有蒸发-风反馈和海-气相互作用的CISK开尔文波——热带季节内振荡机制的进一步研究   总被引：3，自引：0，他引：3  

Li Chongyin  Han-Ru Cho  Jough-Tai Wang 《大气科学进展》2002,19(3):379-390

将波动－CISK（积云对流加热反馈）、海－气相互作用和蒸发－风反馈都引入一个简单理论模式，研究了他们在驱动热带大气季节内振荡（ISO）中的作用。其结果表明：波动－CISK在减慢激发波的位相速度以接近观测到的热带ISO的移速过程中起主要作用；而蒸发－风反馈的主要作用是使激发波不稳定；海－气相互作用在减慢激发波的移速方面也有一定作用。因此，波动－CISK和蒸发－风反馈可认为是热带ISO的主要动力学机制。本研究还表明，由于蒸发－风反馈和海－气相互作用的影响，激发波是一种频散波，这种频散性可以更好地解释热带大气中ISO的活动特征。  相似文献   

Vertical Structure Of Turbulence In Offshore Flow During Rasex     

L. Mahrt  Dean Vickers  Jim Edson  James M. Wilczak  Jeff Hare  Jørgen Højstrup 《Boundary-Layer Meteorology》2001,100(1):47-61

The adjustment of the boundary layer immediately downstream froma coastline is examined based on two levels of eddy correlation data collected on a mast at the shore and six levels of eddy correlation data and profiles of mean variables collected from a mast 2 km offshore during the Risø Air-Sea Experiment. The characteristics of offshore flow are studied in terms of case studies and inter-variable relationships for the entire one-month data set. A turbulent kinetic energy budget is constructed for each case study.The buoyancy generation of turbulence is small compared to shear generation and dissipation. However, weakly stable and weakly unstable cases exhibit completely different vertical structure. With flow of warm air from land over cooler water, modest buoyancy destruction of turbulence and reduced shear generation of turbulence over the less rough sea surface cause the turbulence to rapidly weaken downstream from the coast. The reduction of downward mixing of momentum by the stratification leads to smaller roughness lengths compared to the unstable case. Shear generation at higher levels and advection of stronger turbulence from land often lead to an increase of stress and turbulence energy with height and downward transport of turbulence energy toward the surface.With flow of cool air over a warmer sea surface, a convective internal boundary layer develops downstream from the coast. An overlying relatively thick layer of downward buoyancy flux (virtual temperature flux) is sometimes maintained by shear generation in the accelerating offshore flow.  相似文献   

Observations Of A Progressive Warm-Fresh Oceanic Front and A Cool-Moist Atmospheric Front At Duck, North Carolina     

Todd D. Sikora  David L. Porter  Steven M. Babin  Michael D. Wisecup 《Boundary-Layer Meteorology》2001,100(2):349-361

This paper presents a unique set of observations of nearlycoincident and progressive oceanic and marine atmospheric boundary-layer (MABL) fronts in a coastal zone. The event was observed during the afternoon of 12 May 1996 at the United States Army Corps of Engineers, Coastal Engineering Research Center, Field Research Facility pier at Duck, North Carolina. The oceanic front was warm and fresh. Current variabilityaccompanied the oceanic front. A marked MABL front preceded the oceanic front by several minutes and had characteristics of a sea-breezefront. This MABL front separated warmer and dryer pre-frontal air from cooler and moister post-frontal air. Wind direction and wind speedvariability accompanied the MABL front. The sea-surface roughness signatures of both fronts were detected by an X-band pulsed Doppler radar. Supporting data are used to identify each front detected by the radar and to calculate each front's velocity. In an attempt to explain the sea-surface roughness variations associated with each front, the radar data are compared to corresponding variations in wind speed, wind direction, and air-sea temperature difference.  相似文献   

Air-sea exchange of CO2 in the Gulf of Kutch,northern Arabian Sea based on bomb-carbon in corals and tree rings     

S. Chakraborty  R. Ramesh  S. Krishnaswami 《Journal of Earth System Science》1994,103(2):329-340

Radiocarbon analyses were carried out in the annual bands of a 40 year old coral collected from the Gulf of Kutch (22.6°N, 70°E) in the northern Arabian Sea and in the annual rings of a teak tree from Thane (19°14′N, 73°24′E) near Bombay. These measurements were made in order to obtain the rates of air-sea exchange of CO₂ and the advective mixing of water in the Gulf of Kutch. The Δ¹⁴C peak in the Thane tree occurs in the year 1964, with a value of ∼630‰, significantly lower than that of the mean atmospheric Δ¹⁴C of the northern hemisphere (∼ 1000‰). The radiocarbon time series of the coral was modelled considering the supply of carbon and radiocarbon to the gulf through air-sea exchange and advective water transport from the open Arabian Sea. A reasonable fit for the coral data was obtained with an air-sea CO₂ exchange rate of 11–12 mol m⁻² yr⁻¹, and an advective velocity of 28 m yr⁻¹ between the Arabian Sea and the Gulf of Kutch; this was based on a model generated time series for radiocarbon in the Arabian Sea. The deduced velocity (∼ 28 m yr⁻¹) of the advective transport of water between the gulf and the Arabian Sea is much lower than the surface tidal current velocity in this region, but can be understood in terms of net fluxes of carbon and radiocarbon to the gulf to match the observed coral Δ¹⁴C time series.  相似文献   

A study on dynamical features of air-sea coupling waves in the tropics   总被引：2，自引：0，他引：2  

Yang Xiuqun  Huang Shisong 《海洋学报(英文版)》1993,12(3):379-393

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.  相似文献   

一种船载海面通量观测的校正方法   总被引：2，自引：0，他引：2  

钱莉英  周乐义  周晓平 《海洋科学》1994,18(4):59-63

设计了一种用滤波法校正船载超声测风测量仪数据、计算海－气通量交换的方法。对１９８８，１９８９两年西太平洋海域考察期间超声测风测温仪的实测资料作了订正，订正了船体运动、特别是摇摆运动对风速的影响，用涡旋相关法计算了海面边界层的感热能量、动量通量、阻力系数和稳定度值。分析了海面上能量、阻力系数随大气状况的变化规律。计算结果表明，海面上的通量、阻力系数与水平风速和稳定度之间存在着合理的有规律的关系，证明  相似文献   

Gabriel T. Csanady: Understanding the physics of the ocean     

J.L. Pelegrí  J.H. Churchill  A.D. Kirwan  Jr.  S.-K. Lee  R.E. Munn  N.R. Pettigrew 《Progress in Oceanography》2006,70(2-4):91

Gabriel T. Csanady turned 80 in December 2005 and we celebrate it with this special Progress in Oceanography issue. It comprises 20 papers covering some of the many areas that Gabe contributed significantly throughout his professional career. In this introductory paper we briefly review Gabe’s career as an engineer, meteorologist and oceanographer, and highlight some of his major contributions to oceanography, both as a scientist as well as an educator. But we also use this opportunity to remember and thank Gabe, and his wife Joyce, for being such good friends and mentors to several generations of oceanographers. The authors of the collection of papers in this volume deserve special thanks for their efforts. We also are pleased to acknowledge the support of Progress in Oceanography’s editor, Detlef Quadfasel, and the many anonymous reviewers who generously contributed their time and expertise.  相似文献   

Air-Sea Interaction, Coastal Circulation and Primary Production in the Eastern Arabian Sea: A Review     

Alvarinho J. Luis  Hiroshi Kawamura 《Journal of Oceanography》2004,60(2):205-218

Air-sea interaction, coastal circulation and primary production exhibit an annual cycle in the eastern Arabian Sea (AS). During June to September, strong southwesterly winds (4∼9 m s⁻¹) promote sea surface cooling through surface heat loss and vertical mixing in the central AS and force the West India Coastal Current equatorward. Positive wind stress curl induced by the Findlater jet facilitates Ekman pumping in the northern AS, and equatorward-directed alongshore wind stress induces upwelling which lowers sea surface temperature by about 2.5°C (compared to the offshore value) along the southwestern shelf of India and enhances phytoplankton concentration by more than 70% as compared to that in the central AS. During winter monsoon, from November to March, dry and weak northeasterly winds (2–6 m s⁻¹) from the Indo-China continent enhance convective cooling of the upper ocean and deepen the mixed layer by more than 80 m, thereby increasing the vertical flux of nutrients in the photic layer which promotes wintertime phytoplankton blooms in the northern AS. The primary production rate integrated for photic layer and surface chlorophyll-a estimated from the Coastal Zone Color Scanner, both averaged for the entire western India shelf, increases from winter to summer monsoon from 24 to 70 g C m⁻²month and from 9 to 24 mg m⁻², respectively. Remotely-forced coastal Kelvin waves from the Bay of Bengal propagate into the coastal AS, which modulate circulation pattern along the western India shelf; these Kelvin waves in turn radiate Rossby waves which reverse the circulation in the Lakshadweep Sea semiannually. This review leads us to the conclusion that seasonal monsoon forcing and remotely forced waves modulate the circulation and primary production in the eastern AS. This revised version was published online in July 2006 with corrections to the Cover Date.  相似文献   

与夏季北太平洋副热带中尺度海洋涡旋相联系的海气关系     

徐全倩  徐海明  马静 《大气科学》2018,42(6):1191-1207

采用高分辨率卫星和再分析资料,利用涡旋探测技术、滤波和合成分析等方法,对夏季北太平洋副热带地区中尺度海洋涡旋与大气的耦合关系进行了分析。结果表明:在日时间尺度上,海洋涡旋的海表温度（Sea SurfaceTemperature,简称SST）与海表风速之间不仅存在同位相的正相关关系,还存在反位相的负相关关系,即在涡旋这种中尺度上既存在海洋对大气的强迫,也存在大气对海洋的强迫。海表风速与SST同位相时,对暖（冷）涡来说,向上（下）的净热通量增强,云和降水增多（减少）;其海水温度异常和海流旋度较强,暖（冷）涡较为深厚,一定程度上表明了海洋对大气的强迫。海表风速与SST反位相时,对暖（冷）涡而言,当其处在正（负）位势高度异常、中低层相对湿度较小（大）、气温较高（低）的大气配置下,海表风速较小（大）;同时向下（上）净热通量增强,云和降水减少（增多）;涡旋海水温度异常和海流旋度较弱,这种暖（冷）涡较为浅薄;表明晴空（阴雨）条件下有利于暖（冷）涡的维持,一定程度上反映了大气对海洋的强迫作用。  相似文献   

热带印度洋的大尺度海气相互作用事件   总被引：28，自引：4，他引：24  

巢纪平  袁绍宇  蔡怡 《气象学报》2003,61(2):251-256

分析了热带温跃层上海温距平资料后指出 ,在印度洋东西方向的海温距平分布呈现出距平符号相反的偶极子现象 ,在大气中的纬圈环流即Walker环流上也呈现出与海温距平相协调的或匹配的上升和下沉分支 (距平意义下 )分布。这一分析表明 ,印度洋也存在和太平洋类似ENSO的大尺度海气相互作用事件  相似文献