Climatological features of Land–Sea breeze circulation along the red sea Coasts

Coastal cities often experience land–sea breeze (LSB) circulations that strongly affect weather, air quality, and pollutant dispersion. The Red Sea, surrounded by several coastal cities, is significantly influenced by LSB circulations, whose climatological understanding is crucial for developing effective policies and mitigation plans. To investigate their characteristics and variability, LSBs along the Red Sea coasts were identified based on a high-resolution (5 km) regional reanalysis that was generated for the Arabian Peninsula (AP) using the Weather Research and Forecasting (WRF) model over the period 1980 to 2019. The AP reanalysis validated against Automatic Weather Station (AWS) observations, showed consistently higher index of agreement (0.70–0.90 vs. 0.50–0.75) and lower root-mean-square error (1.5–2.2 vs. 2.5–3.0 m s⁻¹) compared to ERA5, confirming improved representation of coastal wind fields. Subsequently, using temperature gradient thresholds and diurnal wind direction shifts, a long-term climatology of the LSB frequency, onset, cessation, and duration along the Red Sea coasts was developed. Results reveal that LSBs occur throughout the year, with the highest frequency in September–November, particularly over the central and northern east coast of the Red Sea, where topographic gaps enhance circulations. LSBs are observed most frequently in the central region, occurring 23–25 days per month, compared to 15–18 days per month in the southern and northern regions. The onset typically begins between 0800 and 1200 UTC, while withdrawal occurs between 1800 and 2000 UTC, resulting in an average duration of 10–13 h, which is longest during summer. A spatial analysis shows that the eastern coast records substantially more LSB days than the western coast, with a maximum over the northern–central KSA coast. Trend analysis (1980–2019) indicates pronounced spatiotemporal variability, with a positive trend ( ~ + 0.2 days yr⁻¹) over the northeast Red Sea during October–November, contrasted by declines ( ~ − 0.2 days yr⁻¹) in other seasons. In the southern Red Sea, LSB occurrences show a declining trend during monsoon (JAS) and autumn (ON), whereas the southwestern regions display positive trends in winter (DJF). These patterns suggest that long-term changes in background monsoon winds likely play a key role in shaping LSB variability across the Red Sea basin.