A wind tunnel simulation of the dynamic processes involved in sand dune formation on the western coast of Hainan Island

The western coast of Hainan Island exhibits a savanna landscape. Many types of sand dunes, including transverse dune ridges, longitudinal dune ridges, elliptical dunes, coppice dunes, and climbing dunes, are widely distributed in the coastal zone. In winter, high-frequency and high-energy NE winds （dominant winds） are prevalent, with a resultant drift direction （RDD） of S35.6°W. In spring, low-frequency and low-energy SW secondary winds prevail, with a RDD of N25.1°E. Wind tunnel simulations revealed that the airflow over the dune surface is the main factor controlling the erosion and deposition patterns of dune surfaces and the morphological development of dunes. In the region＇s bidirectional wind environment, with two seasonally distinct energy levels, the airflow over the surface of elliptical dunes, barchan dunes, and transverse dune ridges will exhibit a transverse pattern, whereas the airflow over longitudinal dunes ridges exhibits a lateral pattern and that over climbing dunes exhibits a climbing-circumfluent pattern. These patterns represent different dynamic processes. The coastal dunes on the western coast of Hainan Island are influenced by factors such as onshore winds, sand sources, coastal slopes, rivers, and forest shelter belts. The source of the sand that supplements these dunes particularly influences the development pattern： when there is more sand, the pattern shows positive equilibrium deposition between dune ridges and dunes; otherwise, it shows negative equilibrium deposition. The presence or absence of forest shelter belts also influences deposition and dune development patterns and transformation of dune forms. Coastal dunes and inland desert dunes experience similar dynamic processes, but the former have more diversified shapes and more complex formation mechanisms.

Zonal displacement of western Pacific warm pool and zonal wind anomaly over the Pacific Ocean

The thermal condition anomaly of the western Pacific warm pool and its zonal displacement have very important influences on climate change in East Asia and even the whole world. However, the impact of the zonal wind anomaly over the Pacific Ocean on zonal displacement of the warm pool has not yet been analyzed based on long-term record. Therefore, it is important to study the zonal displacement of the warm pool and its response to the zonal wind anomaly over the equatorial Pacific Ocean. Based on the NCDC monthly averaged SST (sea surface temperature) data in 2°×2° grid in the Pacific Ocean from 1950 to 2000, and the NCEP/NCAR global monthly averaged 850 hPa zonal wind data from 1949 to 2000, the relationships between zonal displacements of the western Pacific warm pool and zonal wind anomalies over the tropical Pacific Ocean are analyzed in this paper. The results show that the zonal displacements are closely related to the zonal wind anomalies over the western, central and eastern equatorial Pacific Ocean. Composite analysis indicates that during ENSO events, the warm pool displacement was trigged by the zonal wind anomalies over the western equatorial Pacific Ocean in early stage and the process proceeded under the zonal wind anomalies over the central and eastern equatorial Pacific Ocean unless the wind direction changes. Therefore, in addition to the zonal wind anomaly over the western Pacific, the zonal wind anomalies over the central and eastern Pacific Ocean should be considered also in investigation the dynamical mechanisms of the zonal displacement of the warm pool.

Late Jurassic-Early Cretaceous Erg Deposits in the Mengyin Basin, Western Shandong Province, China: Inferences about the Wind Regime and Paleogeography

The Late Jurassic-Early Cretaceous Santai Formation, sporadically distributed in western Shandong Province, comprises terrestrial alluvial-eolian successions, which records regional wind patterns and paleogeography in eastern North China. This paper conducts an analysis of eolian stratification, bounding surfaces, facies architecture and paleowind direction of the Santai Formation in the east of the Mengyin Basin, western Shandong Province. Three basic types of eolian stratification are recognized in the Santai Formation, including grainflow strata, wind ripple strata and adhesion strata, and have been grouped into eolian dune and interdune facies associations. The occurrences of reactivation surfaces and superimposition surfaces within eolian dune deposits indicate active compound dunes or draas. The association of adhesion strata with grainflow or windripple strata is the development of a wet eolian system. Cross-strata dip direction indicates different paleowind directions from the lower to the upper part of the Santai paleoerg. The lower part of the paleoerg was characterized by paleowinds blowing from northwest to northeast, whereas the upper part was under the influence of paleowinds consistently towards east to northeast. The identified changes in wind directions possibly suggest wind regime shifts from monsoon circulation to westlies of planetary wind system, which may be related with the collapse of the East China Plateau during the Late Jurassic to Early Cretaceous.

Relationship analysis between September precipitation in western China and 700 hPa wind field in East Asia

The regional wind index influencing September precipitation in western China has been defined using the 700 hPa u and v components of NCAR/NCEP reanalysis data of 1961 to 2006. There are three regional wind field indices： southwest, southeast, and north, and these indices reflect the change of East Asian monsoon. The relationship between the indices was studied, and results show that they not only have a close relationship, but also have independence. Moreover, there is an obvious relationship between the wind indices and the autumn in particular the September precipitation in western China. The effect of wind indices on rain occurrence is most different： the influenced area of the southwest wind index is larger than that of the southeast wind index, and the southwest wind index is a controlling factor on autumn precipitation in western China. The weakening of southwest wind is the main cause resulting in reduction of autumn precipitation on the east side of the Tibetan Plateau.

Recent Enhancement in Co-Variability of the Western North Pacific Summer Monsoon and the Equatorial Zonal Wind

The western North Pacific summer monsoon(WNPSM)is an important subcomponent of the Asian summer monsoon.The equatorial zonal wind(EZW)in the lower troposphere over the western Pacific may play a critical role in the evolution of the El Niño-Southern Oscillation(ENSO).The possible linkage between the EZW over the western Pacific and the offequatorial monsoonal winds associated with the WNPSM and its decadal changes have not yet been fully understood.Here,we find a non-stationary relationship between the WNPSM and the western Pacific EZW,significantly strengthening their correlation around the late 1980s/early 1990s.This observed shift in the WNPSM–EZW relationship could be explained by the changes in the related sea surface temperature(SST)configurations across the tropical oceans.The enhanced influence from the springtime tropical North Atlantic,summertime tropical central Pacific,and maritime continent SST anomalies may be working together in contributing to the recent intensified WNPSM–EZW co-variability.The observed recent strengthening of the WNPSM–EZW relationship may profoundly impact the climate system,including prompting more effective feedback from the WNPSM on subsequent ENSO evolution and bolstering a stronger biennial tendency of the WNPSM–ENSO coupled system.The results obtained herein imply that the WNPSM,EZW,ENSO,and the tropical North Atlantic SST may be closely linked within a unified climate system with a quasi-biennial rhythm occurring during recent decades,accompanied by a reinforcement of the WNPSM–ENSO interplay quite possibly triggered by enhanced tropical Pacific–Atlantic cross-basin interactions.These results highlight the importance of the tropical Atlantic cross-basin influences in shaping the spatial structure of WNPSM-related wind anomalies and the WNPSM–ENSO interaction.

Response of western equatorial Pacificto a westerly wind burst

Atmospheric jets-with shear-can induce a vertical oceanic circulation with upwelling and down -welling even over the open ocean in regions where the Coriolis parameter can be regarded as a constant. Winds with nosheard that bloe parallel to the equator can also induce a vertical oceanic circulation with upwelling and downwellingwithin an equatorial radius of deformation. This study concerns the oceanic response to a westerly wind burst, in theform of an atmospheric jet, similar to those that occur over the western equatorial Pacific . It is shown that the shear ofthe wind, if it is within an equatorial radius of deformation, can alter the vertical circulation substantially, especially ifthere are westerly and easterly winds near the equator. A commentary on measurements amde during a westerly windburst over the western equatorial Pacific has been given.

The Heat Balance in the Western Equatorial Pacific Warm Pool during the Westerly Wind Bursts: A Case Study

The responses of sea surface temperature (SST) in the western equatorial Pacific warm pool to the westerly wind bursts (WWBs) play an important role in the relationship between WWB and ENSO. By using data collected from eight buoys of TOGA (Tropical Ocean-Global Atmosphere)- COARE (Coupled Ocean-Atmosphere Response Experiment), the heat balances of the upper ocean in the western equatorial Pacific around 0 degrees, 156 degreesE during two WWB events were calculated according to Stevenson and Niiler's (1983) method. In both events, SST increased before and after the WWBs, while decreased within the WWBs. The SST amplitudes approximated to 1 degreesC. Although sometimes the horizontal heat advections may become the biggest term in the heat balance, the variation of SST was dominated by the surface heat flux. On the other aspect, some different features of the two events are also revealed. The two cases have different variation of mixed layer depth. The depth of mixed layer is almost double in the first case (35 in to 70 m), which is caused by Ekman convergence, while only 10m increments due to entrainment in the second one, There are also differences in the currents structure. The different variations of thermal and currents structure in the mixing layers accounted for the different variation of the heat balance during the two events, especially the advection and residue terms. The seasonal variation of SST in this area is also investigated simply. The first WWB event happened just during the seasonal transition. So we considered that it is a normal season transition rather than a so-called anomaly. That also suggested that the seasonal distinction of the WWB is worthy of more attention in the researches of its relationship to ENSO.

UPPER OCEAN RESPONSE TO SURFACE MOMENTUM AND FRESHWATER FLUXES IN THE WESTERN PACIFIC WARM POOL

A series of numerical experiments are carried out to study the tropical upper ocean response to combined momentum and buoyancy forcing, with emphasis on the three-dimensional thermohaline structure in the western Pacific warm pool. In response to climatological winds, heat fluxes and freshwater input, the model is able to simulate the salient dynamic and hydrographic features of the tropical Pacific Ocean and their seasonal variability. In response to idealized episodic westerly wind bursts and rainfall, the simulated upper ocean conditions compare favorably with available observations, thus enabling us to identify important physical processes involved. Local forcing, vertical mixing and meridional advection dominate the salt and heat budgets in the warm pool on short time scales, but it is necessary to include the saline water coming from the east with the South Equatorial Current to close the salt budget on seasonal and longer time scales. Strong westerly wind bursts generate a swift eastward equatorial jet and a pair of meridional circulation cells with convergence at the equator. This results in an equatorward advection of relatively fresh water from the north and a depression of the thermocline at the equator. Heavy rainfall reduces the surface mixed layer depth by creating a shallow halocline, thus trapping the momentum and heat inputs near the surface. The remote influences of the episodic momentum and buoyancy fluxes are very different. Westerly wind bursts can generate large downstream disturbances in both dynamic and thermal fields through the propagation of equatorial waves, while the effect of rainfall is mostly confined to the forcing area.

Linking moisture and near-surface wind with winter temperature to reveal the Holocene climate evolution in arid Xinjiang region of China

An increasing number of palaeo-climatic records have been reported to identify the Holocene climate history in the arid Xinjiang region of northwest China. However, few studies have fully considered the internal linkages within the regional climate system, which may limit our understanding of the forcing mechanisms of Holocene climate change in this region. Here, we systematically consider three major issues of the moisture/precipitation, temperature and near-surface wind relevant to the Holocene climate history of Xinjiang. First, despite there still has debated for the Holocene moisture evolution in this region, more climatic reconstructions from lake sediments, loess, sand-dunes and peats support a long-term regional wetting trend. Second, temperature records from ice cores, peats and stalagmites demonstrate a long-term winter warming trend during the Holocene in middle-to high-latitudes of Asia. Third, recent studies of aeolian sedimentary sequences reveal that the near-surface winds in winter gradually weakened during the Holocene, whereas the winter mid-latitude Westerlies strengthened in the Tienshan Mountains. Based on this evidence, in the arid Xinjiang region we propose an early to middle Holocene relatively cold and dry interval, with strong near-surface winds;and a warmer, wetter interval with weaker near-surface winds in the middle to late Holocene during winter. Additionally,we develop a conceptual model to explain the pattern of Holocene climate changes in this region.From the early to the late Holocene, the increasing atmospheric COcontent and winter insolation,and the shrinking of high-latitude continental ice-sheets, resulted in increasing winter temperatures in middle to high latitudes in the Northern Hemisphere. Subsequently, the increased winter temperature strengthened the winter mid-latitude Westerlies and weakened the Siberian high-pressure system,which caused an increase in winter precipitation and a decrease in near-surface wind strength. This scenario is strongly supported by evidence from geological records, climate simulation results, and modern reanalysis data. Our hypothesis highlights the important contribution of winter temperature in driving the Holocene climatic evolution of the arid Xinjiang region, and it implies that the socio-economic development and water resources security of this region will face serious challenges presented by the increasing winter temperature in the future.

Seasonal variation of the surface North Equatorial Countercurrent (NECC) in the western Pacific Ocean

The North Equatorial Countercurrent(NECC) is an important zonal fl ow in the upper circulation of the tropical Pacifi c Ocean, which plays a vital role in the heat budget of the western Pacifi c warm pool. Using satellite-derived data of ocean surface currents and sea surface heights(SSHs) from 1992 to 2011, the seasonal variation of the surface NECC in the western tropical Pacifi c Ocean was investigated. It was found that the intensity(INT) and axis position(Y_(CM)) of the surface NECC exhibit strikingly different seasonal fl uctuations in the upstream(128°–136°E) and downstream(145°–160°E) regions. Of the two regions, the seasonal cycle of the upstream NECC shows the greater interannual variability. Its INT and Y CM are greatly infl uenced by variations of the Mindanao Eddy, Mindanao Dome(MD), and equatorial Rossby waves to its south. Both INT and YC M also show semiannual signals induced by the combined effects of equatorial Rossby waves from the Central Pacifi c and local wind forcing in the western Pacifi c Ocean. In the downstream region, the variability of the NECC is affected by SSH anomalies in the MD and the central equatorial Pacifi c Ocean. Those in the MD region are especially important in modulating the Y CM of the downstream NECC. In addition to the SSH-related geostrophic fl ow, zonal Ekman fl ow driven by meridional wind stress also plays a role, having considerable impact on INT variability of the surface NECC. The contrasting features of the variability of the NECC in the upstream and downstream regions refl ect the high complexity of regional ocean dynamics.

A modification to the Munk wind-driven ocean circulation theory

In order to fulfill the no-slip condition at the western and eastern boundaries of the ocean basin, introduced ＂effective wind stress＂, which has much larger spatial variations towards the boundaries than in the ocean interior. The effective wind stress can thus be decomposed into spatially slow-varying and fast varying components. Careful scale analysis on the classical Munk winddriven ocean circulation theory, which consists of the interior Sverdrup flow and the western boundary current but of no eastern boundary current, shows that the wind stress curl appearing in the Sverdrup equation must have negligible spatial variations. In the present model the spatially slow-varying component of the wind stress appears in the Sverdrup equation, and the spatially fastvarying component becomes the forcing term of the boundary equations. As a result, in addition to the classical Munk solution the present model has an extra term at the western boundary which （Northern Hemisphere） increases the northward transport as well as the southward return transport, and has a term at the eastern boundary corresponding to the eastern boundary current.

Research on the Response of the Upper Layer Heat Structure in the Western Pacific Warm Pool to the Mean Madden-Julian Oscillation

By using the long-term observed hydro-meteorological data (1985-2002) from the Tropical Atmosphere Ocean System (TAO) during the international Tropical Ocean and Global Atmosphere (TOGA) experiment, the key parameters of the Sea Surface Temperature (SST), thermocline depth, surface sensible heat flux and latent heat flux, and the pseudo wind stress in the Westen Equatorial Ocean are calculated in this paper. On the basis of the calculation, the response of upper layer heat structure in the Westen Pacific Warm Pool to the mean Madden-Julian Oscillation (MJO) and its relation to the El Nio events are analyzed. The results show that within the MJO frequency band (42-108 d), the distributions of sea surface wind stress and upper ocean temperature have several spatial-temporal variation structures. Among these structures, the type-I surface pseudo wind stress field plays the role of inhibiting the eastward transport of ocean heat capacity, while the type-II strengthens the heat capacity spreading eastward. Therefore the type-II surface pseudo wind stress field is the characteristic wind field that provokes El Nio events. During calm periods (July-September) of the wind stress variations, the sensible and latent heat capacity fluxes change considerably, mostly in the region between 137°-140°E, while to the east of 150°E, the heat capacity flux changes less.\ In the mean MJO state, the type-I surface pseudo wind stress field structure dominates in the Western Pacific. This is why El Nio events can not occur every year. However, when the type-II and type-III surface pseudo wind stress field structures are dominant, an El Nio event is likely to occur. In this case, if the heat capacity of the Western Pacific Warm Pool is transported eastward and combined with the Equatorial Pacific heat capacity spreading eastward, El Nio events will soon occur.

Impact of Wind on Tide-Induced Advective Salt Transport in A Well- Mixed Estuary

The tide-induced net advective salt flux in well-mixed estuaries consists of five terms according to the method from Kjerfve.The term resulted from the vertical variation in salinity can be negligible in well-mixed estuaries with four tide-induced salt flux terms,known as F1−F4.To explore the effects of wind on these salt fluxes,the current-salinity analytical model combined with the perturbation analysis is extended by including wind.Analytical expressions for the four salt fluxes are derived separately in the present model.Under the assumption that only the M_(2) tidal component is accounted for and the salt flux generated by diffusion is not studied,the tide-induced net advective salt flux Q_(sx) is in the seaward direction without the wind effect.By applying the Western Scheldt estuary case,the wind influence on the tidal advection salt flux(TASF)distribution in the F4 term was investigated.The phase difference between zero-order velocity and first-order salinity(Δφ)at the surface layer of the estuary is larger than 90°and smaller than 90°at the bottom layer,which leads to landward TASF in the surface layer and seaward TASF in the bottom layer.The distribution ofΔφis not uniform in the horizontal direction with wind included,which differs from the result without wind.In the case of seaward wind with the speed of 18 m/s,the decrease in the zeroth-order velocity phase(φu)at the surface layer is larger than that of the first-order salinity phase(φs)downstream,which leads to an abnormal seaward TASF in this region.Owing to the surface stress caused by wind,the Stokes compensation flow in the middle and lower reaches increases/decreases with the increase of the landward/seaward wind,while the upstream situation is opposite.Thus,the first-order velocity in the middle and lower reaches increases/decreases with the increase of the landward/seaward wind,while the upstream situation is also opposite.The first-order salinity also increases/decreases with the increase of landward/seaward wind,while the upstream salinity tends to zero.Therefore,the tide-induced net advective salt flux Q_(sx) increases/decreases with the increase of the landward/seaward wind,which is contrary to the usual recognition.

Comparison of the water-crossing behavior of Western Marsh Harriers(Circus aeruginosus) and European Honey Buzzards(Pernis apivorus) during autumn migration

We investigated the water-crossing behavior of Western Marsh Harriers(Circus aeruginosus),mostly adults,and European Honey Buzzards(Pernis apivorus),mostly juveniles,in relation to wind conditions,time of the day,flocking and age classes,at a watchsite in central Italy during the autumn migration en route to Africa.Although European Honey Buzzards are less suited than Western Marsh Harriers to undertake long sea crossings,they were more inclined to leave the coast when migrating in flocks.Few birds of both species chose to fly along the coast.Western Marsh Harriers,such as European Honey Buzzards migrating alone,undertook the water crossing rather than stopping migration(birds roosting at the site or flying back inland) during the absence of wind and vice versa during head winds.Conversely,European Honey Buzzards migrating in flocks were not affected in their decision(crossing or stopping migration) by wind direction.Both species undertook the water crossing rather than stopping migration during mornings and vice versa during afternoons.Finally,in both species,adults and juveniles showed the same behavior in front of a water barrier.This result was expected in the case of the Western Marsh Harrier but not from the European Honey Buzzard since,in this species,the water-crossing tendency is age dependent with adults avoiding sea crossings.Our study confirms that flocking significantly affects the water-crossing behavior of European Honey Buzzards during migration.Moreover,in this species,inexperience of juveniles and presumably younger adults,about the high energetic costs of long powered flight and about the existence of shorter routes over water,might explain the strong water-crossing tendency shown by migrants independently from their age.

真方白丸子加减联合依达拉奉右莰醇治疗风痰阻络型首次缺血性中风急性期临床观察

目的观察真方白丸子加减联合依达拉奉右莰醇治疗风痰阻络型首次缺血性中风急性期的临床效果及对炎症因子的影响。方法选取首次缺血性中风患者78例,根据治疗方法分为治疗组、对照组,各39例。对照组给予依达拉奉右莰醇治疗,治疗组在对照组基础上给予真方白丸子加减治疗,均连续治疗14 d。观察两组临床疗效,以美国国立卫生研究院卒中量表(NIHSS)和改良Rankin量表(mRS)评估神经功能缺损严重度和残疾程度,并监测人血浆脂蛋白磷脂酶A2(Lp-PLA2)、C-反应蛋白(CRP)水平。结果治疗组总有效率为97.44%(38/39),高于对照组的89.74%(35/39)(P<0.05)。治疗后,两组NIHSS、mRS评分及Lp-PLA2、CRP水平均降低,且治疗组低于对照组(P<0.05)。两组均无不良反应。结论真方白丸子加减联合依达拉奉右莰醇治疗首次缺血性中风急性期风痰阻络证临床效果确切,可显著降低其Lp-PLA2、CRP水平,减轻神经功能缺损和残疾程度,且安全性较好。

东亚夏季风与热带海气相互作用研究进展

在东亚夏季风变异的众多影响因子中,热带海温是影响夏季风系统变化的主要原因。近年来,国内外学者在热带海温异常对东亚夏季风影响的研究方面取得了很大进展。本文从季节内、年际到年代际时间尺度,简要回顾了近年来关于热带海气相互作用影响东亚夏季风变异及其机理的研究进展,特别综述了关于ENSO(El Ni?o-Southern Oscillation)、热带印度洋和大西洋海温异常对东亚夏季风系统的影响和机理方面的主要研究进展。此外,本文还系统回顾了热带海温对东亚夏季风与冬季风关联的影响及过程。最后,提出了在热带海温异常影响东亚夏季风季节内尺度变化、全球变暖下热带海温的变化及其对东亚夏季风的影响等方面值得深入探讨的科学问题。

2021年山东夏季降水异常特征及成因分析

基于NCEP再分析资料和山东省122个国家地面观测站数据,对2021年山东夏季降水异常特征及成因进行研究。2021年夏季山东平均降水量较常年偏多25.3%,降雨过程较多,其中,6月降水偏多主要是由于西太平洋副热带高压(简称“副高”)北抬造成;7月中旬降水偏多主要是由于副高强度偏强,副高边缘暖湿气流为山东降水提供了充足水汽,下旬降水偏多是由于台风“烟花”带来强降水;8月降水偏多主要是下旬副高强度偏强,水汽输送充沛造成。此外,2021年夏季山东降水空间分布不均匀,呈西多东少的空间分布。进一步分析近3次拉尼娜事件发现,夏季副高强度偏强是造成近3个拉尼娜衰减年夏季山东降水空间分布异常的主要原因。夏季副高强度是拉尼娜次年山东夏季降水的重要预测因子。

ERA5-Land再分析资料对吉林省西部地区地面风速再现能力评估

文章利用2005-2021年吉林省西部8个站点的小时平均风速资料和ERA5-Land再分析资料分析了风速的变化特征,并比较了不同强度观测与再分析风速的误差特征,及再分析资料对风速日变化特征的再现能力。结果表明:观测风速春季最大、秋季次之;夏、冬季观测风速最小,再分析资料误差也相应减小,但再分析资料整体大于观测资料,标准差小;春季观测风速大于3 m/s时,部分站点再分析资料相对偏小;镇赉站各月风速大于3 m/s时,再分析资料普遍对风速日变化的再现能力较弱,在午后风速最大时段风速误差超1.5 m/s。研究结果能够为提高ERA5-Land再分析资料的数据准确性提供参考。

基于探空数据的测风激光雷达在黄海西部海岸带的适用性分析

利用2021年4月至2022年12月期间位于黄海西部海岸带青岛国家基本气象站观测场内的多普勒测风激光雷达和L波段气球探空系统(以下简称L波段探空,Lradar),经过观测数据时间和空间相互匹配,以L波段探空测风数据为参照标准,对测风激光雷达探测高度、水平风速和水平风向的探测能力进行对比分析,结果表明:最大探测高度日变化特征与边界层高度日变化较为吻合,每日09:00探测高度最低约1 000 m,17:00则达到探测高度的峰值约1 300 m。在筛选出的共计1 768次二者共同观测时刻中,超过90%测风激光雷达最大观测高度低于2 000 m,不足500 m的时刻约占16%。二者水平风速和水平风向的线性拟合效果较好,相关系数分别高达0.97和0.98,其探测能力在海风和陆风时刻存在微小差异。测风激光雷达水平风速误差随高度和风速大小的变化存在差异,在500 m以下测风激光雷达平均风速明显大于L波段探空测得的平均风速,在500 m至1 500 m误差较小。在4级风及以下,风速误差分布较为集中;5到7级风,风速误差离散程度最大,离散值最多;8级风以上,离散误差明显减少。二者水平风向变化趋势具有较好的一致性,测风激光雷达风向误差以正值为主,即相较于L波段探空顺时针偏转。在低层以偏北和偏南风向为主,在西北(NW)、北西北(NNW)、正南(S)和南东南(SSE)方向上其频率小于L波段探空,在正北(N)、北东北(NNE)、南西南(SSW)和西南(SW)方向上大于L波段探空,高层开始转为偏西风向,在正西(W)方向频率明显大于L波段探空。以上结果表明,测风激光雷达可以较好地刻画出黄海西部海岸带边界层内的风场信息,为后续测风激光雷达在海岸带和海上观测的业务应用提供有效参考。

辽西走廊地区乡村住宅组团风环境模拟及优化设计

辽西走廊地区由于其独特的地理位置,春季和冬季多发大风天气,给当地风环境带来一定程度的影响。文章以该地区乡村住宅组团为研究对象并构建基本模型,以流体模拟软件Phoenics分析其风环境,参照相关评估方法判断不舒适区域并进行统计。通过对比多种优化方法,讨论提高住宅组团风环境舒适程度的合理方案。结果表明,通过控制组团布局方式、道路节点和院落空间等措施均能有效增加住宅组团的风环境舒适面积。