Local balance in the air-sea boundary processes

In the course of the new treatment of the growth process of wind waves presented in part I of the present series of the articles, there was a point where the wave energy and wave momentum were not related correctly. This point has been revised with critical argument, and at the same time, the form of the ratior, between the wind stress that directly enter the wind waves and the total wind stress, has been derived analytically. The growth equation, under the condition that the wind stress is constant, is still the same with that derived in part I, with the exception that the ratior is given analytically.A comparison between the ratior obtained analytically and that estimated empirically in part I, raises a problem to be studied about the wave current of the actual wind waves.     

Local balance in the air-sea boundary processes

A new growth equation for wind waves of simple spectrum is presented upon three basic concepts. The period and the wave height of significant waves in dimensionless forms, which are considered to correspond to the peak frequency and the energy level, respectively, are used as representative quantities of wind waves. One of the three basic concepts is the concept of local balance, and the other two concern the acquisition of wave energy and the dissipation of wave energy, respectively. It is shown from some actual data that the equation, together with two universal constants concerning the acquisition and the dissipation of wave energy (B=6.2×10^?2 andK=2.16×10^?5, respectively), is applied universally to wide ranges of wind waves from those in a wind-wave tunnel to fully developed sea in the open ocean. “The three-second power law for wind waves of simple spectrum”, and a few relations as the lemmas, are derived, such that the mean surface transport due to the orbital motion of wind waves is always proportional to the friction velocity in wind, and that the steepness is inversely proportional to the root of the wave age. It is also derived that the portion of wind stress which directly enters the wind waves decreases exponentially with increasing wave age and is 7.5 % of the total wind stress for very young waves. Also, equations are presented as to the increase of momentum of drift current, and as to the supply of turbulent energy by wind waves into the upper ocean.     

Dynamics of air-sea planetary boundary layer under the geostrophic momentum approximation condition

In this paper, the air-sea planetary boundary is divided into three layers. With the aid of geostrophic momentum approximation, wind and current profiles, surface wind, surface wind stress and Ekman pumpinii in the atmosphere as well as in the ocean affected by the atmospheric baroclini-city, stratification and nonlinear effects are investigated systematically for an ocean of infinite depth. Meanwhile, the characteristics of the air-sea interaction is analyzed.     

不同边界层稳定性下海气湍流热通量日变化的前沿问题探讨

海气湍流热通量(潜热和感热)是研究海气相互作用和大洋环流的关键要素, 认识其变化机理对理解“海洋动力过程及气候效应”有重要意义。然而, 受观测手段和计算能力两方面的限制, 过去对海气湍流热通量日变化研究存在“特征认识较粗、机制理解较疏”的现象。本文探讨了在不同边界层稳定性下海气湍流热通量日变化研究中的问题与难点, 并讨论了“不同边界层稳定性下海气湍流热通量日变化过程和机理”这一关键科学问题。本文提出, 可基于海洋浮标、平台和波浪滑翔机等综合观测数据和高时空分辨率再分析资料, 利用块体算法和脉动分离方法, 揭示全球海气湍流热通量的精细化日变化特征和决定因素, 以及海气湍流热通量日变化强度(日内小时级变化的标准差)与极端天气过程和气候事件的动力关联。同时, 为更精准认识日变化过程, 在技术上可通过耦合高频海表流速和校正边界层物理参数观测高度等方式提升海气湍流热通量估算的精确度。本文提出可将多时空尺度海气湍流热通量变化维度转换到边界层稳定性上, 以便集中认识其日变化特征和机理, 支撑全球海气能量平衡的科学认识。     

Reflection of large-scale inhomogeneities in the air-sea boundary layer on the intensity of surface wave breaking in the ocean

An overview of experiments is given on the observation of the dependence of the intensity of wind wave breaking on large-scale currents' inhomogeneities and atmospheric boundary layer stratification. The data were interpreted using a model in which the variance of the wind wave breaking intensity reflects fluctuations in the influx of energy to wind waves due to various factors. Translated by V. Puchkin.     

The effect of wave disturbances of the near-surface layer on the structure of the air-sea boundary layers

A method is suggested to consider energy transfer to surface waves via introducing wave stresses into the numerical model for the interaction of air-sea boundary layers. In numerical simulations, the wave stresses are shown to influence the air-sea interaction parameters and the profiles of the major quantities.Translated by V. Puchkin.     

Benthic boundary layer processes in the Lower Florida Keys

 This special issue of Geo-Marine Letters, “Benthic Boundary Layer Processes in the Lower Florida Keys,” includes 12 papers that present preliminary results from the Key West Campaign. The Dry Tortugas and Marquesas Keys test sites were selected by a group of 115 scientists and technicians to study benthic boundary layer processes in a carbonate environment controlled by bioturbation and biogeochemical processes. Major activities included remote sediment classification; high-frequency acoustic scattering experiments; sediment sampling for radiological, geotechnical, biological, biogeochemical, physical, and geoacoustic studies; and hydrodynamic studies using an instrumented tetrapod. All these data are being used to improve our understanding of the effects of environmental processes on sediment structure and behavior.     

Adaptive balance of global development processes

We study the processes of global self-regulation of Earth’s biota (GAIA-theory) by applying the method of adaptive balance of causes proposed by the authors. By using, as an example, the Daisy World model constructed by this method, we reveal the phenomenon of preservation of the mean temperature of Earth’s surface due to the presence of the vegetation cover. We develop an integral model of global natural, social, and economic processes in which the World Ocean is one of the factors regulating the amount of greenhouse gases in the atmosphere. The decrease in the amount of greenhouse gases in the atmosphere caused by the GAIA-effects increases the number of hurricanes and floods on the Earth. As a result, the levels of ecological and social hazards for the mankind become much higher. To eliminate these threats, it is necessary to intensify the processes of self-organization of the society realized via the improvement of education, development of science, and global regulation of the competition for natural resources. We present the results of numerical experiments performed by using the model demonstrating possible scenarios of global development with regard for the processes of self-organization of the society. __________ Translated From Morskoi Gidrofizicheskii Zhurnal, No. 3, Pp. 62–80, May–June, 2007.     

SST年循环对El Niño事件局地海气过程的影响

利用Hadley中心逐月海表温度、欧洲中心ERA-40的10 m风场及CMAP降水资料探讨了年循环对热带太平洋El Niño海气相互作用过程的影响。尽管El Niño对应的海表温度异常主要出现在赤道东太平洋,经向上呈南北对称分布,然而其对应的大气响应在El Niño年衰减阶段却有着强的向南移动特征。在El Niño发展年的11月之前,强的西风和降水异常主要出现在赤道中太平洋;在12月份之后,赤道上的西风和降水异常迅速南移至5°S,随后西风一直维持在该位置直至衰亡。同时,西太平洋负降水和反气旋异常向北移动。这种SST异常与其大气响应的经向移动不一致,主要是由热带中太平洋气候态SST的季节性南移导致的。由于对流与海温之间存在非线性关系,即当总SST超过一定的阈值,对流降水才会迅速增强;因此相应的对流响应也随着总海温的南移而南移,风场响应也同时南移。此外,南半球增强的对流会通过经向环流进一步抑制北半球的降水,从而使西太平洋负降水和反气旋异常增强并北移。通过分析有/无年循环的两组数值试验结果验证了上述结论,即有年循环的试验较真实地模拟出了观测中异常西风南移和西北太平洋反气旋异常的出现;无年循环试验尽管能模拟出El Niño年赤道中太平洋的西风异常,但其却没有南北向的移动,西北太平洋的反气旋也没有出现。因此,热带中太平洋气候态暖海温的季节循环对El Niño事件大气响应有着至关重要的作用。     

Benthic boundary layer processes in coastal environments: An introduction

This special issue ofGeo-Marine Letters Benthic Boundary Layer Processes in Coastal Environments includes 20 papers devoted to results of recent near-shore experiments supported by the Coastal Benthic Boundary Layer (CBBL) program. Experiments were conducted in gas-rich muddy sediments of Eckernförde Bay of the Baltic Sea and on relict sandy sediments of the West Florida Sand Sheet. In this introductory paper we present scientific justification for experiments and summarize preliminary results.     

Prediction of natural processes by the method of adaptive balance of causes

The problem of estimation of the future values of processes is studied as a problem of their adaptation to the known data of observations in the past. The method of adaptive balance of causes (ABC-method) is used for the construction of a dynamic model of the coefficients of influence. This model enables one to compute the current values of these coefficients according to the current correlation matrix determined as a result of reanalysis of the observed processes. We propose an ABC-model with variable coefficients of influence guaranteeing the optimal (from the viewpoint of accuracy) prediction of natural processes and present an example of its application.Translated from Morskoi Gidrofizicheskii Zhurnal, No. 5, pp. 53–63, September–October, 2004.This revised version was published online in May 2005 with corrections to cover date.     

气体交换速率和时间平均尺度对海-气碳通量估计的影响

基于卫星资料建立的CCMP风场、ECMWF波浪和最新CO₂分压数据, 分别用4种以风速为单参数和2种包含海况影响的双参数气体交换速率公式, 估算了全球海-气CO₂通量, 发现前者的结果比后者平均小30%左右, 从整体上看, 与单参数公式相比, 双参数公式使得海洋中CO₂源和汇的强度均明显增强。在此基础上, 讨论了时间平均尺度对海-气CO₂通量估计的影响, 结果表明, 标量平均法比矢量平均具有更好的稳定性, 但依然使得短时间平均比长时间平均得到的CO₂通量值要大, 月平均与6 h平均相比, 单参数公式和双参数公式分别使海洋的净吸收量减少33%和5%, 说明双参数公式具有较好的稳定性。研究还发现, 1988-2009年间, 全球平均风速有增大的趋势, 2006年前后出现一个极大值, 但相应的CO₂年净通量基本保持稳定, 甚至其绝对值有所减小、海洋的吸收能力减弱的倾向。     

三沙湾夏季底边界层动力过程及悬沙输运特征

基于2018年8月福建三沙湾湾内外共两个定点站位的船基和座底三脚架观测数据,研究了三沙湾底边界动力过程及悬沙输运特征。结果表明,三沙湾湾内湾外两个站位均表现出涨落潮历时相近但涨落潮流速明显不对称的现象,即湾内涨潮流速大于落潮流速,湾外则相反。湾内水体受淡水输入影响较大,表现出落潮期间显著的温盐层化,而涨潮期间水体混合良好;湾外水体受淡水影响不明显,表现为水体温度主导的层化。通过对底边界层动力过程的分析表明,湾内(距底0.75m)、湾外(距底0.50m)站位底边界层的平均摩阻流速分别是0.016m/s、0.013m/s,且两个站位拖曳系数基本相等(2.03×10^–3),表明在相同流速下湾内站位的底部切应力更大,近底沉积物再悬浮和搬运相对湾外站位更为显著。因此观测期间悬沙浓度最大值出现在湾内站位,为109mg/L,且悬沙在垂向上的分布可达上层水体;湾外站位悬沙浓度更低,并且底部悬浮泥沙仅能影响至距底5m的水体。悬沙通量机制分解结果表明,三沙湾夏季的潮周期单宽悬沙从湾外向湾内方向净输运,湾内站位向湾内方向净输运74.88 g/(m·s),平流输沙占主导作用,贡献率41....     

Analysis of the air-sea heat exchange during the El Nino event in 1983

In this paper,by using the ECMWF objective analysed data as well as CAC and NOAA grid point data of 1981 and 1983,the sensible and latent heat fluxes at the air and sea boundary surface within the range of 45°E-75°W, 35°N-35°S over the Pacific and the Indian Ocean are calculated. The purpose is to analyse the different revealing features during the mature stage and at the end of the 1982 -1983 El Nino event and to compare the difference of the features between thd El Nino and the normal. The result shows that the air and sea heat exchange west of the dateline over the central tropical Pacific during the EJ Nino period is more intense than that of the normal. However,the fluxes of the sensible and latent heat on the sea surface with strong warming of SSTneat by and on the south side of the equator east of 170°W are low and even negative,and the patterns of the sensible and latent heat fluxes over the Indian Ocean during the year of 1983 are similer to that of normal. Spatial patterns of the sensible     

A study on dynamical features of air-sea coupling waves in the tropics

The dynamical features of air-sea coupling waves and their stabilities in a simple coupled air-sea model in the tropics have been studied with respect to interaction occurring among different types of the free waves in the o-cean and in the atmosphere. It is pointed out that there exist a stable and an unstable air-sea interaction modes in the tropical coupled system , respectively. The propagation of the unstable mode relies greatly on the zonal space scale, i. e. only for wave length ranging from 5 000 km to 10 000 km can the disturbance unstably move slowly eastward. The waves that slowly propagate unstably eastward agree well with the observational facts. Finally,it is also proposed that the interaction between Kelvin wave in one medium and Rossby wave in another medium is a necessary condition for the occurrence of destabilization of the coupled air-sea system in the tropics.     

The influences of environmental factors on the air-sea coupling coefficient

The response relationship between equivalent neutral wind speed anomaly(ENWSA) and sea-air temperature difference anomaly(SATDA) has been analyzed over four typical sea regions, i.e., the Kuroshio Extension, the Gulf Stream, the Brazil-Malvinas Confluence and the Agulhas Return Current. The results show that ENWSA is more sensitive to SATDA than sea surface temperature anomaly(SSTA), which implies that SATDA seems to be a more suitable parameter than SSTA to analyze the mesoscale air-sea interac...     

波浪以增大交换面积的方式影响海-气通量

为体现波浪起伏增大交换面积进而增强通量这一事实,本文在已有海-气通量模型基础上提出了一种新的波面增长因子计算公式。就线性波叠加方法产生的波面而言,在风速为10 m/s时充分成长的波浪至少可使热通量增加7.9%,这比用单个正弦波得到的最大增加量3.7%的2倍还多。当风速增大到20 m/s时由新公式给出的增加量则能达到30%。研究还表明,借用经验波谱进行海面模拟难以体现毛细波,真实海面的面积增加量不止模拟的那么少,波浪对海-气通量的影响还应更强。