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1.
本文以2006年9月日本以南海域的台风YAGI为例,应用黑潮延伸体附近的KEO浮标观测资料,并结合卫星遥感等融合资料,分析海洋飞沫在台风不同发展阶段对海气界面间热量通量和动量通量的影响。首先,定量地分析台风期间海洋飞沫对海气热通量的影响。结果表明,在台风YAGI过境期间,海洋飞沫能够显著地加剧海气界面间的热量交换,尤其是潜热交换。海洋飞沫增加的热通量随着风速的增强而增大,随着波龄的增大而减小。随后,通过动量分析表明,在台风YAGI过境期间,海洋飞沫显著地增强了由大气向海洋的动量转移。当风速达到台风量级后,考虑海洋飞沫所增加的动量通量与界面动量通量大小相当,同时,在此风速条件下,海洋飞沫在海气界面形成极限饱和悬浮层,抑制风到海表面的动量转移,导致海气界面间总的动量通量的增长率随之减小。 相似文献
2.
以渤中８号采油平台为基地，对海上大气表面层的风速、温度和湿度廓线进行了同步测量。据测量数据的统计分析，确定了较好适用于渤海中部大气表面层的大气稳定度函数模式（不稳定状态），从而确定了一种海上大气表面层风湿廓线的参量化模式。依此模式，可由实测风温湿廓线数据计算海－气动量、感热和水汽通量。 相似文献
3.
海-气界面动量通量的估计方法分析与应用 总被引：3，自引：1，他引：2
首次将经验模态分解方法引入湍流稳定性分析,与传统的线性和滑动平均去势方法进行了比较,发现经验模态分解方法的去势效果最好。基于"南海平台通量观测计划"(FOPSCS)近两年的连续通量观测数据,得到了22 476个摩擦速度的估算值,结果表明,当风速小于5m/s时,拖曳系数随风速增大而减小,而风速大于5m/s时,拖曳系数随风速增大而增大,两种情形分别反映了黏性表皮摩擦和波浪引起的形状阻力对海面风应力的贡献。同时发现短风区情形的拖曳系数大于长风区情形,说明波浪成长状态会对海-气界面动量交换产生影响。 相似文献
4.
大气和海洋是影响地球气候系统的两个重要因素，它们之间的相互作用是海洋和大气研究的重要课题，海气耦合模式则是研究海气相互作用的重要工具，而海气耦合模式重点考虑的参数是海气通量。针对传统的大尺度海气耦合模式缺少湍流尺度分析的问题，本文使用并行大涡模拟海气耦合模式（The Parallelized Large-Eddy Simulation Model，PALM），在小尺度上探究风速对海气通量及湍流动能收支（Turbulence Kinetic Energy Budget，TKE Budget）的影响，设置了5、10和15m/s三种地转风速度对大气边界层（Atmospheric Boundary Layer，ABL）和海洋混合层（Oceanic Mixed Layer，OML）进行海气耦合模拟。研究表明：海气通量的分布与风速大小密切相关，风速越大，净热通量和浮力通量相对越大，由于温度上升导致海水蒸发加剧，使得大气的淡水通量增大；海洋湍流动能收支各项在近海面处受风速影响较大，且随着深度加深而逐渐减弱。本研究初步展示了小尺度海气耦合模式在海气通量研究中的应用，对进行小尺度海气相互作用研究具有一定的意义。 相似文献
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6.
深水风浪破碎发生率与风速和风区的关系 总被引：1，自引：0，他引：1
徐德伦 《中国海洋大学学报(自然科学版)》1994,(1)
根据于渤海中部采油平台测得的数据，结合实验室的测量，提出一种深水风浪破碎发生率与风速和风区关系的经验公式，与现已发表的少量海上测量结果相比较，此式符合良好。利用此式较好地解释了风浪破碎起始风速问题。 相似文献
7.
High winds in a typhoon over the ocean can produce substantial amounts of spray in the lower part of the atmospheric boundary layer, which can modify the transfer of momentum, heat, and moisture across the air-sea interface. However, the consequent effects on the boundary layer structure and the evolution of the typhoon are largely unknown. The focus of this paper is on the role of sea spray on the storm intensity and the structure of the atmospheric boundary layer. The case study is Typhoon Imbudo in July 2003. The results show that sea spray tends to intensify storms by increasing the sea surface heat fluxes. Moreover, the effects of sea spray are mainly felt in boundary layer. Spray evaporation causes the atmospheric boundary layer to experience cooling and moistening. Sea spray can cause significant effects on the structure of boundary layer. The boundary-layer height over the eyewall area east to the center of Typhoon Imbudo was increased with a maximum up to about 550 m due to sea spray, which is closely related with the enhancements of the heat fluxes, upward motions, and horizontal winds in this region due to sea spray. 相似文献
8.
海气动量通量研究综述 总被引：1，自引：0，他引：1
海气界面动量通量也称为风应力,是海流和表面海浪的主要驱动力,是海洋从大气获得动量的重要途径。因此,合理可靠的海洋表面风应力的参数化对于海洋、大气和波浪以及气候模式的准确预报都具有非常重要的科学意义和实用价值。对风应力拖曳系数的参数化是风应力参数化的主要内容。近来的观测发现,风应力拖曳系数随着风速的增加出现了先增后减的趋势,同时还与海面的波浪状态以及海流有关。基于观测或理论分析,目前已经得到了一系列的风应力拖曳系数计算方法或公式,有的考虑了海浪的作用,有的没有,但这些方案大都是适合中低风速,在高风速下的适用性还有待检验。本文回顾了目前在海气动量通量观测和参数化方面的研究进展,并建议应增加高风速下风速、海流以及海浪等的同步观测,以进一步完善风应力参数化方案。 相似文献
9.
For any specific wind speed, waves grow in period, height and length as a function of the wind duration and fetch until maximum values are reached, at which point the waves are considered to be fully developed. Although equations and nomograms exist to predict the parameters of developing waves for shorter fetch or duration conditions at different wind speeds, these either do not incorporate important variables such as the air and water temperature, or do not consider the combined effect of fetch and duration. Here, the wind conditions required for a fully developed sea are calculated from maximum wave heights as determined from the wind speed, together with a published growth law based on the friction velocity. This allows the parameters of developing waves to be estimated for any combination of wind velocity, fetch and duration, while also taking account of atmospheric conditions and water properties. 相似文献
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G. S. Golitsyn 《Izvestiya Atmospheric and Oceanic Physics》2010,46(1):6-13
The problems of wind-induced waves on the sea surface are considered. To this end, the empirical fetch laws that determine
variations in the basic periods and heights of waves in relation to their fetch are used. The relation between the fetch and
the physical time is found, as are the dependences of the basic characteristics of waves on the time of wind forcing. It is
found that about 5% of wind energy dissipated in the near-water air layer contributes to the growth of wave heights, i.e.
wave energy, although this quantity depends on the age of waves and the exponent in the fetch laws. With consideration for
estimates of the probability distribution functions for the wind over the world ocean [11], it is found that the rate of wind-energy
dissipation in the near-water air layer is on the order of 1 W/m2. The calculations of wind waves [19] for the world ocean for 2007 have made it possible to assess the mean characteristics
of the cycle of wave development and their seasonal variations. An analysis of these calculations [19] shows that about 20%
of wind energy is transferred to the water surface. The remaining amount (80%) of wind energy is spent on the generation of
turbulence in the near-water air layer. About 2%, i.e., one tenth of the energy transferred to water, is spent on turbulence
generation due to the instability of the vertical velocity profile of the Stokes drift current and on energy dissipation in
the surf zones. Of the remaining 18%, 5% is spent directly on wave growth and 13% is spent on the generation of turbulence
during wave breaking and on a small-scale spectral region. These annually and globally mean estimates have a seasonal cycle
with an amplitude on the order of 20% in absolute values but with a smaller amplitude in relative values. According to [19]
and to the results of this study, the annually mean height of waves is estimated as 2.7 m and their age is estimated as 1.17. 相似文献
12.
海—气相互作用与海流、风暴潮 总被引：3，自引：4，他引：3
从方法论上说,除潮汐以外,通常在处理海洋动力学问题时,大多撇开海洋对大气的影响,强调大气对海洋的主导作用,把大气运动当作诱发海水运动的唯一原动力,视海面风场为给定条件,而后用经验或半经验公式算出海面风应力场,作为施加于海水的强迫力。因此,一个成功的海浪、海流或风暴潮的预报,除了具备反映海水运动的主要物理性能的数学模型外,还必须以客观的、准确的海面风场的数值计算和预报为前提。由于问题的复杂性,迄今为止似乎还不能说在实用上已经提供了海面风的一种足够精确的估算或预报方法。海上气象观测资料,尤其是测风资料的稀少,给海面风应力的实际计算带来不少困难。 相似文献
13.
本文是“海面动量、热量及水汽通量的浪沫效应”的第２部分。文中根据本课题第１部分方程组及初值化等改写所得方程组,对不同初始滴径和垂直速度的飞沫,在不同背景风场和温度场的情况下,计算飞沫入海距离、速度、滴径和滴温,以及估算飞沫出入海面所携带的动量、热量及水汽量等的变化量。计算结果所作比较说明了飞沫在海气相互作用中的重要作用。 相似文献
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15.
The parameter that describes the kinetics of the air-sea exchange of a poorly soluble gas is the gas transfer velocity which
is often parameterized as a function of wind speed. Both theoretical and experimental studies suggest that wind waves and
their breaking can significantly enhance the gas exchange at the air-sea interface. A relationship between gas transfer velocity
and a turbulent Reynolds number related to wind waves and their breaking is proposed based on field observations and drag
coefficient formulation. The proposed relationship can be further simplified as a function of the product of wind speed and
significant wave height. It is shown that this bi-parameter formula agrees quantitatively with the wind speed based parameterizations
under certain wave age conditions. The new gas transfer velocity attains its maximum under fully developed wave fields, in
which it is roughly dependent on the square of wind speed. This study provides a practical approach to quantitatively determine
the effect of waves on the estimation of air-sea gas fluxes with routine observational data. 相似文献
16.
近十余年来,海洋和大气相互作用这一课题日益受到人们的关注。从海-气边界层结构以及通过海面的物理量和化学量输送机制的研究到大尺度海洋和大气相互作用的研究都取得了可喜的成果。此外,还从海洋和大气相互作用的观点探索了风暴潮预报的新的可能途径[2]。然而,由于问题的复杂性,通过海面以及海-气边界层的物理量的小尺度输送机制迄未得到澄清,企图从本质上改善大尺度海洋和大气相互作用的理论是不现实的。 相似文献
17.
海浪不仅决定着海洋表面的粗糙度,由热带气旋引起的海浪,还通过其发展演化控制着大部分的海气之间的动量和能量传递。本文采用热带气旋观测数据IBTrACS和海浪模式WW III的模拟结果探究了热带气旋下海浪对大气向海洋输入的动量和能量的影响。结果发现,近30 a热带气旋的强度约每10 a增加 1 m/s,但移速没有明显变化。热带气旋的强度越大,从大气输入到海浪和从海浪输入到海流中的动量之差和能量之差也越大。由于热带气旋的风场和海浪场都有较强的不对称性,海气动量差和能量差也表现出非均匀分布:动量差较大的区域在热带气旋移动方向的后方,能量差的最大值则分布在右后象限,且二者均为左前方比较小。逆波龄与动量差和能量差呈高度正相关,相关系数约为0.95,说明波越年轻吸收的动量和能量越多。气旋移速越快逆波龄越大,且热带气旋移动速度与动量差和能量差呈正相关,相关系数在0.8以上。因此,海浪影响着大气向海洋输入的动量和能量的分布和大小,在以后关于海洋边界动力学和热力学的研究中,考虑海浪的演化可能会使结果更加准确。 相似文献
18.
风浪状态参数常用于对海面粗糙度的参数化。中等风速条件下考虑风浪状态参数影响的海面粗糙度参数化方案常存在自相关效应,本文通过分析实测数据得到了无量纲粗糙度随波陡变化的参数化方案,该方案能够有效去除自相关效应;高风速下风浪状态对海面粗糙度仍存在影响,文中基于新得出的中等风速下的海面粗糙度参数化方案,考虑海面飞沫悬浮层的影响,建立了适用于高风速条件下的海面粗糙度参数化方案,该海面粗糙度方案同样考虑了波陡的作用,将该方案计算出的理论值与实测数据进行比对,发现随着波陡的变化,理论值基本涉及测量值的覆盖范围,说明新建立的高风速条件下海面粗糙度方案对海面风浪状态具有较好的敏感性,且该方案能够较合理地描述海气界面之间动量传输。将新提出的适用于高风速下的海面粗糙度方案加入到海浪数值模式中,模拟飓风Ivan产生的台风浪,利用浮标数据进行验证,结果显示模拟的有效波高相对模式默认方案具有较高的精度,说明采用本文新建立的适合高风速的海面粗糙度方案能够改进海浪模式的台风浪有效波高模拟结果。 相似文献
19.
We present the results of investigation of the transformation of a momentum flux coming from the atmosphere into a water reservoir
and establish the relationship between the surface velocity of the drift current and the dynamic velocity of wind. For the
initial stage of the development of wind waves, we propose a dependence that enables one to determine the momentum flux spent
for an increase in the intensity of waves via the momentum flux coming into the water reservoir from the wind. The behavior
of the ratio of the momentum flux spent for the increase in the intensity of waves to the total momentum flux coming from
the atmosphere into the water is studied depending on the dimensionless fetch and age of waves. In our analysis, we used both
our own experimental data and the data available from the scientific literature.
Translated by Peter V. Malyshev and Dmitry V. Malyshev 相似文献
20.
This study investigates atmospheric responses to the directions of surface wind over the Kuroshio front in the East China Sea, using wintertime satellite-derived data sets. Composite maps of sea surface temperature, wind speed, precipitation, turbulent heat flux, surface wind divergence, and the curl of wind vectors above the atmospheric boundary layer are depicted based on the classification of intense northeasterly (along the front) and northwesterly (across the front) winds over the East China Sea. When northeasterly winds prevail, considerable precipitation occurs on the offshore side of the Kuroshio front, in contrast to periods when northwesterly winds prevail. First, the northeasterly winds strengthen above the front because of the downward transfer of momentum from the fast-moving air at higher levels and/or an adjustment of sea level pressure over the oceanic front, although the process by which the influence of the Kuroshio penetrates beyond the marine atmospheric boundary layer remains unclear. Second, a cyclonic vortex forms above the marine atmospheric boundary layer (at 850-hPa height) on the offshore side of the front, and thereafter, surface wind convergence via Ekman suction (hence, enhanced precipitation) occurs over the East China Sea shelf breaks. The northeasterly winds blow over the East China Sea when the Aleutian Low retreats to the east and when high sea level pressure covers the northern Sea of Japan. 相似文献