NUMERICAL SIMULATION OF INTERANNUAL AND INTERDECADAL VARIABILITY OF SURFACE WIND OVER THE TROPICAL PACIFIC   总被引：2，自引：0，他引：2  

吴爱明  赵永平  白学志  胡敦欣 《中国海洋湖沼学报》2002,20(1):1-8

A global atmospheric general circulation model (L9R15 AGCMs) forced by COADS SST was integrated from 1945 to 1993. Interannual and interdecadal variability of the simulated surface wind over the tropical Pacific was analyzed and shown to agree vey well with observation. Simulation of surface wind over the central-western equatorial Pacific was more successful than that over the eastern Pacific. Zonal propagating feature of interannual variability of the tropical Pacific wind anomalies and its decadal difference were also simulated successfully. The close agreement between simulation and observation on the existence of obvious interdecadal variability of tropical Pacific surface wind attested to the high simulation capability of AGCM.  相似文献   

Solar wind-magnetosphere interaction as simulated by a 3-D em particle code     

Ken-Ichi Nishikawa  Torsten Neubert  Oscar Buneman 《Astrophysics and Space Science》1995,227(1-2):265-276

We have studied the solar wind-magnetosphere interaction using a 3-D electromagnetic particle code. The results for an unmagnetized solar wind plasma streaming past a dipole magnetic field show the formation of a magnetopause and a magnetotail, the penetration of energetic particles into cusps and radiation belt and dawn-dusk asymmetries. The effects of interplanetary magnetic field (IMF) have been investigated in a similar way as done by MHD simulations. The simulation results with a southward IMF show the shrunk magnetosphere with great particle entry into the cusps and nightside magnetosphere. This is a signature of a magnetic reconnection at the dayside magnetopause. After a quasi-stable state is established with an unmagnetized solar wind we switched on a solar wind with an northward IMF. In this case the significant changes take place in the magnetotail. The waving motion was seen in the magnetotail and its length was shortened. This phenomena are consistent with the reconnections which occur at the high latitude magnetopause. In our simulations kinetic effects will determine the self-consistent anomalous resistivity in the magnetopause that causes reconnections.Deceased January 24, 1993; R. Bunemanet al. 1993.  相似文献   

Problems of the aquatic environment and countermeasures in the rapid economic development in the Zhujiang River Delta     

Yanmao Wen  Cheng Guopei 《中国地理科学(英文版)》1995,5(1):39-43

The Zhujiang (Pearl) River Delta is the rapid economic development region in China since the opening and reform door policy was carried out in 1978. Being the rapid development of industry and city, the impact on the aquatic environmental quality was significant. The pollution caused the water quality descended and the ecological system degraded, and also impeded the economic development. The characteristics and problems of the aquatic environment are: the capacity of aquatic environment is large but hasn’t been utilized rationally, the water quality is influenced by saline sea water and tide current, the main pollutants are organic matter and the pollution is going heavier, the concentration of pollutants change seasonally. The countermeasures of aquatic environmental protection are: carrying out the environmental functional regionalization and controlling the total amount of pollutant discharge, revising the industrial structure and making a rational industrial arrangement, raising the rate of waste water treatment and making a full assessment of the water conservancy project.  相似文献   

Spatial closeness of the white hypergiants HD 168607 and HD 168625     

E. L. Chentsov  E. S. Gorda 《Astronomy Letters》2004,30(7):461-468

Our spectroscopic monitoring of the hypergiants HD 168607 (B9.5 Ia-0) and HD 168625 (B5.5 Ia-0) with resolutions from 15000 to 70000 confirms that both stars belong to the Ser OB1 association, proves their spatial closeness, and increases the probability that they constitute a physical pair.  相似文献   

通过卫星双向双频观测对电离层时延的测定     

李慧茹  李志刚 《时间频率学报》2005,28(1):29-36

介绍了利用卫星双向双频(C波段)观测来测定电离层时延的方法,并对不同经纬度的观测结果进行了比较和分析。卫星双向双频(C波段)观测精度高,采样间隔短,能测定电离层总电子含量的细微变化。  相似文献   

中尺度磁绳结构的行星际观测     

宋其武  吴德金 《天文学报》2004,45(4):381-388

由磁绳结构主导、平均尺度约二、三十个小时的行星际磁云是日冕物质抛射在行星际膨胀、传播的体现。最近，Moldwin等人报道在太阳风中还观测到一些尺度在几十分钟的小尺度磁绳结构，并认为太阳风中的磁绳结构在尺度分布上可能具有双峰特征，在全面检视了WIND卫星(1995年-2000年)和ACE卫星(1998年-2000年)的观测资料后，发现了在行星际太阳风中一些尺度为几个小时的中尺度磁绳结构，利用初步整理的其中28个中尺度磁绳结构事件，认为太阳风中的磁绳结构在尺度分布上可能是连续的，这对行星际太阳风中磁绳结构物理起源的研究可能提出重要的物理限制。  相似文献   

固体潮潮汐因子的特征频谱及其应用     

蒋骏  张雁滨  周翠屏 《大地测量与地球动力学》1994,(2)

本文应用非线性谱分析中的最大熵谱分析方法（ＭＥＭ）、和一般线性功率谱的分析方法，对固体潮潮汐因子的时间序列进行了综合研究，指出固体潮潮汐因子的时间序列中普遍存在明显的半月左右周期的特征频谱；将其应用于地震前兆的分析与探索，对固体潮潮汐因子特征频谱中的前兆变化特征进行了解释，得出结论：半月左右周期的频率域，是固体潮观测中前兆响应的一个重要主频域。  相似文献   

Ekman层风速随高度分布方程的数值解试验     

刘敏  郭鹏 《中国科学院上海天文台年刊》2005,(1):31-38

根据大气水平运动方程推导出Ekman层风速随高度分布方程,该分布可用二阶线性微分方程表示,用有限差分法求解该二阶线性微分方程的边值问题的数值解,并给出计算程序,输出结果。将结果与经典解析解比较,讨论了经典解的正确性和适用范围。  相似文献   

Solar wind interactions with Comet 19P/Borrelly     

D.T Young  F.J Crary  J.E Nordholt  D Boice  A Eviatar  J.J Hanley  D.J McComas  D Reisenfeld  R.C Wiens 《Icarus》2004,167(1):80-88

The Plasma Experiment for Planetary Exploration (PEPE) made detailed observations of the plasma environment of Comet 19P/Borrelly during the Deep Space 1 (DS1) flyby on September 22, 2001. Several distinct regions and boundaries have been identified on both inbound and outbound trajectories, including an upstream region of decelerated solar wind plasma and cometary ion pickup, the cometary bow shock, a sheath of heated and mixed solar wind and cometary ions, and a collisional inner coma dominated by cometary ions. All of these features were significantly offset to the north of the nucleus-Sun line, suggesting that the coma itself produces this offset, possibly because of well-collimated large dayside jets directed 8°-10° northward from the nucleus as observed by the DS1 MICAS camera. The maximum observed ion density was 1640 ion/cm³ at a distance of 2650 km from the nucleus while the flow speed dropped from 360 km/s in the solar wind to 8 km/s at closest approach. Preliminary analysis of PEPE mass spectra suggest that the ratio of CO⁺/H₂O⁺ is lower than that observed with Giotto at 1P/Halley.  相似文献   

Low-frequency solar radiophysics with LOFAR and FASR     

T.S. Bastian   《Planetary and Space Science》2004,52(15):1381-1389

Low-frequency radio observations offer unique diagnostics of the solar corona and solar wind. After a prolongued hiatus, there is renewed interest in this important frequency regime. Two new ground-based instruments will provide critical new low-frequency observations: the low-frequency array (LOFAR) and the frequency agile solar radiotelescope (FASR). This brief topical review summarizes low-frequency radio phenomena that will be accessible to detailed study by LOFAR and FASR in the coming decade. Energy release, drivers of space weather, and studies of the solar wind are emphasized. Both instruments are expected to play important roles in both basic research problems and national and international space weather capabilities. While FASR is a solar-dedicated instrument, LOFAR is not. Solar observing requirements for LOFAR are briefly discussed.  相似文献