Wind Climate Research Articles

Multi-decadal shoreline morphodynamics of a shelf-edge reef island, Great Barrier Reef: Implications for future island persistence

Future climatic change and sea-level rise threaten the persistence of reef islands potentially making them uninhabitable over the next century. Improved understanding of island morphodynamics at multiple time scales is required for resolving major drivers of shoreline change and predicting future island resilience. Utilising 45 individually mapped shorelines, the morphodynamic change of a shelf-edge reef island (Raine Island, Great Barrier Reef) has been quantified over a 57-year time scale in the context of environmental change and anthropogenic impacts. Results show that between 1963 and 2020, there has been an average net shoreline movement (NSM) of −4.71 m and an average rate of retreat of −0.11 m/yr. However, only 23% of the shoreline has exhibited statistically significant erosion while the remaining 77% has remained stable. Importantly, data reveal a remarkable level of long-term shoreline stability despite large seasonal fluctuations in wind and wave climate, episodic storm events, and a regional sea level rise currently outpacing the global mean. Direct human impact, through modifications of the beach profile since 2014, have resulted in localised increases in rates of shoreline change but have only slightly decreased the proportion of stable shoreline (91% since modifications commenced versus 96% prior to modifications). Interestingly, there is a significant decreasing trend in island planform area over the 57-year period and especially over the last decade. However, the length of the observation interval between sampled shorelines has a strong effect on the change in planform area recorded over the interval, suggesting increased sampling frequency, rather than sea level rise, is a more likely cause of the decreasing trend. The findings of this study have direct implications for more accurate assessments of past, present and future shoreline change on reef islands. They also support the concept of 21st century island persistence in the face of climate change although the relative resilience of a given island to change (e.g., sea level, human modifications) will depend on a continuous adequate supply of sediment from organisms living on the surrounding reef, which may or may not be threatened in the future.

Calibration of the design wind load and snow load considering the historical climate statistics and climate change effects

In the present study, an updating of the probabilistic models used for calibrating the wind load, snow load and companion load factors for the National Building Code of Canada (NBCC) are presented. The update of probabilistic models for the extreme wind speed and ground snow depth is based on historical climatological data over Canadian sites. For the updating of the statistics of the extreme wind speed, the effect of mixed wind climate (i.e., thunderstorm winds and non-thunderstorm winds) is considered. Reliability analysis is carried out based on this update by considering different load combinations. The results indicate that, for an improved reliability consistency, the use of a high return period to specify the environmental loads and with a unit load factor is preferable to the use of 50 year return period and a load factor greater than one for structural design code making, if the coefficient of variation of the extreme climatological elements is spatially varying. Most importantly, based on these findings and the results from the climate change modelling results, sets of load scaling factors accounting for climate change effects are calibrated for different regions in Canada. Both the use of the target reliability index for a 50-year design working life as well as of the target minimum required annual reliability index within each of the 50-year design working life are considered for the reliability-based calibration. Specific recommendations on the load and companion load factors are suggested for a future edition of NBCC.

Future wind and wave energy resources and exploitability in the Mediterranean Sea by 2100

A state-of-the-art regional assessment of future wind and wave energy resource in the Mediterranean Sea and the projected changes with respect to hindcast is presented. A multi-model EURO-CORDEX ensemble of future wind field and wave climate conditions with a spatial resolution of ≈10–12.5 km and 3–6 h temporal resolution in the Mediterranean Sea is used for the assessment of future changes wind power, wave energy and combined exploitability under the climate change scenario RCP8.5. The results allow to identify climate change impacts in wind and wave power potential and the projected changes in the locations in the Mediterranean basin that were considered suitable for joint exploitations in previous studies. The future ES-Index allows to assess the optimized temporal-availability of combined wind and wave resources in a changing climate. Results show a robust decrease in the ES-Index during fall and winter in regions previously identified as suitable for coupled systems which would reduce the overall energy extraction but also attenuate the seasonal fluctuation. In addition, the Alboran Sea presents increases in ES-Index emerging as a probable suitable area for coupled systems under RCP8.5.

Performance of Steel Monopole Transmission Line Supporting Structure in Various Wind Zones of India

The design of every new transmission line can address the solutions to fresh engineering problem. Therefore, the selection of the monopole structures in place of conventional lattice towers summarized the obligatory design parameters. The reliability climatic wind loads and the security longitudinal broken wire load combinations influence the internal parameter assessment of the steel pole structures. To assess them, a 60m high double circuit (DC) 220kV line with 305 m basic span is selected. All the Six wind zones (33, 39, 44, 47, 50, and 55 m/s) of India are selected to compute the transverse wind loads on the tower. Secondly broken wire security load in the longitudinal direction is adopted for the load combination for the monopole transmission tower design. With the above data, this paper presented the variation of the internal parameters in the wind zones. It is found that even though the basic wind speed from 33 m/s to 55 m/s is increased to 66.66%, top deflection is increased by 1.6%, a bending moment is enhanced by 6.3 % and shear force is increased by 12.6% only. The results show the change of wind speed has a little effect on the monopole tower. However, the variations of internal parameters in the wind zone are strongly depending on the Longitudinal loading only. The ASCE 48-19 steel monopole code is adopted to design the monopole since the Indian standard design code for monopole was not found. However, when comparing with the Indian Standard general Steel code IS 800-2007(Limit state) design guidelines, the Indian steel code contributes 10% more weight.

Quantifying the Contributions of Environmental Factors to Wind Characteristics over 2000–2019 in China

Global climate change and human activities have resulted in immense changes in the Earth’s ecosystem, and the interaction between the land surface and the atmosphere is one of the most important processes. Wind is a reference for studying atmospheric dynamics and climate change, analyzing the wind speed change characteristics in historical periods, and studying the influence of wind on the Earth-atmosphere interaction; additionally, studying the wind, contributes to analyzing and alleviating a series of problems, such as the energy crisis, environmental pollution, and ecological deterioration facing human beings. In this study, data from 697 meteorological stations in China from 2000 to 2019 were used to study the distribution and trend of wind speed over the past two decades. The relationships between wind speed and climate factors were explored using statistical methods; furthermore, combined with terrain, climate change, and human activities, we quantified the contribution of environmental factors to wind speed. The results show that a downward trend was recorded before 2011, but overall, there was an increasing trend that was not significant; moreover, the wind speed changes showed obvious seasonality and were more complicated on the monthly scale. The wind speed trend mainly increased in the western region, decreased in the eastern region, was higher in the northeastern, northwestern, and coastal areas, and was lower in the central area. Temperature, bright sunshine duration, evaporation, and precipitation had a strong influence, in which wind speed showed a significant negative correlation with temperature and precipitation and vice versa for sunshine and evapotranspiration. The influence of environmental factors is diverse, and these results could help to develop environmental management strategies across ecologically fragile areas and improve the design of wind power plants to make better use of wind energy.

A Weather-Type Classification and Its Application to Near-Surface Wind Climate Change Projections over the Adriatic Region

The main goal of this study is to present a recently developed classification method for weather types based on the vorticity and the location of the synoptic centers relative to the Adriatic region. The basis of the present objective classification, applied to the Adriatic region, is the subjective classification developed by Poje. Our algorithm considered daily mean sea-level pressure and 500 hPa geopotential height to define one out of 17 possible weather types. We applied the algorithm to identify which weather type was relevant in the generation of the two typical near-surface winds over the Adriatic region, namely Bora and Sirocco. Two high-resolution (0.11°) EURO-CORDEX regional climate models were used, SMHI-RCA4 and DHMZ-RegCM4, forced by several CMIP5 global climate models and analyzed for two 30-year periods: near-present day and mid-21st century climate conditions under the high-end Representative Concentration Pathway (RCP8.5) scenario. Bora and Sirocco days were extracted for each weather type and a distribution over the 30-year period was presented. Our results suggest that in the winter season, climate model projections indicate a reduction in the main cyclonic types relevant in the formation of Bora over the entire Adriatic region and an increase in the number of anticyclonic types relevant in Sirocco events. In contrast, for the summer season, an increase in the main anticyclonic Bora-related weather types is found in the ensemble over the northern Adriatic region.

Multi-fidelity shape optimization methodology for pedestrian-level wind environment

In this study, a multi-fidelity shape optimization framework is proposed for the pedestrian-level wind environment (PLWE). In the proposed framework, low-fidelity computational fluid dynamics (CFD) models based on steady Reynolds-averaged Navier–Stokes equations (RANS) models and high-fidelity CFD models based on large-eddy simulation (LES) are efficiently integrated into the optimization process to improve the optimization reliability while maintaining its computational speed in an affordable range for practical engineering applications. The optimization solver is coupled with an approximation model generated by low-fidelity CFD samples obtained using a design of experiments (DOE) technique. The optimal candidates are then evaluated according to the degree of improvement of the objective function compared to the reference case. If the degree of improvement shows significant deviations between the low-fidelity and high-fidelity models, suitable corrections and modifications are applied to improve the reliability of the optimization process. The applicability of the proposed method was investigated in terms of minimizing the high-wind-speed area, as the optimization objective, around a high-rise building considering (a) uniform urban blocks and (b) real urban blocks with different frequency distributions of wind directions associated with two different local wind climates. In summary, a significant reduction in the critical strong-wind area around the target building was realized using the proposed optimization framework. Furthermore, the application of the proposed multi-fidelity optimization framework highlighted the importance of considering the local wind climate in architectural design.

A Refined Study of Atmospheric Wind Properties in the Beijing Urban Area Based on a 325 m Meteorological Tower

The urban atmospheric boundary layer (UABL) is complex due to the heterogeneous underlying city surface. The nine anemometers installed at different heights along the 325 m meteorological tower provide an opportunity to carry out a refined study of wind properties in the UABL in central Beijing, China. Based on the recent 5-year high-resolution measured data, in total, 229,488 10-min length segments of wind records related to each anemometer are reliable for further analyses. Accordingly, the statistical properties of the wind speed and direction are first analyzed to present the local wind climate in a comprehensive way. Moreover, the pattern of the wind profiles related to two typical synoptic intense events are illustrated in order to give a preliminary perspective, then the statistical properties corresponding to a series of intense windstorms are described. Here, the deviations in the wind direction occur between 200 m and 280 m of the atmosphere, which might be due to the existence of an Ekman spiral; besides this, the laws of wind profiles based on open terrain are not suitable for the UABL, and the aerodynamic characteristic parameters of the UABL based on vertical stratified structures have to be considered. The results contribute to the establishment of revised models for the wind profile and are useful for the further understanding of the structure of UABL wind.

Multi-parameter analysis and mapping of the levelised cost of energy from floating offshore wind in the Mediterranean Sea

Floating offshore wind, far less constrained by water depths than bottom-fixed, has great potential in the Mediterranean Basin. The levelised cost of energy (LCOE) is arguably the single most reliable metric to measure the viability of energy projects. In this work, the levelised cost of energy for floating offshore wind is mapped for the first time in the European and Eastern Mediterranean with a detailed cost breakdown and a focus on semi-submersible platforms. A multi-parameter analysis is conducted in a case study to discern the effects of specific elements on the LCOE. Expressions are formulated as functions of site-specific variables: distance to shore, water depth and annual energy production. The latter is estimated accurately by combining the power curve of an exemplar wind turbine with hindcast, site-specific wind data. The mapping shows the paramount importance of the wind climate, i.e., the resource, for the LCOE. The lowest values (~95 €/MWh) occur where the wind resource is most abundant, i.e., the Gulf of Lion and the Aegean Sea. The highest values (>250 €/MWh) are found where the resource is scarce, i.e., around the Balearic Islands and in the North Adriatic, Tyrrhenian and Levantine Seas. Moderate values of the LCOE (130–180 €/MWh) occur off South Spain (Alboran Sea), Sardinia, Sicily and Malta, and in the South Adriatic. In addition to the local wind resource, other parameters that play a relevant role in the LCOE are those related to the production of energy (number of turbines in the wind farm and installed power), on the one hand, and to substantial sources of costs (cost of turbines and substructure), on the other, as well as the project lifetime and discount rate. These results identify hotspots for the deployment of floating offshore wind in the Mediterranean and opportunities for cost reductions, and contribute to decision-making in a region much in need of renewable energy.

Observation analysis of wind climate in China for 1971–2017 under the demand of wind energy evaluation and utilization

To meet the requirement of the wind energy resource assessment and utilization, the statistical characteristics of wind climate in the China mainland were analyzed in this study by using observation wind dataset for 1971–2017 from the China Meteorological Administration (CMA). A series of key factors closely related to wind power development were analyzed, systematically including the spatial and temporal characteristic of wind speed, the distribution of wind speed at different density grades, the density of the cumulative distribution, strong wind days and weak wind days. The characteristics of wind patterns in different regions are also compares. Results indicate that: (1) the regions with the highest wind speed in China centrally locate in Northwest China, North China and Northeast China with the highest wind speed occurs in spring. The annual variation of wind speed in northern China is bimodal while in southern China it is unimodal. (2) The wind speed probability density distribution shows a significant spatial–temporal difference. The wind speed probability distribution is the most concentrated in spring for almost all regions. For each season, the concentrated and stable wind speed occurs in Xinjiang region in spring. While it appears in the region from Northwest China to the northern part of North China for summer and autumn, and in the southern part of North China and Central China for winter. In the case of equal cumulative probability, the highest wind speed locates in Northeast China and the lowest in Sichuan Basin. (3) For 1971–2017, the wind speed in all regions of China showed a decreasing trend on the whole. But this trend slowed down since 1990s. It is​ worth noting that the wind speed in some regions even increased since 2000. (4) The numbers of strong wind day have been decreasing in all regions, but the numbers of weak wind day demonstrate an evolutionary feature of a growth followed by decrease. In most regions, the numbers of weak wind day reached the maximum in the vicinity of 2000 and then decreased rapidly.

Residual dune ridges: Sedimentary architecture, genesis, and implications for palaeo‐climate reconstructions

AbstractSedimentary architecture and genesis of residual dune ridges in a temperate climate are presented and implications for their use as archive of changes in long‐term precipitation and wind climate are discussed. Residual dunes are common features of wet aeolian systems, where they form sets of shallow ridges, oriented perpendicular to the prevailing wind direction. Residual dune ridges of the study area are vegetated and typically elevate 0.6 to 2.5 m above the surrounding interdune flats. They develop on the lower stoss side of active transgressive dunes, triggered by periods of elevated groundwater table and hence colonization of the foot of the dune by rapid growing pioneer vegetation. Stabilized by plants, the growing ridge detaches from the active transgressive dune and gets abandoned within years in the course of the downwind‐migration of the transgressive dune. Grain‐size data suggest a main sediment supply from the transgressive dune and only minor input from other sources. Ground‐penetrating radar reveals that the residual dune ridges are composed of windward‐dipping as well as leeward‐dipping sedimentary beds. Leeward‐dipping strata reflect sediment supply from the parental dune, whereas windward‐dipping beds are seen to result from sediment redistribution along the ridge and sediment supply from the adjacent swales during the ridge growth period. Multi‐annual to multi‐decadal variability in precipitation leads to the development of sequences composed of tens of ridges, spanning time periods of several centuries. Spacing of individual ridges in these sequences is controlled not by long‐term variability in precipitation alone, but probably also reflects variable wind intensity which affects the migration rate of the parental dune. The important role of vegetation in ridge construction makes these landforms a demonstrative example of landscape development by geo‐biosphere interacting processes.

Wind Climate and Wind Power Resource Assessment Based on Gridded Scatterometer Data: A Thracian Sea Case Study

The present analysis utilized the 6-hourly data of wind speed (zonal and meridional) for the period between 2011 and 2019, as retrieved from the Copernicus Marine Environmental Service (CMEMS), covering the Thracian Sea (the northern part of the Aegean Sea). Data were estimated from the global wind fields derived from the Advanced Scatterometer (ASCAT) L2b scatterometer on-board Meteorological Operational (METOP) satellites, and then processed towards the equivalent neutral-stability 10 m winds with a spatial resolution of 0.25° × 0.25°. The analysis involved: (a) descriptive statistics on wind speed and direction data; (b) frequency distributions of daily-mean wind speeds per wind direction sector; (c) total wind energy content assessment per wind speed increment and per sector; (d) total annual wind energy production (in MWh/yr); and (e) wind power density, probability density function, and Weibull wind speed distribution, together with the relevant dimensionless shape and scale parameters. Our results show that the Lemnos Plateau has the highest total wind energy content (4455 kWh/m2/yr). At the same time, the area to the SW of the Dardanelles exhibits the highest wind energy capacity factor (~37.44%), producing 7546 MWh/yr. This indicates that this zone could harvest wind energy through wind turbines, having an efficiency in energy production of 37%. Lower capacity factors of 24–28% were computed at the nearshore Thracian Sea zone, producing between 3000 and 5600 MWh/yr.

Accelerating deployment of offshore wind energy alter wind climate and reduce future power generation potentials

The European Union has set ambitious CO2 reduction targets, stimulating renewable energy production and accelerating deployment of offshore wind energy in northern European waters, mainly the North Sea. With increasing size and clustering, offshore wind farms (OWFs) wake effects, which alter wind conditions and decrease the power generation efficiency of wind farms downwind become more important. We use a high-resolution regional climate model with implemented wind farm parameterizations to explore offshore wind energy production limits in the North Sea. We simulate near future wind farm scenarios considering existing and planned OWFs in the North Sea and assess power generation losses and wind variations due to wind farm wake. The annual mean wind speed deficit within a wind farm can reach 2–2.5 ms−1 depending on the wind farm geometry. The mean deficit, which decreases with distance, can extend 35–40 km downwind during prevailing southwesterly winds. Wind speed deficits are highest during spring (mainly March–April) and lowest during November–December. The large-size of wind farms and their proximity affect not only the performance of its downwind turbines but also that of neighboring downwind farms, reducing the capacity factor by 20% or more, which increases energy production costs and economic losses. We conclude that wind energy can be a limited resource in the North Sea. The limits and potentials for optimization need to be considered in climate mitigation strategies and cross-national optimization of offshore energy production plans are inevitable.

Extreme wind climate of the Arabian Peninsula characterized by using WRF simulation

Wind hazard is one of the most severe natural hazards. Structures and infrastructure can be vulnerable to wind load effects due to extreme wind speeds. Mitigation and the reduction of wind-related risks of structures and infrastructures can be made by considering the wind load effects within the structural design process. Building design codes or standards for some countries in the Arabian Peninsula do not formally define the wind load effects. For countries with wind load provisions in their building codes and standards, the spatial resolution of design wind speeds may not be sufficient to cover many cities or areas. To date, there has not been a comprehensive study on the extreme wind hazards at the design level in the Arabian Peninsula. Extreme wind hazards have been conventionally evaluated by using historical surface observations. However, an investigation showed that many meteorological stations in the Arabian Peninsula cannot be used to evaluate the design wind speeds due to low data quality or insufficient sampling resolution. This study used the Weather Research and Forecasting (WRF) model to obtain data with a high spatial-temporal resolution. The simulated extreme wind speeds across the Arabian Peninsula were characterized statistically. Spatial distributions of the extreme wind speeds and their associated attributes were investigated. The simulated wind speeds were separated into convective event-induced wind speeds and synoptic wind speeds to obtain the design wind speeds. The convective wind events were identified using a statistical algorithm defining the threshold values of the Lifted Index and the Convective Available Potential Energy values. A numerical parametric cyclone model was used to simulate the cyclone-induced extreme wind speeds for the southern coastal regions of the Arabian Peninsula. The design wind speeds were evaluated by using the most appropriate probability distribution and preferred fitting method. Contour maps of various return period wind speeds were developed.

Comprehensive Wind and Wave Statistics and Extreme Values for Design and Analysis of Marine Structures in the Adriatic Sea

Wind and waves present the main causes of environmental loading on seagoing ships and offshore structures. Thus, its detailed understanding can improve the design and maintenance of these structures. Wind and wave statistical models are developed based on the WorldWaves database for the Adriatic Sea: for the entire Adriatic Sea as a whole, divided into three regions and for 39 uniformly spaced locations across the offshore Adriatic. Model parameters are fitted and presented for each case, following the conditional modelling approach, i.e., the marginal distribution of significant wave height and conditional distribution of peak period and wind speed. Extreme significant wave heights were evaluated for 20-, 50- and 100-year return periods. The presented data provide a consistent and comprehensive description of metocean (wind and wave) climate in the Adriatic Sea that can serve as input for almost all kind of analyses of ships and offshore structures.

Production and Cost Assessment of Offshore Wind Power in the North Sea

A minimalistic model complex for determining the available wind power and associated costs related to the development of large–scale offshore wind power was recently developed by Sørensen and Larsen [1]. The model complex demands only a few global input parameters, such as turbine rotor diameter, nameplate capacity, area of wind farm, number of turbines, water depth, and mean wind speed Weibull parameters for the site. Using actual wind climate and bathymetric data for the North Sea, the model is in the present work used to map the annual energy production and levelized cost of energy (LCoE) for wind farms located in the North Sea. As a main conclusion, exploiting all locations with water depths down to about 45 m comply with the electrical power demand of Europe, which is about 3500 TWh/year. In this case, the LCoE is found to be about 7 ∈cents/kWh for wind farms consisting of 15 MW wind turbines and an interspacing between the wind turbines of 8 diameter, corresponding to 2 km.

Preconditioning wind speeds for standardised structural design

The statistical treatment of historical wind data has a significant impact on the design wind load, standardisation of which requires characterisation of the wind climate across a large region. Improved spatial resolution is afforded by asymptotic extreme value distributions as they require a lower temporal data resolution. The Gumbel distribution is shown to be preferred, given the available South African data, according to the Akaike Information Criterion. However, its relative inflexibility means that estimates of small probability fractiles could be significantly biased, a difficulty illustrated by disagreement on which is more appropriate: fitting the Gumbel distribution to the wind speed versus to the wind-induced pressure (squared wind speed). By generalising this choice to the problem of finding the most appropriate real-valued exponent to raise the wind speeds by (i.e. not just 1 or 2), this paper aims to reduce this modelling-bias. As estimates of this exponent parameter from a single station would have low confidence given the typical quantity of data, a method of estimating the exponent that maximises the likelihood of observing the entire dataset is developed instead. The method is demonstrated using over 3500 annual gust measurements at 131 stations throughout South Africa, the most likely exponent is found to be 1.59 with confidence intervals sufficiently narrow to reject fitting to both the wind speed as well as to the squared wind speed. It is shown that using an exponent of 1.6 in deriving the design wind load for structural design would result in a substantial reduction in modelling-bias, providing a suitable baseline for future South African loading standards.

Layered Stochastic Approximation Monte-Carlo method for tall building and tower fragility in mixed wind load climates

Performance-based wind engineering has emerged as an active research field due to potential applications into design standards [e.g., by the American Society of Civil Engineers (ASCE) in the United States of America]. Therefore, novel and accurate methodologies are necessary to successfully implement practice-oriented guidelines. This study will systematically examine the use of the Layered Stochastic-Approximation Monte-Carlo method, recently explored to assess of wind-induced structural dynamic analysis of vertical structures. The study will utilize a standard tall building and a monopole tower structure to investigate maximum response in terms of lateral displacement and acceleration, and the behavior of a structural member in terms of demand-to-capacity index. Both serviceability and ultimate limit states will be considered. The proposed method will be verified against standard Monte-Carlo sampling to assess its adequacy, accuracy and potential limitations. Particular consideration will be devoted to the study of wind loads and response in mixed wind climates, characterized by the presence of both tropical cyclones (hurricanes) and extra-tropical depressions.

Spatiotemporal long-term trends of wind and wave climate and extreme characteristics over the Sea of Marmara

The Sea of Marmara is a typical example of enclosed seas and an inland sea bounded by land-masses in four directions, and it links the Black Sea and the Mediterranean via the Bosphorus and the Dardanelles straits. Moreover, The sea of Marmara has strategic importance with possessing marine structures such as various types of terminals, cruise terminals, and marinas, and also providing a strong economic contribution with tourism revenue. This situation brings the necessity of determining the design wind and wave parameters properly. The wind and wave characteristics and their variabilities were evaluated covering the last 40 years (1979–2018) by using two well-known wind fields, i.e., ECMWF ERA-Interim and NCEP/CFSR. Wave parameters were generated from the calibrated and validated SWAN model with ERA-Interim wind data. The spatial and temporal variability of the long-term averages and long-term trends of the wind and wave characteristics were investigated, and also extreme wave conditions were evaluated in detail. This study shows that the modeling of waves in enclosed seas is more challenging compared to open seas due to several affecting factors such as land which affect the wave fields and need high spatial resolution. The results indicate that orography and islands largely affect the wind and wave climate in the Sea of Marmara. The northern side of the Sea of Marmara is characterized by stronger wind and wave climate compared to the southern side. The annual mean values of wave height have decreasing tendencies while the annual maxima tend to increase in most parts of the Sea of Marmara. The dominant wind and wave directions are observed to be in the northeast and southwest sector and their magnitudes are controlled by the orographic features over the Marmara Region.

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

Climate pattern in the Persian Gulf is of great interest due to the strategic geographical location of the gulf as a waterway of major oil transportation and its increasing regional economic importance. However, long term and continues climate observations in this region are rare, especially for high resolution data. High resolution wind pattern and climate conditions were measured at 3 heights on a 9 m tower on the shoreline north of Qatar (26.08 N, 51.36 E) from August 2015 to September 2016. In this work, the annual wind and climate patterns (wind velocity, temperature, relative humidity, and air pressure) are first presented. Drag coefficient, turbulent kinetic energy and sensible heat flux are calculated using the high speed measured data to explain the observed climate pattern. The results show the wind in the southern part of the gulf is dominant by a northwest stream with a diurnal average speed of 4.7 m/s. During the test year, the diurnal average temperature and relative humidity were 27°C and 70%, respectively. The drag coefficient is much higher for the wind from 270o-330o, corresponding to the wind coming mainly from northwest. The Turbulent Kinetic Energy (TKE) is strong during the daytime, especially around noon when the diurnal value is at its peak, and weak during the night. The result of this analysis may be used for better understanding of the local climate, allowing for further assessment of wind energy and pollution diffusion in the region.