Spatiotemporal Distribution Characteristics of Sea Fog in Qingdao and Comparative Analysis of Multi-Source Radar Data

Qingdao is situated in a high-frequency sea fog zone along the western Huanghai Sea coast, where the interplay between the East Asian monsoon and the Huanghai Sea Cold Water Mass fosters a distinct advection cooling fog system during the fog season, characterized by low-level jet-driven warm-moist air advection and sea surface cooling effects. Based on ground-based observations, L-band radar sounding, and Doppler wind lidar data, this paper analyzes the spatial distribution characteristics of sea fog in Qingdao from 2021 to 2022. The results show that 42 and 33 sea fog events occurred during the fog seasons of the two years respectively. The spatial distribution is characterized by more foggy days on islands and at offshore stations than in the inner part of Jiaozhou Bay. The calibration between Doppler lidar and L-band radar sounding observations shows that the trends of their horizontal wind speeds are consistent, but there are differences in height and time. The linear fitting correlation coefficients of wind speed and direction are relatively high, and the strength of the correlation varies with the development stage of sea fog.