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31.
Size-Fractionated Primary Production Estimated by a Two-Phytoplankton Community Model Applicable to Ocean Color Remote Sensing 总被引:3,自引:0,他引:3
In order to estimate primary production from ocean color satellite data using the Vertical Generalized Production Model (VGPM; Behrenfeld and Falkowski, 1997), we propose a two-phytoplankton community model. This model is based on the two assumptions that changes in chlorophyll concentration result from changes of large-sized phytoplankton abundance, and chlorophyll specific productivity of phytoplankton tends to be inversely proportional to phytoplankton size. Based on the analysis of primary production data, P
opt
B
, which was one parameter in the VGPM, was modeled as a function of sea surface temperature and sea surface chlorophyll concentration. The two-phytoplankton community model incorporated into the VGPM gave good estimates in a relatively high productive area. Size-fractionated primary production was estimated by the two-phytoplankton community model, and P
opt
B
of small-sized phytoplankton was 4.5 times that of large-sized phytoplankton. This result fell into the ranges observed during field studies. 相似文献
32.
根据土力学原理 ,推导出一种在不考虑渗流力的情况下 ,确定斜坡临界滑动面和计算斜坡稳定系数的新方法。介绍了该方法在若干土石方工程中的应用实例。 相似文献
33.
基于GIS的无人机地面监控系统的设计与实现 总被引:3,自引:0,他引:3
在分析无人机领域飞行数据特征的基础上,设计实现了一套功能较为完善的无人机地面监控系统。该系统主要完成了无人机飞行状态实时显示、航线规划和航线回放等功能模块。系统借助于G IS技术,导入矢量形式的电子地图,利用丰富的地理信息来辅助实现无人机的地面监控,在V isual C 6.0开发环境下利用基于异步方式和事件驱动方式的串口通信实现了系统与地面控制站的通信,利用地图控制文件实现了地图数据的调度,利用显示缓存实现了视图实时刷新。经过实际联调,系统运行良好,实用性较好。 相似文献
34.
Long-term Sensor Drift Found in Recovered Argo Profiling Floats 总被引:5,自引:0,他引:5
We recovered three Argo profiling floats after 2 to 2.5 years of operation, and recalibrated their temperature, conductivity, and pressure sensors. The results demonstrate that these floats exhibited a significant drift in salinity of −0.0074 to −0.0125, primarily due to the conductivity sensor drift. Combined with the recalibration result for another previously recovered float, the indication is that the negative salinity drift increases nearly in proportion to the operating period of floats. The increasing rate is −0.0041 (±0.0015) year−1, which yields a salinity drift of −0.016 (±0.006) for the expected float lifetime of four years. The present result suggests that reducing the float surfacing time would improve the accuracy of the salinity measurements. 相似文献
35.
Takushi?NikiEmail author Taiki?Fujinaga Mariyo?F.?Watanabe Junji?Kinoshita 《Journal of Oceanography》2004,60(5):913-917
Solid-phase microextraction (SPME) is a simple, sensitive and less destructive method for the determination of dimethylsulfide
(DMS) in seawater. Combined with detection by gas chromatography-mass spectrometry (GC-MS), the method had sufficient sensitivity
(minimum detectable concentration of DMS was 0.05 nM), and practical levels of reproducibility (relative standard deviation
≤7%) and linearity (r
2 > 0.995) over a wide concentration range (0.5 to 910 nM). The protocol developed was applied to a Sagami Bay water sample
to determine concentrations of DMS and DMSP, and in situ DMSP-lyase activity. 相似文献
36.
Eddy Shedding from the Kuroshio Bend at Luzon Strait 总被引:16,自引:1,他引:16
TOPEX/POSEDIENT-ERS satellite altimeter data along with the mean state from the Parallel Ocean Climate Model result have been used to investigate the variation of Kuroshio intrusion and eddy shedding at Luzon Strait during 1992–2001. The Kuroshio penetrates into the South China Sea and forms a bend. The Kuroshio bend varies with time, periodically shedding anticyclonic eddies. Criteria of eddy shedding are identified: 1) When the shedding event occurs, there are usually two centers of high Sea Surface Height (SSH) together with negative geostrophic vorticity in the Kuroshio Bend (KB) area. 2) Between the two centers of high SSH there usually exists positive geostrophic vorticity. These criteria have been used to determine the eddy shedding times and locations. The most frequent eddy shedding intervals are 70, 80 and 90 days. In both the winter and summer monsoon period, the most frequent locations are 119.5°E and 120°E, which means that the seasonal variation of eddy shedding location is unclear. 相似文献
37.
In this paper we analyze seismic regime and earthquake depth distribution and correlation of seismicity and mud volcanism in the Azerbaijan and the Caspian Sea region. For the present region we have calculated accurate source locations, seismic activity, earthquake repetition and released earthquake energy parameters. It is shown that the active tectonic processes in the region are concentrated within the thick sedimentary cover that we consider as a general source of contemporary stress and a main structural element responsible for the origin of regional earthquakes. The correlation of seismicity and mud volcanism is of paragenetic character. 相似文献
38.
末次冰期-间冰期气候旋回研究是过去的全球变化(PAGES)研究的三大重点之一,通过孢粉分析和热释光断代建立了北京西山末次间冰期植被的演化序列,研究了该地区古植被与古环境的演化规律.研究表明:北京末次间冰期植被演化经过了6个阶段,从古到今依次对应深海沉积MIS5e,5d,5c,5b,5a及末次间冰期向末次冰期的过渡期.末次间冰期森林分布于北京西山,暖期发育以鹅耳枥属、榆属、栎属、松属、桦属为主的落叶阔叶林或针阔叶混交林,冷期则主要发育以松科、桦科、蔷薇科、毛茛科、蒿属、菊科为主的森林草甸草原或森林草原,末次间冰期气候由早期的暖湿经过波动变化向温干、凉干演化.5e是末次间冰期的大暖期,其暖湿程度好于5c,5c又好于5a,而5d的气候环境优于5b.在MIS5e阶段北京西山植被的演潜过程可分为5个阶段,揭示气候存在千年时间尺度的不稳定性,5e1为水热组合最佳时期.由末次间冰期向末次冰期过渡的降温时期,存在一次明显的气候回返事件,热释光年龄为78.5~72.5 kaBP.对比研究表明北京西山末次间冰期气候环境与深海沉积、极地冰心记录具有很好的可比性,变化幅度小于极地地区,与黄土高原及青藏高原环境演化具有更大的相似性. 相似文献
39.
40.