检索结果-南通市图书馆

Advances in Atmospheric Sciences 2022年第3期39卷 519-528页

作者： Xiaoyu REN Yi LIU Zhaonan CAI Yuli ZHANG Carbon Neutrality Research Center Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing100029China University of Chinese Academy of Sciences Beijing 100049China

We present characterizations of the dynamic turbulence in the lower stratosphere measured by a new balloon-based system designed for detecting finer scale dynamic turbulence. The balloon-based system included a constant temperature anemometer(CTA) operating at a sampling rate of 2 k Hz at an ascent speed of 5 m s^(-1)(corresponding to a vertical resolution of 2.5 mm), an industrial personal computer, batteries, sensors for ambient temperature and humidity, an A/D converter, and others. The system was successfully launched to 24 km altitude over Bayannur City, Inner Mongolia Province. Results show the spatial intermittence of the turbulence layers, with clear boundaries between turbulent and nonturbulent regions. This is the first time that the dynamic turbulence spectrum down to the viscous sub-range has been obtained throughout the lower stratosphere over China. With that, the energy dissipation rates of dynamic turbulence could be calculated with high precision. The profile of the dissipation rates varied from 7.37 × 10^(-7) to 4.23 W kg^(-1) and increased with altitude in the stratosphere.

关键词： dynamic turbulence stratosphere balloon payload high spatial resolution dissipation rates Inner Mongolia

Multi-disciplinary design optimization with variable complexity modeling for a stratosphere airship

在线全文

学校读者我要写书评

暂无评论

Chinese Journal of Aeronautics 2019年第5期32卷 1244-1255页

作者： Shi YIN Ming ZHU Haoquan LIANG School of Aeronautic Science and Engineering Beihang University School of Automation Science and Electrical Engineering Beihang University

This paper proposes a hybrid architecture based on Multi-disciplinary Design Optimization(MDO) with the Variable Complexity Modeling(VCM) method, to solve the problem of general design optimization for a stratosphere airship. Firstly, MDO based on the Concurrent SubSpace Optimization(CSSO) strategy is improved for handling the subsystem coupling problem in stratosphere airship design which contains aerodynamics, structure, and energy. Secondly, the VCM method based on the surrogate model is presented for reducing the computational complexity in high-fidelity modeling without loss of accuracy. Moreover, the global-to-local optimization strategy is added to the architecture to enhance the process. Finally, the result gives a prominent stratosphere airship general solution that validates the feasibility and efficiency of the optimization architecture. Besides, a sensitivity analysis is conducted to outline the critical impact upon stratosphere airship design.

关键词： Multi-disciplinary design optimization Sensitivity analysis stratosphere airship Surrogate model Variable complexity modeling

Probability Distribution Function of a Forced Passive Tracer in the Lower stratosphere

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2007年第2期24卷 163-180页

作者：胡永云 Department of Atmospheric Sciences School of Physics Peking University

The probability distribution function （PDF） of a passive tracer, forced by a ＂mean gradient＂, is studied. First, we take two theoretical approaches, the Lagrangian and the conditional closure formalisms, to study the PDFs of such an externally forced passive tracer. Then, we carry out numerical simulations for an idealized random flow on a sphere and for European Center for Medium-Range Weather Forecasts （ECMWF） stratospheric winds to test whether the mean-gradient model can be applied to studying stratospheric tracer mixing in midlatitude surf zones, in which a weak and poleward zonal-mean gradient is maintained by tracer leakage through polar and tropical mixing barriers, and whether the PDFs of tracer fluctuations in midlatitudes are consistent with the theoretical predictions. The numerical simulations show that when diffusive dissipation is balanced by the mean-gradient forcing, the PDF in the random flow and the Southern-Hemisphere PDFs in ECMWF winds show time-invariant exponential tails, consistent with theoretical predictions. In the Northern Hemisphere, the PDFs exhibit non-Gaussian tails. However, the PDF tails are not consistent with theoretical expectations. The long-term behavior of the PDF tails of the forced tracer is compared to that of a decaying tracer. It is found that the PDF tails of the decaying tracer are time-dependent, and evolve toward flatter than exponential.

关键词： chaotic mixing probability distribution function stratosphere turbulence passive tracer

Parallel Comparison of the 1982/83,1997/98 and 2015/16 Super El Nios and Their Effects on the Extratropical stratosphere

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2017年第9期34卷 1121-1133页

作者： Jian RAO Rongcai REN Key Laboratory of Meteorological Disaster Ministry of Education (KLME)/Joint International Research Laboratory of Climate and Environment Change (ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science and Technology State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of Sciences

This study uses multiple sea surface temperature （SST） datasets to perform a parallel comparison of three super El Nifios and their effects on the stratosphere. The results show that, different from ordinary El Nifios, warm SST anomalies appear earliest in the western tropical Pacific and precede the super El Nifio peak by more than 18 months. In the previous winter, relative to the mature phase of El Nifio, as a precursor, North Pacific Oscillation-like circulation anomalies are observed. A Pacific-North America （PNA） teleconnection appears in the extratropical troposphere during the mature phase, in spite of the subtle differences between the intensities, as well as the zonal position, of the PNA lobes. Related to the negative rainfall response over the tropical Indian Ocean, the PNA teleconnection in the winter of 1997/98 is the strongest among the three super El Nifios. The northern winter stratosphere shows large anomalies in the polar cap temperature and the circumpolar westerly, if the interferences from other factors are linearly filtered from the circulation data. Associated with the positive PNA response in a super El Nino winter, positive polar cap temperature anomalies and circumpolar easterly anomalies, though different in timing, are also observed in the mature winters of the three super El Nifios. The stratospheric polar vortex in the next winter relative to the 1982/83 and 1997/98 events is also anomalously weaker and warmer, and the stratospheric circulation conditions remain to be seen in the coming winter following the mature phase of the 2015/16 event.

关键词： super El Nifio Pacific-North America （PNA） teleconnection stratosphere proceeding winter

HCl Quasi-Biennial Oscillation in the stratosphere and a Comparison with Ozone QBO

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2005年第5期22卷 751-758页

作者：陈月娟施春华郑彬 School of Earth and Space Sciences University of Science and Technology of China Institute of Tropical and Marine Meteorology China Meteorological Administration

HALOE data from 1992 to 2003 are used to analyze the interannual variation of the HCl volume mixing ratio and its quasi-biennial oscillation （QBO） in the stratosphere, and the results are compared with the ozone QBO. Then, the NCAR two-dimensional interactive chemical, dynamical and radiative model is used to study the effects of the wind QBO on the distribution and variation of HCl in the stratosphere. The results show that the QBO signals in the HCl mixing ratio are mainly at altitudes from 50 hPa to 5 hPa; the larger amplitudes are located between 30 hPa and 10 hPa; a higher HCl mixing ratio usually corresponds to the westerly phase of the wind QBO and a lower HCl mixing ratio usually corresponds to the easterly phase of the wind QBO in a level near 20 hPa and below. In the layer near 10 hPa-5 hPa, the phase of the HCl QBO reverses earlier than the phase of the wind QBO; the QBO signals for HCl in the extratropics are also clear, but with reversed phase compared with those over the Tropics. The HCl QBO signals at 30°N are clearer than those at 30°S; the QBOs for HCl and ozone have a similar phase at the 50 hPa-20 hPa level while they are out of phase near 10 hPa; the simulated structures of the HCl QBO agree well with observations. The mechanism for the formation of the HCl QBO and the reason for differences in the vertical structure of the HCl and ozone QBO are attributed to the transport of HCl and ozone by the wind QBO-induced meridional circulation.

关键词： HCl quasi-biennial oscillation stratosphere

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 210044, China 2. LAGEO, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China) 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 2001 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.

Observed Long-and Short-lived North Atlantic Oscillation Events:Role of the stratosphere

在线全文

同方期刊数据库

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2020年第12期37卷 1338-1358页

作者： Jie SONG Jingjing ZHAO State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China College of Earth and Planetary Sciences University of Chinese Academy of SciencesBeijing 100049China

Utilizing three different sets of reanalysis data,this study examines the long-and short-lived observed positive North Atlantic Oscillation(NAO)events(referred to as NAO+_LE and NAO+_SE)and long-and short-lived observed negative NAO events(referred to as NAO−_LE and NAO−_SE).Composite results indicate that the NAO-like circulation anomalies associated with the long-lived NAO events can reach the stratosphere,while they are primarily confined to the troposphere in the short-lived NAO events.Thus,the coupling/connection of stratospheric and tropospheric circulation anomalies is much better(worse)in the long-lived(short-lived)NAO events.A series of modified stratospheric initial-value experiments conducted with a simplified model indicate that a better(worse)connection between stratospheric and tropospheric circulation anomalies in the initial-value fields tend to gradually induce the NAO-like tropospheric circulation anomalies in the troposphere on the subsequent days,and thus naturally elongate(reduce)the lifetimes of the original NAO events by altering the tropospheric synoptic eddy vorticity flux over the North Atlantic region.

关键词： North Atlantic Oscillation lifetimes stratosphere eddy forcing

Arctic oscillation and the antarcic oscillation modes in the atmospheric stratosphere

在线全文

学校读者我要写书评

暂无评论

Acta Oceanologica Sinica 2005年第6期24卷 46-53页

作者： QU Weizheng HUANG Fei ZHAO Jinping YANG Liang HE Hui DENG Shenggui CAO Yong Physical Oceanography Laboratory Ocean University of China Qingdao 266003 China Physical Oceanography Laboratory Ocean University of China Qingdao 266003 China Physical Oceanography Laboratory Ocean University of China Qingdao 266003 China Physical Oceanography Laboratory Ocean University of China Qingdao 266003 China Physical Oceanography Laboratory Ocean University of China Qingdao 266003 China Physical Oceanography Laboratory Ocean University of China Qingdao 266003 China Physical Oceanography Laboratory Ocean University of China Qingdao 266003 China

On the basis of the EOF analysis of global geopotential height anomaly (GHA)field at 10 hPa level, the arctic oscillation (AO) and the means antarctic oscillation (AAO) can bedetected more obviously at the upper level of atmosphere than the AO or the AAO in surface layer.Unlike the hemisphere pattern of the AO and the AAO in the surface lager given by previous authors,the AO or the AAO in the stratosphere has its global features. The zonal oscillations—the SouthernOscillation (SO) and the north oscillation (NO) in atmospheric surface layer become less clear inthe upper air. The first mode (AO mode, abbreviated to AOM hereafter) and the second mode (AAO mode,abbreviated to AAOM hereafter) respectively have 41.47% and 27.04% of the total variancecontribution. The cumulative variance contribution of the first two modes reaches 68.51%. These twomodes are the main components for the interdecadal or decadal oscillation in the stratosphere. Inaddition, there still exist two kinds of oscillation patterns with less probability, namely, thesymmetric pattern at mid-high latitudes in the Southern Hemisphere and the asymmetric pattern.Spectral analysis shows that the AOM and the AAOM all have a spectral peak for 22 a period, beingconsistent with the periodic variations of the solar magnetic field, and a peak for 11 a period,being consistent with the period of the numbers of sunspots. Step filter analysis shows that theinfluencing factor for the upper atmospheric oscillation is the solar activity. The fluctuation ofthe solar magnetic field is the more influencing factor than the variation of the sunspot number.

关键词： solar activity arctic oscillation antarctic oscillation stratosphere

Study on the Trace Species in the stratosphere and Their Impact on Climate

在线全文

学校读者我要写书评

暂无评论

Advances in Atmospheric Sciences 2006年第6期23卷 1020-1039页

作者：陈月娟周任君施春华毕云 School of Earth and Space Sciences University of Science and Technology of ChinaHefei 230026

The trace gases （O3, HCl, CH4, H2O, NO, NO2） in the stratosphere play an important role, not only in the photochemical processes in which the ozone layer destroyed, but also in the radiative processes. In this paper, we review the works on the distribution and variation of the trace gases in the stratosphere and their impact on climate, which have been carried out at the University of Science and Technology of China in the recent 20 years. The Halogen Occultation Experiment （HALOE） data were used to analyse the distribution and variation of the mixing ratio of these trace gases and the temperature trends in the stratosphere in the most recent decade. And the reanalyzed National Centers of Environmental Prediction （NCEP）/NCAR data were also used to give the temperature trends and compared with the results from HALOE data. Numerical simulations were also carried out to study the impact of ozone depletion on the global climate. In this review, the distributions of the trace gases, especially those over the Qinghai-Xizang Plateau, are discussed, and the variations and trends for the trace gases in various levels in the stratosphere have been given for the most recent decade. The temperature variation and the cooling trend obtained from HALOE data in the middle and lower stratosphere for the last 13 years are significant, which agree well with the results from NCEP/NCAR data. While the temperature trend in the upper stratosphere in this period do not seem to have much cooling. The numerical simulations show that either the Antarctic ozone hole or the ozone valley over Qinghai-Xizang Plateau affect not only the temperature and circulation in the stratosphere, but also the temperature, pressure and wind fields in the troposphere, then lead to the global climate change.

关键词： stratosphere trace gases global climate

THE PREVIOUS stratosphere CHARACTERISTICS OF EL NINO

在线全文

学校读者我要写书评

暂无评论

Chinese Science Bulletin 1992年第10期37卷 842-846页

作者：顾润源刘晓东王玉玺 Lanzhou University Lanzhou 730000PRC Lanzhou Institute of Plateau Atmospheric Physics Lanzhou 730000PRC

El Nio usually happens with the anomaly of general circulation of atmosphere and climate in the world. El Nio has close statistical relationships with the rainfall decrease in Africa, the monsoon weakening in India, and the Australian aridity. In recent years, it is also pointed out that there is a certain correlation between El Nio and Chinese climate and weather. In El Nio year, the summer temperature is lower than normal in the northeast of China. The happening and development of El Nio can also cause the anomalies of rainfalls in Changjiang River valley and the typhoon in China. Therefore, the fore-

关键词： El Nino stratosphere departure