A Climatology of Easterly Wind Lake-Effect and Lake-Enhanced Precipitation Events over the Western Lake Superior Region
A Climatology of Easterly Wind Lake-Effect and Lake-Enhanced Precipitation Events over the Western Lake Superior Region
复制标题
苏必利尔湖西部地区东风湖效应和湖泊增强降水事件的气候学
DOI：
10.1175/jamc-d-22-0080.1
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发表时间：
2023
影响因子：
3
通讯作者：
Metz, Nicholas D.
中科院分区：
文献类型：
--
作者：
Sandstrom, Joshua D.;Cordeira, Jason M.;Hoffman, Eric G.;Metz, Nicholas D.
湖泊效应降水是相对冷空气通过较大和相对温暖的水体而产生的对流降水。这种现象最常发生在北美五大湖南部和东部海岸，在盛行的西部和西北部气流下，那里经常发生每年的高降雪量和强影响的暴风雪。当对流层下部存在条件不稳定或中性层结的空气时，由于湖泊增强的天气降水，局部也会出现较高的降雪量或降雨量。虽然可能不太常见，但湖泊效应和湖泊增强的降水也可能在东风中发生，影响五大湖的西海岸。本研究描述了2003年至2018年在苏必利尔湖西部由东向东-东北气流中发展的东湖效应(ELEfP)和湖泊增强(ELEnP)降水[联合称为东湖集体降水(ELCP)]事件的15年气候学。厄尔尼诺环流很少发生，但经常发生，足以对苏必利尔湖西部产生显著的气候影响，平均每年发生14.6次。由于苏必利尔湖的西海岸凸起，这种形态有利于单一的岸边平行的ELEfP带，而由于ELEnP事件与“超限”天气尺度降水有关的混合型带状分布。ELEfP经常与苏必利尔湖以北的地面反气旋有关。ELEnP通常具有类似的向北移动的反气旋和位于中西部上部的地面气旋，有利于苏必利尔湖西部的东边界层风。
Lake-effect precipitation is convective precipitation produced by relatively cold air passing over large and relatively warm bodies of water. This phenomenon most often occurs in North America over the southern and eastern shores of the Great Lakes, where high annual snowfalls and high-impact snowstorms frequently occur under prevailing west and northwest flow. Locally higher snow or rainfall amounts also occur as a result of lake-enhanced synoptic precipitation when conditionally unstable or neutrally stratified air is present in the lower troposphere. Although likely less common, lake-effect and lake-enhanced precipitation can also occur with easterly winds, impacting the western shores of the Great Lakes. This study describes a 15-yr climatology of easterly lake-effect (ELEfP) and lake-enhanced (ELEnP) precipitation [conjointly, easterly lake collective precipitation (ELCP)] events that developed in east-to-east-northeasterly flow over western Lake Superior from 2003 to 2018. ELCP occurs infrequently but often enough to have a notable climatological impact over western Lake Superior, with an average of 14.6 events per year. The morphology favors both single shore-parallel ELEfP bands due to the convex western shoreline of Lake Superior and mixed-type banding due to ELEnP events occurring in association with “overrunning” synoptic-scale precipitation. ELEfP often occurs in association with a surface anticyclone to the north of Lake Superior. ELEnP typically features a similar northerly displaced anticyclone and a surface cyclone located over the upper Midwest that favor easterly boundary layer winds over western Lake Superior.