Diurnal Wind Pattern and Climate Condition on the Coastal Region of Qatar

2023

Preprint

<p>Summer Shamal, a strong low-level northwesterly wind in the Middle Eastern region, is the major trigger for dust storm activity with a broad impact on regional transport and human safety. Due to the scarcity of high-frequency data, near-ground turbulent mixing analyses under Shamal are still rare. The current study investigates the near-surface turbulence characteristics of the atmospheric boundary layer (ABL) in the coastal region of Qatar under summer Shamal conditions (26.08 N, 51.36 E). The results show that, in the absence of monsoon, Shamal prevents the development of summer sea breezes in the Persian Gulf. Compared to non-Shamal days (NSD), Shamal days (SD) are characterized by higher sensible heat flux magnitude and turbulent kinetic energy (TKE) with lower humidity, especially around noon time. Turbulence stability analysis indicates the probability of different dust activities during summer SD and NSD. Wind velocity spectra are investigated to evaluate the TKE dissipation rate. A Weibull distribution is observed for PDFs of TKE dissipation rate under SD for both stable and unstable conditions.</p>

Section: Resultsmentioning

confidence: 99%

“…There are a few, old, low-level buildings far away from the measurement tower. The distance between the tower and the sea was around 40 m which varied due to the tide (Li & Sadr, 2021).…”

Section: Experimental Site and Instrumentmentioning

confidence: 99%

Atmospheric Turbulent Characteristics under Summer Shamal in Coastal Qatar

2023

Preprint

“…It is important to remember that (until very recently) monsoon climate was very rare in the Persian Gulf and the northwesterly Shamal wind is the prevailing wind here, not only in summer but throughout the year (Hubert et al., 1983; Li & Sadr, 2021). The wind direction distributions for daytime and nighttime are shown in Figures 3a and 3b.…”

Section: Resultsmentioning

confidence: 99%

“…Figure 9 shows the averaged TKE dissipation rate variations for all SD and NSD during MJJ with the error bar representing the typical 95% confidence level (Kline, 1985). The TKE dissipation rate is estimated using the common inertial-dissipation method and the outliers where the spectral slope in the inertial subrange deviated >20% from the theoretical −5/3 value was excluded from the analysis (Grachev et al, 2018(Grachev et al, , 2021Li & Sadr, 2021). Overall, analysis of TKE dissipation rate for both SD and NSD indicates similar diurnal trends with a higher level during the daytime; ε increases after sunrise and decreases after reaching the noon peak.…”

Section: Resultsmentioning

confidence: 99%

See 1 more Smart Citation

Atmospheric Turbulent Characteristics Under Summer Shamal in Coastal Qatar

2023

JGR Atmospheres

Self Cite

Shamal wind, a strong northwesterly wind in the Persian Gulf (and the larger Middle East region), has a broad effect on the health, transportation, and safety of the regional environment (Membery, 1983;Yu et al., 2016). For instance, Shamal is known to be the major trigger for dust storm activities across the Arabian Peninsula (Middleton, 1986). Severe dust storms triggered by Shamal cause considerable environmental concerns in >10 countries in the Middle East (Hamidi et al., 2014), which seem to be intensifying due to global warming and excessive drought in the region (Namdari et al., 2018). Shamal wind also plays an important role in the propagation and transportation of atmospheric pollutants in the region, like ozone and discharged plume related to the oil industry (Smoydzin et al., 2012;Yu et al., 2016). Further, Shamal wind velocity creates a high wind load (up to 30 m/s at 300 m above the ground) that can become a threat to tall building stability (Irvin, 2009). It is important to emphasize that Shamal is not an event limited only to the Persian Gulf, but also the Gulf of Oman, the North Arabian Sea, and even as far as the west coast of India (Al Senafi & Anis, 2015;Glejin et al., 2013).

Turbulence characteristics within the atmospheric surface layer of the coastal region of Qatar

Boundary-Layer Meteorol

2022

The atmospheric turbulence characteristics in the coastal region of Qatar are analyzed using the measurements conducted on the shoreline (26.08 N, 51.36 E). The micrometeorological data were collected, from August 2015 to September 2016, using sonic anemometers (20 Hz) at three heights and a weather station atop a 9-m tower. The turbulence characteristics are studied within the framework of Monin–Obukhov similarity theory (MOST), in the presence of the coastal inhomogeneities generated by the sea and land surfaces coming together. The results show the wind from the north-west prevails during the entire test period, with the wind speed higher than that from other directions. The non-dimensional standard deviations of velocity components are found to be consistent the results reported around the world and match suggested MOST scaling, with a relatively greater value for the dissipation rate of turbulent kinetic energy. The flux Richardson number shows a larger scatter under the super-stable and super-unstable regimes. Moreover, the non-dimensional standard deviation of temperature does not align with the suggested model under near-neutral and very stable regimes, and the gradient Richardson number shows some negative values under stable regimes. Two different atmospheric daily stability patterns, ‘orderly’ and ‘disheveled,’ are identified based on the wind conditions. 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 two patterns are then related to the wind continuity and direction relative to the shoreline.