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1.
Tidal effects on temperature front in the Yellow Sea 总被引：5，自引：0，他引：5
Temperature front (TF) is one of the important features in the Yellow Sea, which forms in spring, thrives in summer, and fades
in autumn as thermocline declines. TF intensity ⋎S
T
⋎ is defined to describe the distribution of TF. Based on the MASNUM wave-tide-circulation coupled model, temperature distribution
in the Yellow Sea was simulated with and without tidal effects. Along 36°N, distribution of TF from the simulated results
are compared with the observations, and a quantitative analysis is introduced to evaluate the tidal effects on the forming
and maintaining processes of the TF. Tidal mixing and the circulation structure adapting to it are the main causes of the
TF.
Supported by the National Basic Research Program of China (No. G1999043809) and the National Science Foundation of China (No.
49736190). 相似文献
2.
Simulation of double cold cores of the 35°N section in the Yellow Sea with a wave-tide-circulation coupled model 总被引：1，自引：0，他引：1
Based on the MASNUM wave-tide-circulation coupled numerical model, the temperature structure along 35°N in the Yellow Sea
was simulated and compared with the observations. One of the notable features of the temperature structure along 35°N section
is the double cold cores phenomena during spring and summer. The double cold cores refer to the two cold water centers located
near 122°E and 125°E from the depth of 30m to bottom. The formation, maintenance and disappearance of the double cold cores
are discussed. At least two reasons make the temperature in the center (near 123°E) of the section higher than that near the
west and east shores in winter. One reason is that the water there is deeper than the west and east sides so its heat content
is higher. The other is invasion of the warm water brought by the Yellow Sea Warm Current (YSWC) during winter. This temperature
pattern of the lower layer (from 30m to bottom) is maintained through spring and summer when the upper layer (0 to 30m) is
heated and strong thermocline is formed. Large zonal span of the 35°N section (about 600 km) makes the cold cores have more
opportunity to survive. The double cold cores phenomena disappears in early autumn when the west cold core vanishes first
with the dropping of the thermocline position.
Supported by the National Basic Research Program of China (No. G1999043809) and the National Science Foundation of China (No.
49736190). 相似文献
3.
历次核试验进入海洋的~(137)Cs对中国近海影响的模拟研究 总被引：1，自引：0，他引：1
1945年以来,世界各主要核国家进行了数千次核试验,这些核试验产生的绝大部分放射性物质通过多种途径进入海洋,对海洋环境造成放射性污染。本文建立了一个准全球海洋的放射性物质输运和扩散数值模式,通过数值模拟手段评估了历史核试验释放的放射性物质137 Cs对中国近海海洋环境的影响。本文借助前人工作评估了核试验释放137Cs进入海洋的途径和总量;通过比较模拟结果与观测资料,表明本文建立的放射性物质模式能够较好地模拟出137Cs在中国近海及其邻近海域的分布情况和随时间演变特征;模拟结果表明中国近海里的137Cs浓度在20世纪50年代中期达到最大,其中吕宋海峡海域137Cs浓度最高,达80.99Bq/m3;进一步分析了2011年3月份日本福岛核事故前中国近海137Cs浓度分布状况,2011年整个中国近海137Cs浓度介于1.0~1.6Bq/m3间,且其浓度垂向分布较均匀,相对封闭的南海浓度略高于其他海域。 相似文献
4.
A new three-dimensional numerical model is derived through a wave average on the primitive N-S equations, in which both the＂Coriolis-Stokes forcing＂ and the＂Stokes-Vortex force＂ are considered. Three ideal experiments are run using the new model applied to the Princeton ocean model （POM）. Numerical results show that surface waves play an important role on the mixing of the upper ocean. The mixed layer is enhanced when wave effect is considered in conjunction with small Langmuir numbers. Both surface wave breaking and Stokes production can strengthen the turbulent mixing near the surface. However, the influence of wave breaking is limited to a thin layer, but Stokes drift can affect the whole mixed layer. Furthermore, the vertical mixing coefficients clearly rise in the mixed layer, and the upper ocean mixed layer is deepened especially in the Antarctic Circumpolar Current when the model is applied to global simulations. It indicates that the surface gravity waves are indispensable in enhancing the mixing in the upper ocean, and should be accounted for in ocean general circulation models. 相似文献
5.
Journal of Oceanology and Limnology - Thymidylate synthase (TS) is a key enzyme in the de novo biosynthesis of thymidine monophosphate, serving as a well-known drug target in chemotherapy against... 相似文献
6.
利用2000-2010年每年5-9月MODIS数据根据比值算法提取乌梁素海湖区黄苔的面积和空间分布信息并进行统计分析,探求乌梁素海黄苔产生的时空分布规律及特征,从而为黄苔的预防和治理提供支持.结果表明:(1)黄苔面积变化的年际和月际特征方面,2000、2001、2005、2006、2008、2010年黄苔面积超过了多年平均值(24 km2).5—7月份黄苔面积较小,保持在20 km2左右;8月黄苔面积迅速增长(约28 km2),9月黄苔面积最大,达到40 km2左右.(2)黄苔发生频率方面,2001年黄苔的规模和频率最高,发生频率达到0.58;2005、2006、2010年次之,发生频率在0.25附近波动(多年年均黄苔暴发频率为0.19);其他年份黄苔的发生频率处于低于0.10的水平.黄苔发生规模较大、次数较多的月份集中在8、9月,发生频率分别达到0.27、0.52,超过多年月均黄苔暴发频率0.19;其他月份黄苔的发生频率处于低于0.10的水平.(3)黄苔出现的空间分布方面,西大滩为东大滩的北部至中部,以及乌梁素海南部明水区排干口附近的西部沿岸是黄苔出现频率较高的区域.(4)2个月前的日均温度、降雨和营养盐浓度及当月风速与黄苔的产生具有极显著相关性;营养盐含量(TN、TP)的空间分布与黄苔的空间分布表现出较好的相关性.乌梁素海黄苔面积的年际变化受人类活动特别是生态补水的影响明显. 相似文献
7.
Fangli Qiao Yeli Yuan Tal Ezer Changshui Xia Yongzeng Yang Xingang Lü Zhenya Song 《Ocean Dynamics》2010,60(5):1339-1355
A theoretical framework to include the influences of nonbreaking surface waves in ocean general circulation models is established
based on Reynolds stresses and fluxes terms derived from surface wave-induced fluctuation. An expression for the wave-induced
viscosity and diffusivity as a function of the wave number spectrum is derived for infinite and finite water depths; this
derivation allows the coupling of ocean circulation models with a wave number spectrum numerical model. In the case of monochromatic
surface wave, the wave-induced viscosity and diffusivity are functions of the Stokes drift. The influence of the wave-induced
mixing scheme on global ocean circulation models was tested with the Princeton Ocean Model, indicating significant improvement
in upper ocean thermal structure and mixed layer depth compared with mixing obtained by the Mellor–Yamada scheme without the
wave influence. For example, the model–observation correlation coefficient of the upper 100-m temperature along 35° N increases
from 0.68 without wave influence to 0.93 with wave influence. The wave-induced Reynolds stress can reach up to about 5% of
the wind stress in high latitudes, and drive 2–3 Sv transport in the global ocean in the form of mesoscale eddies with diameter
of 500–1,000 km. The surface wave-induced mixing is more pronounced in middle and high latitudes during the summer in the
Northern Hemisphere and in middle latitudes in the Southern Hemisphere. 相似文献
8.
Reconstruction of eddies by assimilating satellite altimeter data into Princeton Ocean Model 总被引：2，自引：1，他引：1
An optimal interpolation assimilation model for satellite altimetry data is developed based on
Princeton Ocean Model (POM), which is applied in a quasi-global domain, by the method of
isotropic correlation between sea level anomaly (SLA) and sea temperature anomaly. The perfor-
mance of this assimilation model is validated by the modeled results of SLA and the current patterns.
Comparisons between modeling and satellite data show that both the magnitudes and distribution
patterns of the simulated SLA are improved by assimilation. The most signiˉcant improvement is
that meso-scale systems, e.g., eddies, are well reconstructed. The evolution of an eddy located in
the northwest Paciˉc Ocean is traced by using the assimilation model. Model results show that
during three months the eddy migrated southwestward for about 6 degrees before merging into the
Kuroshio. The three dimensional structure of this eddy on 12 August 2001 is further analyzed.
The strength of this warm, cyclonic eddy decreases with the increase of depth. The eddy shows
di?erent horizontal patterns at di?erent layers, and the SLA and temperature ˉelds agree with each
other well. This study suggests that this kind of data assimilation is economic and reliable for eddy
reconstruction, and can be used as a promising technique in further studies of ocean eddies as well
as other ˉne circulation structures. 相似文献
9.
渤海夏季环流的高分辨率海浪-潮汐-环流耦合模式研究 总被引：2，自引：0，他引：2
The Bohai Sea is a shallow semi-enclosed inner sea with an average depth of 18 m and is located at the west of the northern Yellow Sea. The climatological circulation pattern in summer of the Bohai Sea is studied by using a wave-tide-circulation coupled model. The simulated temperature and the circulation agree with the observation well. The result shows that the circulation pattern of the Bohai Sea is jointly influenced by the tidal residual current, wind and baroclinic current. There exists an obvious density current along the temperature front from the west part of the Liaodong Bay to the offshore area of the Huanghe Estuary. In the Liaodong Bay there exists a clockwise gyre in the area north to the 40°N. While in the area south to the 40°N the circulation shows a two-gyre structure, the flow from the offshore area of the Huanghe Estuary to the Liaodong Bay splits into two branches in the area between 39°N and 40°N. The west branch turns into north-west and forms an anti-clockwise gyre with the south-westward density current off the west of the Liaodong Bay. The east branch turns to the east and forms a clockwise gyre with the flow along the east coast of the Liaodong Bay. The forming mechanism of the circulation is also discussed in this paper. 相似文献
10.
The Fukushima nuclear accident in 2011 released large amounts of radionuclides, including ~(137)Cs, into the Pacific Ocean. A quasi-global ocean radioactive transport model with horizontal grid spacing of 0.5°×0.5° and 21 vertical layers was thereafter established to study the long-term transport of the Fukushima-derived ~(137)Cs in the ocean.The simulation shows that the plume of ~(137)Cs would be rapidly transported eastward alongside the Kuroshio Current and its extensions. Contaminated waters with concentrations lower than 2 Bq/m3 would reach the west coast of North America 4 or 5 years after the accident. The ~(137)Cs tends to be carried, despite its very low concentration, into the Indian and South Pacific Oceans by 2016 via various branches of ocean currents.Meanwhile, the ~(137)Cs concentrations in the western part of the North Pacific Ocean decrease rapidly with time. Up to now the highly contaminated waters have remained in the upper 400 m, showing no evidence of significant penetration to deeper layers. 相似文献