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《大气和海洋科学快报》2021,(1)
陆海风是由于海陆表面之间的比热容不同而导致的昼夜热量分布差异,从而在海岸附近引发的大气中尺度循环系统.本文利用多普勒风激光雷达Windcube100s首次对黄海西海岸的海陆风的循环结构进行了观测研究.在2018年8月31日至9月28日观测期间发现,海陆风发展高度一般在700 m至1300 m.海陆风转化持续的时间为6小时至8小时.在425m高度,海风水平风速出现最大值,平均为5.6 m s~(-1).陆风最大水平风速出现在370 m,约为4.5 ms~(-1).最大风切变指数在1300m处,为2.84;在陆风向海风转换过程中,最大风切变指数在700m处,为1.28.在同一高度上,风切变指数在海风盛行和陆风盛行时的差值范围为0.2-3.6,风切变能反映出海陆风的发展高度. 相似文献
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利用2011年2月湛江东海岛风廓线雷达资料,系统分析了湛江东海岛2月平均风场特征及海陆风特征,结果表明:2月湛江东海岛150 m高度处以东偏北出现频率最大,在E、ENE和NE三个方位的风向出现频率之和为66.6%,偏西七个方位的风向出现频率之和仅为1%。以SSW方位为界,偏东风与偏西风的出现频率差异明显。各整点的月平均风速1:00—15:00变化较小,均在1 m/s左右波动;15:00—20:00风速及风速波动都较大,最大值出现在16:00时,为2.1 m/s。2011年2月中只有2日与14日两日符合海陆风日条件,两日共同海风时段为13:00—20:00,持续7 h;陆风时段为2:00—7:00,持续5 h。海风平均风速为2.1 m/s,陆风平均风速为0.8 m/s,海风平均风速明显大于陆风风速。海风与陆风环流垂直高度相差甚小,约1.2 km,风速随高度变化趋势均为先增后减;海风最大风速出现在750 m高度处,陆风出现在500 m高度处,500～750 m高度区间海风环流强度明显强于陆风环流。2 km之上为均匀一致的系统性西风环流。 相似文献
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利用葫芦岛观测站1980—2009年观测资料,分析了葫芦岛沿岸海陆风风速的季节特征和日变化规律,以及海陆风环流对沿岸环境的影响。结论如下:1)葫芦岛站点在冬季出现海陆风日数最多,其他依次为秋季、夏季和春季。陆风风速从春季到冬季呈现递减趋势;海风在春季最大,其次为秋季的,冬季的最小。总体上,海陆风日中海风要强于陆风。2)对海陆风风速椭圆拟合结果表明,海陆风在10:32由陆风转化为海风,海风在16:32达到最大,在21:42由海风转化为陆风,陆风在04:32达到最大。3)由于海风的存在,沿岸地带在春夏两季日最高气温在12时出现,秋冬季的在13时出现。4)能见度日变化在四季中表现一致,早晨能见度转好的时刻比最低气温出现时刻滞后约2 h,在海风维持较长时间后空气绝对湿度增加导致能见度开始转差。5)冬季静止型海陆风日比例最高,再循环型海陆风日在秋季出现最多,而夏季通风型海陆风日出现最多。 相似文献
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利用江苏沿海5座测风塔长序列(连续42个月)、高时间分辨率(10 min一次)的梯度风、气温、气压等观测资料,分析不同地区、不同高度层的风切变指数变化规律,并筛选出对江苏产生较大影响的7次台风和17次寒潮天气过程,分析强风条件下的风切变指数变化特征。结果表明:(1)风切变指数随环境在0. 15～0. 26之间变化,风机有效风速段和15 m·s-1特征风速段的风切变指数分别平均为0. 20和0. 19,不同高度层之间风切变指数随高度增加而减少,随风速增大呈对数关系减少。(2)台风影响时垂直混合运动强烈,风切变指数变小,平均为0. 19。台风中心经过时的风切变指数和风速具有M型变化形态,最低为0. 05,加上风向剧变,易对风机叶片产生破坏。(3)寒潮影响时的风切变指数平均为0. 22,小于同期平均。风速倒置现象明显,在50～100 m之间风切变指数为负值的出现概率超过8%,50 m高度处容易出现近地层的最大风速层。 相似文献
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利用2014—2018年辽宁省探空资料分析了水平风速的垂直风廓线分布特征。用2座代表性测风塔逐时梯度风观测分析了采用不同高度组合方案计算出风切变指数的月、日变化特征, 分别用月、小时、年风切变指数推算高层风速和风功率密度, 并与实测对比。结果表明: 沈阳相较于大连地区风速随高度增加较快, 180 m高度以上风速基本保持不变, 而大连因其纬度低且靠近海洋, 300 m以下风速均匀上升。在非复杂地形情况下, 距地面10 m高度以上间隔一定高度设立4层风观测, 基本可以满足近地层风资源评估需求。受太阳辐射、下垫面、海陆热力性质差异等影响, 辽宁省风切变指数日变化特征比月变化更显著。利用小时风切变指数推算高层风速和风功率密度的方案优于采用月、年风切变指数方案。风切变指数日变化越显著, 采用逐时风切变指数推算方案越优于其他计算方案。 相似文献
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利用2008年全年渤海湾西岸(天津)14个自动气象站逐小时资料和6 h一次的地面常规资料,采用统计分析的方法,研究了天津城市热岛效应对渤海湾西岸海陆风的影响.结果表明:在冷岛和强热岛条件下,渤海湾西岸海风的发生频率较低,强热岛阻碍了海风向内陆的传播;内陆站在弱热岛条件下出现最大海风的频次较高,但其海风强度与无热岛或冷岛状况下相比要小一些;城市热岛效应的出现,推迟了城市周围郊区站海风的开始时间,缩短了海风的持续时间;城市站的海风风速与热岛强度呈负相关关系,但热岛效应对陆风风速的影响较强,陆风风速在热岛强度小于2.6℃时,随着其值的增大而减小,反之则增加;当海风向内陆延伸时,热岛强度会在午后海风盛行时段内增强,并与传播到此处的海风环流叠加,导致近地层海风风速增强,并可西伸至城市中心. 相似文献
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阳江地区海陆风特征及其影响 总被引：5，自引：1，他引：4
以阳江地区常规气象站、中尺度观测网的自动气象站和海边的2个80m梯度观测塔资料为依据,对该地区海陆风特征及其影响进行研究,结果表明,阳江地区海陆风西岸早于东岸.在近地层,海陆风随高度升高而增大,5月份前后有时海陆风较浅,不能影响到80m高度.陆风转海风多发生在11:00-12:00之间,海风转陆风发生在23:00前后,都发生在日气压变化的峰值时段.海陆风与山谷风叠加可以达到离海岸线70～75km的内陆地区,但并不能越过云雾山山脉.海陆转换时期,在沿海海湾地区形成辐合区,这个辐合区使其北侧阳江市区附近成为广东4-7月的多雨中心,海风加强向北进到达阳春附近的"喇叭口"地区产生辐合,又使该地成为阳江4-7月另一个多雨地区,这些都是阳江成为广东省暴雨中心的重要因素之一.另外,如果海陆风环流没有受到破坏,阳江沿海地区不会出现高温天气. 相似文献
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应用2008年天津市14个自动气象站逐小时观测资料、北京站探空资料和天津站6h一次的地面常规观测资料,分析了2008年天津地区夏季海陆风对城市热岛日变化特征的影响.结果表明:在大气层结稳定条件下,海陆风日与非海陆风日相比,天津市热岛强度的日变化幅度增大,海风能使城市降温,削弱城市热岛强度,推迟夜间热岛的出现时间,而陆风能使夜间热岛显著增强;天津市热岛强度与海风向内陆传播的距离有密切关系,在海陆风日,当天气尺度地转风与离岸风的方向一致时,海风的传播距离较近,而当天气尺度地转风与向岸风方向一致时,海风的传播距离较远,当海风只能到达津南、东丽或宁河站时,天津市热岛强度增幅最大,随着海风传播距离的增加,热岛强度的总体增幅减小. 相似文献
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刘成 《沙漠与绿洲气象(新疆气象)》2013,7(2):56-60
利用大连风廓线雷达高时空分辨率风场观测资料,统计2011年雷达站上空各层水平及垂直风速的分布特征.通过分析发现:最大水平风速通常出现在12 km上下,受高空急流的影响,各季节高空最大水平风速出现高度不同,4 km以下高空水平风速随高度的变化各月份存在一定差异,4 km以上至最大风速层,水平风速随高度的升高而增大,最大风速层以上至雷达测量的上限水平风速随高度增加先减小后增大;高空垂直风速在夏季较为明显,秋季次之,冬春季节最小;6月是全年月均垂直风速最大的月份,在500～1300 m高度层存在一个上升气流中心,平均风速大于0.6 m/s,2月各高度平均垂直风速全年最小. 相似文献
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Land–sea breeze circulation structure on the west coast of the Yellow Sea,China: 中国黄海西岸海陆风循环结构研究 
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下载免费PDF全文 《大气和海洋科学快报》2021,14(1):100003
Land–sea breeze (LSB) is an atmospheric mesoscale circulation that occurs in the vicinity of the coast and is caused by uneven heating resulting from the difference in specific heat capacity between the sea and land surfaces. The circulation structure of LSB was quantitatively investigated with a Doppler wind lidar Windcube100s on the west coast of the Yellow Sea for the first time. The time of observation was 31 August to 28 September 2018. It was found that the height of LSB development was 700 m to 1300 m. The duration of conversion of LSB was between 6 h and 8 h. The biggest average horizontal sea-breeze wind speed at 425 m was 5.6 m s−1, and at 375 m it was 4.5 m s−1. During the conversion process from sea breeze to land breeze, the maximum wind shear exponent was 2.84 at 1300 m altitude. During the conversion process from land breeze to sea breeze, the maximum wind shear exponent was 1.28 at 700 m altitude. The differences in wind shear exponents between sea-breeze and land-breeze systems were between 0.2 and 3.6 at the same altitude. The maximum value of the wind shear exponent can reflect the height of LSB development.摘要陆海风是由于海陆表面之间的比热容不同而导致的昼夜热量分布差异, 从而在海岸附近引发的大气中尺度循环系统.本文利用多普勒风激光雷达Windcube100s首次对黄海西海岸的海陆风的循环结构进行了观测研究.在2018年8月31日至9月28日观测期间发现, 海陆风发展高度一般在700 m至1300 m.海陆风转化持续的时间为6小时至8小时.在425m高度, 海风水平风速出现最大值, 平均为 5.6 m s−1.陆风最大水平风速出现在370 m, 约为4.5 m s−1.最大风切变指数在1300m处, 为2.84;在陆风向海风转换过程中, 最大风切变指数在700m处, 为1.28.在同一高度上, 风切变指数在海风盛行和陆风盛行时的差值范围为0.2–3.6, 风切变能反映出海陆风的发展高度. 相似文献
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Simultaneous observations were made of the Marine Boundary Layer at Tarapur, a site near Bombay on the sea coast, by acoustic sounder and instrumented tower. The meteorological tower was used to sense wind and temperature at various levels up to a height of 120 m while the acoustic sounder was used to examine the thermal structure of the boundary layer up to a height of 700 m. Data recorded for the year 1982 have been analysed.Analysis of the data shows that while the normal structures of thermal echoes and shear echoes represent the mixing depth of the atmospheric boundary layer, the often observed elevated layers are due to sea breeze reversals with their base giving a measure of the depth of the sea-breeze circulation during the day. A sea breeze has been detected during both spring (March to May) and autumn (October to December) months. The onset times are around 1000 hr during spring months and around noon during the autumn period, the height of development being respectively up to 500 and 350 m. The capability of the sodar to detect the base and thickness of the sea breeze, is clearly revealed. 相似文献
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V. Puygrenier F. Lohou B. Campistron F. Saïd G. Pigeon B. Bnech D. Sera 《Atmospheric Research》2005,74(1-4):329-353
Surface and remote-sensing instruments deployed during ESCOMPTE experiment over the Marseille area, along the Mediterranean coast, were used to investigate the fine structure of the atmospheric boundary layer (ABL) during sea-breeze circulation in relation to pollutant transport and diffusion. Six sea-breeze events are analyzed with a particular focus on 25 June 2001.Advection of cool and humid marine air over land has a profound influence on the daytime ABL characteristics. This impact decreases rapidly with the inland distance from the sea. Nearby the coast (3 km inland), the mixing height Zi rises up to 750 m and falls down after 15:00 (UT) when the breeze flow reaches its maximum intensity. A more classical evolution of the ABL is observed at only 11-km inland where Zi culminates in the morning and stabilizes in the afternoon at about 1000 m height.Fine inspection of the data revealed an oscillation of the sea-breeze with a period about 2 h 47 min. This feature, clearly discernable for 3 days at least, is present in several atmospheric variables such as wind, temperature, not only at the ground but also aloft in the ABL as observed by sodar/RASS and UHF wind profilers. In particular, the mixing height Zi deduced from UHF profilers observations is affected also by the same periodicity. This pulsated sea-breeze is observed principally above Marseille and, at the northern and eastern shores of the Berre pond.In summary, the periodic intrusion over land of cool marine air modifies the structure of the ABL in the vicinity of the coast from the point of view of stability, turbulent motions and pollutants concentration. An explanation of the source of this pulsated sea-breeze is suggested. 相似文献
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J.-F. Miao L. J. M. Kroon J. Vilà-Guerau de Arellano A. A. M. Holtslag 《Meteorology and Atmospheric Physics》2003,84(3-4):157-170
Summary A three-dimensional non-hydrostatic atmospheric model RAMS, version3b, is used to examine the impact of complex topography on the sea breeze under heterogeneous and degradation land use characteristics. In the study, it is shown that topography plays an important role in the sea-breeze circulation by aligning the sea breeze front to the coastline and locating the convergence zones close to the mountain range. When the sea breeze is coupled with the upslope wind, the sea-breeze circulation is strengthened by the topography.Sensitivity analyses are carried out to determine the influence of vegetation and soil moisture, i.e., land surface modifications, to this thermally driven flow. Land degradation results in an enhanced sea-breeze circulation which is characterized by a stronger onshore flow, a stronger return current, a larger updraft velocity associated with the sea-breeze front and further inland penetration. Other important features are a deeper sea-breeze depth, a larger downdraft velocity behind the sea-breeze front, and a longer offshore extent. The results also show how land changes modify the sea breeze temporal evolution resulting in an earlier onset and later end. The study stresses the convenience of using three-dimensional models with detailed land surface information to model the sea breeze in complex terrain where land use is rapidly modified.Received February 25, 2002; accepted October 7, 2002
Published online April 10, 2003 相似文献
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利用位于江苏海岸陆地的两座测风塔以及福建海面的一座测风塔气象要素资料,分析了这两种下垫面风速、湍流等要素的日变化规律及廓线特征,探讨了这两种不同下垫面特征导致的风力特征差异。结果表明:海岸陆面日最大风速出现时间较内陆滞后,最小风速出现时间与内陆相差不大,风速日变化位相随高度滞后,日振幅随高度减小,冬季70 m高度风速日变化特征与10 m高度风速日变化特征相反,夜间大于白天,说明冬季的过渡层转换高度低于夏季;海面风速的日变化位相、日振幅等特征随高度变化很小。两种下垫面的风廓线用对数律、指数律拟合的效果相当,海岸陆面的风廓线指数呈现的规律为离岸风组大于向岸风组,冬季大于夏季;海面风廓线指数呈现的规律则是向岸风组大于离岸风组,夏季大于冬季。 相似文献
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Dhanya Pushpadas P. Vethamony K. Sudheesh Smitha George M. T. Babu T. M. Balakrishnan Nair 《Meteorology and Atmospheric Physics》2010,109(3-4):91-106
A high-resolution mesoscale numerical model (MM5) has been used to study the coastal atmospheric circulation of the central west coast of India, and Goa in particular. The model is employed with three nested domains. The innermost domain of 3 km mesh covers Goa and the surrounding region. Simulations have been carried out for three different seasons—northeast (NE) monsoon, transition period and southwest (SW) monsoon with appropriate physics options to understand the coastal wind system. The simulated wind speed and direction match well with the observations. The model winds show the presence of a sea breeze during the NE monsoon season and transition period, and its absence during the SW monsoon season. In the winter period, the synoptic flow is northeasterly (offshore) and it weakens the sea breeze (onshore flow) resulting in less diurnal variation, while during the transition period, the synoptic flow is onshore and it intensifies the sea breeze. During the northeast monsoon at an altitude of above 750 m, the wind direction reverses, and this is the upper return current, indicating the vertical extent of the sea breeze. A well-developed land sea breeze circulation occurs during the transition period, with vertical extension of 300 and 1,100 m, respectively. 相似文献
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为研究大尺度系统风对海风的影响以及海风三维结构特征,利用山东省123个地面自动站资料、青岛地区三十多个内陆及沿海、海岛观测站以及奥帆赛场3个浮标站资料,对2006年8月21日青岛一次海风个例进行了分析,并利用美国俄克拉荷马大学风暴分析预测中心开发的ARPS(the Advanced Regional Prediction System)模式,对海风过程进行了数值模拟研究。结果发现:在较强的离岸风背景下,当内陆气温高于海面气温2℃左右时,海风也可以发生。海风首先在海岸线附近的海上开始,发展的同时向内陆及远海地区推进。海风低层环流很浅,主要位于500 m以下。在较强的偏北离岸风下,海风向内陆推进的距离很短。偏北的大尺度系统风由于渤海冷下垫面的影响,不利于青岛海风的维持。海风开始时,在1500～2500 m高度处同时有反环流出现,但直到傍晚前后,海风的垂直环流圈才发展得比较清晰,其高度也更接近地面。海风消亡后,高层的垂直环流圈及反环流维持3 h左右才逐渐消亡。 相似文献