Showing papers on "Wind shear published in 1987"
TL;DR: In the first two weeks of December 1985, measurements of the wind stress, the three-component wind speed variances, and the vertical flux of sensible heat were collected from a research platform in the North Sea as discussed by the authors.
Abstract: During the first two weeks of December 1985, measurements of the wind stress, the three-component wind speed variances, and the vertical flux of sensible heat were collected from a research platform in the North Sea. Obtained using a sonic anemometer, the turbulence data represent an extensive range of wind speed conditions (5–30 m/s), and the air-sea temperature difference was observed to span from −3° to +3°C. The data were collected from a boom extending 17 m to the west of the North Sea Platform at 33 m above the water surface. The results indicated that the 10-m-height neutral drag coefficient, CDN, exhibited a strong dependence on wave age, i.e., CDN was larger for growing waves than for steady state or decaying sea. The normalized turbulence statistics were found to corroborate the results of Smith (1980) and Large and Pond (1981).
185 citations
TL;DR: In this article, a 1D option of the CSU Cloud/Mesoscale Model, a partially diagnostic higher-order turbulence model, an atmospheric radiation model, a partial condensation parameterization, and drizzle process were used to simulate the stratocumulus-capped mixed layer.
Abstract: In order to simulate the stratocumulus-capped mixed layer, a one-dimensional stratocumulus model is developed. This model consists of five major points: 1) a one-dimensional (1D) option of the CSU Cloud/Mesoscale Model, 2) a partially diagnostic higher-order turbulence model, 3) an atmospheric radiation model, 4) a partial condensation parameterization, and 5) the drizzle process. This model is tested against the observed structure of the marine stratocumulus layer reported by Brost et al. In this paper we also investigate the interactions among the following physical processes: atmospheric radiation, cloud microphysics, vertical wind shear, turbulent mixing, large-scale divergence, the sea surface temperature and the presence of high-level clouds above the capping inversion. The model simulated fields were found to be in generally good agreement with observations, although the amount of cloud liquid water predicted was too large. This may have been a result of employing a wind profile that exhib...
177 citations
TL;DR: The vertical and horizontal structure of the atmospheric boundary layer near the northern California coast was investigated during spring upwelling conditions as part of the 1981 Coastal Ocean Dynamics Experiment as mentioned in this paper, where two daytime aircraft flights were devised to measure mean and turbulent quantities for 25-km tracks along and across the continental shelf from 30- to 1200m altitude.
Abstract: The vertical and horizontal structure of the atmospheric boundary layer near the northern California coast was investigated during spring upwelling conditions as part of the 1981 Coastal Ocean Dynamics Experiment. Two daytime aircraft flights were devised to measure mean and turbulent quantities for 25-km tracks along and across the continental shelf from 30- to 1200-m altitude. The Pacific high offshore and an inland thermal low characterized the synoptic situations, and equatorward winds resulted, which produced intense ocean upwelling. The wind profile was found to be jet shaped: maximum wind speeds were 25 m s−1 and 16 m s−1 at 400 and 100 m, respectively, in the two flights. Above and below the heights of the jet speed maxima, the wind speed decreased rapidly. Sharp density inversions existed at the levels of the peak wind speeds; in one flight the inversion also sloped down toward the coast. Turbulence was effectively confined below the inversions. Strong, zonal temperature gradients above the inversion between the hot land and cool marine air caused a thermal wind for which the wind speed decreased with height. Below the inversion, turbulent stress divergence was large and effective in transferring the horizontal momentum of the wind to the sea, slowing the wind. There was also a small thermal wind below the inversion but opposite to the one above owing to the well-mixed air temperature following the sea surface temperature, which was cold at the coast and relatively warmer offshore owing to the upwelling. These effects explain the jet-shaped wind profile. The mean momentum equations show that an acceleration toward the coast can balance the pressure gradient, Coriolis, and turbulent stress divergence forces, and there were some observations to support this. Complete balance was not obtained for the turbulent kinetic energy budget; inferred dissipation rates were too large.
129 citations
TL;DR: Guidance strategies for near-optimum performance in a wind shear are examined in this paper, where the takeoff problem is considered with reference to flight in a vertical plane; the presence of a downdraft is assumed.
Abstract: Guidance strategies for near-optimum performance in a wind shear are examined The takeoff problem is considered with reference to flight in a vertical plane; the presence of a downdraft is assumed Trajectories for optimum performance in a wind shear are determined for different wind shear models and intensities Numerical experiments with the optimum control approach lead to the conclusion that, for weak to moderate shear/downdraft combinations, the optimal trajectory is characterized by a monotonic climb, and for severe shear/downdraft combinations, it is characterized by an initial climb, followed by a nearly horizontal flight, followed by renewed climbing after the aircraft has passed through the shear region An acceleration guidance scheme based on relative acceleration is presented in both analytical form and feedback control form Numerical results with this scheme result in trajectories close to the optimum and considerably superior to those arising from alternative guidance schemes
70 citations
01 Jan 1987
67 citations
TL;DR: The results of barium-strontium (Ba-Sr) releases and Langmuir probe measurements at the onset time of equatorial spread-F by two RH-560 rockets launched from SHAR on 16 February 1982 are discussed in this paper.
62 citations
TL;DR: In this paper, the authors determined if variation in small-scale wind gustiness (on the order of several seconds duration) has a significant effect on sand movement, detailed field measurements were made of wind speed and transport rate.
Abstract: Estimates of aeolian sand transport generally use an average wind speed to assess the wind energy. To determine if variation in small-scale wind gustiness (on the order of several seconds duration) has a significant effect on sand movement, detailed field measurements were made of wind speed and transport rate. Average wind speed and several gust parameters were derived from the wind data. The results indicate that small-scale gust information does not improve prediction of transport rates.
60 citations
TL;DR: In this paper, wind velocity profiles were obtained over alluvial plains, lava flows, and a cinder cone in the Mojave Desert to determine the wind shear and the potential for particle transport.
Abstract: Wind velocity profiles were obtained over alluvial plains, lava flows, and a cinder cone in the Mojave Desert to determine the wind shear and the potential for particle transport. It was found that aerodynamic roughness for winds increases nearly a factor of 5 as flow crosses from the alluvium to the lava surface, resulting in wind shear that is 21 percent greater. Thus, wind erosion and sand flux may be substantially enhanced over the lava field. Moreover, wind flow turbulence is enhanced in the wake of the cinder cone, which also increases erosion and sediment transportation by the wind.
47 citations
TL;DR: In this paper, a study designed to accumulate statistics on the gust frontal signature in Doppler radar data, nine gust front cases were analyzed and data were collected on those characteristics thought to be most important in developing rules for automatic gust-front detection such as gust front length and height, maximum and minimum values of reflectivity, velocity and spectrum width, and estimates of radial shear.
Abstract: Gust fronts produce low altitude wind shear that can be hazardous to aircraft operations, especially during takeoff and landing. Radar meteorologists have long been able to identify gust front signatures in Doppler radar data, but in order to use the radar efficiently, automatic detection of such hazards is essential. In a study designed to accumulate statistics on the gust frontal signature in Doppler radar data, nine gust front cases were analyzed. Data were collected on those characteristics thought to be most important in developing rules for automatic gust-front detection such as gust front length and height, maximum and minimum values of reflectivity, velocity and spectrum width, and estimates of radial shear. To provide the reader with a concrete example, photographs of the Doppler radar displays of just two (in the interests of brevity) of the nine gust fronts are presented and discussed, as well as summary data for all cases. For these cases, outflows could be detected most reliably in t...
47 citations
TL;DR: In this article, the relationship between lightning location and storm structure was examined for one radar volume scan in each of two mature, severe storms, one of which was a supercell storm and the other was a multicell storm.
Abstract: Relationships between lightning location and storm structure are examined for one radar volume scan in each of two mature, severe storms. One of these storms had characteristics of a supercell storm, and the other was a multicell storm. Data were analyzed from dual-Doppler radar and dual-VHF lightning-mapping systems. The distributions of VHF impulse sources were compared with radar reflectivity, vertical air velocity, and their respective gradients. In the supercell storm, lightning tended to occur along streamlines above and down-shear of the updraft and reflectivity cores; VHF impulse sources were most concentrated in reflectivities between 30 and 40 dBZ and were distributed uniformly with respect to updraft speed. In the multicell storm, on the other hand, lightning tended to coincide with the vertical reflectivity and updraft core and with the diverging streamlines near the top of the storm. The results suggest that the location of lightning in these severe storms were most directly associated with the wind field structure relative to updraft and reflectivity cores. Since the magnitude and vertical shear of the environmental wind are fundamental in determining the reflectivity and wind field structure of a storm, it is suggested that these environmental parameters are also fundamental in determining lightning location.
37 citations
Patent•
10 Feb 1987
TL;DR: In this paper, a wind shear detection and alerting system using inertially derived accelerations is proposed to provide visual and aural warnings for a variety of weather conditions, such as, head shear, tail shear and wind trend.
Abstract: A wind shear detection and alerting system (30) compares inertially derived accelerations (32, 34) with air speed rate (52) to provide a wind shear warning signal. Inertially derived accelerations are used instead of urely inertial accelerations because purely inertial systems generally require a vertical gyro. By utilizing angle of attack (alpha) and flight path angle (gamma) instead of pitch signal () in the calculation, no vertical gyro signal is required and the system will be responsive to vertical as well as horizontal shear conditions. An enhanced version of the system is also compensated for roll angle (O/), with the roll angle being derived from the rate of change of heading (psi) to avoid the need for a vertical gyro. The alerting system is capable of providing visual and aural warnings for a variety of wind shear conditions, such as, head shear, tail shear, head shear followed by tail shear and wind shear, trend. The warning system is also capable of providing a wind shear warning which is a function of the radio altitude (112) of the aircraft.
TL;DR: In this paper, the authors used Doppler radar data collected each spring in 1979-1984 with the two radars operated by the National Severe Storms Laboratory (NSSL) are used to investigate the asymmetry of low-altitude divergent outflows of convective storm downbursts in central Oklahoma.
Abstract: Doppler radar data collected each spring in 1979–1984 with the two Doppler radars operated by the National Severe Storms Laboratory (NSSL) are used to investigate the asymmetry of low-altitude divergent outflows of convective storm downbursts in central Oklahoma. Outflows in Oklahoma storms can be highly asymmetric with horizontal shear along the axis of maximum divergence as much as 5.5 times the shear along the axis of minimum divergence. The downbursts observed in central Oklahoma, all large-scale (4–10 km) events, were superposed with the maximum reflectivity core of the storms. However, scanning strategies may have precluded detection of smaller scale (>4 km) microbursts. Typical downbursts observed during the Joint Airport Weather Studies (JAWS) Project were of small scale (>4 km) and were often associated with little or no rain at the surface. The mechanism for the initiation of the majority of JAWS microbursts was evaporative cooling, which occurred when precipitation fell into a dry, dee...
TL;DR: In this paper, a conically scanned optical Doppler technique has been used to measure the turbulence spectrum accurately at frequencies up to 10 Hz and the signal-to-noise ratio is not a limiting factor.
Abstract: Measurement of air motion relative to an aircraft by a conically scanned optical Doppler technique has advantages over measurements with conventional gust probes for many applications. Advantages of the laser air motion sensing technique described here include calibration based on physical constants rather than experiment for an accurate measurement of mean wind, freedom from flow distortion effects on turbulence measurements, all-weather performance, reduction in error from mechanical vibrations and ability to measure vertical wind shear. An experiment comparing a single-component laser velocimeter and a differential pressure gust probe shows that the optical approach measures the turbulence spectrum accurately at frequencies up to 10 Hz and that the signal-to-noise ratio is not a limiting factor. In addition, we have observed the effect of spectral skewing caused by airflow distortion in cloud.
TL;DR: In this paper, the authors present two examples of mesospheric radar observations that suggest the characteristic 'cat's-eye'-like turbulent structures often associated with them in other parts of the atmosphere, the ocean and in laboratory experiments.
Abstract: Observations of noctilucent clouds indicate the frequent occurrence of wave-like motions and Kelvin–Helmholtz billows at the high latitude summer mesospause1,2 (∼83 km), but to date no other technique appears to have produced direct evidence of their pres-ence at these heights3. High-powered mesosphere–stratosphere–troposphere very high frequency Doppler radars with good height and time resolution (∼150∼300 m and ∼10 s respectively) capable of making such observations have recently become available, and the backscattering regions in the mesosphere detected by such radars often take the form of thin layers that appear to be pro-duced by dynamical instabilities in the region of maximum wind shear4. Such wind conditions should produce Kelvin–Helmholtz instabilities, and here we present two examples of mesospheric radar observations that suggest the characteristic 'cat's-eye'-like turbulent structures often associated with them in other parts of the atmosphere5, the ocean6 and in laboratory experiments7.
TL;DR: In this paper, measurements of the profiles of mean wind velocity, of temperature, and of specific humidity in the unstable atmospheric boundary layer over macro-rough terrain were made from radiosonde observations in a calibrated watershed of 3.2 km2 in the hilly Pre-Alps of Switzerland during the summer of 1982.
Abstract: Measurements were made of the profiles of mean wind velocity, of temperature, and of specific humidity in the unstable atmospheric boundary layer over macro-rough terrain; these data were obtained from radiosonde observations in a calibrated watershed of 3.2 km2 in the hilly Pre-Alps of Switzerland during the summer of 1982. The regional evaporation was reasonably well correlated (R = 0.7) with these profile measurements through a logarithmic height dependency between roughly 2h0 (where h0 ≈ 100 m is the mean height of the roughness obstacles) and 0.6h (where h is the height of the boundary layer above the mean valley level). The shapes of the profiles appear to be essentially independent of the Monin–Obukhov parameter (z− d0)/L, but they display a dependency on the wind shear aloft and on the value of (z0/h) (where z0 is the roughness height). Over this rugged surface the relative importance of mechanical turbulence, as compared to convective turbulence, is larger than over terrain with smaller ...
TL;DR: In this article, the mean kinematic properties of the wind field over Colorado and an area-averaged geostrophic and age-ostrophic wind were derived from a network of three VHF Doppler radars.
Abstract: Wind fields derived from a network of three VHF Doppler radars are used to calculate the mean kinematic properties of the wind field over Colorado and an area-averaged geostrophic and ageostrophic wind. A numerical technique that is equivalent to the line integral method is used to compute the kinematic quantities. Details of this technique, termed the linear vector point function method (LVPF) are discussed. The behavior of the vorticity, divergence, deformation, geostrophic wind and ageostrophic wind are examined for two case studies when the synoptic scale weather patterns over Colorado are dominated by moderately intense upper-level troughs and jet streams. We find that the computed quantities of divergence, absolute vorticity, deformation, geostrophic and ageostrophic wind are modified by the passage of the weather systems in a manner consistent with our present understanding of upper-level dynamics. In addition, temporal variations in the kinematic properties, geostrophic wind and ageostrop...
TL;DR: In this article, a computer simulation model of the measurement process for a ground-based Fabry-Perot interferometer (FPI) has been developed and used to study how variations of wind and temperature along the instrument line-of-sight affect the Doppler shift and width of the observed nightglow O(1D) emission line at high spectral resolution.
Patent•
23 Mar 1987
TL;DR: An aircraft performance instrument which provides a first indicator which represents the line of level flight of the aircraft and a second indicator representative of the maximum permissible angle of attack of an aircraft.
Abstract: An aircraft performance instrument which provides a first indicator which represents the line of level flight of the aircraft and a second indicator representative of the maximum permissible angle of attack of the aircraft.
TL;DR: In this article, the mean wind velocity and turbulence in the atmospheric boundary layer under wintertime conditions of cold offshore advection were measured and it was shown that at a height of 50 m, the wind speed increases with offshore distance by roughly 20% over a horizontal scale of order 10 km.
Abstract: Airborne measurements of mean wind velocity and turbulence in the atmospheric boundary layer under wintertime conditions of cold offshore advection suggest that at a height of 50 m the mean wind speed increases with offshore distance by roughly 20% over a horizontal scale of order 10 km. Similarly, the vertical gust velocity and turbulent kinetic energy decay on scales of order 3.5 km by factors of 1.5 and 3.2, respectively. The scale of cross‐shore variations in the vertical fluxes of heat and downwind momentum is also 10 km, and the momentum flux is found to be roughly constant to 300 m, whereas the heat flux decreases with height. The stability parameter, z/L (where z = 50 m and L is the local Monin‐Obukhov length), is generally small over land but may reach order one over the warm ocean. The magnitude and horizontal length scales associated with the offshore variations in wind speed and turbulence are reasonably consistent with model results for a simple roughness change, but a more sophistic...
TL;DR: In this article, the dynamics of gravity-wave/convective-cell interaction using NOAA data collected in NE Colorado during July and August 1983 were studied using microbarographs, the tropospheric wind profiles obtained with a UHF wind profiler radar, and precipitation data collected with a 10-cm weather radar for four events (A, B, C, and D).
Abstract: The dynamics of gravity-wave/convective-cell interaction is studied using NOAA data collected in NE Colorado during July and August 1983. The pressure fields measured with microbarographs, the tropospheric wind profiles obtained with a UHF wind profiler radar, and precipitation data collected with a 10-cm weather radar for four events (A, B, C, and D) are analyzed. The four disturbances are detected through a substantial depth of the troposphere. It is observed that in event A the wave and convective cells appear to be locked together; in event B, the wave and convective cells commence about the same time, but the wave velocities differ from the cell velocities; and in events C and D, the waves move faster than the maximum wind in the jet and faster than the convective cells. It is suggested that events A and B are generated by wind shear in the jet stream, and the excitation of events C and D depends on mechanisms such as vertical convective motion and acceleration in the jet flow.
TL;DR: In this article, a statistical study using a total of 71 events shows that there is a significant correlation between the propagation velocity of turbulence structures and the mean wind, being consistent with the assumption that turbulence is advected by large scale motions.
TL;DR: In this paper, the authors show that the maximum equatorial zonal wind speed is proportional to the product of the buoyancy frequency and the magnitude of the driving region's thickness.
TL;DR: In this paper, the authors provided both point and interval estimates of 10-, 20-, 50-, and 100-year return values for wind speeds at the five locations in the United States, and the starting point for this analysis is the sequence of consecutive daily maxima of the hourly wind-speed observations over the given period of record, for each station.
Abstract: The analysis which follows provides both point and interval estimates of 10-, 20-, 50-, and 100-year return values for wind speeds at the five locations. Wind speed is the primary quantity of interest, and it was decided to ignore wind direction and surface pressure, the other two potentially useful variables. Furthermore, the frequency of measurement is unnecessary for the problem at hand, and it was felt that little loss in information would result from replacing hourly wind-speed observations by daily maxima. Thus, the starting point for this analysis is the sequence of consecutive daily maxima of the hourly wind-speed observations over the given period of record, for each station.
Patent•
31 Jul 1987
TL;DR: In this paper, an improved wind shear warning system for aircraft is presented, which is modified in response to the pilot controlled excess of the airspeed of the aircraft over a reference airspeed during the approach to a landing so as to avoid unnecessary warnings.
Abstract: An improved wind shear warning system for aircraft. A wind shear signal representing wind shear as modified by the downdraft drift angle of the aircraft is used to provide a warning signal when the wind shear signal exceeds (negatively) a variable threshold. The threshold for the warning signal is modified in response to the pilot controlled excess of the airspeed of the aircraft over a reference airspeed during the approach to a landing so as to avoid unnecessary warnings. The threshold is further altered when the wind shear signal during approach indicates the high likelihood of a reversal of wind shear conditions.
TL;DR: In this article, the wind field of the middle atmosphere (60-100 kin) is sampled by the Saskatoon Medium Frequency radar: temporal resolution is normally 5 rain, and vertical is 1.5/3 kin.
TL;DR: The design of a prototype system for recognizing low-attitude wind shear events from Doppler radar displays is presented, consisting of a conventional expert system augmented by a specialized capability for processing radar images.
Abstract: This paper describes an artificial intelligence-based approach for automated recognition of wind shear hazards. The design of a prototype system for recognizing low-attitude wind shear events from Doppler radar displays is presented. This system, called WX1, consists of a conventional expert system augmented by a specialized capability for processing radar images. The radar image processing component of the system employs numerical and computer vision techniques to extract features from radar data. The expert system carries out symbolic reasoning on these features using a set of heuristic rules expressing meteorological knowledge about wind shear recognition. Results are provided demonstrating the ability of the system to recognize microburst and gust front wind shear events.
TL;DR: In this article, data from two aircraft flights in the marine atmospheric boundary layer are analyzed in an investigation of entrainment processes at the top of the well-mixed layer.
Abstract: Data from two aircraft flights in the marine atmospheric boundary layer are analyzed in an investigation of entrainment processes at the top of the well-mixed layer. Both days had strong wind shear across the inversion, which is reflected in the horizontal wind statistics. Conditional sampling is used to show that near the top of the mixed layer most updrafts are cool, moist and deficient in along-wind momentum (slow) with respect to their environment. About half of these updrafts are still positively buoyant. Downdrafts that are warm, dry and have an excess of along-wind momentum (fast) occupy the greatest area of any downdraft type. Most of them are positively buoyant. Also found near the top of the mixed layer are large numbers of warm/dry/fast updrafts and cool/moist/slow downdrafts, i.e., drafts that have overturned. Time series from this level reveal large masses of cool/moist/slow and warm/dry/fast air, usually containing both upward-moving and downward-moving elements. These observations ...
TL;DR: In this article, the authors presented a case study of wind speed and wind direction data with a dataset of approximately 17 x 106 observations of wind speeds and 6 × 106 of surface pressure, and the last two were included on the speculation that they might be useful in understanding the behaviour of observed winds.
Abstract: What strikes one most about the data set of this case study is its sheer size; there are approximately 17 x 106 observations each of wind speed and wind direction, and 06 x 106 observations of surface pressure The last two were included on the speculation that they might be useful in understanding the behaviour of the observed winds Indeed, strong spatial gradients of surface pressure are strongly linked to high wind speeds through the geostrophic equation (see Holton 1972), and strong spatial gradients at a particular time are also generally associated with strong temporal gradients of surface pressure Thus, on the face of it, the surface pressure record should contain useful information about "extreme" winds However, because of the size of the data set and the limited amount of time available, this connection has not been pursued In order to make the data-handling task a manageable one, only the daily maxima of the hourly observations were studied This decision reduces the total number of wind-speed observations to approximately 69,000 The second thing which impresses one is the fact that this is a very "dirty" data set, as are almost all long geophysical time series The observations, one-minute "mean" wind speeds recorded hourly, are taken subjectively either from a chart recorder or by observing the movements of a dial over a one-minute period Judging from the instructions which meteorological technicians are given regarding the method for taking these observations, the observations might be better described as subjectively determined one-minute median wind speeds Observers are instructed to ignore short gusts and lulls The observations were taken with a variety of instruments over the years The height and/or location of the measuring instruments has been changed at least once at every station, and the information which is available about the history of these changes is rather scant The local topography, which has a profound effect on the characteristics of air flow past a given point, has changed over time with encroaching urbanization and the gradual development of the airports at which the instruments are located Additional complications which are present in most geophysical time series include the effect of the seasonal cycle on the characteristics of the wind speed and the fact that the atmosphere exhibits variability on long time scales which is not seen in "textbook" weakly stationary stochastic processes
TL;DR: In this article, the feasibility of using the next generation weather radar (NEXRAD) system to detect low-altitude wind shear near airports is investigated, and the authors compare surface-measured horizontal shear with that observed aloft with Doppler radar to determine how the radar-estimated shear above the surface relates to the surface measured shear.
Abstract: The feasibility of using the next generation weather radar (NEXRAD) system to detect low-altitude wind shear near airports is investigated. We compare surface-measured horizontal shear with that observed aloft with Doppler radar to determine how the radar-estimated shear above the surface relates to the surface-measured shear. For five Oklahoma gust fronts, the Doppler radar estimate of shear (at heights between 50–600 m) averaged 1.6 times the shear measured at the surface. For none of 43 comparisons was the surface radial velocity difference across the gust front stronger than the radial velocity difference measured by Doppler radar aloft When the five gust fronts passed an instrumented tower a vertical profile through the lowest 440 m of the gust front could be determined. In all cases the wind speed and wind shear increased in the lowest 90 m of the atmosphere. In one case, the 90 m height had the peak wind shear, in all other case the peak wind shear was at a much higher altitude. The Federa...
10 Apr 1987
TL;DR: In this article, it is demonstrated that the wind speed and direction measurements made from the three standard anemometer locations on board a Nimitz class ship are distorted by the wind blockage produced by the ship's superstructure, mast, and antennas.
Abstract: : The available literature describing the errors in wind measurements produced by the flow distribution around ships, masts, and towers is briefly reviewed. It is demonstrated that the wind speed and direction measurements made from the three standard anemometer locations on board a Nimitz class ship are distorted by the wind blockage produced by the ship's superstructure, mast, and antennas. Even though the wind measurements are made near the top of two masts, the wind speed error was found to be as large as 19% and the wind direction error as large as 6 deg. A correction scheme for determining the true wind speed and direction is presented. Keywords: Air flow; Ship masts; Ship antennas; Nuclear powered ships; Aircraft carriers; Boundary layer flow; Ship models; Wind tunnel tests; Ship-induced errors of meteorological measurements; Correction of shipboard wind speed and direction measurements; Boundary-layer ship model wind tunnel tests; Errors in bulk method determined fluxes; Air-sea interaction.