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A dipole mode at thermocline layer in the tropical Indian Ocean

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Acta Oceanologica Sinica 2003年第1期22卷 15-24页

作者：田纪伟刘慧卿钱维宏 Physical Oceanography Laboratory Ocean University of China (Ocean University of Qingdao)Qingdao 266003China department of atmospheric sciences Peking UniversityBeijing 100871China

Temperature data at different layers of the past 45 years were studied and we found adiploe mode in the thermocline layer (DMT): anomalously cold sea temperature off the coast of Sumatra and warm sea temperature in the western Indian Ocean. First, we analyzed the temperature and the temperature anomaly (TA) along the equatorial Indian Ocean in different layers. This shows that stronger cold and warm TA signals appeared at subsurface than at the surface in the tropical Indian O-cean. This result shows that there may be a strong dipole mode pattern in the subsurface tropical Indian Ocean. Secondly we used Empirical Orthogonal Functions (EOF) to analyze the TA at thermocline layer. The first EOF pattern was a dipole mode pattern. Finally we analyzed the correlations between DMT and surface tropical dipole mode (SDM), DMT and Nino 3 SSTA, etc. and these correlations are strong.

关键词： Temperature anomaly dipole mode in thermocline layer tropical Indian Ocean empirical orthogonal function

Characteristics and Seasonal Variations of PM2.5, PM10, and TSP Aerosol in Beijing

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Biomedical and Environmental sciences 2006年第6期19卷 461-468页

作者： WEN-JIE ZHANG YE-LE SUN GUO-SHUN ZHUANG DONG-QUN XU Center for atmospheric Environmental Study Department of Chemistry Beijing Normal University Beijing 100875 China Institute for Environmental Health and Related Products Safety China CDC Beijing 100021 China Center for atmospheric Chemistry Study Department of Environmental Science ＆ Engineering Fudan University Shanghai 200433 China The Institute of atmospheric Physics CAS LAPC Beijing 100029 China

Objective To investigate the seasonal characteristics and the sources of elements and ions with different sizes in the aerosols in Beijing. Methods Samples of particulate matters （PM2,5）, PM10, and total suspended particle （TSP） aerosols were collected simultaneously in Beijing from July 2001 to April 2003. The aerosol was chemically characterized by measuring 23 elements and 18 water-soluble ions by inductively coupled plasma-atomic emission spectroscopy （ICP-AES） and ion chromatography （IC）, respectively. Results The samples were divided into four categories： spring non-dust, spring dust, summer dust, and winter dust. TSP, PM10, and PM2.5 were most abundant in the spring dust, and the least in summer dust. The average mass ratios of PM〉10, PM2,5-10, and PM2.5 to TSP confirmed that in the spring dust both the large coarse （PM〉10） and fine particles （PM2.5） contributed significantly in summer PM2.5, PM2,5-10, and PM〉10 contributed similar fractions to TSP, and in winter much PM2.5. The seasonal variation characteristics of the elements and ions were used to divide them into four groups： crustal, pollutant, mixed, and secondary. The highest levels of crustal elements, such as AI, Fe, and Ca, were found in the dust season, the highest levels of pollutant elements and ions, such as As, F, and Cl^-, were observed in winter, and the highest levels of secondary ions （SO4^2-, NO3^-, and NH4^＋） were seen both in summer and in winter. The mixed group （Eu, Ni, and Cu） showed the characteristics of both crustal and pollutant elements. The mineral aerosol from outside Beijiug contributed more than that from the local part in all the reasons but summer, estimated using a newly developed element tracer technique.

关键词： PM2,5 PM10 TSP Seasonal variation Sources

STUDIES ON RETRIEVAL OF THE TURBULIVITY OF atmospheric BOUNDARY LAYER

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Journal of Hydrodynamics 2006年第2期18卷 177-183页

作者： WANG Ting-fang HUANG Si-xun XIANG Jie Institute of Meteorology PLA University of Science and Technology Nanjing 211101 China Center of Meteorology Chengdu Air Force Chengdu 610041China Key Laboratory of Meso-Scale Severe Weather/MOE Depariment of Atmospheric Sciences Nanjing UniversityNanjing 210093 China

The variational adjoint method was applied to retrieving the turbulivity of the atmospheric Ekman boundary layer along with the regularization principle, The validity of the method was verified by using the idealized data, and then the turbulivity profile and the geostrophic wind profile were retrieved through it for real observational wind filed data.

关键词： atmospheric boundary layer turbulivity,Tikhonov regularization principle parameter retrieval

Theoretical analyses and numerical experiments of variational assimilation for one-dimensional ocean temperature model with techniques in inverse problems

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Science china Earth sciences 2004年第7期47卷 630-638页

作者： HUANG Sixun1,2, HAN Wei1 & WU Rongsheng2 1. P. O. Box 003, Nanjing 211101,china 2. Key Laboratory of Meso-Scale Severe Weather /MOE, department of atmospheric sciences, Nanjing university, Nanjing 210093, china Correspondence should be addressed to Huang Sixun Nanjing China Key Laboratory of Meso-Scale Severe Weather /MOE Department of Atmospheric Sciences Nanjing University Nanjing China

In the present work, the data assimilation problem in meteorology and physical oceanography is re-examined using the variational optimal control approaches in combination with regularization techniques in inverse problem. Here the estimations of the initial condition, boundary condition and model parameters are performed simultaneously in the framework of variational data assimilation. To overcome the difficulty of ill-posedness, especially for the model parameters distributed in space and time, an additional term is added into the cost functional as a stabilized functional. Numerical experiments show that even with noisy observations the initial conditions and model parameters are recovered to an acceptable degree of accuracy.

关键词： ocean temperature model, variational data assimilation, regularization.

ARE THERE INTERANNUAL-TO-DECADAL SCALE OSCILLATIONS ASSOCIATED WITH SEA ICE-THERMOHALINE CIRCULATION INTERACTIONS IN A SIMPLE COUPLED ATMO-SPHERE-OCEAN-SEA ICE MODEL?

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气象科学 2000年第3期20卷 413-426页

作者： Zhaomin Wang Lawrence A.Mysak (department of atmospheric and Oceanic sciences and Centre for Climate and Global Change Research, McGill university,Montreal,Quebec,Canada,H3A 2K6) department of atmospheric and Oceanic sciences and Centre for Climate and Global Change Research McGill UniversityMontrealQuebecCanadaH3A 2K6

A thermodynamic sea ice model is coupled to an annual mean,zonally averaged,one basin ocean thermohaline circulation(THC)model and an energy moisture balance model(EMBM)of the atmosphere in order to investigate the interactions between sea ice and the *** first,the coupled sea ice ocean model is run under mixed boundary conditions(MBCs),which precludes feedbacks from the *** occur on timescales ranging from interannual to decadal and are spatially confined to the sinking(deep convection)region of the *** negative feedback loop that explains these oscillations is essentially the same as proposed by Zhang,Lin and Greatbatch.A scale analysis shows that in this model only the process of deep convection can occur on interannual to decadal timescales,whereas changes in the basin scale THC occur on centennial to millennial *** means that interactions between sea ice and the large scale THC on interannual to decadal timescales are not possible under ***,after the atmosphere model is coupled to the above sea ice ocean model,the above oscillations due to the interactions between sea ice and deep convection are suppressed because of the following sequence of processes(positive feedback loop):when the ice retreats in a fully coupled system,the atmosphere warms up at high latitudes and hence the ice surface temperature increases,which then causes a further ice retreat.

关键词： Decadal acale oscillations Sea ice thermohaline Atmosphere ocean sea ice model

Edge Effect Correction in the S-A Method for Geochemical Anomaly Separation

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Journal of china university of Geosciences 2004年第4期15卷 379-387页

作者： Ge Yong department of Earth and atmospheric Science, York university, Toronto, ON, M3J 1P3, Canada State Key Laboratory of Resources and Environmental Information System, Institute of Geographic sciences & Natural Resources Research, Chinese Academy of sciences, Beijing 100101, china Cheng Qiuming department of Earth and atmospheric Science, York university, Toronto, ON, M3J 1P3, Canada Earth Systems and Mineral Resource Engineering Lab, china university of Geosciences, Wuhan 430074, china Zhang Shenyuan department of Earth and atmospheric Science, York university, Toronto, ON, M3J 1P3, Canada department of Resource and Earth Science, china university of Mining & Technology, Beijing 100083, china department of Earth and atmospheric Science York University Toronto ON M3J 1P3 Canada State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences & Natural Resources Research Chinese Academy of SciencesBeijing 100101China department of Earth and atmospheric Science York University Toronto ON M3J 1P3 Canada Earth Systems and Mineral Resource Engineering Lab China University of Geosciences Wuhan 430074 China department of Earth and atmospheric Science York University Toronto ON M3J 1P3 Canada department of Resource and Earth Science China University of Mining & Technology Beijing 100083 China

Anomaly separation using geochemical data often involves operations in the frequency domain, such as filtering and reducing noise/signal ratios. Unfortunately, the abrupt edge truncation of an image along edges and holes (with missing data) often causes frequency distribution distortion in the frequency domain. For example, bright strips are commonly seen in frequency distribution when using a Fourier transform. Such edge effect distortion may affect information extraction results; sometimes severely, depending on the edge abruptness of the image. Traditionally, edge effects are reduced by smoothing the image boundary prior to applying a Fourier transform. Zero-padding is one of the most commonly used smoothing methods. This simple method can reduce the edge effect to some degree but still distorts the image in some cases. Moreover, due to the complexity of geoscience images, which can include irregular shapes and holes with missing data, zero-padding does not always give satisfactory results. This paper proposes the use of decay functions to handle edge effects when extracting information from geoscience images. As an application, this method has been used in a newly developed multifractal method (S-A) for separating geochemical anomalies from background patterns. A geochemical dataset chosen from a mineral district in Nova Scotia, Canada was used to validate the method.

关键词： edge effect correction fractal modeling spatial information extraction zero-padding decay functions.

藏北高原典型草甸下垫面与HEIFE沙漠区辐射平衡气候学特征对比分析

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太阳能学报 2003年第4期24卷 453-460页

作者：钱泽雨胡泽勇杜萍马耀明石川裕彦中国科学院寒区旱区环境与工程研究所兰州730000 兰州大学资源环境学院大气科学系兰州730000 日本京都大学防灾研究所日本京都府宇治市

利用中日合作"全球能量与水分平衡试验青藏高原季风试验(GAME Tibet)"和中日合作"黑河地区地—气相互作用野外观测实验研究(HEIFE)"IOP、FOP资料,计算分析了藏北高原典型草甸下垫面安多站和HEIFE沙漠站的辐射平衡各相关特征量时频变化... 详细信息

利用中日合作"全球能量与水分平衡试验青藏高原季风试验(GAME Tibet)"和中日合作"黑河地区地—气相互作用野外观测实验研究(HEIFE)"IOP、FOP资料,计算分析了藏北高原典型草甸下垫面安多站和HEIFE沙漠站的辐射平衡各相关特征量时频变化的气候学特征。结果表明:无论是高原安多站还是黑河沙漠站,夏季均出现超太阳常数现象(只是安多更为明显);总辐射、大气逆辐射、地表长波辐射、地表有效辐射和地表辐射平衡等的日变化(晴天)无论是安多站还是沙漠站均表现为早晚出现最小值而正午附近(地方时)达到最大值,而地表反照率的日变化(晴天)相反表现为早晚大而正午附近小的规律;上述各分量均表现有程度不等的季节变化规律:总辐射、大气逆辐射、地表长波辐射和地表辐射平衡均表现为夏半年增大达到最大值百而冬半年降低量出现最小值;另外,大气长波辐射、地表有效辐射和地表反照率在沙漠站的年际变化的振幅较安多站更为显著和有规律。

关键词：青藏高原 HEIFE 草甸下垫面辐射平衡气候学特征

Propagation of planetary-scale zonal mean wind anomalies and polar oscillations

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Science Bulletin 2012年第20期 2619-2627页

作者： QIAN WeiHong & LIANG HaoYuan department of atmospheric and Oceanic sciences,School of Physics,Peking university,Beijing 100871,china

Global atmospheric variables can be physically decomposed into four components:(1) the zonal time averaged climate symmetric component,(2) the time averaged climate asymmetric,(3) the zonal-mean transient symmetric anomaly,and (4) the transient asymmetric *** study analyzes the relationships between the intra-seasonal and inter-annual variability of planetary scale decomposed zonal and meridional winds in the tropopause,and oscillations such as those from the El Ni o-Southern Oscillation (ENSO),the Arctic Oscillation (AO) and the Antarctic Oscillation (AAO).The tropical inter-annual zonal mean wind anomalies in the tropopause are linked with the ENSO cycle and can propagate into the subtropics,mid-latitudes,and polar front regions via abnormal meridional vertical ***,tropical intra-seasonal (40-60-d) zonal wind anomalies can reach the subtropics and *** polar intra-seasonal zonal wind anomalies in the tropopause can propagate toward high-latitude ***,the AO and the AAO are the result of the interaction and propagation of these planetary scale zonal wind anomalies.

关键词： physical decomposition El Ni o-Southern Oscillation Arctic Oscillation Antarctic Oscillation planetary scale intraseasonal oscillations

Numerical prediction experiment on Typhoon Maggie (9903)

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Acta Oceanologica Sinica 2001年第2期20卷 171-182页

作者： Fong Soi Kun, Wu Chisheng, Hao I Pan, Lam Kin Hang Ku Chi Meng, Wang Anyu, Lin Wenshi (1. Macao Meteorological and Geophysical Bureau, Macao, china 2. department of atmospheric sciences, Zhongshan university, Guangzhou 510275, china) Macao Meteorological/Geophysical Bur Department of Atmospheric Sciences Zhongshan University Macao Macau

The movement of Typhoon Maggie (9903) in June 1999 is one of the rare cases ever seen in the history. At 00U on June 6 Maggie was located at about 70 km to the southwest of Taiwan. When it arrived at the coastal region of Shanwei City (22.8N, 116.5E), it turned suddenly to move southwestward along the southern china coastal line. De June 7 Maggie finally turned to move northward, making landfall to the north of Shangchuan Island. The experimental numerical prediction system on typhoon movement that was designed based on MM5 is proved quite successful for the 48h prediction of Maggie's movement and rainfall. The mean prediction error of typhoon track is 81 km for 0-24 h and 74 km for 24-48 h. The location of typhoon center in the initial field of the model is approximately 100 km away from the actual observations. In order to modify the location of typhoon center, a bogus typhoon was intro- duced into the model and the prediction of typhoon track was improved in 0-24 h time interval. But the prediction error was enlarged in 24-36 h. We also performed a sensitivity experiment of changing the land of southern china into the ocean. It is found that the orientation of South china coastal line and the topography have no obvious effect on the movement of Typhoon Maggie.

关键词： Typhoon movement numerical prediction South china coastal line