for spaceborne remote sensing application. Based on the physical process of interaction of solar radiation with the surface and the atmosphere, a new model on bidirectional reflectance surface-atmospheric coupled radiation is developed in this paper. As shown in numerical simulation, this model is evidently better than the 6S model. The standard error among 110112 sets of upward radiance data calculated by this new model is only 0.49%, which is about one fourth of the one by 6S. In the condition of the solar zenith angle θs?75° and the viewing angle θ v? 60°, the error by the new model is usually smaller than 2.5%.

关键词： Bidirectional reflectance, coupling, upward radiance, remote sensing.

A Preliminary Study on the Polar Climate Predictability

在线全文

学校读者我要写书评

暂无评论

Advances in atmospheric sciences 1999年第3期16卷 361-366页

作者：王会军 LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing

Studies have revealed that predictability of the atmospheric general circulation is generally high in the tropics throughout the year and that there is some predictability in the Northern extra-tropical winter atmospheric circulation through some patterns of tele connection. Predictability of the general circulation at the polar regions has still remained as a ‘ cold’ topic and little has been known about this question. Based on a preliminary study on the predictability by using the institute of atmospheric physics (IAP) general circulation model, it is found that the SST-related predictability of the Southern winter lower atmospheric circulation in Antarctica is reasonably high and that there is some predictability in the 500 hPa and 200 hPa geopotential height fields over Europe and the Okhotsk Sea region during the Northern winter. It is suggested that more researches on this issue based on data analysis and model simulations are needed to obtain better understanding.

关键词： Polar climate predictability El Nino Climate variability

Satellite remote sensing reveals overwhelming recovery of forest from disturbances in Asia

在线全文

学校读者我要写书评

暂无评论

atmospheric and Oceanic Science Letters 2025年第1期18卷 46-51页

作者： Yiying Zhu Hesong Wang Anzhi Zhang School of Ecology and Nature Conservation Beijing Forestry UniversityBeijingChina Key Laboratory of Regional Climate and Environment for Temperate East Asia Institute of Atmospheric PhysicsChinese Academy of SciencesBeijingChina College of Forestry and Landscape Architecture Xinjiang Agricultural UniversityUrumqiChina

Forest ecosystems play key roles in mitigating human-induced climate change through enhanced carbon uptake;however,frequently occurring climate extremes and human activities have considerably threatened the stability of *** the same time,detailed accounts of disturbances and forest responses are not yet well quantified in *** study employed the Breaks For Additive Seasonal and Trend method-an abrupt-change detection method-to analyze the Enhanced Vegetation Index time series in East Asia,South Asia,and Southeast *** approach allowed us to detect forest disturbance and quantify the resilience after *** showed that 20%of forests experienced disturbance with an increasing trend from 2000 to 2022,and Southeast Asian countries were more severely affected by ***,95%of forests had robust resilience and could recover from disturbance within a few *** resilience of forests suffering from greater magnitude of disturbance tended to be stronger than forests with lower disturbance *** summary,this study investigated the resilience of forests across the low and middle latitudes of Asia over the past two *** authors found that most forests exhibited good resilience after disturbance and about two-thirds had recovered to a better state in *** findings of this study underscore the complex relationship between disturbance and resilience,contributing to comprehension of forest resilience through satellite remote sensing.

关键词： Forest ecosystem Enhanced vegetation index Breaks for additive seasonal and trend method Disturbance Resilience

Large-scale Circulation Anomalies Associated with Interannual Variation in Monthly Rainfall over South China from May to August

在线全文

学校读者我要写书评

暂无评论

Advances in atmospheric sciences 2014年第2期31卷 273-282页

作者： SU Qin LU Riyu LI Chaofan State Key Laboratory of Numerical Modeling for atmospheric sciences and Geophysical Fluid Dynamics institute of atmospheric physics Chinese Academy of Sciences University of the chinese academy of sciences Center for Monsoon System Research institute of atmospheric physics Chinese Academy of Sciences

Interannual variation in summer rainfall over South China （SC） was investigated on the monthly *** was found that monthly rainfall from May to August exhibits different features of variation,and the amounts are basically independent of each *** is a significant negative correlation,however,between May and July SC rainfall,which is partially related to the developing phases of ENSO *** was also found that stronger （weaker） lower-tropospheric winds over SC and the upstream parts are responsible for more （less） SC rainfall in every month from May to *** this monthly consistent enhancement of horizontal winds,the wind anomalies exhibit distinct differences between May-June and July-August,due to the remarkable change in climatological winds between these two *** SC rainfall is associated with a lower-tropospheric anticyclonic anomaly over the SCS and the Philippine Sea in May and June,but with a cyclonic anomaly centered over SC in July and August.

关键词： subseasonal variation interannual variation South China rainfall general circulation anomalies

On the Nonlinear Response of Lower Stratospheric Ozone to NO_x and ClO_x Perturbations for Different CH_4 Sources

在线全文

学校读者我要写书评

暂无评论

Advances in atmospheric sciences 2006年第5期23卷 750-757页

作者：王革丽杨培才 institute of atmospheric physics chinese academy of sciences Beijing 100029

The impact of sulfate aerosol, ClOx and NOx perturbations for two different magnitudes of CH4 sources on lower stratospheric ozone is studied by using a heterogeneous chemical system that consists of 19 species belonging to 5 chemical families （oxygen, hydrogen, nitrogen, chlorine and carbon）. The results show that the present modeled photochemical system can present several different solutions, for instance, periodic states and multi-equilibrium states appearing in turn under certain parameter domains, through chlorine chemistry and nitrogen chemistry together with sulfate aerosol as well as the increasing magnitude of CH4 sources. The existence of catastrophic transitions could produce a dramatic reduction in the ozone concentration with the increase of external sources.

关键词： lower stratosphere atmospheric ozone aerosol multi-equilibrium catastrophic transition