Spatial variability of summer hydrography in the central Arabian Gulf

The Arabian Gulf is a very significant ocean body, which hosts more than 55% of the oil reserves of the world and produces about 30% of the total production, and thus, it is likely to face high risk and adverse problems by the intensified environmental stressors and severe climatic changes. Therefore, understanding the hydrography of the Gulf is very essential to identify various marine environmental issues and subsequently, developing marine protection and management plans. In this study, hydrography data collected at 11 stations along 3 linear transects in the early summer of 2016 were analyzed. The physicochemical parameters exhibited apparent variations along each transect, both laterally and vertically, connected to stratification, formation of different water masses and excessive heating. The temperature and salinity decreased laterally from nearshore to offshore, while layered density structures were identified in the offshore regions. The pH, dissolved oxygen (DO) and chlorophyll fluorescence (Fo) exhibited distinct horizontal and vertical variations. The observed pH is within the normal ranges, indicating that seawater acidification may not be a threat. The highest DO (6.13–8.37 mg/l) was observed in a layer of 24-36 m water depth in the deeper regions of the central transect

Observed variability in physical and biogeochemical parameters in the central Arabian Gulf

In situ measurements of physical and biogeochemical variables were conducted along a transect in the Exclusive Economic Zone (EEZ) of Qatar during late summer (September 2014) and winter (January 2015) to investigate their vertical, spatial and temporal variability. The study reveals that the water column is characterized by strong stratification during late summer in the deepest station, where the water depth is around 65 m and the surface to bottom temperature variation is around 9.1°C. The water column is vertically homogeneous during winter due to surface cooling and wind mixing. The surface to 23 m water column is characterized by ample dissolved oxygen (DO) during late summer and winter in the offshore regions, however, relatively low DO is found during late summer due to weak mixing and advection under weak winds and currents. Dissolved oxygen drops to hypoxic levels below the summer thermocline, and the winter high DO layer extends up to the bottom. Chlorophyll-a (Chl-a) is relatively high during late summer in the offshore region, while that in the nearshore regions is very low, which is linked to the anthropogenic stresses from the central east coast of Qatar. The results identified in this study fill an essential gap in the knowledge of regional primary production dynamics.Environmental Science Center (ESC) & Department of Biological and Environmental Sciences (DBES), Qatar University (QU

Elemental distributions in the marine sediments off Doha, Qatar: role of urbanisation and coastal dynamics

This research investigates the present status and decadal variability of element distributions in the marine sediments off Doha, on the east coast of Qatar. Twenty elements were considered from 11 sediment sampling stations and 3 dust sampling stations by grouping them into major elements, toxic elements, and other trace elements. The results show elevated concentrations of certain toxic and trace elements, including Ba, Be, Co, Cr, Cu, Fe, Mg, V, Zn, Mg, and Ti, in the nearshore region, primarily influenced by the settling of dissolved elements under weak hydrodynamic circulations in the Doha Bay. The relatively higher currents in offshore enable quick advection and dispersion of the elements. On the other hand, the dust deposits have caused significant contributions to the Al, As, Mg, Ca, Sr, Fe, Zn, and Cd concentrations. Decadal variability is evident in element concentrations, which are linked to the urbanisation of the capital city in the State of Qatar. The Cu, Ni, V, Zn, and Cd concentrations indicate a notable increase in recent years compared to the last two decades, with values of about 20.7, 17.9, 25.0, 25.9, 0.66 ppm in 2022. In contrast, a few other elements fluctuate between the decades/years. The results pointed out the increased elemental concentrations in the bay due to the vast expansion of infrastructure facilities in the vicinity of Doha Bay in recent years. The Geoaccumulation Index resulted in a slight pollution of Cd, while other elements are unpolluted. The Degree of Contamination reveals low degree of contamination of sediments, and the Pollution Load Index illustrates no significant pollution in the sediments off Doha

Wind energy potential along the onshore and offshore Qatar

Wind energy is one among the clean and renewable energy resources. The utilization of non-conventional energies over the conventional sources helps to reduce the carbon emissions significantly. The present study aims at investigating the wind energy potential at select coastal locations of Qatar using ERA5 winds. ERA5 is the updated reanalysis product of the European Centre for Medium-range Weather Forecasts (ECMWF), in which the scatterometer and in situ wind data are assimilated to improve the accuracy of predictions, thus the long-term and short-term variabilities are reasonably well captured. Compared to the earlier studies, in this work, we have assessed the wind power at inland and o?shore areas of Qatar, considering 40-year long (1979-2018) time series data with hourly ERA5 winds at 10-m height. The results show that there is no signi?cant increase or decrease of wind power around Qatar in the last 40 years in most of the locations, while there is a slight decreasing trend in the o?shore areas of Ruwais. This indicates that the average wind power is consistently available throughout the years. The links of climatic indices, especially the ENSO events with the wind climate of Qatar, are clearly evident in the long-term data. As obvious, the o?shore regions of Qatar have relatively high wind power compared to the land areas. Among the select locations, the highest annual mean wind power density is obtained in the o?shore Ruwais (152 W/m2), followed by o?shore Ras La?an (134 W/m2) and land area of Al Khor (120 W/m2). The maximum wind power density varies between 1830 and 2120 W/m2 in the land areas, while it is between 1850 and 2410 W/m2 in the o?shore areas of Qatar. The highest wind power is consistently available during the prevalence of shamal winds in winter (January-March) as well as summer (June)