Analysis of Occurrence Patterns and Influencing Mechanism of Atmospheric Ducts in the South China Sea Areas in 2024
Year: 2025
Type: article
Abstract: 利用ERA5再分析数据，统计分析了南海及附近海域大气波导发生的时空分布特征，并对其影响机制进行分析。结果表明该海域大气波导发生次数最多的月份是4月，产生次数为34,526次，占全年的19.30%；产生次数最少的是12月，共计4112次，仅为全年总次数的2.30%。从空间分布上看，春季整个海域几乎都有大气波导的产生，其他季节的分布较为零散，秋季多发生在南部和北部，夏季和冬季以中部为主。从影响机制上主要分析了季风和副热带高压的影响，在冬季风与夏季风转换期间，海表上层会形成干燥的暖层，覆盖在冷且潮湿的海面上，形成了∂T/∂z > 0的稳定层结。受副热带高压影响，强烈的逆温下沉会阻止海面水汽上升，水汽在低层长时间的停留，会在近海面层形成∂e/∂z Utilizing ERA5 reanalysis data, this study statistically analyzes the spatiotemporal distribution characteristics of atmospheric duct occurrences in the South China Sea and its adjacent areas and examines the influencing factors. The results show that the month with the highest frequency of atmospheric duct in this area is April, with 34,562 occurrences, accounting for 19.32% of the annual total; December has the fewest occurrences, totaling 4112, which is only 2.30% of the annual total. Spatially, atmospheric duct occurs almost throughout the entire sea area in spring, while their distributions is more scattered in other seasons. In autumn, they mostly occur in the southern and northern parts, while in summer and winter, they are mainly concentrated in the central part. Regarding influencing mechanisms, this study primarily analyzes the impacts of monsoons and the subtropical high-pressure system. During the transition period between the winter monsoon and the summer monsoon, a dry warm layer forms above the sea surface, overlaying the cold and moist sea surface, creating a stable stratification with ∂T/∂z > 0. Influenced by the subtropical high-pressure, strong subsidence inversions prevent the rise of moisture from the sea surface. The prolonged retention of moisture in the lower layers leads to the formation of water vapor conditions with ∂e/∂z < 0 near the sea surface, creating an atmospheric stratification conductive to the formation of atmospheric duct.
Source: Climate Change Research Letters
Author: 露 王
Language: English
Subfield: Aerospace Engineering
Field: Engineering
Domain: Physical Sciences
SDG: Climate action
Open Access status: hybrid
OpenAlex ID: W4412729701