Analysis of Low-Level Wind Shear at the Incheon International Airport in Coastal Region
摘要
This study analyzed the characteristics and mechanisms of low-level wind shear at Incheon International Airport (IIA), which is located in a coastal region with gentle terrain, using 1-minute wind data from the Aerodrome Meteorological Observation System (AMOS) and hourly ERA5 reanalysis data. Wind measurements from 8 AMOS stations positioned along runways revealed a dominant channeling effect along the runway, with prevailing northwesterly and southeasterly winds, along with small-scale horizontal variability. The analysis of joint frequency distributions between near-surface and upper-level winds indicated that the northwesterly winds resulted from downward momentum transport, while the southeasterly winds occurred due to baroclinicity and pressure-driven channeling under stable stratification. These southeasterly winds were enhanced by the land breezes. Thermally-driven circulations, including land-sea breezes and slope winds, further contributed to the horizontal heterogeneity in wind patterns. On strong-synoptic forcing days, wind heterogeneity increased with wind speed, whereas on weak-synoptic forcing days, it peaked in the early afternoon due to local sea breeze development. Vertical wind shear events exceeding 7.7 m s-1 (15 knots) between the surface and 975 hPa were more frequent at night, accounting for 3.0% (headwind) and 4.2% (crosswind) of study period. Strong shear events were often accompanied with strong synoptic winds, but some events were associated with moderate synoptic southeasterly and southwesterly winds due to interactions with land-breeze forcing. The results emphasize the importance of the interaction between synoptic forcing and land breeze forcing in low-level wind shear in coastal regions and provide insights for enhancing flight safety and small air mobility operations.