Meteorology and haze structure during AGASP-II,Part 1: Alaskan Arctic flights, 2–10 April 1986     

G. A. Herbert  R. C. Schnell  H. A. Bridgman  B. A. Bodhaine  S. J. Oltmans  G. E. Shaw 《Journal of Atmospheric Chemistry》1989,9(1-3):17-48

The second Arctic Gas and Aerosol Sampling Program (AGASP-II) was conducted across the Alaskan and Canadian Arctic in April 1986, to study the in situ aerosol, and the chemical and optical properties of Arctic haze. The NOAA WP-3D aircraft, with special instrumentation added, made six flights during AGASP-II. Measurements of wind, pressure, temperature, ozone, water vapor, condensation nuclei (CN) concentration, and aerosol scattering extinction (b_sp) were used to determine the location of significant haze layers. The measurements made on the first three flights, over the Arctic Ocean north of Barrow and over the Beaufort Sea north of Barter Island, Alaska are discussed in detail in this report of the first phase of AGASP II. In the Alaskan Arctic the WP-3D detected a large and persistent region of haze between 960 and 750 mb, in a thermally stable layer, on 2, 8, and 9 April 1986. At its most dense, the haze contained CN concentrations >10,000 cm^–3 and b_sp of 80×10^–6 m^–1 suggesting active SO₂ to H₂SO₄ gas-to-particle conversion. Calculations based upon observed SO₂ concentrations and ambient relative humidities suggest that 10⁴–10⁵ small H₂SO₄ droplets could have been produced in the haze layers. High concentrations of sub-micron H₂SO₄ droplets were collected in haze. Ozone concentrations were 5–10 ppb higher in the haze layers than in the surrounding troposphere. Outside the regions of haze, CN concentrations ranged from 100 to 400 cm^–3 and b_sp values were about (20–40)×10^–6 m^–1. Air mass trajectories were computed to depict the air flow upwind of regions in which haze was observed. In two cases the back trajectories and ground measurements suggested the source to be in central Europe.  相似文献   

论冷战后国际政治的基本态势及世界政治地理的研究任务与重点     

王国梁  刘养洁 《世界地理研究》1997,(2)

本文立足于政冶地理学的基本理论，从冷战后国际政治基本态势的分析入手，系统阐述了当前世界政治地理研究的基本任务，并在此基础上提出了当前及今后一段时期世界政治地理研究应以世界政治地理格局的演变、国家形成与消亡的地理政治背景、国际领土及边界争端和各国行政区划的基本原则为重点。  相似文献   

Book Reviews     

《The Professional geographer》1997,49(3):372-389

Aryeetey-Attoh, SamuelGeography of Sub-Saharan Africa Chew, Sing C. and Denemark, Robert A.(eds) The Underdevelopment of Development: Essays in Honor of Andre Gunder Frank Chinn, Jeff and Kaiser, RobertRussians as the New Minority: Ethnicity and Nationalism in the Soviet Successor States Curtis, Sarah and Taket, AnnHealth and Societies: Changing Perspectives Dudley, Nigel; Jeanrenaud, Jean-Paul and Sullivan, FrancisBad Harvest? The Timber Trade and the Degradation of the World's Forests Ellis, Steven and Mellor, AnthonySoils and Environment Gradus, Yehuda and Lithwick, Harvey (eds)Frontiers in Regional Development Green, Milford B. and McNaughton, Rod B. (eds)The Location of Foreign Direct Investment: Geographic and Business Approaches Greenberg, Michael and Schneider, DonaEnvironmentally Devastated Neighborhoods: Perceptions, Policies, and Realities Griffiths, Ieuan Ll.The African Inheritance Harrison, Lynn C. and Husbands, Winston (eds)Practicing Responsible Tourism: International Case Studies in Tourism Planning, Policy, and Development Jensen, John R.Introductory Digital Image Processing: A Remote Sensing Perspective Pacione, MichaelGlasgow: The Socio-Spatial Development of the City Platt, Rutherford H.Land Use and Society: Geography, Law, and Public Policy Rhodes, Martin (ed.)The Regions and the New Europe: Patterns in Core and Periphery Development Salant, Priscilla and Waller, Anita J.Guide to Rural Data Schnell, Izhak; Sofer, Michael and Drori, Israel Arab Industrialization in Israel: Ethnic Entrepreneurship in the Periphery Shelley, Fred M.; Archer, J. Clark; Davidson, Fiona M. and Brunn, Stanley D.Political Geography of the United States Taffe, Edward J.; Gauthier, Howard L. and O'Kelly, Morton E.Geography of Transportation  相似文献   

Late Cretaceous planktonic foraminifera from Kerguelen Plateau (ODP Leg 183): new data to improve the Southern Ocean biozonation     

Maria Rose Petrizzo 《Cretaceous Research》2001,22(6):829

An almost complete Upper Cretaceous sedimentary sequence recently recovered on the Kerguelen Plateau (southern Indian Ocean) during ODP Leg 183 was analysed for planktonic foraminifera in order to refine and integrate the zonal schemes previously proposed for the Southern Ocean area. Detailed biostratigraphic analysis carried out on holes 1135A, 1136A and 1138A (poleward of 50°S palaeolatitude during Late Cretaceous time) has allowed recognition of low and mid–high latitude bioevents, useful for correlation across latitudes, in addition to known Austral bioevents. The low latitude biozonation can be applied to Turonian sediments, because of the occurrence of Helvetoglobotruncana helvetica, which marks the boundary between Whiteinella archaeocretacea and Helvetoglobotruncana helvetica zones. The base of the Whiteinella archeocretacea Zone falls within the uppermost Cenomanian–Turonian black shale level in Hole 1138A. The stratigraphic interval from upper Turonian to uppermost Santonian can be resolved using bioevents recognized in the mid–high latitude sections. They are, in stratigraphic order: the last occurrence of Falsotruncana maslakovae in the Coniacian, the first occurrence of Heterohelix papula at the Coniacian/Santonian boundary, the extinction of the marginotruncanids in the late Santonian, and the first occurrence of Globigerinelloides impensus in the latest (?) Santonian. The remainder of the Late Cretaceous fits rather well in the Austral zonal scheme, except that Globigerinelloides impensus exhibits a stratigraphic range in agreement with its record at the mid–high latitude sections and extends further downwards than previously recorded at southern sites. Therefore, despite the poor recovery in certain intervals and the presence of several hiatuses of local and regional importance as revealed by correlation among holes, a more detailed zonal scheme has been obtained (mainly for the less resolved Turonian–Santonian interval). Remarks on some species often overlooked in literature are also provided.  相似文献   

On the meridional circulation and balance of momentum in the Southern Ocean of POP     

Dirk Olbers  Vladimir O. Ivchenko 《Ocean Dynamics》2001,52(2):79-93

 The circulation of the Southern Ocean is studied in the eddy-resolving model POP (Parallel Ocean Program) by an analysis of zonally integrated balances. The TEM formalism (Transformed Eulerian Mean) is extended to include topography and continental boundaries, thus deviations from a zonally integrated state involve transient and standing eddies. The meridional circulation is presented in terms of the Eulerian, eddy-induced, and residual streamfunctions. It is shown that the splitting of the meridional circulation into Ekman and geostrophic transports and the component induced by subgrid and Reynolds stresses is identical to a particular form of the zonally integrated balance of zonal momentum. In this balance, the eddy-induced streamfunctions represent the interfacial form stresses by transient and standing eddies and the residual streamfunction represents the acceleration of the zonal current by density fluxes in a zonally integrated frame. The latter acceleration term is directly related to the surface flux of density and interior fluxes due to the resolved and unresolved eddies. The eddy-induced circulation is extremely vigorous in POP. In the upper ocean a shallow circulation, reversed in comparison to the Deacon cell and mainly due to standing eddies, appears to the north of Drake Passage latitudes, and in the Drake Passage belt of latitudes a deep-reaching cell is induced by transient eddies. In the resulting residual circulation the Deacon cell is largely cancelled and the residual advection of the zonal mean potential density is balanced by diapycnal eddy and subgrid fluxes which are strong in the upper few hundred meters but small in the ocean interior. The balance of zonal momentum is consistent with other eddy-resolving models; a new aspect is the clear identification of density effects in the zonally integrated balance. We show that the wind stress and the stress induced by the residual circulation drive the eastward current, whereas both eddy species result in a braking. Finally, we extend the Johnson–Bryden model of zonal transport to incorporate all relevant terms from the zonal momentum balance. It is shown that wind stress and induction by the residual circulation carry an eastward transport while bottom form stress and the stress induced by standing eddies yield westward components of transport. Received: 26 June 2001 / Accepted: 2 November 2001  相似文献   

铁砚磨穿指蘸墨 不用扬鞭自奋蹄——志《山西地震》创刊20周年     

袁正明 《山西地震》1993,(4)

回顾了《山西地震》创刊20年的历史,叙述了《山西地震》.编辑部在自身建设、执行科技期刊编排标准、为防震减灾事业默默奉献的情况,总结了经验、教训,指出了今后努力的方向.  相似文献   

遥测地震台网实时处理系统          下载免费PDF全文

刘凤祥 《地震工程学报》1994,16(3):73-77

本文介绍了采用程序驻留内存技术，利用系统的硬件中断和时钟中断，在微机上研制成功了实时处理系统。该系统具有前后台处理功能，能够在主机ＣＰＵ中同时运行多道程序，使数据采集、事件检测、数据转存、地震定位等均能进行实时处理。该系统可用于区域遥测地震台网和地方遥测地震台网的实时处理。  相似文献   

南京地区中暑天气条件指数研究预报   总被引：4，自引：1，他引：4  

焦艾彩  茅志成等 《气象科学》2001,21(2):246-252

本文采用南京地区1988－1997年每年夏季逐日各项气象要素及全市各医院同期重症中暑人数进行统计筛选出热夏年：1988年、1994年、1995年，对这三年中暑期重症中暑病例资料与气象资料进行相关统计分析，找出相关性较好的气象因子，经过方程化筛选，得出气温、湿度、气压、对中暑影响较大。三日滑动平均值为主要预报因子。设计中暑指数数学模式。根据中暑病病理、程度将中暑天气条件分三个等级，给出三个不同的中暑天气条件指数临界值，经过1998年、1999年试报验证，准确率较高，社会效益较好。该指数预测模式基本可行。  相似文献   

《气象报文自动处理分发系统》开发与应用     

吴占华  赵世文等 《山西气象》2001,(4):34-37

利用Visual Basic 6.0编程和mtimer定时进程控制技术，建立了《气象报文自动处理分发系统》。县（区）局测报员应用该系统的县局部分，能够实现报文编辑、转换、发送；市台预报员应用该系统的市局部分，可以实现报文收集、整理、打包传输。系统在一年多的实际业务应用中，简化了工作程序，实用性强，初步实现了气象信息传输的自动化。  相似文献   

中国科学院固体地球科学知识创新工程现状与发展态势     

周少平  张金东  范蔚茗 《地球科学进展》2002,17(5):776-781

回顾了中国科学院国家知识创新试点工程实施以来特别是启动阶段3年里固体地球科学知识创新工程试点各项工作的进展情况，包括项目与经费、创新成果、人才吸引、科研竞争力提升、院地合作推进等方面，分析和总结了中国科学院固体地球科学知识创新工程现状，并展望了固体地球科学知识创新工程若干重要发展态势。  相似文献