论文部分内容阅读
利用中尺度气象模式WRF,设计了陆地生态环境好转、维持现状和退化3种情境下的模拟试验,分析了夏季黄河上游鄂陵湖湖泊效应的特征和生态环境变化对该湖泊效应的影响。结果表明,夏季晴天中午至傍晚,鄂陵湖有显著的湖风环流;白天湖面感热和潜热较小,昼（夜）表现出明显的冷（暖）湖效应;湖区低层全天呈现出＂湿岛＂效应;受湖风作用影响,环湖陆上白天形成＂湿墙＂和感热高值区;随着陆地生态环境由好转到退化,湖风环流加强,环湖＂湿墙＂增高,湖陆边界层高度差增大,陆面感热和潜热变化显著大于湖面;陆面边界层中下部的气温和比湿主要受下垫面影响,环境退化后分别升高和减小,而在边界层顶部由于受湖风环流的作用,两者变化趋势与中下部相反。“,”A three-dimensional mesoscale atmospheric model WRF is used to examine the characteristic of lake effect over Lake Ngoring in the upper reach of the Yellow River and the influence of terrestrial environment change on the lake effect.Three groups of experiments have been simulated which include environmental improvement,status quo,degradation.The main results show:(1)From noon to nightfall in sunny summer,there is a clear lake-breeze circulation in Lake Ngoring;both sensible heat flux and latent heat flux are small over the lake in daytime,moreover,there is a strong cold(warm)lake effect over Lake Ngoring region in daytime(nighttime);the specific humidity over lake is larger than that over land in surface layer,but there is converse above it;the water vapor wall and high value areas of sensible flux can be found on land along the lake under the influence of lake breezes.(2)Environment degradation results in an enhanced lake-breeze circulation and higher water vapor wall.In addition,the difference of the boundary layer height increases between land and lake;for the different surface characteristics,the changes of sensible heat and latent heat fluxes over land are much more than that over the lake.(3)Environment changes impact on the distributions of air temperature and specific humidity in the bottom and top of the boundary layer through the underlying surface and the lake breeze,respectively,as a result,there is a reverse trend in different heights.