Exploitation of conventional energy resources has caused a deliberate increase in the emitted carbon in the atmosphere, which catalyzes global warming trends. This is a matter of concern, especially in Qatar, where fossil fuels (oil and gas) are largely relied upon for power production. The dependency on such resources could be gradually reduced by utilizing clean and renewable energy. Resource characterization is an important step to evaluate the potentiality of available renewable energy sources. Wind energy is one among them, which has not been assessed reliably so far in Qatar. We analyzed the wind energy potential along the onshore and offshore areas of Qatar using 40 years (1979–2018) of hourly wind data extracted from the ECMWF Reanalysis v5 (ERA5) database. Monthly, seasonal, annual, and decadal mean wind power densities have been derived. Reliability tests have been carried out at select onshore and offshore locations. Trends and inter-annual variability have been assessed. The study reveals that the available wind resources are generally moderate but consistent with no intense trends during the 40 year period. An inter-annual variability in wind power has been identified, which has secured links with the El Niño–Southern Oscillation (ENSO).

Seasonal variability of hydrography along a nearshore-offshore transect in the eastern part of the EEZ of Qatar has been analyzed using in situ measurements carried out during 5 different months. The study reveals distinct features in temperature, salinity, density, dissolved oxygen (DO), and chlorophyll fluorescence. The sea surface temperature (SST) varies from nearshore to offshore with a positive gradient during January, June, and August, of the order of 1.0–2.0 °C, and with a negative gradient during October and April, of the order of 1.0 °C. Thermal stratification began in June, reached a well-defined thermocline with a vertical difference in temperature of about 10 °C during August, and started to de-stratify during October. The low salinity and low-density inflow of IOSW is evident in the surface layer of the middle of the transect during August, which has enriched the DO in the surface layer up to 20 m depth, while hypoxia prevailed below 50 m depth. The lowest chlorophyll fluorescence was measured in April 2013 (~ 1.0 μg l⁻¹), moderate in June 2013 (~ 1.5 μg l⁻¹), and relatively high in August 2013 (~ 6.0 μg l⁻¹).

In situ observations of physical, chemical, and biological parameters of the Qatari water column were conducted to understand the temporal (seasonal) and spatial (regional) variability in the vertical and horizontal distribution of oceanographic properties within the exclusive economic zone (EEZ) of Qatar. Samples were collected from 5 different offshore shallow and deep stations covering the northern and eastern marine regions of the Qatar EEZ during two seasons: late summer (September 2014) and winter (January 2015). Eighteen (18) water samples were analyzed for temperature, salinity, density, dissolved oxygen concentration, dissolved oxygen saturation (DO%), and chlorophyll-a concentration (Chl-a). These data reveal several interesting and unique features that are related to surface warming that give rise to a large excess of evaporation over precipitation, resulting in the formation of several high salinity water masses. The deep offshore EEZ of Qatar was characterized by stratification (seasonal thermocline and pycnocline) during summer when deep water temperature was about 23.5°C (colder than the surface 32.6°C) where reduced stratification appeared to dominate in winter. Well-oxygenated water exists within the surface layer (0-23 m) during both summer and winter. Oxygen saturation layer (concentration 4.53 ml/l; saturation 94.49%) in the deep water extends to bottom (63 m) in winter however oxygen level falls below the summer thermocline (1.35 ml/l corresponding to 28.95% saturation) at Station 5 (63 m depth). Chl-a concentration was high in summer due to high primary productivity but remained sustained at moderate levels in winter. The procedures and methods were carefully applied to ensure the accuracy of the study results. In-situ measurements have high reliability in detecting hydrographic properties; however, it is costly, time consuming, requires ship time and as well as large number of scientific personnel and resources.

Atmospheric dust samples have been collected from different areas in Qatar and analyzed for major and trace element composition. This region of the Arabian Gulf represents an area largely affected by dust from natural and anthropogenic sources. Twenty one samples were collected during 2014 and 2015 from Al-Khor, Katara, Sealine, Al-Waab, and Qatar University by passive and active sampling techniques. Some bulk samples were collected during the massive megastorm that occurred in April 2015. Back trajectories were determined for each sample set using the NOAA HYSPLIT model over a 50 hour time interval. Samples were equally divided between northerly (n=12; northern Saudi Arabia, Kuwait or Iraq) and southerly (n=8; SE Saudi Arabia, United Arab Emirates and Oman) sources. One sample is expected to originate from westward, in Saudi Arabia. There is more variability noticed in source locations throughout the winter months (October to March), with more of them coming from the south (9 times) compared to summer months (April to September) for twice only. Dust samples were microwave-assisted, total acid digested (HF+HCl+HNO3) and oxidized with H2O2 before analyses were conducted by ICP-OES. Only 12 out of 23 elements (Al, Ca, Fe, K, Mg, Na, Ag, As, Ba, Be, Cd, Co, Cr, Cu, Li, Mn, Mo, Ni, Pb, Sr, V, Zn, P) of the Qatari dust samples were enriched relative to Upper Continental Crust (UCC). Calcium was especially enriched to a level of 400% relative to UCC. About 33% of the total sample mass was CaCO3, reflecting the composition of surface rocks in the source areas. Of the elements typically associated with anthropogenic activity, Ag, Ni, and Zn were the most enriched relative to UCC, with enrichment factors of 182%, 233%, and 209%, respectively. Other metals like Pb and V were not significantly enriched, with enrichment factors not exceeding 25% and 3%, respectively. Major elements (Al, Mn and Fe) were depleted relative to UCC due to the strong enrichment of CaCO3, with enrichment factors of -58%, -35% and -5%, respectively. Samples with northern and southern origins were separated to investigate if the elemental composition could be used to identify source/origin. Only three elements were observed to have a statistical difference. Pb and Na were higher in the samples collected from the south while Cr was higher in those from the north. This study aims to investigate present-day geochemistry of dust particles and its effect on the marine environment of the Arabian Gulf. The geochemical composition of dust is essential component for correcting lithogenic input to water column suspended matter samples. Acknowledgement This study was made possible by a grant from the Qatar National Research Fund under the National Priorities Research Program award number NPRP 6-1457-1-272. The abstract contents are solely the responsibility of the authors and do not necessarily represent the official views of the Qatar National Research Fund.

We present data on bioactive trace metal concentrations of suspended particulate matter (SPM) samples from the Exclusive Economic Zone (EEZ) of Qatar as part of a broader study examining the distributions of particulate bioactive metals, biogenic and lithogenic influences, and biogeochemical controls on particulate trace metal concentrations in the Arabian Gulf. The influence of dust deposition and hydrography was also investigated as factors controlling on bioactive metal concentrations. In this study, we analyzed the composition of water column SPM (> 1 µm) along a transect across the Gulf during two seasonal periods: late spring (May) and late summer (September) 2019. Eight bioactive trace metals (Fe, V, Mn, Zn, Co, Cu, Ni and Ba) were measured in SPM using ICP-MS. Our results show that Fe and Zn are enriched in SPM, likely due to aerosol depositions, while Mn, Ni, Cu, Co and Ba exhibited trends corresponding to hydrographic parameters such as density. Fe, Mn, Co, Ba demonstrated negative correlations with oxygen, explaining their depletion at depth and near sediment layer.