Dominant Energy Source Research Articles

ALMA IMAGING OF MILLIMETER/SUBMILLIMETER CONTINUUM EMISSION IN ORION KL

We have carried out high resolution observations with Atacama Large Millimeter/Submillimeter Array (ALMA) of continuum emission from Orion KL region. We identify 11 compact sources at ALMA band 6 (245 GHz) and band 7 (339 GHz), including Hot Core, Compact Ridge, SMA1, IRc4, IRc7, and a radio source I (Source I). Spectral energy distribution (SED) of each source is determined by using previous 3 mm continuum emission data. Physical properties such as size, mass, hydrogen number density and column density are discussed based on the dust graybody SED. Among 11 identified sources, Source I, a massive protostar candidate, is a dominant energy source in Orion KL. We extensively investigate its SED from centimeter to submillimeter wavelengths. The SED of Source I can be fitted with a single power-law index of 1.97 suggesting an optically thick emission. We employ the H$^{-}$ free-free emission as an opacity source of this optically thick emission. The temperature, density, and mass of the circumstellar disk associated with Source I are constrained by the SED of H$^{-}$ free-free emission. Still the fitting result shows a significant deviation from the observed flux densities. Combined with the thermal dust graybody SED to explain excess emission at higher frequency, a smaller power-law index of 1.60 for the H$^{-}$ free-free emission is obtained in the SED fitting. The power-law index smaller than 2 would suggest a compact source size or a clumpy structure unresolved with the present study. Future higher resolution observations with ALMA are essential to reveal more detailed spatial structure and physical properties of Source I.

Do allochthonous inputs represent an important food resource for benthic macrofaunal communities in tropical estuarine mudflats?

Tropical estuarine mudflats receive a variety of allochthonous organic material made up of riverine mangrove litter, as well as marine particulate organic matter (POM), and seagrass litter. Autochthonous microphytobenthos are also an abundant type of organic matter in these systems. Previous studies show that allochthonous mangrove detritus is the dominant energy source of the mudflat food web; however, recent studies suggest that its importance has been overestimated. To elucidate the food-web dynamics of tropical estuarine mudflats, we analyzed the stable carbon-nitrogen isotope ratios of primary producers (drift mangrove litter, drift seagrass litter, marine and riverine POM, and microphytobenthos), mudflat in situ organic matter, and benthic macro-invertebrates (as the primary consumers, they are an important biological link between organic matter and predators) in three estuarine mudflats in Trang Province, Thailand. Bayesian SIAR revealed that the mudflat sediments primarily originated from an allochthonous riverine source (i.e. imported mangroves), whereas mudflat in situ POM was mainly comprised of allochthonous marine POM. Isotope analysis indicated that most benthic invertebrates in mudflats depend on autochthonous benthic micro-algae and marine allochthonous seagrass litter (including epiphytes) for food, but this is not the case for allochthonous riverine mangroves. Our results suggest that the impact of allochthonous riverine inputs as a food resource is not notable in these particular estuarine mudflats. Further study is needed to explore the function of autochthonous and marine allochthonous resources in other tropical estuarine mudflats.

Energy availability and energy sources as determinants of societal development in a long-term perspective

The dominant energy sources used by human societies and the transitions from one energy source to another have fundamental implications for societal development. A future energy transition is pending but it remains unclear what its socioeconomic corollaries will be. The history of the dominant energy sources used by human societies and their implications for societal development are traced in this review. “Passive solar energy utilization” in the hunting and gathering mode requires mobility of societies following the biomass that is their sole energy input. Fertility is constrained both by the available nutrition and by the need to migrate: population density is low. The agrarian mode relies on “active solar energy utilization”. Solar energy is harnessed through cultivated crops providing energy to humans. This mode requires a sedentary way of life and allows for much higher population density; progress in raising yields is achieved by additional labor-inputs and drives population growth. The industrial mode relies largely on fossil energy carriers supplying human societies with an amount of energy never accessible before, and with new materials. It relieves human societies of their dependence on land, fosters urban growth, and decreases fertility. At the same time, the industrial mode is based on a dominant energy source that will not be available indefinitely and that is associated with severe impacts on the environment. A future energy transition seems unavoidable and historical evidence suggests that it will be associated with fundamental socioeconomic change.

Recent progress in the thermocatalytic processing of biomass into advanced fuels

Recent progress in the thermocatalytic processing of biomass into advanced fuels

Requested characteristics of new sustainable coal-fired thermal power plants in Bosnia and Herzegovina

World energy needs increase. Coal is still globally dominant primary energy source in the electric power system, but its future importance in that sense is doubtful. Fossil fuels dependence is unsustainable in long-term period because of limited coal reserves, environment pollution and climate changes. Achieving sustainable developmenassumes greater deployment of renewable (basically undispatchable) energy sources, environment influence reduction, and energy efficiency increase. Accordingly, new coal-fired thermal power plants must be flexible in operation, energy efficient, environmentally acceptable, and in addition to all of that economically sustainable with the purpose of providing place in global future power plants portfolio. Bosnia and Herzegovina must pay attention to those requests during designing and building of new thermal power plants, since as collectivity among all fossil fuels possesses only proven coal reserves. Knowledge-based decision mak­ing about possible best characteristics of new coal-fired thermal power plants in Bosnia and Herzegovina requires performing of research with respect to: coals combustion, cofiring coal with biomass, co-generation or tri-generation of electrical and other forms of useful energy, installing plants for reduction of emission of pollutants and carbon dioxide, and possibility of flexible operation. This paper outlines required characteristics of future coal-fired thermal power plants, according to current understanding of Europeenergy future. In case of the Kakanj thermal power plant possibility of positive answer to those requests was analysed. Results of that analysis were also shown in the paper.

Energy configuration and operation optimization of refinery fuel gas networks

The production of regular clean fuels is faced with a problem of declining profit under more strict and costly environmental regulations. To satisfy the desire for higher profit and the firm requirements of environmental protection, it is imperative to improve the efficiency of energy systems within refineries. Over the past decade numerous attempts were made to enhance the energy system, addressing the steam power system and hydrogen system in particular. However, the fuel gas system, which serves as the dominant energy source of refineries, has drawn little attention in the research community. Industrial practices indicate that the energy efficiency of the fuel gas systems can be improved remarkably by optimizing the operation schedules. This paper presents a multi-period optimizing model for the scheduling of fuel gas system within refineries. Modeling of the pipeline system is considered important, which was usually ignored in the former studies. Flow reversal and flow transition in the pipe segments are taken into consideration. Pipelines with branching structure and loop structure can be easily modeled and solved with rational computation effort. Complementarity formulations are utilized in modeling of discrete decisions instead of the commonly used binary variables. Application of this method is illustrated with a case study.

Energy for Transport

Global transportation energy use is steeply rising, mainly as a result of increasing population and economic activity. Petroleum fuels remain the dominant energy source, reflecting advantages such as high energy density, low cost, and market availability. The movement of people and freight makes a major contribution to economic development and social well-being, but it also negatively impacts climate change, air quality, health, social cohesion, and safety. Following a review published 20 years ago in the Annual Review of Environment and Resources (then named the Annual Review of Energy and the Environment) by Lee Schipper, we examine current trends and potential futures, revising several major global transport/energy reports. There are significant opportunities to slow travel growth and improve efficiency. Alternatives to petroleum exist but have different characteristics in terms of availability, cost, distribution, infrastructure, storage, and public acceptability. The transition to low-carbon equitable and sustainable transport will take time but can be fostered by numerous short- and medium-term strategies that would benefit energy security, health, productivity, and sustainability.

Energetics of East Pacific Easterly Waves during Intraseasonal Events

Abstract The background atmospheric state of the east Pacific warm pool in which easterly waves develop varies dramatically on intraseasonal time scales. East Pacific intraseasonal variability is well known to modulate local convective and circulation patterns. Westerly (easterly) intraseasonal phases are associated with westerly (easterly) low-level wind and positive (negative) convective anomalies. This study investigates the perturbation available potential energy (PAPE) and perturbation kinetic energy (PKE) budgets of easterly waves composited during westerly, easterly, and neutral intraseasonal phases, respectively. The mechanisms, magnitudes, locations, and vertical structures of easterly waves are shown to strongly vary as a function of intraseasonal phase. Easterly waves draw energy from low-level barotropic conversion, regardless of phase, although the location and magnitude of the conversion varies strongly. During neutral and westerly intraseasonal phases, the generation of PAPE associated with perturbation diabatic heating that is subsequently converted to PKE is the dominant energy source for easterly waves. A novel and previously unrecognized result is the detection of strong barotropic generation of PKE at midlevels during westerly intraseasonal phases. This previously unidentified source of PKE at midlevels is in part due to strong intraseasonal modulation of the background midlevel winds.

A pilot test of ethanol gel as a paraffin replacement in a low-income urban environment

This paper describes the results of a pilot programme to introduce ethanol gel as a replacement for paraffin for cooking in a low-income informal settlement, Samora Machel, in the Philippi district of Cape Town. A baseline study had shown that paraffin was the dominant source of energy in this community, and that the community knew that its use was both hazardous and unhealthy, but they had no apparent alternative. A gel fuel meeting the requirements of SANS 448 was identified and supplies ordered. A burner system meeting the requirements of SANS 666 was not available on the market; instead it was necessary to use all that could be found. The Agrifood Technology Station at the Cape Peninsula University of Technology (CPUT) was tasked with finding ways to cook using ethanol gel, with accent being placed on cooking safely and using the least possible quantity of gel for a standard menu. After several fruitless attempts to launch a programme, a successful meeting was held at the crèche in Samora Machel at which a number of residents agreed to take part in the pilot programme. Soon thereafter, there was a fire in which many residents lost all their possessions, and when stoves were distributed free of charge, and five litres of gel sold at a subsidised price, all stoves were eagerly taken. The demonstration of how to cook using the gel was held at the point of distribution, and people taking stoves were shown how they worked and how to keep them clean. Every week for four weeks, a sample of the participants was contacted to determine their response to cooking on gel. Virtually every response was most positive, and at the end of that period the participants in the pilot programme requested that the supply of gel should continue as long as possible.

Greenhouse gas mitigation potential of electricity from biomass

In the European Union, the share of renewable energy has increased significantly over the past few years. Among renewable energy options, bioenergy is considered to be the dominant energy source. Previous literature is inconclusive regarding the suitability of bioenergy to mitigate greenhouse gases. The goal of this paper is to address this research gap. Life Cycle Assessments (LCAs) of biomass systems for electricity generation were gathered via a systematic literature review and form the empirical basis of this study. A quantitative exploratory analysis and a Qualitative Comparative Analysis were carried out to identify the greenhouse gas mitigation potential of different biomass systems used for electricity generation. Significant variations in LCA results are due to the heterogeneity of these systems; therefore, the transferability of LCA results to similar systems must be investigated on a case-by-case basis. Results show that electricity from biomass can be an appropriate measure for greenhouse gas mitigation in the European Union. To mitigate greenhouse gases, it is recommended to promote the employment of (1) non-dedicated lignocellulosic biomass with thermochemical conversion, (2) dedicated lignocellulosic biomass with thermochemical conversion, and (3) dedicated lignocellulosic biomass with direct combustion. For a more holistic assessment, future research should focus not only on greenhouse gas emissions, but also on other environmental, economic, and social impact categories.

FIRST DIRECT MEASUREMENTS OF TRANSVERSE WAVES IN SOLAR POLAR PLUMES USING SDO /AIA

There is intense interest in determining the precise contribution of Alfv\'enic waves propagating along solar structures to the problems of coronal heating and solar wind acceleration. Since the launch of SDO/AIA, it has been possible to resolve transverse oscillations in off-limb solar polar plumes and recently McIntosh et al. (2011, Nature, 475, 477) concluded that such waves are energetic enough to play a role in heating the corona and accelerating the fast solar wind. However, this result is based on comparisons to Monte Carlo simulations and confirmation via direct measurements is still outstanding. Thus, this letter reports on the first direct measurements of transverse wave motions in solar polar plumes. Over a 4 hour period, we measure the transverse displacements, periods and velocity amplitudes of 596 distinct oscillations observed in the 171 \AA channel of SDO/AIA. We find a broad range of non-uniformly distributed parameter values which are well described by log-normal distributions with peaks at $234$ km, $121$ s and $8$ km s$^{-1}$, and mean and standard deviations of $407\pm297$ km, $173\pm118$ s and $14\pm10$ km s$^{-1}$. Within standard deviations, our direct measurements are broadly consistent with previous results. However, accounting for the whole of our observed non-uniform parameter distribution we calculate an energy flux of $9-24$ W m$^{-2}$, which is $4-10$ times below the energy requirement for solar wind acceleration. Hence, our results indicate that transverse MHD waves as resolved by SDO/AIA cannot be the dominant energy source for fast solar wind acceleration in the open-field corona.

The Influence of Solvents and Salts on the Properties of High-Voltage Cathode Materials at High Loads and High Temperatures

Lithium - ion batteries play an increasingly important role in the battery industry and they have become the dominant source of energy in the recnt years, especially for portable electronic devices due to their high gravimetric energy density. The new generations of lithium – ion battery cells are based on high-voltage cathode materials. These materials are characterized by a voltage near 5 V and higher energy density than the one currently used in lithium -ion cells. This advantage could help to increase battery expansion especially in transport. Representatives of this type of cathode materials are for example LiNi0,5Mn1,5O4, LiCoPO4 and Li2CoPO4F. The advantage of these materials is also their disadvantage - high working voltage means a big ballast for the electrolytes leading to deterioration of their stability. The stability of conventional carbonate electrolytes is strongly related to the stability and properties of cathode materials in the de-lithiated state. This article examines the influence of mixtures of solvents with different combinations of lithium salts on the stability of two types of high-voltage cathode materials: LiNi0,5Mn1,5O4 and LiCr0,1Ni0,5Mn1,5O4 produced by a solid phase reaction. These materials were combined with several different electrolytes, cycled at various loads and elevated temperature. For these measurements various combinations of solvents ethylene carbonate (EC), dimethyl carbonate (DMC) and sulfolane were used. Salts LiPF6 , LiNO3 and LiTFSI were used.Authors gratefully acknowledge financial support from the Centre for Research and Utilization of Renewable Energy under project No. CZ.1.05/2.1.00/01.0014, FEKT-S-11-7 and Company FEI.

Quantitative flux analysis reveals folate-dependent NADPH production

ATP is the dominant energy source in animals for mechanical and electrical work (e.g., muscle contraction, neuronal firing). For chemical work, there is an equally important role for NADPH, which powers redox defense and reductive biosynthesis1. The most direct route to produce NADPH from glucose is the oxidative pentose phosphate pathway (oxPPP), with malic enzyme sometimes also important. While the relative contribution of glycolysis and oxidative phosphorylation to ATP production has been extensively analyzed, similar analysis of NADPH metabolism has been lacking. Here we demonstrate the ability to directly track, by liquid chromatography-mass spectrometry, the passage of deuterium from labeled substrates into NADPH, and combine this approach with carbon labeling and mathematical modeling to measure cytosolic NADPH fluxes. In proliferating cells, the largest contributor to cytosolic NADPH is the oxPPP. Surprisingly a nearly comparable contribution comes from serine-driven one-carbon metabolism, where oxidation of methylene tetrahydrofolate to 10-formyl-tetrahydrofolate is coupled to reduction of NADP+ to NADPH. Moreover, tracing of mitochondrial one-carbon metabolism revealed complete oxidation of 10-formyl-tetrahydrofolate to make NADPH. Since folate metabolism has not previously been considered an NADPH producer, confirmation of its functional significance was undertaken through knockdown of methylenetetrahydrofolate dehydrogenase (MTHFD) genes. Depletion of either the cytosolic or mitochondrial MTHFD isozyme resulted in decreased cellular NADPH/NADP+ and GSH/GSSG ratios and increased cell sensitivity to oxidative stress. Thus, while the importance of folate metabolism for proliferating cells has been long recognized and attributed to its function of producing one carbon units for nucleic acid synthesis, another crucial function of this pathway is generating reducing power.

Utilization pattern of biomass energy and socioeconomic dimensions associated with Yelandur, Karnataka, India

Energy is considered as a key factor which determines the economic development in the entire sector of any region. Biomass is one of the primary energy sources in rural areas. The study was carried out to examine the utilization pattern of biomass energy and socioeconomic dimensions associated with rural areas of Yelandur, Karnataka, India. Field studies in these villages covering 645 households were made to collect the data and assess the socioeconomic conditions that govern the biomass utilization pattern for meeting energy requirements. Firewood is the primary energy source (94.78 %) for cooking and heating among these rural folk. Most of them are illiterates (60 %) with 28.96 % of them having a meagre income. Traditional biomass stoves are used predominantly. The study shows that there is a positive correlation (R 2 = 0.98) between the households size and volume of firewood consumption. The study has revealed that the firewood fuels are the dominant source of energy for cooking and heating purposes.

Trapped diurnal internal tides, propagating semidiurnal internal tides, and mixing estimates in the California Current System from sustained glider observations, 2006–2012

From 2006–2012, along 3 repeated cross-shore transects (California Cooperative Oceanic Fisheries Investigations lines 66.7, 80, and 90) in the California Current System, 33609 shear and 39737 strain profiles from 66 glider missions are used to estimate mixing via finescale parameterizations from a dataset containing over 52000 profiles. Elevated diffusivity estimates and energetic diurnal (D1) and semidiurnal (D2) internal tides are found: (a) within 100km of the coast on lines 66.7 and 80 and (b) over the Santa Rosa-Cortes Ridge (SRCR) in the Southern California Bight (SCB) on line 90. While finding elevated mixing near topography and associated with internal tides is not novel, the combination of resolution and extent in this ongoing data collection is unmatched in the coastal ocean to our knowledge.Both D1 and D2 internal tides are energy sources for mixing. At these latitudes, the D1 internal tide is subinertial. On line 90, D1 and D2 tides are equally energetic over the SRCR, the main site of elevated mixing within the SCB. Numerous sources of internal tides at the rough topography in the SCB produce standing and/or partially-standing waves. On lines 66.7 and 80, the dominant energy source below about 100m for mixing is the D1 internal tide, which has an energy density of the D2 internal tide. On line 80, estimated diffusivity, estimated dissipation, and D1 energy density peak in summer. The D1 energy density shows an increasing trend from 2006 to 2012. Its amplitude and phase are mostly consistent with topographically-trapped D1 internal tides traveling with the topography on their right. The observed offshore decay of the diffusivity estimates is consistent with the exponential decay of a trapped wave with a mode-1 Rossby radius of 20–30km. Despite the variable mesoscale, it is remarkable that coherent internal tidal phase is found.

PINPOINTING THE MOLECULAR GAS WITHIN AN Lyα BLOB ATz∼ 2.7

We present IRAM PdBI observations of the CO(3-2) and CO(5-4) line transitions from a Ly-alpha blob at z~2.7 in order to investigate the gas kinematics, determine the location of the dominant energy source, and study the physical conditions of the molecular gas. CO line and dust continuum emission are detected at the location of a strong MIPS source that is offset by ~1.5" from the Ly-alpha peak. Neither of these emission components is resolved with the 1.7" beam, showing that the gas and dust are confined to within ~7kpc from this galaxy. No millimeter source is found at the location of the Ly-alpha peak, ruling out a central compact source of star formation as the power source for the Ly-alpha emission. Combined with a spatially-resolved spectrum of Ly-alpha and HeII, we constrain the kinematics of the extended gas using the CO emission as a tracer of the systemic redshift. Near the MIPS source, the Ly-alpha profile is symmetric and its line center agrees with that of CO line, implying that there are no significant bulk flows and that the photo-ionization from the MIPS source might be the dominant source of the Ly-alpha emission. In the region near the Ly-alpha peak, the gas is slowly receding (~100km/s) with respect to the MIPS source, thus making the hyper-/superwind hypothesis unlikely. We find a sub-thermal line ratio between two CO transitions, I_CO(5-4)/I_CO(3-2)=0.97+/-0.21. This line ratio is lower than the average values found in high-z SMGs and QSOs, but consistent with the value found in the Galactic center, suggesting that there is a large reservoir of low-density molecular gas that is spread over the MIPS source and its vicinity.

Renewable Energy and Energy Security in the Philippines

This paper focused on the importance of renewable energy to Philippine energy security and sustainability agenda. It examined the status of renewable energy in the Philippines and discussed the opportunities and challenges in the further development and deployment of renewable energy. This research relied on secondary data from the Philippine Department of Energy, ASEAN Centre for Energy, World Bank, and APEC Secretariat. Relevant informative journalistic reports were also consulted. Among the major findings are: (1) renewable energy will account for an increasingly significant share of the Philippine energy mix for power generation in the foreseeable future and (2) fossil fuels, oil in particular, however, will remain the dominant energy source. Whether or not the Philippine government will achieve its renewable energy targets largely depends on how efficient and fast it will be in addressing the related issues. This study builds on the existing knowledge base on Philippine renewable energy.

EVOLUTION OF THE STRATOSPHERIC TEMPERATURE AND CHEMICAL COMPOSITION OVER ONE TITANIAN YEAR

Since the Voyager 1 (V1) flyby in 1980, Titans exploration from space and the ground has been ongoing for more than a full revolution of Saturn around the Sun (one Titan year or 29.5 Earth years was completed in May 2010). In this study we search for temporal variations affecting Titans atmospheric thermal and chemical structure within that year. We process Cassini CIRS data taken during the Titan flybys from 2006-2013 and compare them to the 1980 V1IRIS spectra (re-analyzed here). We also consider data from Earth-based and -orbiting observatories (such as from the ISO, re-visited). When we compare the CIRS 2010 and the IRIS data we find limited inter-annual variations, below the 25 or35 levels for the lower and middle, or the high latitudes, respectively. A return to the 1980 stratospheric temperatures and abundances is generally achieved from 50degN to 50degS, indicative of the solar radiation being the dominating energy source at 10 AU, as for the Earth, as predicted by GCM and photochemical models. However, some exceptions exist among the most complex hydrocarbons (C4H2 and C3H4), especially in the North. In the Southern latitudes, since 2012, we see a trend for an increase of several trace gases, possibly indicative of a seasonal atmospheric reversal. At the Northern latitudes we found enhanced abundances around the period of the northern spring equinox in mid-2009 (as in Bampasidis et al. 2012), which subsequently decreased (from 2010-2012) returning to values similar to those found in the V1 epoch a Titanian year before.

Technology Focus: Tight Reservoirs (October 2013)

Technology Focus Tight reservoirs are still in the early stages of becoming a dominant source of energy and economic growth throughout the world for years to come. I recently read two distinctly different articles particularly relevant to tight reservoirs. One was written by an oil and gas consultant who applied the Pareto principle to the practice of multistage hydraulic fracturing of horizontal wells, which has pushed oil production to 20-year highs in North America. The other was authored by a major asset holder’s policy expert, who objectively addressed public perception of the oil and gas industry. Although our industry has developed a number of new technologies enabling better reservoir characterization, horizontal-well placement, and reservoir drainage, as well as gaining public trust, there does appear to be room for improvement. We must continue to listen to the public and understand the concerns and issues. Our response should include transparency, research to address concerns, and development of workflows and technologies to address safety and protection of health and the environment. One such response by our industry is the growing priority of improving long-term wellbore integrity. Improvements are being made in mud removal, cement-system-design software and techniques, and environmentally friendly cementing systems with improved bonding and mechanical integrity. From a production perspective, if 80% of production is coming from 20% of the stages, our industry needs to Ensure that wellbores and fracture stages result in quality production Recover the bypassed oil and gas Evolve laboratories to understand the complex chemistry and physics of tight reservoirs Experience demonstrates that generalized field development and production planning do not offer optimal resource recovery in tight reservoirs. Case studies show us that customized planning for landing the well, stimulating the reservoir, and producing the asset is the way to go. As this decade unwinds, we will see new workflows and technologies to ensure that wellbores are landed better, fracture stages are placed better, and bypassed oil and gas are recovered. The laboratories of the future and new technologies created for refracturing/re-entry programs are of particular interest to me. Laboratory studies to determine fluid efficiency in a fracture need to reflect tight-reservoir conditions and not that of American Petroleum Institute RP 13M-4. Rock/fluid interactions are much more influential in tight reservoirs, and the industry needs to improve its methodology and standardization in such test measurements. Refracturing programs will be challenged to promote stimulation of new zones outside of those stimulated by the initial fracturing and restimulation of closed or damaged networks. New diversion technologies to simplify operations and reduce costs are to be anticipated for tight-reservoir production. Recommended additional reading at OnePetro: www.onepetro.org. SPE 159546 Stimulated-Shale-Volume Characterization: Multiwell Case Study From the Horn River Shale: II. Flow Perspective by Christine A. Ehlig-Economides, Texas A&M University, et al.

Waves in the Red Sea: Response to monsoonal and mountain gap winds

An unstructured grid, phase-averaged wave model forced with winds from a high resolution atmospheric model is used to evaluate wind wave conditions in the Red Sea over an approximately 2-year period. The Red Sea lies in a narrow rift valley, and the steep topography surrounding the basin steers the dominant wind patterns and consequently the wave climate. At large scales, the model results indicated that the primary seasonal variability in waves was due to the monsoonal wind reversal. During the winter, monsoon winds from the southeast generated waves with mean significant wave heights in excess of 2m and mean periods of 8s in the southern Red Sea, while in the northern part of the basin waves were smaller, shorter period, and from northwest. The zone of convergence of winds and waves typically occurred around 19–20°N, but the location varied between 15 and 21.5°N. During the summer, waves were generally smaller and from the northwest over most of the basin. While the seasonal winds oriented along the axis of the Red Sea drove much of the variability in the waves, the maximum wave heights in the simulations were not due to the monsoonal winds but instead were generated by localized mountain wind jets oriented across the basin (roughly east–west). During the summer, a mountain wind jet from the Tokar Gap enhanced the waves in the region of 18 and 20°N, with monthly mean wave heights exceeding 2m and maximum wave heights of 14m during a period when the rest of the Red Sea was relatively calm. Smaller mountain gap wind jets along the northeast coast created large waves during the fall and winter, with a series of jets providing a dominant source of wave energy during these periods. Evaluation of the wave model results against observations from a buoy and satellites found that the spatial resolution of the wind model significantly affected the quality of the wave model results. Wind forcing from a 10-km grid produced higher skills for waves than winds from a 30-km grid, largely due to under-prediction of the mean wind speed and wave height with the coarser grid. The 30-km grid did not resolve the mountain gap wind jets, and thus predicted lower wave heights in the central Red Sea during the summer and along the northeast coast in the winter.