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渤海海冰特征厚度分析 总被引：8，自引：2，他引：6
通过海冰生消机理和数值试验,讨论了渤海海冰特征厚度的存在条件;对不同厚度的海冰表面温度、冰面热量收支、冰面下热传导和太阳辐射透射量进行了对比分析,分析了渤海海冰向特征冰厚的动态演化过程;在不同气温、风速、相对湿度和海洋热通量等气象和水文条件下,对渤海特征冰厚进行了计算;讨论了海冰生消的动态平衡过程,分析了1997/1998年冬季辽东湾JZ20-2海域实测冰厚与特征冰厚的相互关系。对渤海特征冰厚分析将有助于渤海海冰数值模拟工作的开展和对不同重现期设计冰厚的推算。 相似文献
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渤海冰-海洋耦合模式Ⅱ.个例试验 总被引：4，自引：1，他引：3
以渤海1998~1999和2000~2001年度冬季的海冰发展过程为例,采用实时气象数值预报场作为大气强迫,利用渤海冰海洋耦合模式模拟渤海整个冬季的海冰生消和演变以及渤海冰季冰气、冰水和气水界面的热收支.模拟结果显示大气和海洋的热力效应对渤海的海冰发展非常重要,特别在海冰的冻结和融化阶段,海洋热通量在热力耦合中起着重要作用.模拟还显示了冰覆盖内部区域和冰外缘线附近不同的热力特征,分析讨论了冰区内和冰边缘两个特征点冰厚分布、界面热量收支和海表水温等. 相似文献
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The coupled ice-ocean model for the Bohai Sea is used for simulating the freezing, melting, and variation of ice cover and the heat balance at the sea-ice, air-ice, and air-sea interfaces of the Bohai Sea during the entire winter in 1998～1999 and 2000～2001. The coupled model is forced by real time numerical weather prediction fields. The results show that the thermodynamic effects of atmosphere and ocean are very important for the evolvement of ice in the Bohai Sea, especially in the period of ice freezing and melting. Ocean heat flux plays a key role in the thermodynamic coupling. The simulation also presents the different thermodynamic features in the ice covered region and the marginal ice zone. Ice thickness, heat budget at the interface, and surface sea temperature, etc. between the two representative points are discussed. 相似文献
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A coupled ice-ocean model for the Bohai Sea Ⅱ. Case study 总被引：1，自引：0，他引：1
The coupled ice-ocean model for the Bohai Sea is used for simulating the freezing, melting, and variation of ice cover and the heat balance at the sea-ice, air-ice, and air-sea interfaces of the Bohai Sea during the entire winter in 1998-1999 and 2000-2001. The coupled model is forced by real time numerical weather prediction fields. The results show that the thermodynamic effects of atmosphere and ocean are very important for the evolvement of ice in the Bohai Sea, especially in the period of ice freezing and melting. Ocean heat flux plays a key role in the thermodynamic coupling. The simulation also presents the different thermodynamic features in the ice covered region and the marginal ice zone. Ice thickness, heat budget at the interface, and surface sea temperature, etc. between the two representative points are discussed. 相似文献
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基于MODIS热红外数据的渤海海冰厚度反演 总被引：3，自引：1，他引：2
Level ice thickness distribution pattern in the Bohai Sea in the winter of 2009–2010 was investigated in this paper using MODIS night-time thermal infrared imagery.The cloud cover in the imagery was masked out manually.Level ice thickness was calculated using MODIS ice surface temperature and an ice surface heat balance equation.Weather forcing data was from the European Centre for Medium-Range Weather Forecasts(ECMWF) analyses.The retrieved ice thickness agreed reasonable well with in situ observations from two off-shore oil platforms.The overall bias and the root mean square error of the MODIS ice thickness are –1.4 cm and 3.9 cm,respectively.The MODIS results under cold conditions(air temperature –10°C) also agree with the estimated ice growth from Lebedev and Zubov models.The MODIS ice thickness is sensitive to the changes of the sea ice and air temperature,in particular when the sea ice is relatively thin.It is less sensitive to the wind speed.Our method is feasible for the Bohai Sea operational ice thickness analyses during cold freezing seasons. 相似文献
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波弗特海海冰的剧烈变化对区域内生态系统以及经济活动具有重要影响。基于美国国家冰雪数据中心发布的海冰密集度数据,本文对2019年波弗特海夏季海冰面积出现极端低值的机制进行了探讨。2019年融冰季（5–9月）海冰覆盖面积为1.38×105 km2,远低于1998–2020年平均面积2.28×105 km2,统计2019年前秋（2018年10–12月）和前冬季节（2019年1–4月）海冰覆盖面积,发现其与1998–2019年多年平均结果无显著差异;先前季节的海冰冰况不是造成极端低值事件的主要原因。综合海冰漂移场、海冰厚度、10 m风场以及海表面净热通量数据发现,2019年5月份海冰面积减小2.33×105 km2,是1998年以来5月海冰损失量最大的年份,占融冰季节海冰面积减小量的62%。与1998年、2008年、2012年以及2016年波弗特海夏季发生海冰覆盖面积极端低值现象的机制不同,不断减小的海冰厚度以及2019年5月异常强的风场,促使海冰快速向外输出,波弗特海南部5月16日就形成开阔水域;伴随着异常高的海表面净热通量使得海冰更多地融化,造成了2019年夏季海冰的异常现象。随着海冰厚度的不断变薄,海冰对风场的响应越来越强,海冰消退时间不断提前,波弗特海夏季海冰的极端低值现象可能更为频繁地出现。 相似文献
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The Bohai Sea is a seasonal icy sea area that has the lowest latitude of any sea experiencing icing in the northern hemisphere, and simulation studies on oil spills during its sea ice period are the key to analyzing winter oil spill accidents. This study applied the three-dimensional free surface to establish a high-resolution hydrodynamic model and simulate tidal distributions in the Bohai Sea. Then, the oil spill model of the open sea area and thermodynamic model were combined to establish a numerical model for the Bohai oil spill during the winter sea ice period. The hydrodynamic model and sea ice growth and melting model were verified, and the parameters were adjusted based on the measured values, which indicate that the numerical model established in this paper is of high accuracy,stability and ubiquity. Finally, after checking the calculations repeatedly, the diffusion coefficient for the Bohai Sea was determined to be 1.0×10~(–7 )m~2/s. It is better that the comprehensive weathering attenuation coefficient is lower than that of a non-winter oil spill, with 1.3×10~(–7 )m~2/s being the most appropriate coefficient. This study can provide the reliable technical support for the operational safety and reduction in losses caused by winter oil spill accidents for the petroleum industry. 相似文献
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为给寒区海域的波浪能估算提供科学依据,提出一种合理推算冰水共存海域波浪条件及波能流密度的方法,该方法将海冰模型与水动力学模型耦合模拟得到的冰浓度以线性修正函数的方式纳入波浪模型的海面摩阻风速方程中,并基于MCT (model coupling toolkit)耦合器将海冰模型、水动力学模型与波浪模型进行实时耦合。基于该方法模拟了渤海冬季寒潮大风期间的海冰以及波能流密度的演化。模拟结果表明,在2012年2月5~8日寒潮大风期间,结冰区域占到渤海总面积的1/3,约有76%的渤海海域的平均波能流密度受海冰影响减小,其中辽东湾近岸的波能流密度平均受冰影响最多减小了100%,而渤海湾和莱州湾近岸受冰影响最多分别减小了60%和50%。即使是无冰覆盖的老铁山水道,其波能流密度的最大值也受冰影响减少了14%。耦合模拟可以更为准确地对渤海冬季的波能流密度分布进行评估,为波浪能发电厂选址提供依据。 相似文献
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海冰厚度是监测与研究渤海海冰的重要参数。为了获取更加可靠的渤海海冰厚度数据,本研究基于MODIS数据对海冰厚度反演中的冰水分离环节和冰厚计算方法都进行了改进。对于冰水分离环节,本文在Canny边缘检测算子提取海冰基础上,加入了二值化处理、阈值判别等步骤,实现了较高精度的渤海海冰范围自动化提取。通过试验确定了海冰厚度与反照率指数关系模型中的参数,包括海冰衰减系数和海水反照率参数,使其更加符合渤海海区的物理特征。将改进后算法的海冰厚度反演结果与渤海海上石油平台实测数据进行比较,并分析了误差来源。结果表明,经过对算法的改进,海冰厚度与反照率指数关系模型的反演结果与实测数据之间的平均绝对误差由7.05 cm缩小到2.74 cm,相关系数由0.434提高到0.485。 相似文献
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渤海冬季海冰反照率变化 总被引：1，自引：1，他引：0
渤海海冰对于大尺度气候变化比较敏感,基于CLARA-A1-SAL数据分析了1992~2008年冬季（12、1、2月）渤海海冰区域反照率的时空变化,同时分析了海冰密集度、海冰外延线面积和海水表面温度的变化与海冰反照率的相互关系。渤海海冰区域反照率随时间波动变化且变化趋势不明显,趋势线斜率仅为0.0388%。年际变化在9.93%~14.5%之间,平均值为11.79%。海冰反照率在1999,2000和2005等重冰年的值明显高于其他年份,在1994,1998,2001和2006等轻冰年的值较低。从单个月份反照率来看,12月海冰反照率的增加趋势（趋势线斜率0.0988%）明显高于1月和2月,1月的海冰反照率平均值（12.9%）高于另外两个月份。海冰反照率和海冰密集度呈明显的正相关关系;和海表面温度呈负相关关系（显著性水平90%）。 相似文献
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基于长时间的FRA-JCOPE数据,本文着重对渤海海峡水交换的多时间尺度变化特征进行了分析。通过分析认为,渤海海峡水交换具有明显的季节(360天和180天周期)、季节内(120天周期)和年际变化特征,且空间分布呈现较为明显的“南出北进”特点。360天季节变化特征表现为夏强冬弱,局地风场、海峡两侧海表高度梯度、陆地径流的季节变化对其具有重要影响;180天周期的季节变化和120天周期季节内变化信号与局地风场关系不大,主要受到海峡两侧海表高度梯度的调制。同时,渤海海峡水交换受1997—1998年ENSO影响较为显著:正常年份时,渤海海峡水交换流入、流出量基本相当,但当1997—1998年ENSO显著年份时,流出量略大于流入量,这是由于黄渤海环流增强,进而导致渤海海峡水交换增强造成的。 相似文献