9 research outputs found

    Model Aided Observational Study of Physical Processes in Fresh Water Reservoirs

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    The aim of this study is to compare observational data to data simulated by a one dimensional model. Observational data collected from January to July 2006 at Lake Whitney, Texas, included water current velocities from an Acoustic Doppler Current Profiler, and an Acoustic Doppler Velocimeter from which shear stress, turbulent kinetic energy dissipation rates, and turbulence kinetic energy were computed using several methods. Numerical model experiments, forced by the surface heat and momentum fluxes, velocity profiles, and temperature profiles were conducted to simulate the development of the turbulence parameters. Two equation models, k-epsilon and k-kl, were used to find which model best describes the observed physical processes (turbulence kinetic energy, turbulent kinetic energy dissipation rate and velocity variances). The combined observational and simulated results show a change in stratification levels that consequently leads to variations in turbulent kinetic energy dissipation rate, turbulent kinetic energy, and the velocity variances. In order to investigate the accuracy of the model, we quantitatively compared these parameters to estimates from the observed data in the bottom boundary layer. In general, the model and observational data agree well for the three parameters, with the exception of some time periods, during which the model prediction differed from the observed. This was at times when the Acoustic Doppler Velocimeter measurements were at the noise level of the instrument. Overall, the k-kl model simulation results appear to be closer to the observational results during the weakly and strongly stratified periods than the k-epsilon model

    Surface heat fluxes over the northern Arabian Gulf and the northern Red Sea: Evaluation of ECMWF-ERA5 and NASA-MERRA2 reanalyses

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    © The Author(s), 2019. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Al Senafi, F., Anis, A., & Menezes, V. Surface heat fluxes over the northern Arabian Gulf and the northern Red Sea: Evaluation of ECMWF-ERA5 and NASA-MERRA2 reanalyses. Atmosphere, 10(9), (2019): 504, doi:10.3390/atmos10090504.The air–sea heat fluxes in marginal seas and under extreme weather conditions constitute an essential source for energy transport and mixing dynamics. To reproduce these effects in numerical models, we need a better understanding of these fluxes. In response to this demand, we undertook a study to examine the surface heat fluxes in the Arabian Gulf (2013 to 2014) and Red Sea (2008 to 2010)—the two salty Indian Ocean marginal seas. We use high-quality buoy observations from offshore meteorological stations and data from two reanalysis products, the Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA2) from the National Aeronautics and Space Administration (NASA) and ERA5, the fifth generation of the European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalyses of global climate. Comparison of the reanalyses with the in situ-derived fluxes shows that both products underestimate the net heat fluxes in the Gulf and the Red Sea, with biases up to −45 W/m 2 in MERRA2. The reanalyses reproduce relatively well the seasonal variability in the two regions and the effects of wind events on air–sea fluxes. The results suggest that when forcing numerical models, ERA5 might provide a preferable dataset of surface heat fluxes for the Arabian Gulf while for the Red Sea the MERRA2 seems preferable.This study was funded by the Research Sector at Kuwait University (project #ZS03/16) and by NSF (grant #OCE-1435665) supporting V.M

    Expanding ocean protection and peace: a window for science diplomacy in the Gulf.

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    The ecological state of the Persian or Arabian Gulf (hereafter 'Gulf') is in sharp decline. Calls for comprehensive ecosystem-based management approaches and transboundary conservation have gone largely unanswered, despite mounting marine threats made worse by climate change. The region's long-standing political tensions add additional complexity, especially now as some Gulf countries will soon adopt ambitious goals to protect their marine environments as part of new global environmental commitments. The recent interest in global commitments comes at a time when diplomatic relations among all Gulf countries are improving. There is a window of opportunity for Gulf countries to meet global marine biodiversity conservation commitments, but only if scientists engage in peer-to-peer diplomacy to build trust, share knowledge and strategize marine conservation options across boundaries. The Gulf region needs more ocean diplomacy and coordination; just as critically, it needs actors at its science-policy interface to find better ways of adapting cooperative models to fit its unique marine environment, political context and culture. We propose a practical agenda for scientist-led diplomacy in the short term and lines of research from which to draw (e.g. co-production, knowledge exchange) to better design future science diplomacy practices and processes suited to the Gulf's setting.We acknowledge support from the Smithson Fellowship (C.M.F.)

    Model Aided Observational Study of Physical Processes in the Northwestern Arabian / Persian Gulf in Response to the Shamal Wind Event

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    In the present study we define a Shamal event as a WNW-N wind with an hourly average speed ≥ 9.85 m/s blowing during at least 3 hours/day. These events have a significant impact on surface heat fluxes (shortwave, longwave, sensible and latent), momentum fluxes, and as a result on vertical water column stratification, currents, and mixing intensities. We examined mixing processes and volume transport in response to Shamal events using observational data (time-series of temperature, dissolved oxygen, light intensity, and currents as well as surface meteorological data) collected over two periods (mid-January to mid-April 2013 and mid-October to mid-January 2014) in the vicinity of Qarooh Island, Kuwait. We further estimated turbulence parameters (Reynolds stresses, eddy diffusivities, TKE, and its dissipation rates) and compared them to two equation turbulence model simulations (k-kl and k-ϵ) during three Shamal events. The comparison of the measured and simulated turbulence parameters demonstrated satisfactory agreement between the two. Mixing in the bottom boundary layer was mainly controlled by two main forcings. The first forcing was the increase in mixing resulting from the current shear frequency generated by tides. The second was by the Shamal induced convection. Using time-series of the observational current structure, we show that winds parallel to the coast generated a subsurface volume transport that was perpendicular to the coast causing upwelling / downwelling. The extent of the upwelling / downwelling region was found to be confined in the region near the coast and did not extend to Qarooh Island (24 nm offshore). The thermal structure at Qarooh was mainly influenced by a warm tongue that extended across the Gulf from the SE

    Surface Heat Fluxes over the Northern Arabian Gulf and the Northern Red Sea: Evaluation of ECMWF-ERA5 and NASA-MERRA2 Reanalyses

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    The air–sea heat fluxes in marginal seas and under extreme weather conditions constitute an essential source for energy transport and mixing dynamics. To reproduce these effects in numerical models, we need a better understanding of these fluxes. In response to this demand, we undertook a study to examine the surface heat fluxes in the Arabian Gulf (2013 to 2014) and Red Sea (2008 to 2010)—the two salty Indian Ocean marginal seas. We use high-quality buoy observations from offshore meteorological stations and data from two reanalysis products, the Modern-Era Retrospective analysis for Research and Applications version 2 (MERRA2) from the National Aeronautics and Space Administration (NASA) and ERA5, the fifth generation of the European Centre for Medium-Range Weather Forecasts (ECMWF) atmospheric reanalyses of global climate. Comparison of the reanalyses with the in situ-derived fluxes shows that both products underestimate the net heat fluxes in the Gulf and the Red Sea, with biases up to −45 W/m 2 in MERRA2. The reanalyses reproduce relatively well the seasonal variability in the two regions and the effects of wind events on air–sea fluxes. The results suggest that when forcing numerical models, ERA5 might provide a preferable dataset of surface heat fluxes for the Arabian Gulf while for the Red Sea the MERRA2 seems preferable

    Environmental conditions during a 6 month biofouling experiment in the Arabian Gulf

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    The development of a mature biofouling community on solid surfaces in the marine environment primarily involves the availability of colonizing bacterial communities and their ability to persist over time in any given environment. This study was undertaken as part of a collaborative project titled Biotechnological Applications of Marine Biofilms developing on solid surfaces in the Arabian Gulf funded by research grant (SQU-GCC/CL/17/02). The succession of marine biofouling communities (mature biofilms) on plastic panels were investigated over a period of six months in four locations in the Arabian Gulf (Fintas and Salmiya marinas in Kuwait, and Bandar Rowdha and Al Mouj marinas in Oman). Monthly assessment of the physico-chemical parameters of the seawater at each location was done using portable meters (thermometer, refractometer, pH meter, turbidity meter and conductivity/TDS meter). The concentrations of nutrients and elements were analysed using ion chromatography (IC) and inductively coupled plasma optical emission spectrometry (ICP-OES), respectively

    Monthly succession of marine biofouling communities in the Arabian Gulf

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    This study was undertaken as part of a collaborative project titled Biotechnological Applications of Marine Biofilms developing on solid surfaces in the Arabian Gulf funded by research grant (SQU-GCC/CL/17/02). The succession of marine biofouling communities (mature biofilms) on plastic panels were investigated over a period of six months in four locations in the Arabian Gulf (Fintas and Salmiya marinas in Kuwait, and Bandar Rowdha and Al Mouj marinas in Oman). Monthly assessment of the physico-chemical parameters of the seawater at each location was done using portable meters (thermometer, refractometer, pH meter, turbidity meter and conductivity/TDS meter). The concentrations of nutrients and elements were analysed using ion chromatography (IC) and inductively coupled plasma optical emission spectrometry (ICP-OES), respectively. After each month, the developed biofilm on each panel was quantitatively and qualitatively analyzed as follows; total wet weight, abundance of bacteria using epifluorescence microscopy, chlorophyll a concentrations using spectrophotometry, percent coverage of macrofoulers, and presence or absence of signs of grazing based on visual observations and/or photodocumentation (using Image J software), which was also used to assess the presence/absence and dominance of macrofouling species. Additionally, the composition of the microbial community was investigated using 16S amplicon sequencing, resulting in supplementary data sets for bacterial community composition, predicted bacterial metabolic pathways (Bowman and Ducklow 2015, doi:10.1371/journal.pone.0135868), and presence/absence of microalgae based on their chloroplast 16S

    Expanding ocean protection and peace: a window for science diplomacy in the Gulf

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    The ecological state of the Persian or Arabian Gulf (hereafter ‘Gulf') is in sharp decline. Calls for comprehensive ecosystem-based management approaches and transboundary conservation have gone largely unanswered, despite mounting marine threats made worse by climate change. The region's long-standing political tensions add additional complexity, especially now as some Gulf countries will soon adopt ambitious goals to protect their marine environments as part of new global environmental commitments. The recent interest in global commitments comes at a time when diplomatic relations among all Gulf countries are improving. There is a window of opportunity for Gulf countries to meet global marine biodiversity conservation commitments, but only if scientists engage in peer-to-peer diplomacy to build trust, share knowledge and strategize marine conservation options across boundaries. The Gulf region needs more ocean diplomacy and coordination; just as critically, it needs actors at its science-policy interface to find better ways of adapting cooperative models to fit its unique marine environment, political context and culture. We propose a practical agenda for scientist-led diplomacy in the short term and lines of research from which to draw (e.g. co-production, knowledge exchange) to better design future science diplomacy practices and processes suited to the Gulf's setting

    Diplomacy for the world's hottest sea

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    Countries that border the Persian or Arabian Gulf [hereafter, “Gulf ”] are adopting ambitious global commitments to protect their marine environments. The United Arab Emirates (UAE) has committed to protecting 30% of its lands and waters by 2030, with other Gulf states expected to soon join. Gulf countries will not meaningfully meet these and other global commitments (such as the post-2020 biodiversity framework) without rebuilding trust, exchanging knowledge, and jumpstarting conservation coordination across their maritime boundaries. Gulf scientists have an overlooked role in this work
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