Abstract

Land and sea breezes are formed due to differential heating between land and sea surfaces and are prominent local circulation in the tropical region. We present the first observational analysis of the overview of sea-breeze characteristics based on Automatic Weather Station (AWS) data and radiosonde ascends at Bachok Marine Research Station in peninsular Malaysia. Onset criteria for sea breeze were defined based on the variations of Sea Breeze Component (SBC). Associated parameters such as surface wind direction, wind speed, humidity, and air temperature are analysed for 3 yrs (2015–2017) from the AWS. The radiosonde data taken during two field experiments during northeast monsoon and southwest monsoon are utilised to investigate the impact of monsoons on the sea breeze in greater detail. The influence of synoptic-scale motion on the sea breeze is also investigated using radiosonde and reanalysis data. Generally, the sea breeze sets in from the east at about 10:00 AM and occasionally, prevailing monsoon flow intruded into the local circulation. An increase in station pressure is noted during the onset. The time of onset, as well as the strength of the sea breeze, is influenced by conditions such as clear, cloudy, partially cloudy days and the presence of thunderstorms.

Research highlights

• First time observation of the sea breeze circulation over the northeast peninsular Malaysia during different seasons.

• Detailed spatial and vertical structure of sea breeze and its evolution are studied.

• Combined use of AWS data and radiosonde data in addition to the reanalysis data are brought out for the sea breeze analysis.

• Diurnal and seasonal variation of sea breeze component was used for understanding the onset and evolution of sea breeze.

中文翻译：

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马来西亚半岛沿海站的海风特征

摘要

陆地和海风是由于陆地和海洋表面之间的差异加热而形成的，是热带地区突出的局地环流。我们根据自动气象站 (AWS) 数据和无线电探空仪在马来西亚半岛的 Bachok 海洋研究站对海风特征的概述进行了首次观测分析。海风的起始标准是根据海风分量 (SBC) 的变化定义的。从 AWS 分析了 3 年（2015-2017 年）的表面风向、风速、湿度和气温等相关参数。在东北季风和西南季风期间的两次野外实验中获得的无线电探空仪数据被用来更详细地研究季风对海风的影响。还使用无线电探空仪和再分析数据研究了天气尺度运动对海风的影响。一般来说，海风在上午 10:00 左右从东方吹来，偶尔，盛行的季风流会侵入当地的环流。在开始期间注意到站压力的增加。发生的时间以及海风的强度受晴天、多云、部分多云的日子和雷暴的存在等条件的影响。

研究亮点

• 首次观测马来西亚东北半岛不同季节的海风环流。

• 详细研究了海风的空间和垂直结构及其演变。

• 除了再分析数据外，还结合使用 AWS 数据和无线电探空仪数据进行海风分析。

• 海风分量的日变化和季节变化用于了解海风的发生和演变。