Study of Sea/Land-Breeze Condition in Atmospheric Boundary Layer in the Persian Gulf, Qatar

The sea/land breeze in the coastal region affects the local air quality and provides relief from hot weather. The present study presents near-surface turbulence characteristics of the atmospheric boundary layer (ABL) under sea breeze conditions in the coastal region of Qatar (26.08 N, 51.36 E). Sea breeze days (SBDs) were identified based on the diurnal reversal of wind direction and the land-sea temperature difference from Sep 2015 to Aug 2016. Hodographs of the average wind speed and direction for sea breeze days show a clockwise rotation, characteristics of the Coriolis force veering in the Northern Hemisphere. The diurnal pattern of the relative humidity, sensible heat flux, and turbulent kinetic energy (TKE) during SBDs are investigated. Stability analysis shows mostly unstable and stable ABL during sea and land breeze conditions, respectively. Finally, the ABL heights during SBDs are compared with the general values of local ABL heights in previous observations. Formation of the convective internal boundary layer (CIBL) was observed during sea breeze with the height of the CIBL estimated based on the vertical velocity spectra and the distribution of TKE dissipation rate. The air pollutants can be trapped near the surface layer in this condition since the CIBL dramatically reduces the atmospheric mixing depth.