Sea breezes have been observed to move inland over 100 km. These airmasses can be markedly different from regional airmasses, creating a shallow layer with differences in humidity, wind, temperature and aerosol characteristics. To understand their influence on boundary layer and cloud development on subsequent days, we identify their frequency and characteristics. We visually identified sea breeze fronts on radar passing over the Savannah River Site (SRS) between March and October during 2015–2019. The SRS is ~150 km from the nearest coastal location; therefore, our detection suggests further inland penetration. We also identified periods when sea breeze fronts may have passed but were not visually observed on radar due to the shallow sea breeze airmass remaining below the radar beam elevation that ranges between approximately 1–8 km depending on the beam angle and radar source (Columbia, SC or Charleston, SC). Near-surface atmospheric measurements indicate that the dew point temperature increases, the air temperature decreases, the variation in wind direction decreases and the aerosol size increases after sea breeze frontal passage. A synoptic classification procedure also identified that inland moving sea breezes are more commonly observed when the synoptic conditions include weak to moderate offshore winds with an average of 35 inland sea breezes occurring each year, focused primarily in the months of April, May and June.

中文翻译：

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美国东南部内陆平流海风的频率和特征

已观察到海风向内陆移动超过 100 公里。这些气团可能与区域气团明显不同，形成一个具有不同湿度、风、温度和气溶胶特性的浅层。为了了解它们对随后几天边界层和云发展的影响，我们确定了它们的频率和特征。我们在 2015 年至 2019 年 3 月至 10 月期间通过萨凡纳河站点 (SRS) 的雷达视觉识别了海风锋。SRS 距离最近的沿海位置约 150 公里；因此，我们的检测表明进一步向内陆渗透。我们还确定了海风锋可能已经过去但由于浅海风气团保留在雷达波束仰角下方，根据波束角和雷达源（哥伦比亚， SC 或查尔斯顿，SC）。近地表大气测量表明，海风锋面通过后，露点温度升高，气温降低，风向变化减小，气溶胶粒径增大。天气分类程序还确定，当天气条件包括弱到中度的海上风时，更常观察到内陆移动的海风，每年平均发生 35 次内陆海风，主要集中在 4 月、5 月和 6 月。