BASIC CHARACTERISTICS OF THE ATMOSPHERIC BOUNDARY LAYER OVER THE WESTERN PACIFIC

The western Pacific,one of the most violent air-sea interaction areas,plays an important role in theformation of ENSO events which greatly affect global climate change.Knowledge on the structure of theatmospheric boundary layer and the air-sea exchange over that area is very important and is the key tounderstanding the air-sea interaction. Tethered balloon measurements were made successfully during theSeptember-October,1987 cruise of the R/V SCIENCE 1 in the Philippine Sea at the northwest ofthe Warm Pool.The data collected were used for analysis of the structure of the atmospheric boundary layer showingthat the characteristics of the inversion layers(advection layer,capping inversion layer and radiation layer)are different from those over the land and other sea areas.The wind profiles were simulated with the P-exponent method and the values of P under unstable, sta-ble and neutral conditions were obtained. Moreover,the effect of the ship body on the air above was es-timated to reach 30 meters high.     

Analyses of structure of planetary boundary layer in ice camp over Arctic ocean

The vertical structure of Planetary boundary layer over Arctic floating ice is presented by using about 50 atmospheric profiles and relevant data sounded at an ice station over Arctic Ocean from 22 August to 3 September,2003.It shows that the height of the convective boundary layer in day is greater than that of the stability boundary layer in night.The boundary layer can be described as vertical structures of stability,instability and multipling The interaction between relative warm and wet down draft air from up level and cool air of surface layer is significant,which causes stronger wind shear,temperature and humidity inversion with typical wind shear of 10 m/s/100 m,intensity of temperature inversion of 8 ℃/100 m.While the larger pack ice is broken by such process,new ice free area in the high latitudes of arctic ocean.The interactions between air/ice/water are enhanced.The fact helps to understanding characteristics of atmospheric boundary layer and its effect in Arctic floating ice region.     

RESPONSE OF THE OCEAN UPPER MIXED LAYER TO ATMOSPHERIC FORCING

Using a one-dimension Turbulence Kinetic Energy(TKE)mixed layer model based on a simple eddyKinetic energy parameterization of the ocean upper mixed layer,some numerical examinations are intro- duced in this paper.These examination results show that the TKE ocean mixed layer model can respondwell to the effect of atmospheric forcing on the ocean upper mixed layer.The joint effect of wind stressand heat exchange on the ocean upper layer has nonlinear characteristics.The adjustment time of the re-sponse of the ocean upper mixed layer to the atmospheric forcing is about 12 hours in this model.     

The effect of sloping bottom topography on the source-driven deep tropical circulation

ImODUCTIONInasedrinalseriesofPapersduringthelatel95osandl96()s,StonimlandANns(l958;l96()a,b)PresentedatheoreticalpictUreofthesoaree-drivendeepcirculaionintheoceanbasedongeOst-cd~cs.ItconsistsofaPole-wAninteriorflowresultingforavortexshetchingassociatedwithaslowuniformuPwellingthInllghouttheocean,andawestemboUndeqctirrentbalancingthemassbudget.Kawse(1987)formulatedalinear,tWo-layerbaxlinicmodeltostud}thedeeptroPicalcirculationdrivenbydeepwaterproduction.DistinctlydifferentfromtheStomm…     

夏季青藏高原低涡结构的动力学研究

应用卫星云图资料分析了两例夏季青藏高原低涡发展过程及其结构演变,揭示出高原低涡结构特征的若干观测事实。在此基础上借鉴研究类热带气旋低涡的方法,将暖性青藏高原低涡视为受加热和摩擦强迫作用,且满足热成风平衡的轴对称涡旋系统,通过求解柱坐标系中的线性化涡旋模式,得出边界层动力作用下低涡的流函数解,重点讨论了地面热源强迫和边界层动力"抽吸泵"对高原低涡流场结构的作用。研究认为,由于边界层加热和摩擦的共同作用,高原低涡的温度场呈暖心结构。热源强迫的边界层低涡的散度场存在一个动力变性高度,该高度的位置与边界层顶高度有关。通过边界层动力抽吸作用,当边界层顶有气旋性涡度时,能引起边界层低涡的水平辐合运动和随高度增强的上升运动,并可加强低涡的切向流场;如果低涡的中心区域为"内冷外热"型加热分布,则热源强迫的低涡中心区域下层为辐散气流和随时间减弱的切向流场,上层为辐合气流和随时间增强的切向流场,并伴有下沉运动,从而有利于形成涡眼(或空心)结构,在卫星云图上表现为低涡中心为少云(或无云)区,即这类高原低涡具有与台风类似的眼结构,因而可视为类热带气旋涡旋的新例证。最后通过高原低涡的简化模型对低涡所含的波动进行了分析和讨论,结果表明:高原低涡中既含有涡旋Rossby波,又含有惯性重力波,即低涡波动呈现涡旋Rossby-惯性重力混合波特征。     

水平均匀大气边界层的立方样条方法数值模拟

本文介绍了立方样条方法,并将该方法应用于大气边界层数值模拟,对定常水平均匀大气边界层作了数值研究。     

Recent observations and modeling study about sea fog over the Yellow Sea and East China Sea

This review presents some of the latest achievements in sea fog research,including fog climatology,fog structure in the marine atmospheric boundary layer,and numerical simulations and forecasting of fog.With the development of atmospheric observational techniques and equipments,new facts about sea fog are revealed.The mechanisms involved in the formation,development and dissipation of sea fog are further explored with the help of advanced atmospheric models.     

Structure and seasonal changes in atmospheric boundary layer on coast of the east Antarctic continent

The temperature, humidity, and vertical distribution of ozone in the Antarctic atmospheric boundary layer（ABL） and their seasonal changes are analyzed, by using the high-resolution profile data obtained during the International Polar Year 2008 to 2009 at Zhongshan Station, to further the understanding of the structure and processes of the ABL. The results show that the fre- quency of the convective boundary layer in the warm season accounts for 84% of its annual occurrence frequency. The frequency of the stable boundary layer in the cold season accounts for 71% of its annual occurrence frequency. A neutral boundary layer ap- pears rarely. The average altitude of the convective boundary layer determined by the parcel method is 600 m; this is 200 to 300 m higher than that over inland Antarctica. The average altitude of the top of the boundary layer determined by the potential tempera- ture gradient and humidity gradient is 1 200 m in the warm season and 1 500 m in the cold season. The vertical structures of ozone and specific humidity in the ABL exhibit obvious seasonal changes. The specific humidity is very high with greater vertical gradi- ent in the warm season and very low with a lesser gradient in the cold season under 2 000 m. The atmospheric ozone in the ABL is consumed by photochemical processes in the warm season, which results in a slight difference in altitude. The sub-highest ozone center is located in the boundary layer, indicating that the ozone transferred from the stratosphere to the troposphere reaches the low boundary layer during October and November in Antarctica.     

非线性四阶四点边值问题的正解

利用锥不动点定理,并结合Green函数性质,证明一类四阶四点边值问题的正解的存在性.     

Review of China's scientific research progress in polar meteorology in the last 30 years

The Antarctic and Arctic are sensitive to global climate change; therefore, they are key regions of global climate change research. This paper, the progress in scientific investigations and research regarding the atmosphere in the polar regions over the last 30 years by Chinese scientists is summarized. Primary understanding of the relationship between the polar regions and global change, especially, the variations in time and space in the Antarctic and Arctic regions with respect to climate change is indicated. Operational weather forecasts for investigation of the polar regions have also been established. Moreover, changes in sea ice and their impact on the atmosphere of polar regions have been diagnosed and simulated. Parameterization of the atmospheric boundary layer of different underlying layers and changes in the atmospheric ozone in the polar region has also been experimented. Overall, there has been great progress in studies of the possible impact of changes in the atmospheric environment of polar regions on circulation in East Asia and the climate of China.     

Homotopic Mapping Solving Method for Perturbed Mechanism of Western Boundary Undercurrents in Equator Pacific

1 Introduction The western boundary currents, counter undercurrents observed in the thermocline were studied in many ref- erences (Qu et al., 1997; Wang and Hu, 1998; Huang, 1991). The existence of the western boundary undercur- rents suggests the baroclinity of western boundary cur- rents, so the results of the study on their baroclinic structure and dynamics should have strong bearing on the baroclinic theory of oceanic circulation. However, be- cause of their late discovery, the baroclini…     

可压缩层流边界层系统的一些性质

进一步研究了可压缩流边界层系统解的一些性质,给出了可压缩边界层系统等价的奇异积分方程解存在时参数所在的区间,并通过研究等价的奇异积分方程解的性质,得出可压缩层流边界层系统给出剪应力函数f和温度函数g的一些结果．     

可压缩层流边界层系统的一些性质

进一步研究了可压缩流边界层系统解的一些性质,给出了可压缩边界层系统等价的奇异积分方程解存在时参数所在的区间,并通过研究等价的奇异积分方程解的性质,得出可压缩层流边界层系统给出剪应力函数厂和温度函数g的一些结果．     

地质界线图层的自动化生成方法

地质界线要素是地质图空间数据库的基本要素之一。地质界线图层通常是地质图空间数据库中图元最多的一个图层,其数字化和质量检验工作较为繁重。针对已有地质体面图层,而地质界线图层缺失的情况,本文提供一种快速补充地质界线图层的方法。该方法也可对原生地质界线图层进行属性数据的自动化质量检验。其主要处理环节包括：首先,基于地质体面图层,构建地质体邻接关系图,可实现对地质界线高效、准确地提取;其次,基于产状数据与断层数据,运用地层接触关系识别规则,可分别实现对基本地层接触关系和断层接触关系的自动识别;最后,针对两邻接地质体面实体多段界线间的接触关系识别结果不一致的情形,运用“平行不整合优先”原则和“长度优先”原则,进行了合理的综合判别。基于1:50 000庐山幅地质界线图层的自动化生成实验表明,本文方法可高效、快捷、准确地生成地质界线图层,既能够满足自动化补充地质界线图层的需要,又可作为检验地质界线图层属性的有效工具。     

The effect of the East China Sea Kuroshio Front on the marine atmospheric boundary layer

Various satellite data, JRA-25 (Japan reanalysis of 25 years) reanalyzed data and WRF (Weather Research Forecast) model are used to investigate the in situ effect of the ESKF (East China Sea Kuroshio Front) on the MABL (marine atmospheric boundary layer). The intensity of the ESKF is most robust from January to April in its annual cycle. The local strong surface northerly/northeasterly winds are observed right over the ESKF in January and in April and the wind speeds decrease upward in the MABL. The thermal wind effect that is derived from the baroclinic MABL forced by the strong SST gradient contributes to the strong surface winds to a large degree. The convergence zone existing along the warm flank of the ESKF is stronger in April than in January corresponding to the steeper SST (sea surface temperature) gradient. The collocations of the cloud cover maximum and precipitation maximum are basically consistent with the convergence zone of the wind field. The clouds develop higher (lower) in the warm (cold) flank of the ESKF due to the less (more) stable stratification in the MABL. The lowest clouds are observed in April on the cold flank of the ESKF and over the Yellow Sea due to the existence of the pronounced temperature inversion. The numerical experiments with smoothed SST are consistent with the results from the ovservations.     

风廓线雷达对折射率结构常数的实测分析

大气折射率结构常数（Cn2）是大气中折射率大小的体现,为了改善风廓线雷达（WPR）数据质量,提高WPR数据业务应用的可靠性,对边界层风廓线雷达近1年的实测数据采用归纳对比的方法,分析得到Cn2与温度湿度变化的关系,并总结出成都地区晴朗天气下,四季Cn2量级的变化范围,与理论推导一致.夏天10-12到10-20,春秋10-13到10-20,冬天10-14到10-21,此外,根据降水量大小不同,Cn2提升3到6个量级,获得这些定量的范围,为相关风廓线雷达产品识别提供了方法和依据.     

振荡型Rossby孤立波与大气阻塞

从正压涡度方程出发,在弱非线性和弱基流切变条件下,导得了描述非线性大气长波活动的推广的Ｋｄｖ方程,并得到了方程的孤立波解及其色散关系。取近似于实际大气运动的物理参数作数值计算,得到了振荡型Ｒｏｓｂｙ孤立波的水平结构和移动特征,其结果较之寻常的Ｋｄｖ孤立波更接近于实际大气中的阻塞流型。     

Velocity profile of debris flow based on quadratic rheology model

The quadratic rheology model considers the yield stress, viscous stress, turbulent stress and disperse stress, so it is used in this study to derive the velocity profile of debris flows. The quadratic model with the parabolic eddy viscosity was numerically solved, and an analytical solution was derived for the quadratic model with a constant eddy viscosity. These two solutions were compared with the Arai-Takahashi model that excluded the viscous stress and the yield stress. The three models were tested by using 17 experiment cases of debris flows over rigid beds. The results prove that the quadratic model with parabolic and constant eddy viscosities is applicable to muddy and granular flows, whereas the Arai-Takahashi model tends to overestimate the flow velocity near the water surface if a plug-like layer exists. In addition, the von Karman constant and the zero-velocity elevation in the three models are related to sediment concentration. The von Karman constant decreases first and then increases as the sediment concentration increases. The zero-velocity elevation is below the bed surface, likely due to the invalidity of the non-slip boundary condition for the debris flows over fixed beds.     

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Elevated Ducts and Low Clouds over the Central Western Pacific Ocean in Winter Based on GPS Soundings and Satellite Observation

Both low clouds and elevated ducts are common phenomena in the oceanic atmosphere. Low clouds affect elevated ducts by changing the structure of atmospheric temperature and humidity. However, due to the limitation of met-ocean measurements, research on them is still scattered. This paper presents the distribution of elevated ducts and clouds over the central Western Pacific Ocean(WPO) based on Global Position System(GPS) sounding data and Himawari-8 satellite products from November 2015 to January 2016. Results show that the frequency of elevated ducts detected by ship-based GPS soundings was as high as 77% over the central WPO. The height and frequency of elevated ducts are closely related to the low clouds. If there are no clouds, the occurrence probability and mean base height of the elevated ducts are 14% and 730 m, respectively. By comparison, the occurrence probability and mean base height increase up to 24% and 1471 m, respectively, in the presence of cumulus(Cu) clouds, and 22% and 1511 m, respectively, in the presence of stratocumulus(Sc) clouds. Elevated ducts occur near the cloud top. The analysis of geopotential height and wind fields from the European Centre for Medium-Range Weather Forecasts(ECMWF) reanalysis dataset(ERA-interim) shows that the study area is covered by a strong and stable subtropical high, and slowly sinking dry air masses inside the subtropical high are above the moist boundary-layer air mass. The appearance and evolution of low clouds will adjust the temperature and humidity structure of the lower troposphere. If there are no clouds, the marine boundary layer(MBL) is the classic mixed boundary layer. Humidity gradient and subsidence inversion are formed atop the mixed layer. When low clouds are present, long wave radiation and entrainment atop clouds form a strong temperature inversion and humidity gradient, which strengthen elevated ducts. However, when Sc clouds are decoupled, a weaker temperature inversion and humidity gradient may occur between the surface mixed layer and subcloud layer, leading to a weak elevated duct atop the mixed layer.