Showing papers on "Sea breeze published in 2004"

Flux and turbulence measurements at a densely built‐up site in Marseille: Heat, mass (water and carbon dioxide), and momentum

Abstract: [1] Eddy covariance (EC) observations above the densely built-up center of Marseille during the Experience sur site pour contraindre les modeles de pollution atmospherique et de transport d'emissions (ESCOMPTE) summertime measurement campaign extend current understanding of surface atmosphere exchanges in cities. The instrument array presented opportunities to address issues of the representativeness of local-scale fluxes in urban settings. Separate EC systems operated at two levels, and a telescoping tower allowed the pair to be exposed at two different sets of heights. The flux and turbulence observations taken at the four heights, stratified by wind conditions (mistral wind and sea breeze), are used to address the partitioning of the surface energy balance in an area with large roughness elements. The turbulent sensible heat flux dominates in the daytime, although the storage heat flux is a significant term that peaks before solar noon. The turbulent latent heat flux is small but not negligible. Carbon dioxide fluxes show that this central city district is almost always a source, but the vegetation reduces the magnitude of the fluxes in the afternoon. The atmosphere in such a heavily developed area is rarely stable. The turbulence characteristics support the empirical functions proposed by M. Roth.

Cost Reduction Prospects for Offshore Wind Farms

Abstract: The economics of offshore wind farms are presently less favorable than for onshore wind energy. Consequently there is a strong need for significant cost reductions in order to become competitive. About 70% of the electricity cost of offshore wind farms is determined by the initial investment costs, which mainly consist of the wind turbines, foundations, internal and external grid-connections and installation. Possible cost reductions until 2020 are explored for each of these components. Technological developments and cost reduction trends in both the offshore and onshore wind sector are analyzed. Information is also taken from offshore oil and gas sector and from the experience with high-voltage submarine transmission of electricity. Where possible, cost reduction trends are quantified using the experience curve concept, or otherwise based on expert judgments. Main drivers for cost reduction appear to be (a) design improvements and upscaling of wind turbines, (b) the continuing growth of onshore wind capa...

The impact of anthropogenic land-cover change on the Florida Peninsula Sea Breezes and warm season sensible weather

Abstract: During the twentieth century, the natural landscape of the Florida peninsula was transformed extensively by agriculture, urbanization, and the diversion of surface water features. The purpose of this paper is to present a numerical modeling study in which the possible impacts of this transformation on the warm season climate of the region were investigated. For three separate July‐August periods (1973, 1989, and 1994), a pair of simulations was performed with the Regional Atmospheric Modeling System. Within each pair, the simulations differed only in the specification of land-cover class. The two different classes were specified using highly detailed datasets that were constructed to represent pre-1900 natural land cover and 1993 land-use patterns, thus capturing the landscape transformation within each pair of simulations. When the pre-1900 natural cover was replaced with the 1993 land-use dataset, the simulated spatial patterns of the surface sensible and latent heat flux were altered significantly, resulting in changes in the structure and strength of climatologically persistent, surface-forced mesoscale circulations—particularly the afternoon seabreeze fronts. This mechanism was associated with marked changes in the spatial distribution of convective rainfall totals over the peninsula. When averaged over the model domain, this redistribution was reflected as an overall decrease in the 2-month precipitation total. In addition, the domain average of the diurnal cycle of 2-m temperature was amplified, with a noted increase in the daytime maximum. These results were consistent among all three simulated periods, and largely unchanged when subjected to a number of model sensitivity factors. Furthermore, the model results are in reasonable agreement with an analysis of observational data that indicates decreasing regional precipitation and increasing daytime maximum temperature during the twentieth century. These results could have important implications for water resource and land-use management issues in south Florida, including efforts to restore and preserve the natural hydroclimate of the Everglades ecosystem. This study also provides more evidence for the need to consider anthropogenic land-cover change when evaluating climate trends.

Future for Offshore Wind Energy in the United States: Preprint

Abstract: Until recently, the offshore wind energy potential in the United States was ignored because vast onshore wind resources have the potential to fulfill the electrical energy needs for the entire country However, the challenge of transmitting the electricity to the large load centers may limit wind grid penetration for land-based turbines Offshore wind turbines can generate power much closer to higher value coastal load centers Reduced transmission constraints, steadier and more energetic winds, and recent European success, have made offshore wind energy more attractive for the United States However, US waters are generally deeper than those on the European coast, and will require new technology This paper presents an overview of US coastal resources, explores promising deepwater wind technology, and predicts long-term cost-of-energy (COE) trends COE estimates are based on generic 5-MW wind turbines in a hypothetical 500-MW wind power plant Technology improvements and volume production are expected to lower costs to meet the US Department of Energy target range of $006/kWh for deployment of deepwater offshore wind turbines by 2015, and $005/kWh by 2012 for shallow water Offshore wind systems can diversify the US electric energy supply and provide a new market for wind energy that is complementary tomore » onshore development« less

Role of meteorological processes in two New England ozone episodes during summer 2001

Abstract: [i] We examined the impact of dynamical processes on spatial variability in ozone (O 3 ) mixing ratios at closely spaced air monitoring sites in southern New Hampshire (NH) during two O 3 episodes, July 21-25 and August 2, 2001. The Meso-scale Meteorological Model (MM5) and the Community Multiscale Air Quality (CMAQ) photochemical model were applied together with ground-based atmospheric chemistry observations conducted by the Atmospheric Investigation, Regional Modeling, Analysis and Prediction (AIRMAP) program at the University of New Hampshire. Observations and model simulations suggested that during the July episode long-range transport via the nocturnal low-level jet (LLJ) played an important role in producing elevated daytime mixing ratios of O 3 . The marine site Isle of Shoals experienced the highest level of O 3 , possibly a result of having more diverse upwind sources and less ventilation compared to continental sites. Our model results suggest that during daytime the shallow sea breeze circulation contributes to high levels of O 3 at coastal and marine sites while the channeling effect of the Appalachian Mountains influences inland locations. In contrast to the July event, the event on August 2 was characterized by weak and transient synoptic flows, indicating insufficient time for transport of O 3 and its precursors from distant sources to inland sites in NH. Backward trajectories for both events showed that 03-rich air masses from the Boston metropolitan area can contribute to the high levels of O 3 (>120 ppbv) at coastal and marine sites in southern NH. Our results suggest that the International Consortium of Atmospheric Research on Transport and Transformation (ICARTT), an international field campaign based in the northeastern United States in summer 2004, should coordinate mobile platforms to investigate the vertical structure and chemical composition of the LLJ, the sea breeze, and the terrain-forced flows, and estimate the influx of O 3 and its precursors to central New England.

Observational and numerical study on the influence of large-scale flow direction and coastline shape on sea-breeze evolution

Abstract: In this study radar, surface observations and numericalsimulations are used to examine the inland penetrationand intensity of the sea breeze during various large-scaleflow regimes along the curved coastline of the Carolinas,U.S.A. The results clearly indicate that the flow directionrelative to the curved coastline has a significant effecton the sea-breeze evolution.Overall, during northerly flow regimes alongthe curved North Carolina coast, observationsand numerical simulations show that the sea-breezefront has a tendency to remain close to the south-facingcoast. During these same flow regimes the frontmoves further inland relative to the east-facingcoast. The sea-breeze front during westerly flowcases progressed further inland relative to the southcoast and less so from the east-facing coastline.South-westerly flow allows the sea breeze to moveinland from both coastlines but the coastal shapeinfluence makes the inland penetration less fromthe easterly facing beaches. During periods of lightonshore flow (south-east), the sea breeze movesconsiderable distances inland but is not discernableuntil later in the afternoon. The simulations indicatedthat the sea-breeze intensity is greatest (least) when thelarge-scale flow direction has an offshore (onshore)component. Model results indicate the existence of astrong front well inland in the late afternoon duringlight onshore flow. Also noted was that the simulatedsea-breeze front develops earlier in the afternoon duringoffshore regimes and later in the day as the large-scaleflow becomes more onshore. It is concluded that thecoastline shape and coast-relative flow direction areimportant factors in determining how the sea-breezecirculation evolves spatially.

Wind-driven lateral variability in a partially mixed estuary

Abstract: A circulation study of the upper Neuse River Estuary (NRE) was initiated to characterize the nature of motion in the lateral dimension and to understand the role that this motion may play in the occurrences of warm weather fish kills. Low frequency wind-driven variability in across channel bottom salinity was identified and attributed to variability in the synoptic wind band. Diurnal variability in bottom salinity appeared to be driven by diurnal wind variability, presumably associated with the local sea breeze. In both cases the lateral response of the system was driven predominantly by across channel wind forcing and not by Ekman setup associated with along channel winds. Additional variability at near diurnal periods may have been due to baroclinic seiches. A lateral, barotropic seiche with a period of ∼30 min was also identified. High salinity water was found to be a good marker for low DO water across the estuary. Wind-driven upwelling of low DO/high salinity water and downwelling of high DO/low salinity water was documented and provides a plausible causal mechanism for the death of pelagic fish in the upper NRE.

The surface wind field during winter smog nights in Christchurch and coastal Canterbury, New Zealand

Abstract: In Christchurch and other Canterbury towns on the east coast of New Zealand's South Island, poor dispersion conditions and high emissions of particulate matter and carbon monoxide regularly lead to the build-up of smog during anticyclonic weather conditions in wintertime. This study analyses surface wind fields during smog nights using data collected during the Christchurch Air Pollution Study 2000 (CAPS2000). Westerly land breezes and drainage winds from the foothills of the Southern Alps and the Canterbury Plains are evident in all coastal Canterbury towns, but local terrain features often complicate the wind fields. This holds particularly for Christchurch, where Banks Peninsula causes flow splitting of both the drainage winds on the Canterbury Plains and any superimposed larger scale winds. Furthermore, stagnation of airflow over Christchurch is often caused by the convergence of localized southeasterly drainage winds down the western part of the Banks Peninsula (Port Hills) with the regional-scale northwesterly drainage winds from the Canterbury Plains. Results illustrate the interaction of cold air drainage over Christchurch, although the unusually high frequency of synoptic-scale easterly winds during the study period appeared to reduce the effects of both these sources of cold air drainage on air pollution concentrations. The effects of topographically induced flow splitting and non-stationary drainage wind convergence on urban air pollution dispersion identified here have not previously been studied in detail internationally and should receive greater attention in the future. Copyright © 2004 Royal Meteorological Society

Observed and modelled climatology of the land–sea breeze circulation over the Persian Gulf

Abstract: A combination of observations and a numerical model revealed the meso-scale structure of the near-surface atmospheric conditions over the Persian Gulf. Low-level winds were dominated by a single, coherent, perennial land–sea breeze circulation (LSBC) that varied seasonally and diurnally. In summer the sea breeze was deeper and wider than in winter. At night the core of the LSBC over the Gulf was confluent with uplift, whereas in daytime it was difluent with subsidence. Sensitivity tests with the model revealed the influence on the LSBC of the land–sea distribution, orography and the ambient wind. The latter resulted in different conditions over the north, east, south and west coasts. Over the north coast, where the opposing ambient wind created a sea breeze front, landward penetration was very limited; over the south coast it was over 250 km. The thermal effect of the Iranian mountains accentuated the depth and penetration, landward and seaward, of the LSBC, thus influencing the duration of the land and sea breezes over the east coast. From spring to autumn the marine boundary layer over the Gulf was shallow, cool, moist and stable, with strong vertical gradients of temperature and humidity at its top. Its depth increased in the ambient flow from northwest to southeast and also, in daytime, from west to east, because of different magnitudes of the subsidence in the sea breeze circulation over the west and east coasts. Copyright © 2004 Royal Meteorological Society

Simulation of the New England Sea Breeze: The Effect of Grid Spacing

Abstract: The fifth-generation Pennsylvania State University–National Center for Atmospheric Research (Penn State– NCAR) Mesoscale Model (MM5) was run for seven cases from 2001 in which a sea breeze develops along the eastern New England coast. The results from model runs with 36-, 12-, and 4-km grid spacing are compared with observations as well as output from the National Centers for Environmental Prediction (NCEP) Eta Model on a 40-km grid. As expected, analysis of the individual cases shows that the higher-resolution grids are able to resolve realistic details in the flow, details that the 36-km grids and the 40-km NCEP Eta Model miss entirely. Contrary to expectations, the error statistics show that the ability to forecast specific variables at specific locations does not improve very much when using higher resolution. Even more surprisingly, the 4-km grids produced the biggest errors in forecasting surface dewpoint.

Wind energy plant

Abstract: The invention relates to an offshore or onshore wind energy plant. Such offshore wind energy plants have already been built while others are currently in the planning stage. Whenever man-made edifices are erected in the sea, the structures of the edifice located below the water line are provided with a coating which protects the edifice. Particularly the exterior of ships is known to be provided with a protective coating (TBT) which is not only extremely problematic from a chemical perspective but also prevents marine fauna and flora (mussels, barnacles, and other sea creatures) as far as possible from depositing on offshore wind energy plants. Disclosed is an offshore wind energy plant comprising an underwater construction, the exterior of which is provided with a structure that favors growth of marine fauna and flora thereupon.

The Generation of the Morning Glory

Abstract: A high-resolution cloud model is used to explore in detail the generation of the morning glory, a low-level nonlinear atmospheric internal wave observed on the southwestern side of Cape York Peninsula (Australia). The model is two-dimensional and nonhydrostatic and simulates an east–west cross section of the southern part of Cape York Peninsula at a horizontal resolution of 200 m. Most of the numerical experiments are initialized at sunrise with a 5 m s−1 easterly flow and a sounding taken upstream from the peninsula. The sea breezes that develop over Cape York Peninsula are highly asymmetric with the east-coast sea breeze being both deeper and warmer than its western counterpart. When the sea breezes meet, the east-coast sea breeze rides over that from the west coast and in the process produces a series of waves that propagate on the west-coast sea breeze. The model calculations show that when the phase speed of these waves matches the westward propagation speed of the east-coast sea breeze, the...

PICTURE OF THE MONTH Snowbands during the Cold-Air Outbreak of 23 January 2003

Abstract: A cold-air outbreak east of the Rocky Mountains on 23 January 2003 produced banded clouds and snow across the central and southeastern United States. The bands occurred through two processes: 1) thermal instability in the planetary boundary layer produced horizontal convective rolls (HCRs) over widespread areas, and 2) lake-effect processes downstream of small lakes (fetch , 100 km) produced localized bands. Characteristics of the observed bands associated with the HCRs, such as horizontal scale, depth of circulation, orientation, duration, and dynamics, are explored through observations, previous literature, and theoretical models. Snow from clouds produced by HCRs over land during the cold season has not been extensively studied previously. In this event, cold-air advection over the warm ground led to an upward sensible heat flux, promoting the occurrence of the HCR circulations. As the surface temperature decreased, the height of the lifting condensation level decreased, eventually forming cloud bands within the ascending portion of the HCR circulations. Ice crystals are inferred to have fallen from a large-scale precipitation system aloft into the cloud bands in the planetary boundary layer, which was within the favored temperature regime for dendritic growth of ice crystals. The ice crystals grew and reached the surface as light snow. This seeder‐feeder process suggests one way to anticipate development of such snowbands in the future, as demonstrated by other similar events on other days in Oklahoma and Illinois. As the cloud bands were advected equatorward, they ingested drier air and dissipated. Among the several lakeeffect bands observed on 23 January 2003, one notable band occurred downwind of Lake Kentucky. Midlake convergence of the land breeze may have initially produced a narrow cloud band that broadened as the land breeze ended. That the snowbands due to the HCRs and lake effect were both associated with heat and/or moisture fluxes from the earth’s surface highlights the potential importance of ground- and water-surface temperature measurements for accurate numerical weather prediction.

Role of local wind circulation in plume monitoring at Mt. Etna volcano (Sicily): Insights from a mesoscale numerical model

Abstract: [1] Mesoscale simulations at Mt. Etna volcano (Sicily, Italy), validated by measurements, highlight the fundamental role played by the local wind field in the dispersion of a gaseous volcanic plume. During the night, downslope surface winds (over-hill flow and katabatic breezes) force the plume to follow the steep morphology, whereas during the day very frequent NNW synoptic winds crash into the cone and are contrasted by SE strong sea breezes and anabatic winds, with the consequent formation of convective ascendant currents. The local mesoscale wind reconstruction can provide useful improvements in gaseous flux estimation. Far away synoptic wind velocities, often used in these flux evaluations, might be inadequate. We propose a 3D numerical mesoscale wind reconstruction to evaluate plume dynamics (and from it plume flux and potential hazard) throughout all the hours of the day.

Application of a prognostic model TAPM to sea-breeze flows, surface concentrations, and fumigating plumes

Abstract: We apply The Air Pollution Model (TAPM) (version 2.0), a three-dimensional prognostic model developed as a tool to predict both meteorological and air pollution fields for environmental impact assessments and related air pollution studies, to data from the 1995 Kwinana Coastal Fumigation Study. The field study was conducted over a 12-day summer period in the coastal region of Kwinana in Western Australia in order to investigate the local sea-breeze meteorology, the footprint of SO 2 concentration due to industrial sources, and the behaviour of fumigating plumes from power plant stacks. The National Centers for Environmental Prediction meteorological analyses are used as input synoptic fields in the model, multi-level nesting is applied, and the model is run both with and without assimilation of local surface wind measurements. The results show that TAPM simulates the onset of sea breezes, and their magnitude and decay with time, reasonably accurately. As regards to the plume footprint, TAPM performs as well as a specialised regulatory model driven by observed meteorology in Kwinana. As expected, TAPM gives better predictions when the wind data are assimilated, but the results without data assimilation are also good. Comparison with the hourly-averaged dispersion moments (i.e., the mean plume height, standard deviations and skewness values), obtained using a limited number of lidar plume scans both before and after fumigation, demonstrates that TAPM is capable of realistically simulating the observed fumigation characteristics (e.g., negative vertical skewness) and the influence of vertical wind direction shear (i.e., positive lateral skewness).

Analyzing the basic features of different complex terrain flows by means of a Doppler Sodar and a numerical model: Some implications for air pollution problems

Abstract: A variety of programmes and field experiments were carried out in order to develop and evaluate models of transport and diffusion of pollutants in complex terrain areas. As part of this programme, in this study, we have focused our interest on analyzing the basic features of different flow fields and thermal structures developed in a complex area and their relation to air pollution problems. The area is located in the province of Barcelona (in the northeast of Spain) close to a wide industrial zone, thus a pollutant flux could affect this region. In order to carry out the main purpose of this study we have analysed data from a Doppler Sodar (FAS 64) and a network of near surface meteorological and air quality stations. In addition, different dynamical simulations given by a numerical mesoscale model (MM5) are also analyzed. The results show that the main flow fields and thermal structures generated in this area are: sea breeze, slope drainage winds, channelling winds created by terrain constrictions and cool-air accumulation in low-lying regions. This last structure, developed specially in winter time, gives rise to stagnant cold air masses and strong thermic inversions, with average lapse rate of −4 degrees on 100 m, which contribute to increase air pollution concentration, especially SO2. Hourly and daily averaged SO2 concentration can be higher than 350 and 138 µg m−3 respectively. In addition, as “La Plana” is located not far from the Mediterranean Sea, during summertime the sea breeze arrives into this zone via its southern entrance, thereby reaching the whole area. The arrival of the sea breeze in to “La Plana”, which advects pollutants from the nearby industrial area, is the main cause of some of these pollutants, especially ozone and its precursors, attaining high concentrations during afternoon hours. The contribution of the sea breeze is variable, but could represent between a 25% to a 30% of its total value.

Vertical velocity and turbulence aspects during Mistral events as observed by UHF wind profilers

Abstract: The general purpose of this paper is to exper- imentally study mesoscale dynamical aspects of the Mis- tral in the coastal area located at the exit of the Rh ˆ one- valley. The Mistral is a northerly low-level flow blowing in southern France along the Rhaxis, located be- tween the French Alps and the Massif Central, towards the Mediterranean Sea. The experimental data are obtained by UHF wind profilers deployed during two major field cam- paigns, MAP (Mesoscale Alpine Program) in autumn 1999, and ESCOMPTE (Exp´ erience sur Site pour COntraindre les Mod` eles de Pollution atmosphet de Transports d'Emission) in summer 2001. Thanks to the use of the time evolution of the vertical pro- file of the horizontal wind vector, recent works have shown that the dynamics of the Mistral is highly dependent on the season because of the occurrence of specific synoptic pat- terns. In addition, during summer, thermal forcing leads to a combination of sea breeze with Mistral and weaker Mistral due to the enhanced friction while, during autumn, absence of convective turbulence leads to substantial acceleration as low-level jets are generated in the stably stratified planetary boundary layer. At the exit of the Rh ˆ one valley, the gap flow dynamics dominates, whereas at the lee of the Alps, the dy- namics is driven by the relative contribution of "flow around" and "flow over" mechanisms, upstream of the Alps. This pa- per analyses vertical velocity and turbulence, i.e. turbulent dissipation rate, with data obtained by the same UHF wind profilers during the same Mistral events. In autumn, the motions are found to be globally and signif- icantly subsident, which is coherent for a dry, cold and stable flow approaching the sea, and the turbulence is found to be of pure dynamical origin (wind shears and mountain/lee wave breaking), which is coherent with non-convective situations. In summer, due to the ground heating and to the interac- tions with thermal circulation, the vertical motions are less pronounced and no longer have systematic subsident chara- teristics. In addition, those vertical motions are found to be much less developed during the nighttimes because of the stabilization of the nocturnal planetary boundary layer due to a ground cooling. The enhanced turbulent dissipation-rate values found at lower levels during the afternoons of weak Mistral cases are consistent with the installation of the sum- mer convective boundary layer and show that, as expected in weaker Mistral events, the convection is the preponderant factor for the turbulence generation. On the other hand, for stronger cases, such a convective boundary layer installation is perturbed by the Mistral.

Climate and climatic variability at Lake Myvatn

Abstract: The climate of the Lake Myvatn region is examined through the use of weather station data, using the years from 1971 to 2000 as a reference period. Variations in mean monthly temperature and precipitation at Reykjahlid (Myvatn) are compared with variations at seven other weather stations in north east Iceland. The area is drier and colder than coastal stations and exhibits a seasonal cycle in temperature that is larger than found at the coast. The temperature is significantly influenced by the number of sunlight hours only during the summer months. During summer, the influence of a sea breeze circulation can be clearly identified.

The Australian Air Quality Forecasting System. Part III: Case Study of a Melbourne 4-Day Photochemical Smog Event

Abstract: The performance of the Australian Air Quality Forecasting System (AAQFS) is examined by means of a case study of a 7-day photochemical smog event in the Sydney region. This was the worst smog event for the 2000/ 01 oxidant season, and, because of its prolonged nature, it provided the opportunity to demonstrate the ability of AAQFS to forecast situations involving recirculation of precursors and remnant ozone, fumigation, and complex meteorological dynamics. The forecasting system was able to successfully predict high values of ozone, although at times the peak concentrations for the inland stations were underestimated. The dynamics for the Sydney region require a sensitive balance between the synoptic and mesoscale flows. Often high concentrations of ozone were advected inland by the sea breeze. On two occasions the system forecast a synoptic flow that was too strong, which blocked the inland advancement of the sea breeze. The peak ozone forecasts were underpredicted at the inland stations on those occasions. An examination of possible factors causing forecast errors has indicated that the AAQFS is more sensitive to errors in the meteorological conditions, rather than in the emissions or chemical mechanism in the Sydney region.

Short-term wind power prediction for offshore wind farms Evaluation of Fuzzy-Neural network based models

Abstract: Future major developments of wind power capacities are likely to take place offshore. As for onshore wind parks, short-term wind power prediction up to 48 hours ahead is expected to be of major importance for the management of offshore farms and their secure integration to the grid. Modeling the behavior of large wind farms of several tens or hundreds of MWs installed capacity and covering areas of several square kilometers is going to be a challenge. The adaptation of wind power forecasting methods to reach the specificities of the offshore case is not straightforward and very few results are available in the literature. The paper presents the new considerations that have to be made when dealing with large offshore wind farms and therefore the necessary evolutions of prediction models. Then, a state-of-the-art fuzzy-neural network based wind power forecasting model is described. Its performance is assessed for offshore conditions and compared to its level of performance for typical onshore parks. A general methodology dedicated to large offshore wind farms is developed. In order to deal with the spread of the turbines in such cases, methods based on the division of large wind farms into clusters are proposed. Furthermore, the use of satellite images for mapping the wind flow behavior inside offshore parks is investigated.

Scaling of the sea-breeze strength with observations in The Netherlands

Abstract: In this study we evaluate recently proposed scaling relations for the sea-breeze strength using independent data for a relatively homogeneous area in The Netherlands. We show that several of the scaling relations in the literature incorporate hidden correlation. Furthermore, it appears that the estimate for the sea-breeze strength is better made on the basis of the time-integrated rather than of the instantaneous sensible heat flux. It also turns out that for similar forcing the sea breeze in The Netherlands is about twice as strong as the sea breeze in the Vancouver area of Canada.

The meteorological importance of sea-breezes in the Levant region of Spain

Abstract: Sea-breezes are the main wind circulation during the hot season of the year (April–September) in the Levant region of Spain (Fig. 1). This article reviews the atmospheric features and the main characteristics of these sea-breezes. It also highlights the role that these mesoscale wind circulations play in developing unstable sea-breeze fronts in the coastal hinterland and mountainous areas close to the Mediterranean coast.

Model predictions of coastal winds in a small scale

Abstract: Details of surface winds across a flat and non-curved coastline have been considered, mostly in the 1–10 km scale, by looking at some published observed cases and simulating with a high-resolution numerical model. Stability conditions were emphasized by having the land and sea at slightly different temperatures, but sea breeze conditions were excluded. A warm surface generally enhances momentum transfer and wind speed, and reduces the cross-isobar angle. This transforms to rapid acceleration and downstream veering of offshore winds as they enter a warm, smooth sea. Cold sea, on the other hand, strongly inhibits vertical momentum transfer. This leads to offshore winds temporarily backing downstream off the coast, accelerating only slowly and even decreasing in speed in some cases. These observed facts were well simulated by the model. Onshore flow on to cold land brought along rapid deceleration and strong inland backing of winds. The deceleration was weaker and more gradual over warm land with downstream veering instead. Smaller geostrophic wind speed accentuated these and all other stability effects as the wind shears then were weaker relative to the buoyancy effects (i.e. the absolute values of the local Richardson numbers were larger). For large-scale winds along the shore with land on the right, the induced coastal convergence and rising motion appears only above about 100 m height in the cold sea simulations (typical of early summer). Below, there is divergence and hence relatively weak coastal wind. The case is the opposite for winds with land on the left (e.g. westerlies along a south coast): then the coastal surface winds are relatively strong along a cold sea. For a warm sea (typical of autumn) these low-level features disappear and coastal 10 m winds tend to be close to the geostrophic wind in speed and direction for all onshore directions.

Nonlinear Dynamics and Chaos in the Sea and Land Breeze

Abstract: In this work the evolution of the sea and land breeze is studied using a nonlinear model under calm synoptic conditions and diurnal periodic forcing of ground temperature. The breeze is examined as a function of the strength of the heating amplitude of ground temperature u 0. For u 0 # 68C, the solution is quasi-periodic with two incommensurate oscillations of 24 and 22.6 h; the last is the inertial oscillation at latitude 32 8N. A very low frequency oscillation (VLFO) of 16 days, which is the linear combination of the two incommensurate oscillations, is also obtained. For u 0 5 78C, the solution becomes nonperiodic. For u 0 $ 108C, chaotic solutions are obtained. In the chaotic regime the prominent oscillations can be divided into two classes. One class includes short-time-scale oscillations, such as the 24-h oscillation, the 22.4-h slightly modified inertial oscillation, and their harmonics. The second class incorporates time scales that are larger than a week, such as 15 days, which is a linear combination of the 24- and 22.4-h oscillations. The flow in the second class is in geostrophic balance. The kinetic energy, which manifests spells of very large energy fluctuations, is examined. During these spells the amplitude of the VLFO is large, and the amplitude of the 24-h oscillation is small compared to the spells where the fluctuations in the kinetic energy are small. Analyses of the wind observations in the central coast of Israel in the summer months show great similarity to the model simulation in the chaotic regime. A VLFO of 10 days, which is prominent in its parallel to the shore component, is interpreted to be the result of the nonlinear interaction between the inertial oscillation at the central latitude of the eastern Mediterranean, 33.5 8N, and the 24-h oscillation as obtained in the present model.

Numerical simulation of sea breeze characteristics observed at tropical coastal site, Kalpakkam

Abstract: Sea breeze characteristics around Kalpakkam tropical coastal site are studied using an Advanced Regional Prediction System (ARPS) mesoscale model, which is non-hydrostatic, compressible atmospheric prediction model following the terrain coordinate system. Various options such as surface physics, atmospheric radiation physics, Coriolis force, microphysics, cumulus parameterization and 1.5 level TKE closure scheme for diffusion are included in the model.