青岛市海雾海气通量观测及其作用初探

概述１９９３年６月下旬－７月上旬在青岛市小麦岛东侧进行的风、温、湿梯度观测。其资料经迭代计算得到了黄海北部、青岛市近海平流雾季节海气间动量、热量和水汽的通量。并对７月１—２日的一个海雾过程进行了微物理分析。     

冬季北太平洋海表热通量异常和海气相互作用——基于一个全球海气耦合模式长期积分的诊断分析

利用一个全球海气耦合模式长期积分所给出的资料,分析了冬季北太平洋海表湍流热通量（潜热和感热）异常及其对海表温度（SST）异常的影响,并比较了海表热通量诸分量和海洋内部的动力学过程对SST变化的相对重要性。结果表明,冬季热带外海洋上的湍流热通量是影响SST的主要因子,但在北太平洋中部海水的平流作用也不可忽视。冬季热带外海洋向大气释放的潜热和感热通量与SST倾向（而不是SST本身）之间存在着显著的相关,这同Cayan和Reynolds等利用COADS资料和NCEP资料同化模式分析的结果是一致的。模式诊断的结果支持这样一种看法：和热带海洋不同,冬季热带外海洋上的海气相互作用主要地表现为大气对海洋的强迫作用,而不是相反。模式给出的SST倾向的第一个EOF分量及其与海平面气压场的相关特征同Wallace等从观测资料分析所得到的结果是一致的;进一步的分析表明：在冬季北太平洋的大部分区域（特别是西太平洋）,大尺度大气环流异常在很大程度上决定着SST的异常,而这种决定作用正是通过它对湍流热通量的强烈影响来实现的。     

一次入海气旋在黄渤海造成的海雾过程分析

利用0.25°×0.25°逐小时ERA5再分析数据、中国气象局地面观测资料和卫星遥感监测资料对2020年5月2-4日移入黄海的温带气旋引发大范围的海雾过程进行了分析,结果表明：（1）本次海雾主要发生在入海气旋的西侧和北侧,同时具有平流冷却雾和锋面雾的性质。（2）黄渤海雾发生期间气海温差在0.5～2.5℃,2 m高度露点温度略高于海温。（3）在气旋西侧和北侧都出现了雨转雾的现象,并且从青岛L波段雷达监测温度廓线显示在500 m和1500 m高度上出现“双逆温”。（4）气旋造成的湿空气辐合是本次海雾过程的重要水汽来源,降水的加湿和蒸发冷却效应同样使得近海面大气饱和度快速增长。（5）黄渤海大部海域感热通量和潜热通量均为负值,湍流热通量主要表现为大气向海洋输送,气旋造成的垂直风切变增强了大气机械湍流,使得大气和海洋进行充分的热量交换从而促进海雾在垂直方向发展。     

一个黄渤海海雾大气水平能见度算法

为了提高对黄渤海海雾天气海面大气水平能见度（以下简称“能见度”）的数值预报能力,利用黄渤海23个沿岸和岛屿测站2013—2017年雾天的地面观测数据,构建了基于湿度信息的能见度算法（A-F算法）,并将之应用于黄渤海海雾的能见度数值预报。结果表明,与常用的根据模式预报的云水含量诊断能见度的SW算法（Stoelinga and Warner,1999）相比,A-F算法表现更优,尤其可以诊断出被SW算法漏报的能见度为1～3 km的轻雾,说明A-F算法对黄渤海海雾天气能见度的数值预报具有一定应用价值。若将来加入浮标与船舶观测数据,可以进一步改进A-F算法能见度公式的具体形式;依据本文构建A-F算法的思路,可以发展适合其他海域的海雾天气能见度诊断公式。     

2020年12月一次北部湾海雾过程的生消特征分析

2020年12月26-28日,北部湾出现了持续性大雾,其中炮台角站连续35h出现大雾.利用北部湾沿岸海岛站、浮标站等观测资料和ERA5再分析资料,对此次典型海雾过程的生消特征进行分析.结果表明,此次海雾过程主要受人海高压后部偏东暖湿气流影响.海雾期间,北部湾上空有逆温层,大气层结稳定,湿层深厚且维持时间长,近地层有0～...     

冬季北太平洋海表面热通量异常和海气相互作用的耦合模式模拟

基于中国科学院大气物理研究所大气科学与地球流体力学数值模拟国家重点实验室(LASG/IAP)开发的耦合气候系统模式FGOALS_s1.0控制试验的积分结果,分析了冬季北太平洋海表面湍流热通量(潜热和感热通量之和)异常及其对海表面温度(SST)异常的影响,并通过分析海温倾向方程,比较了各因子对SST变率的相对贡献.结果表...     

黄渤海一次持续性海雾过程形变特征及其成因分析

2016年3月3—5日,渤海和黄海大部出现了一次大范围持续性的海上大雾天气过程。本文从卫星遥感监测上分析海雾在生成、发展和消亡三个阶段的形态演变特征。从海洋气象条件上分析了山东半岛东南近海没有海雾和海雾形态演变的原因。结果表明:(1)在海雾形成初期,在山东半岛东南海域有弱气旋性弯曲,大气层结不稳定,地面形势受低压影响,虽受偏南风控制,但湿度小,无水汽辐合,因此在山东半岛东南近海没有雾。(2)海雾的形成与低层的偏南暖湿气流有关,而这个偏南暖湿气流来源于西北太平洋,雾区对应着水汽辐合区,海气温差为0～1℃的区域与雾区吻合,在海雾发展成熟期,雾顶长波辐射导致雾体降温,出现气温低于海温的现象。(3)925～1000 hPa垂直风切变有利于海雾在逆温层内维持和垂直高度上的发展,形成有一定厚度的海雾。     

赤道不稳定波对海气相互作用影响的数值模拟分析

赤道不稳定波 (tropical instability waves) 存在于热带东太平洋赤道附近, 通常于每年的春末夏初出现, 以约0.6 m/s速度向西传播, 波周期为20～40天左右, 波长约为1000～2000 km.本文利用一个全球高分辨率海气耦合模式对赤道不稳定波在赤道附近的热量输送进行分析, 表明赤道不稳定波产生指向赤道的热通量, 从而部分抵消了热带东太平洋地区由Ekman辐散和温度平流导致的强冷却效应, 维持热带地区的热量平衡.其对赤道冷舌区的增暖作用可以消除和减弱气候模式中热带东太平洋地区的系统性冷偏差, 能使冷舌的强度和分布得到合理的改善, 对气候模式的改进和发展具有潜在贡献.赤道不稳定波还可以改变赤道海洋上空低层大气层结稳定度, 导致近地层强的风场辐合辐散, 并进一步影响大气混合层的温度、 风场等气象要素.模拟分析结果还表明, 赤道不稳定波对大气强迫产生二次响应, 改变赤道上空逆温层的垂直位移和逆温强度.研究赤道不稳定波对热带海洋气候及其海气相互作用机理的理解具有重要意义.     

南海夏季风期间海-气通量整体输送系数分析

利用 2 0 0 0年南海海 气通量观测资料 ,建立了南海季风期间海 气通量整体输送系数的计算公式 ;同时 ,利用2 0 0 0和 2 0 0 2年观测资料与邻近海区同类公式进行了对比试验研究。结果表明 ,使用邻近海区的同类公式计算的海 气通量的误差高于新建立公式所得结果。因此 ,开展南海海 气通量观测试验对建立适合于南海的整体输送系数的计算公式是必要的     

IMPACT OF AIR-SEA INTERACTION ON THE GENESIS OF TROPICAL INCIPIENT VORTEX OVER SOUTH CHINA SEA: A CASE STUDY

Based on 6-hourly sensible heat flux and latent heat flux from the NCEP Climate Forecast System Reanalysis (CFSR) and circulation data from the Japanese 25-year Reanalysis (JRA-25), the initial developing process of tropical cyclone Mindulle (1005) in 2010 has been diagnosed to reveal the impact of air-sea interaction over the South China Sea (SCS) on the genesis of its incipient vortex. The results show that the incipient vortex first occurred east of the Luzon Island on 0000 UTC 20 August, suggesting that the topographic forcing of the Luzon Island for easterly winds over the western Pacific might be one of the factors responsible for the formation of the incipient vortex. During the formation stage of the incipient vortex, strong southeasterlies over the SCS caused warm water of the middle and eastern SCS to flow toward the Luzon Island due to Ekman transport resulting from wind stress, leading to an increase of the sea surface temperature and sensible heat flux into the atmosphere. Although the anomalous sensible heating favored surface pressure to reduce, it was not conducive to the increase of local vorticity associated with the vortex above the heating area because, according to the atmospheric thermal adaptation theory, the anticyclonic vorticity would be created in the lower troposphere due to the decreased vertical gradient of the sensible heating. However, the ascending motions occurred over the eastern area of the anomalous sensible heating due to the augmentation of the vorticity advection with increasing height, causing water vapor to condense in the middle and upper troposphere. In turn, cyclonic vorticity was generated in the lower troposphere due to the increased vertical gradient of the condensation latent heating, resulting in the formation and further growth of the incipient vortex. Therefore, the vorticity creation due to the condensation heating played a dominant role during the subsequent enhancing stage of the incipient vortex.     

NUMERICAL ANALYSIS OF THREE-DIMENSIONAL STRUCTURE OF THE SEA BREEZE OVER SOUTHWESTERN BOHAI GULF

In this paper,a simulation study is made on the sea breeze process over southwestern Bohai Gulf byuse of the Pielke mesoscale meteorological model.The simulated results show that when a south wind of 8m/s blows over the top of the model,a strong wind zone of 15—25 km wide with a maximum speed more than14 m/s,which is close and nearly parallel to the south shore,will appear at 160 m above the sea surface.When a strong sea breeze penetrates inland,there often appears a thermal internal boundary layer(TIBL)near shore.The inversion above the TIBL can damp the vertical dispersion of atmospheric pollution.Besides,it is also found that,for a three-dimensional sea/land breeze circulation,if the divergence centre inthe return flow departs vertically far from the correspondent convergence centre in the sea breeze,a centre ofstrong descending movement will be formed at the middle and upper levels of the return flow.The resultsin this paper is also applicable to the Laizhou Bay.     

南海年际尺度海气相互作用的初探

本文分析了南海海洋大气系统短期气候变化中存在年际振荡的若干观测事实，提出了局地尺度南海海洋与低层大气相互作用的一种可能机制。针对南海表层水温距平和低层风场异常的相关，设计了一个类似与ＭｃＣｒｅａｒｙ和Ａｎｄｅｒ－ｓｏｎ（１９８４）模型的简化海气耦合模式。大气部分为随下垫面海温变化而变化的异常风应力阶梯函数与季节性风场的联合；海洋部分为非线性β－平面的约化重力模式。考虑南海海洋大气相互作用中存在的海温与低层大气风场变化之间反馈过程，耦合模式在气候积分中表现出一类约３ａ的周期性年际振荡。说明这个区域ＳＳＴ、低层大气风场年际振荡是南海海盆尺度的海气相互作用的反映，改进了关于南海ＳＳＴ年际振荡是海洋对大气应力甚低频强迫响应的认识     

STUDY ON THE AIR-SEA INTERACTION ON THE INTERANNUAL TIME SCALE IN THE SOUTH CHINA SEA

In this paper we document the correlationship between sea surface temperature (SST) and lowlevel-winds such as sea level wind and 850 hPa wind in the South China Sea (SCS) based onCOADS (1958—1987) and ECMWF objective analysis data (1973—1986).Further statisticalanalyses tell us that there is a fixed SCS basin mode for variations both of SST and low-level windsin the region on the interannual time scale due to air-sea interactions.A simplified,coupled model that is designed following the McCreary and Anderson's (1985)model and includes the feedback between the upper ocean and the circulation of East Asianmonsoon demonstrates an interannual oscillation in the coupled air-sea system,which is similar tothe observations in the SCS.     

奇异交叉谱在海气相互作用诊断研究中的应用

利用SCSA（奇异交叉谱分析）方法,对中低纬海气及中低纬环流相互作用的耦合同期信号进行分析。结果表明：在3－7年尺度上海气相互作用关系密切,这个尺度与ENSO循环尺度基本一致,且其振荡行为与ENSO根荡相似．从这个意义上说在中低纬海气相互作用中,ENSO是个强信号;中低纬环流相互作用存在10－12年及准4年的优势耦合周期,其中准4年振荡和ENSO循环尺度相一致．这说明中低纬环流相互作用,除受ENSO影响外,自身还存在10年左右的振荡周期。     

南海西北部一次海上海雾的微物理及化学特性分析

利用2017年3月MICAPS资料、欧洲气象中心再分析ERA-Interim数据及在南海西北部海上的海雾观测数据,分析了南海西北部一次海上海雾的微物理特征和雾水化学特性,并将海上海雾与南海岸边海雾进行对比分析。结果表明:此次海雾为南海偏南暖气流移至冷海面发生冷却并达到饱和而形成。海雾过程中气压与气温变化趋势相反,相对湿度不断增加,雾滴数浓度、液态含水量和平均直径的平均值分别为198 cm-3、0.116 g/cm3和5.6 μm。相比广东湛江东海岛和广东茂名博贺地区岸边海雾个例,本次海上海雾水汽充足,雾滴偏大。本次海雾属于酸性海雾,pH值变化范围为2.51~3.50,海雾后的雨水样本pH值则为4.05。海雾发生初期电导率比其它阶段高很多,说明海雾发生的初始阶段雾水溶解了大量的气溶胶。海上雾水中Na+和Cl-浓度最高,浓度分别为32 535 μmol/L和53 466 μmol/L,K+浓度远高于Mg2+和Ca2+,而东海岛岸边海雾相反。      

STUDY ON THE QUASI-FOUR YEAR OSCILLATION OF AIR-SEA INTERACTION

Complex Singular Value Decomposition(CSVD)analysis technique was applied to study theQuasi Four year Oscillation(QFO)of air sea interaction and its coupled pattern evolution duringdifferent phases.Results show that:(1)CSVD method can better reveal phase relation betweentwo physical fields:(2)Not only northerly anomalies from Northern Hemisphere but alsosoutherly anomalies from Southern Hemisphere contribute to EI Nino.They converge in westernequatorial Pacific,leading to outburst of strong equatorial westerly anomalies,and result in strongEl Nino event onset:(3)An abnormal subtropical anticyclone circulation appears overnorthwestern Pacific while El Nino developing.It favors transitions from the warm SST(EINino)to the cold SST(La Nina),just as the tropical westerly anomalies produced by abnormalcyclone during a decaying La Nina.which encourage the development of El Nino:(4)Thewesterly anomalies in equatorial Pacific are mainly induced by eastward abnormal subtropicalcyclone pairs,which are located in north and south Pacific respectively,and are not the eastwardwesterly anomalies from equatorial Indian Ocean.     

SEASONAL DEPENDENCE OF LOCAL AIR-SEA INTERACTION OVER THE TROPICAL WESTERN PACIFIC WARM POOL

Based on the air-sea interface heat fluxes and related meteorological variables datasets recently released by Objectively Analyzed Air-Sea Fluxes (OA Flux) Project of Woods Hole Oceanographic Institution, as well as the outgoing longwave radiation and surface wind datasets from National Oceanic and Atmospheric Administration, the seasonal dependence of local air-sea interaction over the tropical western Pacific warm pool (referred to the region (1o-6oN, 144o-154oE)) is revealed and the probable impacts of remote forcing on the air-sea interaction are examined. The results indicated the dominance of oceanic forcing with the significant impact of ENSO in March and that of atmospheric feedback without notable influence of remote forcing in June. While the interannual variability of sea surface temperature anomaly (SSTA) is larger than that of SSTA tendency when oceanic forcing is dominant, the opposite is true when atmospheric feedback is dominant. The magnitude of the oceanic forcing of the atmosphere tends to decrease in March with the occurrence of ENSO, though ENSO has little influence on the atmospheric feedback to the ocean in June. The local air-sea interaction is substantially the same before and after the removal of the effect of Indian Oceanic Dipole. The reduction of shortwave radiation fluxes into the western Pacific warm pool, due to the enhanced overlaying convection in March associated with ENSO, leads to the decline of SST tendency that will weaken the oceanic forcing of the atmosphere.     

热带西太平洋暖池局地海气相互作用的季节依赖性

采用美国伍兹霍尔海洋研究所的客观分析海气通量项目最新发布的海气热通量和相关气象场、NOAA提供的向外长波辐射和表面风场等数据,研究了暖池区域(144～154 °E,1～6 °N)局地海气相互作用的季节依赖性,并探讨可能对其产生影响的外强迫。结果表明,暖池区域海气相互作用在3月显著表现为受ENSO影响的海洋对大气的强迫,而在6月则显著表现为以局地作用为主的大气对海洋的反馈。当海洋强迫大气占主导时,海温趋势(dSST/dt)的年际变化的数值小于海温;而当大气反馈海洋占主导时,海温趋势的年际变化数值大于海温。ENSO会减弱暖池区域3月海洋对大气的强迫,而6月大气对海洋的反馈受ENSO影响不大;去除印度洋偶极子(IOD)影响后海气关系基本维持不变。3月ENSO通过增强暖池上空的对流,减少短波入射,从而使海温呈降低趋势,减弱海洋对大气的强迫。      

海气相互作用的零维模式

利用文献[4],本文求出了考虑海气耦合时零维模式的平衡态,讨论了它们的稳定性和现代气候的敏感性问题。 结果表明:气候系统存在三个平衡态,两个稳定态分别表示冰期和间冰期气候;当考虑海气作用时,现代气候条件下的敏感性比不考虑海气作用时小,外参数变化为1%,温度平均变化为1°K左右。 在此基础上,就随机模式的反馈系数提出了不同的看法,对随机分析作了简略探讨,并用实际资料进行了检验。