Final report of project Mamex     

Paul E. Carlson 《大气与海洋》2013,51(2):67-69

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Measurements of CO,HCN, and C2H6 Total Columns in Smoke Plumes Transported from the 2010 Russian Boreal Forest Fires to the Canadian High Arctic     

C. Viatte  K. Strong  C. Paton-Walsh  J. Mendonca  N. T. O'Neill  J. R. Drummond 《大气与海洋》2013,51(5):522-531

In August 2010, simultaneous enhancements of aerosol optical depth and total columns of carbon monoxide (CO), hydrogen cyanide (HCN), and ethane (C₂H₆) were observed at the Polar Environment Atmospheric Research Laboratory (PEARL, 80.05°N, ?86.42°W, 0.61 km above sea level, Eureka, Nunavut, Canada). Moderate Resolution Imaging Spectroradiometer (MODIS) hot spots, Ozone Monitoring Instrument (OMI) aerosol index maps, and Hybrid Single Particle Lagrangian Integrated Trajectory (HYSPLIT) back-trajectories were used to attribute these enhancements to an intense boreal fire event occurring in Russia. A ground-based Fourier Transform InfraRed (FTIR) spectrometer at PEARL provided vertically integrated measurements of trace gases transported in smoke plumes. We derived HCN and C₂H₆ equivalent emission ratios with respect to CO of 0.0054?±?0.0022 and 0.0108?±?0.0036, respectively, and converted them into equivalent emission factors of 0.66?±?0.27 g kg^?1 and 1.47?±?0.50 g kg^?1 (in grams of gas per kilogram of dry biomass burnt, with one-sigma uncertainties). These emission factors add new observations to the relatively sparse datasets available and can be used to improve the simulation of biomass burning fire emissions in chemical transport models. These emission factors for the boreal forest are in agreement with the mean values recently reported in a compilation study.  相似文献   

Basaltic thermals and Subplinian plumes: Constraints from acoustic measurements at Shishaldin volcano, Alaska     

Sylvie Vergniolle  Jacqueline Caplan-Auerbach 《Bulletin of Volcanology》2006,68(7-8):611-630

The 1999 basaltic eruption of Shishaldin volcano (Alaska, USA) included both Strombolian and Subplinian activity, as well as a “pre-Subplinian” phase interpreted as the local coalescence within a long foam in the conduit. Although few visual observations were made of the eruption, a great deal of information regarding gas velocity, gas flux at the vent and plume height may be inferred by using acoustic recordings of the eruption. By relating acoustic power to gas velocity, a time series of gas velocity is calculated for the Subplinian and pre-Subplinian phases. These time series show trends in gas velocity that are interpreted as plumes or, for those signals lasting only a short time, thermals. The Subplinian phase is shown to be composed of a thermal followed by five plumes with a total expelled gas volume of .The initiation of the Subplinian activity is probably related to the arrival of a large overpressurised bubble close to the top of the magma column. A gradual increase in low-frequency (0.01–0.5 Hz) signal prior to this “trigger bubble” may be due to the rise of the bubble in the conduit. This delay corresponds to a reservoir located at ≈3.9 km below the surface, in good agreement with studies on other volcanoes.The presence of two thermal phases is also identified in the middle of the pre-Subplinian phase with a total gas release of and . Gas velocity at the vent is found to be and for the Subplinian plumes and the pre-Subplinian thermals respectively.The agreement is very good between estimates of the gas flux from modelling the plume height and those obtained from acoustic measurements, leading to a new method by which eruption physical parameters may be quantified. Furthermore, direct measurements of gas velocity can be used for better estimates of the flux released during the eruption.  相似文献   

Flow-induced vibration analysis of elastic propellers in a cyclic inflow: An experimental and numerical study     

《Applied Ocean Research》2017

In this paper, the flow-induced vibrations of marine propellers in cyclic inflows are investigated both experimentally and numerically. A Laser-Doppler velocimetry (LDV) system is used to measure the axial flow velocity distributions produced by the seven-cycle wake screen in the water tunnel. A customized underwater slip ring and a single axis accelerometer sealed by silicon sealant are employed to measure the acceleration responses of rotating propeller blade. Numerical simulations of pressure fluctuations on the blades are performed using large eddy simulation (LES), while the forced vibrations of the propeller blades are obtained by a combined finite element and boundary element method. Experimental and numerical results are presented for two model propellers with the same geometries and different flexible properties, which show that the propeller blade vibrates at a frequency which is seven times as large as the axial passing frequency (APF) in the seven-cycle inflow. Moreover, the propeller blades are observed to resonance when the 7 APF excitation frequency is equal to the fundamental frequency of the propellers. The results indicate that both the inflow feature and the modal characteristic of blades contribute to flow-induced vibrations of elastic propellers.  相似文献   

实验室信息管理系统在海洋环境监测中的应用          下载免费PDF全文

赵仕兰  孙禾琳  丁丽  姚子伟 《海洋开发与管理》2017,34(3):72-75

实验室信息管理系统是提升实验室运转效率及质量管理水平、促进监测业务工作与信息规范化接轨的重要手段。目前,我国已开启实验室信息化管理的新阶段,各类实验室正大力推广与建设实验室信息管理系统。海洋环境监测业务具有其自身特色,因此广谱性的实验室信息管理系统无法满足海洋环境监测实验室信息管理系统的模块设置与功能需求。文章综合分析了我国海洋环境监测业务工作的特点,提出海洋环境监测实验室信息管理系统的设计需求,特别突出了质量管理与质量控制在实验室信息管理系统中的功能与设计要求,以期为各级海洋监测机构建设实施实验室信息管理系统提供参考。  相似文献   

植被冠层日光诱导叶绿素荧光塔基自动观测方法及系统介绍     

李朝晖  张永光  张乾  吴云飞  张小康  章钊颖 《遥感学报》2021,25(5):1152-1168

植物光合作用所提供的物质和能量是人类赖以生存的关键因素,而日光诱导叶绿素荧光SIF(Sun-Induced chlorophyll Fluorescence)是植物光合作用的副产品,与光合作用关系密切,深入研究SIF将对于更加深入理解光合作用机制有着重要的意义.目前,近地面植被冠层SIF遥感观测发展迅速,但不同SIF观...  相似文献