中国区域加权平均温度的时空分析及模型研究     

聂檄晨  胡伍生  朱明晨  于先文  王庆 《测绘科学》2021,46(2):159-164

加权平均温度(T_m)是全球卫星导航系统技术反演大气可降水量的关键参数,影响着水汽反演的精度。针对传统的Bevis模型运用在中国区域精度不高的问题,该文提出新的增加时空参数的T_m多元线性回归模型。根据2013—2015年中国86个探空站点的探空资料,分析了T_m的时空特征;然后根据2013年站点资料,利用线性回归建模方法建立了中国区域的T_m单因子回归模型和增加了时空参数的T_m多因子回归模型,并利用2014—2015年的探空数据进行验证。T_m单因子回归模型和T_m多因子回归模型的精度分别为3.1 K和2.6 K,比Bevis模型(精度3.3 K)分别提高了约6.0%和21.2%。考虑到季节对T_m的影响,将T_m多因子回归模型按季节分段,得到按季节分段的T_m多因子回归模型,其精度与T_m多因子回归模型大致相当,但能更细致表达出不同季节T_m的精度情况。结果表明增加了时空参数的T_m多因子回归模型更加适合中国区域的加权平均温度T_m的计算。  相似文献   

The soil–water flow system beneath a cotton field in arid north-west China,serviced by mulched drip irrigation using brackish water     

Xianwen Li  Menggui Jin  Jinou Huang  Jingjing Yuan 《Hydrogeology Journal》2015,23(1):35-46

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Tidal Effects on the Bottom Thermal Front of North Yellow Sea Cold Water Mass near Zhangzi Island in Summer 2009     

XIA Yingying  BAO Xianwen  SONG Dehai  DING Yang  WAN Kai  YAN Yuhan 《中国海洋大学学报(英文版)》2019,(4)

Three seabed-mounted TD/CTD chains and two upward-looking acoustic Doppler current profilers(ADCPs) in the southwest of Zhangzi Island are used and a simultaneous cruise observation in the northern North Yellow Sea(NYS) is conducted to study temperature variation in the bottom thermal front zone of the NYS Cold Water Mass(NYSCWM) during the summer of 2009. In the flood-ebb tidal cycles, the bottom temperature decreases(increases) during flood(ebb) tides, which are dominated by the tidal-current induced horizontal advection. The ebb tide-induced temperature increase is larger than the flood tide-induced temperature decrease due to seasonal warming. In the spring-neap tidal cycles, the temperature and the vertical temperature structure show notable fortnightly variation from 16 July to 25 August. The bottom temperature increases from neap to spring tides and decreases from spring to neap. The Richardson number demonstrates strengthened vertical mixing during spring tides but enhanced stratification during neap tides. The spring-neap variation in vertical shear caused by tidal current is the dominant factor that induces the fortnightly variation in vertical mixing and thus bottom temperature.  相似文献   

珠江口洪季最大浑浊带的大小潮变化与机制分析*     

严冬  宋德海  鲍献文 《热带海洋学报》2020,39(1):20-35

基于ROMS三维模型, 模拟了珠江口洪季最大浑浊带的轴、侧向分布和大、小潮变化。模拟结果表明, 珠江口伶仃洋最大浑浊带的轴向位置在22.3°—22.45°N之间, 并随着潮流变化而周期性上下游迁移。控制最大浑浊带形成的主要因素是余流作用下的底层泥沙辐聚, 决定最大浑浊带位置的主要因素是水平对流输沙, 泥沙来源主要是上游浅滩沉积物的再悬浮。小潮期间堆积在浅滩的细颗粒沉积物在大潮期间被悬浮, 搬运到下游的滞流点位置, 在中滩南部和西滩外缘落淤。“潮泵”作用在大潮期间将泥沙向下游输运, 在小潮期间向上游输运; 垂向剪切作用则有利于悬浮泥沙的陆向输运; 二者共同作用产生泥沙辐聚, 形成最大浑浊带。大、小潮期间余流结构差异不大, 主要由密度差和潮汐混合不对称共同导致, 其中前者贡献更大。  相似文献   

Modeling the westward transversal current in the southern Yellow Sea entrance: a case study in winter 2007     

Ding  Yang  Bao  Xianwen  Zhou  Lingling  Bi  Congcong  Yao  Zhigang  Ma  Chao  Chu  Qinqin 《Ocean Dynamics》2020,70(6):803-825

Ocean Dynamics - The westward transversal current (TC) in the southern Yellow Sea entrance was investigated during winter 2007 using a numerical ocean model. The three-dimensional structures and...  相似文献   

基于FVCOM的泉州湾海域三维潮汐与潮流数值模拟   总被引：1，自引：0，他引：1  

林作梁  朱学明  鲍献文  刘钦政 《海洋学报》2013,35(1):15-24

基于FVCOM海洋数值模式,采用非结构的三角形网格和有限体积法,建立了泉州湾海域高分辨率(26 m)的三维潮汐、潮流数值模型。模拟结果同2个验潮站和3个连续测流站的观测资料符合良好,较好地反映了泉州湾内潮汐、潮流运动的变化状况和分布特征,给出了M₂、S₂、K₁、O₁ 4个主要分潮的同潮图、表层潮流椭圆分布,以及模拟区域内最大可能潮差、表层最大可能潮流流速和潮余流分布。分析表明,4个分潮的最大潮汐振幅和迟角差分别为219 cm和19°,85 cm和25°,26 cm和12°,26 cm和9°;石湖港以东海域的潮波为逆时针旋转的驻波,以西海域为前进波;最大可能潮差由湾口的8.0m向湾内增加至8.8 m。湾内潮流类型为规则半日潮流,落潮最大流速大于涨潮最大流速,北乌礁水道为强流区,表层最大可能潮流流速为2.4 m/s;湾口潮流运动以逆时针方向的旋转流形式为主,湾内的潮流运动以往复流形式为主,长轴走向主要沿着水道方向,与等深线和海岸线平行;四个分潮流表层最大流速分别为1.4 m/s,0.58 m/s,0.12 m/s,0.10 m/s。余流流速大小与潮流强弱有密切的联系,表、中、底层最大余流流速分别为26 cm/s,20 cm/s,16 cm/s,三者在水平方向基本呈北进南出的分布形态。  相似文献   

A numerical study of the barotropic tides and tidal energy distribution in the Indonesian seas with the assimilated finite volume coastal ocean model     

Yang Ding  Xianwen Bao  Huaming Yu  Liang Kuang 《Ocean Dynamics》2012,62(4):515-532

The tides and tidal energetics in the Indonesian seas are simulated using a three-dimensional finite volume coastal ocean model. The high-resolution coastline-fitted model is configured to better resolve the hydrodynamic processes around the numerous barrier islands. A large model domain is adopted to minimize the uncertainty adjacent to open boundaries. The model results with elevation assimilation based on a simple nudge scheme faithfully reproduced the general features of the barotropic tides in the Indonesian Seas. The mean root-mean-square errors between the observed and simulated tidal constants are 2.3, 1.1, 2.4, and 1.5 cm for M₂, S₂, K₁, and O₁, respectively. Analysis of the model solutions indicates that the semidiurnal tides in the Indonesian Seas are primarily dominated by the Indian Ocean, whereas the diurnal tides in this region are mainly influenced by the Pacific Ocean, which is consistent with previous studies. Examinations of tidal energy transport reveal that the tidal energy for both of the simulated tidal constituents are transported from the Indian Ocean into the IS mainly through the Lombok Strait and the Timor Sea, whereas only M₂ energy enters the Banda Sea and continues northward. The tidal energy dissipates the most in the passages on both sides of Timor Island, with the maximum M₂ and K₁ tidal energy transport reaching about 750 and 650 kW m^–1, respectively. The total energy losses of the four dominant constituents in the IS are nearly 338 GW, with the M₂ constituent dissipating 240.8 GW. It is also shown that the bottom dissipation rate for the M₂ tide is about 1–2 order of magnitudes larger than that of the other three tidal components in the Indonesian seas.  相似文献   

基于船载ADCP观测对罗源湾湾口断面潮流及余流的分析   总被引：2，自引：1，他引：1  

姚志刚  鲍献文  李娜  李希彬  宋军  万凯 《海洋学报》2012,34(6):1-10

基于对罗源湾可门水道的25 h连续走航ADCP观测,成功构建了沿走航断面共12个站位的连续海流时间序列,并对这些站位的潮流、余流以及潮通量等进行了分析。结果表明可门水道内的潮流为正规半日潮流,驻波性质明显,涨潮首先出现在水道中下层而退潮则首先发生在水道上层。水道内的潮流为往复流,水道南部M₂分潮流流速较大,并且其倾角自北向南逐渐增加。此外,水道两端的浅水区域内浅水分潮M₄振幅较显著。可门水道内余流呈现出两层结构,20 m以浅余流沿东北向流出海湾,并且出流的核心位置偏南,而20 m以深的余流沿西南向流入湾内,入流的流核位于偏北的近底层区域。对潮通量的积分计算表明通过可门水道进入罗源湾的潮通量约为4.81×108 m3。  相似文献   

Timing, Displacement and Growth Pattern of the Altyn Tagh Fault: A Review   总被引：1，自引：0，他引：1  

DAI Shuang  DAI Wei  ZHAO Zhenbin  LUO Junhu  QIANG Lei  MA Xin  ZHANG Xianwen  XU Jianjun 《《地质学报》英文版》2017,91(2):669-687

The Altyn Tagh Fault (ATF) is the longest, lithospheric scale and strike-slip fault in East Asia. In the last three decades, multidisciplinary studies focusing on the timing, displacement of strike-slip and growth mechanics of the ATF have made great progresses. Most studies revealed that the ATF is a sinistral strike-slip and thrust fault, which underwent multiple episodes of activation. The fault is oriented NEE with a length of 1600 km, but the direction, timing of activity and magnitude of its extension eastward are still unclear. The AFT was predominately active during the Mesozoic and Cenozoic, in relation to the Mesozoic collision of the Cimmerian continent (Qiangtang and Lhasa block) and Cenozoic collision of India with Asia. The AFT strike-slipped with a left-lateral displacement of ca. 400 km during the Cenozoic and the displacement were bigger in the western segment and stronger in the early stage of fault activation. The slip-rates in the Quaternary were bigger in the middle segment than in the western and eastern segment. We roughly estimated the Mesozoic displacement as ca. 150-300 km. The latest paleomagnetic data showed that the clockwise vertical-axis rotation did not take place in the huge basins (the Tarim and Qaidam) at both side of ATF during the Cenozoic, but the rotation happened in the small basins along the ATF. This rotation may play an important role on accommodating the tectonic deformation and displacement of the ATF. Even if we have achieved consensus for many issues related to the ATF, some issues still need to be study deeply; such as: (a) the temporal and spatial coupling relationship between the collision of Cimmerian continent with Asia and the history of AFT in the Mesozoic and (b) the tectonic deformation history which records by the sediments of the basins within and at both side of AFT and was constrained by a high-resolution and accurate chronology such as magnetostratigraphy and paleomagnetic data.  相似文献   

Climate projections of spatial variations in coastal storm surges along the Gulf of Mexico and U.S. east coast     

Zhigang Yao  Zuo Xue  Ruoying He  Xianwen Bao  Jun Xie  Qian Ge 《中国海洋大学学报(英文版)》2017,16(1):1-7

Using statistically downscaled atmospheric forcing, we performed a numerical investigation to evaluate future climate's impact on storm surges along the Gulf of Mexico and U.S. east coast. The focus is on the impact of climatic changes in wind pattern and surface pressure while neglecting sea level rise and other factors. We adapted the regional ocean model system(ROMS) to the study region with a mesh grid size of 7–10 km in horizontal and 18 vertical layers. The model was validated by a hindcast of the coastal sea levels in the winter of 2008. Model's robustness was confirmed by the good agreement between model-simulated and observed sea levels at 37 tidal gages. Two 10-year forecasts, one for the IPCC Pre-Industry(PI) and the other for the A1 FI scenario, were conducted. The differences in model-simulated surge heights under the two climate scenarios were analyzed. We identified three types of responses in extreme surge heights to future climate: a clear decrease in Middle Atlantic Bight, an increase in the western Gulf of Mexico, and non-significant response for the remaining area. Such spatial pattern is also consistent with previous projections of sea surface winds and ocean wave heights.  相似文献