Characteristics of Lake Breezes and Their Impacts on Energy and Carbon Fluxes in Mountainous Areas     

Lujun XU  Huizhi LIU  Qun DU  Yang LIU  Jihua SUN  Anlun XU  Xiaoni MENG 《大气科学进展》2021,38(4):603-614

In mountainous lake areas, lake–land and mountain–valley breezes interact with each other, leading to an "extended lake breeze". These extended lake breezes can regulate and control energy and carbon cycles at different scales. Based on meteorological and turbulent fluxes data from an eddy covariance observation site at Erhai Lake in the Dali Basin,southwest China, characteristics of daytime and nighttime extended lake breezes and their impacts on energy and carbon dioxide exchange in 2015 are investigated. Lake breezes dominate during the daytime while, due to different prevailing circulations at night, there are two types of nighttime breezes. The mountain breeze from the Cangshan Mountain range leads to N1 type nighttime breeze events. When a cyclonic circulation forms and maintains in the southern part of Erhai Lake at night, its northern branch contributes to the formation of N2 type nighttime breeze events. The prevailing wind directions for daytime, N1, and N2 breeze events are southeast, west, and southeast, respectively. Daytime breeze events are more intense than N1 events and weaker than N2 events. During daytime breeze events, the lake breeze decreases the sensible heat flux(Hs) and carbon dioxide flux(F_{CO_2}) and increases the latent heat flux(LE). During N1 breeze events, the mountain breeze decreases Hs and LE and increases F_{CO_2}. For N2 breeze events, the southeast wind from the lake surface increases Hs and LE and decreases suppress carbon dioxide exchange.  相似文献   

鄱阳湖地区大气边界层特征的数值模拟   总被引：5，自引：1，他引：4       下载免费PDF全文

杨罡  刘树华  朱蓉  周荣卫 《地球物理学报》2011,54(4):896-908

采用WRFV2.2中尺度数值模式对鄱阳湖地区200 km×200 km范围内,2009年11月5日00∶00至2009年11月6日12∶00不同高度的气象要素进行了数值模拟,得到了水平分辨率为1 km的鄱阳湖地区大气边界层风、温、湿度场和廓线分布的大气边界层物理特征.模拟结果发现:白天鄱阳湖面上空存在着冷岛效应并伴随湖风,而夜间湖面上空存在着热岛效应并伴随陆风,湖面与陆地之间最大温差可达6 ℃;同时地形以及下垫面类型对鄱阳湖区风场的分布具有很大影响,夜间存在一条东北西南走向的低空辐合带,白天逐渐消失;此外受风场和地形作用湖面上空的湿度分布也不均匀,白天湿度层厚度低而夜晚湿度层厚度高,湖中心右侧湿度值大于左侧湿度值.模拟结果能较好地反映鄱阳湖的大气边界层物理特征,有助于了解鄱阳湖地区区域气候的特点,以及由于地形、地理环境、地表特征所形成的不同高度上的风、温、湿的分布规律和大气边界层物理特征,为鄱阳湖地区局地天气预报、风能资源开发、环境保护等提供了科学依据.  相似文献   

青藏高原冬季雪盖增大对夏季东亚大气环流影响的数值试验   总被引：2，自引：1，他引：2  

李海盛  余志豪 《热带气象学报》1998,14(1):70-77

利用二维非线性能量（Ｅ－ε）闭合的边界层数值模式,研究了中纬度地区海岸日间局地海风环流的特征,并对不同海风特性条件下的ＴＩＢＬ高度廓线用幂指数关系进行了数学拟合。对大量的数值试验结果分析表明,ＴＩＢＬ廓线幂指数（α）的取值与海风特性有关,其大小在０．４－１．１之间,α＝０．５只在海风充分发展时的陆上适用,文中还给出了不同海风发展程度（阶段）下的α取值。  相似文献   

海岸地区TIBL廓线与局地海风环流的数值试验   总被引：5，自引：1，他引：5  

王卫国  蒋维楣 《热带气象学报》1998,14(1):63-69

对三次ＥｌＮｉｎｏ发生前后的ＥＣＭＷＦ资料用滤波方法（带通,低通）进行分析,得到的结果清楚地表明,在ＥｌＮｉｎｏ发生前热带季节内振荡较强,而伴随ＥｌＮｉｎｏ发生,季节内振荡明显减弱,这种能量变化最明显的地区是赤道东太平洋地区;对于周期在９０天以上的热带准定常波,伴随ＥｌＮｉｎｏ的发生其能量明显增加,这种增加反映最显著的区域是从大西洋往西一直到西太平洋。对中纬度（２５－３５°Ｎ）及中高纬度（４０－５０°Ｎ）地区的准定常波能量分析表明,中纬度地区的准定常波能量比低纬大,准定常波能量变化在中纬度（２５－３５°Ｎ）表现出与低纬能量变化一致的情形,即伴随着ＥｌＮｉｎｏ的发生,准定常波能量增加;中高纬度（４０－５０°Ｎ）只在亚洲大陆（１００－１７０°Ｅ）表现出与热带一致的能量变化。结果还显示,热带季节内振荡在低层的东传对赤道西风异常及对ＥｌＮｉｎｏ的发生、发展起着很重要的作用。  相似文献   

大理近地层山谷盆地湖陆风及湍流特征分析   总被引：1，自引：0，他引：1       下载免费PDF全文

杨智  刘劲松  孙绩华 《气象与环境学报》2008,24(5):32-37

研究湖陆风特征不仅能够为提高天气气候的预测能力奠定基础,而且对风能资源的开发利用等具有重要的实用意义。利用大理国家气候观象台近地面通量观测系统的2007年3月－2008年5月资料,采用涡动相关法等分析了大理近地层中湖陆风、峡谷风特征及形成原因和影响因素。结果表明：大理地区白天以东风和东南风为主,夜间以西风和西南风为主。进一步对湍流和湍流通量特征分析发现,大理地区白天不稳定层结多于夜间;湍流强度白天强于夜间,并且随着风速的增大而减小;湍流通量具有明显的日变化特征,热量交换形式以潜热为主。  相似文献   

东南极大陆边缘地区夏季近地面层风场特征分析          下载免费PDF全文

薛峰  张占海  周明煜  李诗明  李丙瑞  孙波 《极地研究》2009,21(4):288-298

本文介绍了“2007-2008国际极地年”期间在南极东部大陆边缘伊丽莎白公主地区进行的风场结构观测实验。自动气象站(Automatic Weather Station,AWS)观测数据的统计分析结果表明,夏季该地区冰盖上的近表面风场主要是由下降风控制,而沿海地区的风场则由于海陆热力学性质的差异呈现出冰盖下降风与局地海陆风交互作用的特点。个例研究表明在冰盖下降风占优时段内,伊丽莎白公主地区的近表面风场具有相当规律的日变化特征,太阳人射辐射规律的日变化是这一现象出现的根本原因。多普勒声雷达对风场垂直结构的观测表明,150 m以下的各高度水平风矢量的变化特征与近地面层风场近似一致,冰盖下降风和海陆风旺盛阶段,偏东风和偏西风的高度可达650 m之高。  相似文献   

新生代亚洲形变与海陆相互作用   总被引：26，自引：0，他引：26  

汪品先 《地球科学》2005,30(1):1-18

在现今各个大陆中, 亚洲经历的新生代形变最强. 白垩纪到老第三纪时的亚洲大陆, 不仅面积较今为小, 而且形态偏瘦"; 自从始新世印度与亚洲碰撞之后, 亚洲的面积与高度急剧增大. 随着青藏高原隆升和边缘海的张裂, 东亚原来西倾的地势发生倒转, 形成了从大陆中央隆升区向周围辐射的亚洲大河流系. 亚洲隆升有可能是北极冰盖形成与发展的重要因素, 因为隆升不仅改变大气环流、加剧风化作用, 而且还使西伯利亚河系改向北流, 通过注入北冰洋的淡水促使海水结冰、导致冰盖形成. 新生代亚洲形变, 也使得亚洲季风系统在早中新世形成, 又在约8 Ma与约3 Ma时强化. 同时, 西太平洋边缘海系列的形成, 也改变了亚洲大陆与太平洋之间的物质与能量的交换. 流经边缘海的太平洋西部边界流, 对于洋面升降和构造运动极为敏感, 在冰期低海面时边界流位于边缘海之外, 使大洋输向大陆的热量和水分大为减少. 今天, 亚洲与太平洋之间的能流与物流最为活跃, 可惜亚洲在全球气候环境演变中的重要性至今未能获得学术界的充分认识.   相似文献   

THREE-DIMENSIONAL NUMERICAL SIMULATION OF THE MESOSCALE WIND STRUCTURE OVER SHANDONG PENINSULA          下载免费PDF全文

SHENG Lifang  K. H. SCHLUNZEN  WU Zengmao 《Acta Meteorologica Sinica》2000,14(1):98-107

General features of 3-dimensional mesoscale wind and temperature structure over ShandongPeninsula are described in this paper.Results are achieved by numerical simulation with the 3-dimensional non-hydrostatic mesoscale model METRAS.For the onset and cessation time of sea-land breezes,the simulation results agree well with the statistical analyses of observational dataavailable for the studied area.One interesting result is the 3 hour response time of wind field to thethermal change.Further statistic analysis based on the observational data is needed to make sure ofthis correlation.Important effects of coastal mountains on the wind structure are also exposed indetail by the model.Convergence and divergence centers resulting from the conjunction of sea-landbreezes and complex terrain are clearly shown,which are not noticed before by conventionalsynoptic observation and theoretical analysis.  相似文献   

The Kwinana Coastal Fumigation Study: III – Meteorological and Turbulence Modelling on Selected Days     

Peter J. Hurley  Ashok K. Luhar 《Boundary-Layer Meteorology》2000,94(1):115-138

The Kwinana Coastal Fumigation Study took place inearly 1995 at Kwinana near Perth in Western Australia.The study involved surface and elevated meteorologicaland plume fumigation measurements in sea-breeze flowsnear the coast, and has yielded a comprehensive dataset that is suitable for assessing meteorological andplume dispersion models. In this paper, wesimulate the meteorology and turbulence on four casestudy days, and compare model results with thedetailed surface and aircraft measurements takenduring the study. These days had surface synopticwinds ranging from southerly to northeasterly, witheither stable or near-neutral temperature profilesover the sea.The model used was based on that developed by Hurley(Boundary-Layer Meteorol. 83, 43–73, 1997), but extended here to allow domain nesting,optional non-hydrostatic simulations, and a vegetativecanopy at the surface. The model was forced bystandard weather service synoptic data, and thesimulations have captured the essential features ofthe strong sea-breeze circulation observed on thesedays. The boundary-layer structure over the sea waspredicted to be near-neutral or stable in agreementwith the observations on the particular day. The windspeed and direction in the sea-breeze flow weregenerally predicted well, although the predictedmaximum inflow speed over the land was a little toohigh. The potential temperature was generallyover-predicted, but temperature gradients agreed well.Predicted turbulence levels in the bottom-half of thethermal internal boundary layer compared well to theobservations, but under-estimated the observations inthe in the upper half of this layer. Near-surfacemeasurements of meteorological variables werepredicted well over the entire diurnal cycle, althoughthe predicted sea-breeze onset was generally tooearly. A quantitative model evaluation for thenear-surface sites showed the model performance to bebetter than that from other studies, with Index ofAgreement (IOA) values of 0.8 (wind speed) and 0.96(temperature), compared with values of 0.5–0.6 (windspeed) and 0.33 (temperature) obtained from otherstudies.The availability of new higher resolution synopticanalyses should obviate the lack of spatial andtemporal resolution in synoptic inputs. Theincorporation of these higher resolution synopticinputs and new parameterisation schemes should improvefuture model performance.  相似文献   

北京稳定天气条件下城市边界层环流特征数值研究   总被引：4，自引：0，他引：4  

仲跻芹张朝林  范水勇 《气象科技》2005,33(6):481-486

采用科罗拉多大学和MRC／ASTER共同开发的区域大气模拟系统（RAMS）对北京地区稳定天气条件下的个例进行数值模拟,通过对数值模拟结果与观测事实的比较以及敏感性试验,分析了北京城市边界层环流特征和环流影响因子在环流发展过程中的作用。结果表明：①在山谷风环流和热岛环流相互作用下形成了北京城市边界层流场特有的局地环流。②热岛中心在决定边界层环流的辐合区位置上起相对较大的作用,边界层环流的强度和发展高度由山谷风强度和热岛强度共同决定。  相似文献