Two daily stability patterns in the atmospheric surface layer of the coast of Qatar

The atmospheric stability condition in the coastal region of Qatar are analyzed using the measurements conducted on the shoreline (26.08N, 51.36E). The micrometeorological data are collected, from August 2015 to September 2016, using sonic anemometers (20 Hz) at three heights and a weather station on the top of a 9 m tower. Two different atmospheric daily stability patterns, ‘orderly’ and ‘disheveled’, are identified based on the wind conditions. A day is classified as ‘orderly’ if the amount of wind from the sea lasts less than 10% of the day. Otherwise, a day with an onshore wind of more than 10% is considered ‘disheveled’. The orderly stability pattern shows a daily descending and ascending trend during the sunrise and sunset periods, respectively, while the disheveled days follow a random pattern with no clear order. The probability distribution of the stability parameter shows a narrower distribution for the ‘orderly’ days, containing fewer unstable periods than the ‘disheveled’ days. The chaotic trend during disheveled days could be caused by the inhomogeneity of the roughness between the land and the sea (1000 times). The integral length scales are further investigated to clarify the influence of the local thermally forced flow to the disheveled patterns.