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181.
Environmental management of military activities is of growing global concern by defence forces. As one of the largest landholders
in Australia, the Australian Defence Force (ADF) is increasingly concerned with sustainable environmental management. This
paper focuses on how the ADF is maintaining effective environmental management, especially in environmentally sensitive marine
protected areas. It uses Shoalwater Bay Training Area (SWBTA) as a research example to examine environmental management strategies
conducted by the ADF. SWBTA is one of the most significant Defence training areas in Australia, with a large number of single,
joint and combined military exercises conducted in the area. With its maritime component contained in the Great Barrier Reef
Marine Park (GBRMP), the Great Barrier Reef World Heritage Area (GBRWHA), and abutting Queensland’s State Marine Parks, it
has high protection values. It is therefore vital for the ADF to adopt environmentally responsible management while they are
conducting military activities. As to various tools employed to manage environmental performance, the ISO 14001 Environmental
Management System (EMS) is widely used by the ADF. This paper examines military activities and marine environmental management
within SWBTA, using the Talisman Saber (TS) exercise series as an example. These are extensive joint exercises conducted by
the ADF and the United States defence forces. The paper outlines relevant legislative framework and environmental policies,
analyses how the EMS operates in environmental management of military activities, and how military activities comply with
these regulations. It discusses the implementation of the ADF EMS, including risk reduction measures, environmental awareness
training, consultation and communication with stakeholders. A number of environmental management actions used in the TS exercises
are presented to demonstrate the EMS application. Our investigations to this point indicate that the ADF is complying with
all relevant legislation and policies. Further research is required to confirm compliance and conclude that military activities
have good accord with environmental management objectives. 相似文献
182.
涡分辨率模式模拟的南海中尺度涡旋 总被引：2，自引：2，他引：0
Mesoscale eddies(MEs) in the South China Sea(SCS) simulated by a quasi-global eddy-resolving ocean general circulation model are evaluated against satellite data during 1993–2007. The modeled ocean data show more activity than shown by the satellite data and reproduces more eddies in the SCS. A total of 345(428) cyclonic eddies(CEs) and 330(371) anti-cyclonic eddies(AEs) generated for satellite(model) data are identified during the study period, showing increase of ~24% and ~12% for the model data, respectively. Compared with eddies in satellite, the simulated eddies tend to have smaller radii, larger amplitudes, a slightly longer lifetime, faster movement and rotation speed, a slightly larger nonlinear properties(U/c) in the model. However, the spatial distribution of generated eddies appears to be inhomogeneous, with more CEs in the northern part of SCS and fewer AEs in the southern part. This is attributed to the exaggerated Kuroshio intrusion in the model because the small islands in the Luzon Strait are still not well resolved although the horizontal resolution reaches(1/10)°. The seasonal variability in the number and the amplitude of eddies generated is also investigated. 相似文献
183.
As a connection region between Arctic and North Atlantic oceans, the Nordic seas play a critical role in global climate system. The density waters overflow through Greenland-Scotland Ridge from the Nordic seas, as the main source of the North Atlantic Deep Water (NADW), which plays a key role in global ocean conveyor. The causes and processes, which give some instruction of the overflow variation are still uncertain. Based on a review of current and historical research results of modern Nordic seas overflows, hydrological and flux characteristics and variation features of overflows through three channels, which are Faroe-Shetland Channel, Iceland-Faroe Ridge and Denmark Strait, from Nordic sea were addressed separately. The origins of overflows water and factors and physical processes that may have impact on the three overflows were also analyzed separately. Intense mixing in overflow through Faroe-Shetland Channel was discussed. At last, the changing mechanism of the whole overflow from Nordic seas and relationships among overflows through different channels were summed up. The aim of this paper is to give some instructions and research directions to the internal readers. 相似文献
184.
Tidal shear front off the Yellow River mouth has been observed and modeled in the previous studies. However, a detailed investigation of the front generation has not been conducted. The aim of this paper is to use a three-dimensional tidal model coupled to a sediment transport module to examine the front formation. The model predicted a tidal shear front that propagated offshore and lasted 1–2 h at both flood and ebb phase off the Yellow River mouth. The sensitivity numerical experiments showed that the topography with a strong slope off the Yellow River mouth was a determining factor for the front generation, and a parallel orientation between the major axes of ellipses and co-tidal lines of maximum tidal current was a necessary condition. While the bottom friction and the river runoff had no effect on the front location but affected the front intensity, the front generation was not sensitive to the coastline variation. The study concluded that the bottom slope off the river mouth induces a strong variation in the bottom stress in a cross-shore direction, which produces both maximum phase gradient and sediment concentration variability across the tidal shear front. With the extending Yellow River delta, the tidal shear front under the new bathymetry of year 2003 has been strengthened and pushed further offshore due to an increased bottom slope. 相似文献
185.
《Journal of Atmospheric and Solar》2008,70(16):2061-2076
Based on recent advances in ionospheric storm dynamics that correlate the ionospheric storm effects with space weather parameters such as the magnitude of the interplanetary magnetic field (IMF), its rate of change and the IMF's orientation in the north–south direction and on the availability of these parameters in real time by NASA ACE spacecraft from the vantage L1 point, an empirical storm-time ionospheric model for the middle latitude ionosphere, namely STIM, was recently envisaged. STIM is significantly upgraded and validated here. The model introduces a correction factor to the quiet daily ionospheric variation to anticipate storm conditions. It is triggered by an alert signal for upcoming ionospheric disturbances obtained from the analysis of the IMF measurements provided by ACE spacecraft. In its final version, STIM method includes quantitative criteria for the online analysis of the ACE's observations. The determination of the ionospheric storm onset and the empirical formulation of the ionospheric storm-time response, both in terms of the local time and the latitude of the observation point are also specified here. STIM's forecasts are provided from 13 to 45 h ahead for any middle latitude ionospheric location. Validation tests carried out for 27 storm-time intervals and for four European locations show that the model captures successfully the onset and the recovery of the ionospheric disturbance and follows sufficiently the disturbance pattern, providing also significant improvement over climatology during storm days. STIM was also compared with two well-known prediction models, the IRI2001 and the GCAM, and the findings demonstrate improved performance in favour of STIM, in both quantitative and qualitative aspect. In general, the results presented here support the efficiency of the proposed methodology in providing reliable ionospheric forecasts at middle latitudes several hours in advance. The operational implementation of STIM can support ionospheric forecasting space weather services and is based on the availability of real-time IMF observations from the vantage L1 point. 相似文献
186.
基于2006年夏季和2007年冬季实测温盐数据和悬浮体浓度数据,分析东海内陆架悬浮体水平和垂直分布季节性特征,并结合MIKE3数值模拟海流结果,定量估算东海关键断面悬浮体运移通量,探讨悬浮体输运与泥质区形成和演化的关系。研究表明:东海内陆架悬浮体分布主要受流系控制,且季节变化明显;一般天气条件下,东海内陆架泥质区海域输入悬浮体净通量约为2.24×108t/a,其中夏半年悬浮体向泥质区海域输入净通量约为52.19×106t,贡献约为23.29%,冬半年净通量约为171.87×106t,贡献约为76.71%,浙闽沿岸悬浮体输运净通量均有利于东海内陆架泥质区的发育。本研究将对东海内陆架泥质区物质来源和发育演化研究提供理论支持。 相似文献
187.
2012年夏季挪威海和格陵兰海水文特征分析 总被引：1，自引：1，他引：0
利用2012年夏季在北欧海(挪威海和格陵兰海)的水文考察数据,对调查区域内海洋水团性质和分布进行了分析,并对北欧海冷却对流的发展加深过程进行了研究。在上层,从东侧暖而咸的大西洋水跨越锋区至西侧低温低盐的格陵兰海盆上层水体,温度和盐度的变化分别可以达到8℃和0.4 psu。中层与深层水体的性质则相对均匀和稳定,3个海盆内从浅至深依次分布着北极中层水、海盆深层水、北极深层水以及海盆底层水。格陵兰海盆中深层水体在3 500 m深度上位温约为-0.97℃,相比较1970s观测到的-1.30℃,升温幅度超过了0.3℃,表明海盆深层存储的热量显著增加。在只考虑局地表面冷却的简化条件下,当前格陵兰海内部通过冷却对流混合至季节性跃层下界需要向大气释放0.9×109~1.2×109J的热量,这一过程至少需要2个月的时间而不利于对流向深层的发展。大量的热量被存储于北欧海深海盆中使得北欧海已经成为北半球高纬海域的热量存储器,对当前北极气候变化的影响有待深入研究。 相似文献
188.
海气界面热通量交换对南海深水海盆SST持续增暖的可能贡献 总被引：2，自引：0，他引：2
20世纪后50年南海深水海盆SST持续增暖了0.64℃,为了探究其持续增暖的机制,使用IPCC模式比较试验CGCM3.1(T47)、CGCM3.1(T63)、CSIRO-Mk3.0、GFDL CM2.0这4个模式输出资料中的辐射通量、湍流热通量、比湿、风、云量、气温、海平面气压及海温数据,计算了各海洋、气象要素的变化趋势,估算了热通量各分量,发现20世纪后50年期间SST的持续增暖似乎不能依据海面热通量的变化来解释。主要证据如下:夏季风的减弱使得海面潜热减少了约4.9W/m2,但由于海温升高、蒸发加强又使潜热增多了大约同样的值,使得夏季南海深水海盆总的潜热通量变化较小;夏季大气水汽含量的增多促使海面长波辐射增多了约1.8 W/m2,加上感热通量等变化的效应,海洋净得热增多了约3.0 W/m2;但是,20世纪后50年内冬季风的增强和冬季海温升高致使海洋潜热增多了约7.3 W/m2。由于20世纪后50年潜热释放大于海面长波辐射增多,无法只用海面热通量解释SST持续增暖现象,指出了南海海洋动力过程可能在维持南海深水海盆50年来SST持续增暖中的重要性。 相似文献
189.
190.
基于德国Max-Planck气象研究所的最新大气海洋环流模式(ECHAM5/MPI-OM),对控制试验(control run)下热盐环流(THC)年际及年代际变化进行了分析,揭示了年代际变率的产生机制。研究表明:(1)THC年际振荡的主导周期是4 a,年代际振荡的主导周期是24 a,THC的年代际振荡信号最强,是第一主成分。(2)THC的年代际振荡机制为:首先从大西洋径向翻转环流(MOC)强度最小开始,由于MOC强度处于较弱状态,从低纬度向高纬度输送的热量偏少,副极地海区海表温度出现负异常,持续5 a之后,北大西洋副极地海区海表温度达到最大负异常。此时副极地流环中心(北大西洋)的表层海水变冷,密度增加,海表面下降,产生从副极地流环边缘指向副极地流环的中心的压强梯度力,根据地转平衡关系,北大西洋副极地海区的上层海洋会出现一个气旋式的环流异常(副极地流环得到加强),北大西洋暖流(NAC)同时得到加强。在副极地海区海表温度达到最大负异常的3 a之后,副极地流环和NAC达到最强。由此,作为NAC延伸的法鲁海峡入流水增强,更多的高盐法鲁海峡入流水进入格陵兰-冰岛-挪威海(GIN)海域,使GIN海域层结稳定性减弱。1 a后,GIN海域深层对流增强,格陵兰-苏格兰海脊溢流水增加。在GIN海域深层对流达到最强的3 a之后,MOC强度达到最大。整个状态翻转过程完成的时间大约为12 a,THC年代际振荡的整个周期大约是24 a。 相似文献