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SYSTEM FOR VISUALIZATION OF TRAJEKTORY OF METEOROLOGICAL BALLOON-RADIOSONDES СИСТЕМА ВИЗУАЛИЗАЦИИ ТРАЕКТОРИИ МЕТЕОРОЛОГИЧЕСКИХ ШАРОВ-ЗОНДОВ СИСТЕМА В ЗУАЛ ЗАЦ ТРА КТОР МЕТЕОРОЛОГ ЧНИХ КУЛЬ-ЗОНД В
В.?. Чиг?нь,О.П. Красюк,В.Д. Смичок
Proceedings of National Aviation University , 2012,
Abstract: The system for three-dimensional visualization of flight trajektory of meteorological balloon-radiosondes in real time to improve the safety of military and civil aviation flights. The basis of STV is the modernization of existing radar using computer technology. It is shown that the measuring resolution of the height of ball-probe using the STV is 6 m, while the existing meteorological radars provide 160 m. The STV allows to set the distance to the ball-probe with an accuracy of 10 m at a distance of 300 km. Рассмотрена созданная и испытанная система трехмерной визуализации траектории полета метеорологических шаров-радиозондов в реальном времени для повышения безопасности полетов военной и гражданской авиации. Отмечено, что основой системы трехмерной визуализации является модернизация радиолокационной станции с использованием компьютерных технологий. Показано, что разрешение измерения высоты шара-зонда с помощью системы трехмерной визуализации составляет 6 м, тогда как существующие метеорологические радиолокационные станции обеспечивают 160 м. Описано, что система трехмерной визуализации позволяет установить расстояние до шара-зонда с точностью до 10 м на дистанции до 300 км. Розглянуто створену випробувану систему тривим рно в зуал зац тра ктор польоту метеоролог чних куль-рад озонд в у реальному час для п двищення безпеки польот в в йськово та цив льно ав ац . Зазначено, що основою системи тривим рно в зуал зац модерн зац я рад олокац йно стан-ц з використанням комп’ютерних технолог й.
High frequency boundary layer profiling with reusable radiosondes  [PDF]
D. Legain,O. Bousquet,T. Douffet,D. Tzanos
Atmospheric Measurement Techniques Discussions , 2013, DOI: 10.5194/amtd-6-3339-2013
Abstract: A new system for high frequency boundary layer profiling based upon radiosondes and free balloons was tested during the field phases of the Boundary Layer Late Afternoon and Sunset Turbulence (BLLAST 2011, Lannemezan, France) and of the Hydrological cycle in the Mediterranean Experiment (HyMeX, 2012). The system consists of a conventional Vaisala receiver and a GPS radiosonde (pressure, wind, humidity and temperature) that is tied to a couple of inflated balloons. The principle of the sounding system is to permit the first balloon to detach from the rawinsonde at a predetermined altitude, allowing the rawinsonde to slowly descend with the second balloon to perform a second, new sounding. The instrumentation is then eventually recovered. The expecting landing area is anticipated before the flight by estimating the trajectory of the probe from a forecasted wind profile and by specifying both the balloon release altitude and the mean ascent and descent rates of the system. The real landing point is determined by the last transmission of the radiosonde GPS and the visual landmark provided by the second balloon. About 70 soundings were performed with a recovery rate of more than 80%. Recovered radiosondes were generally reused several times, often immediately after recovery, which definitely demonstrates the high potential of this system.
Numerical simulations of Optical Turbulence at low and high horizontal resolution in Antarctica with a mesoscale meteorological model  [PDF]
F. Lascaux,E. Masciadri,S. Hagelin,J. Stoesz
Physics , 2010, DOI: 10.1051/eas/1040012
Abstract: It has already been demonstrated that a mesoscale meteorological model such as Meso-NH is highly reliable in reproducing 3D maps of optical turbulence. Preliminary measurements above the Antarctic Plateau have so far indicated a pretty good value for the seeing: around 0.3" at Dome C. However some uncertainties remain. That's why our group is focusing on a detailed study of the atmospheric flow and turbulence in the internal Antarctic Plateau. Our intention is to use the Meso-NH model to do predictions of the atmospheric flow and the corresponding optical turbulence in the internal plateau. The use of this model has another huge advantage: we have access to informations inside an entire 3D volume which is not the case with observations only. Two different configurations have been used: a low horizontal resolution (with a mesh-size of 100 km) and a high horizontal resolution with the grid-nesting interactive technique (with a mesh-size of 1 km in the innermost domain centered above the area of interest). We present here the turbulence distribution reconstructed by Meso-NH for 16 nights monitored in winter time 2005, looking at the the seeing and the surface layer thickness.
Mt. Graham: Optical turbulence vertical distribution at standard and high vertical resolution  [PDF]
E. Masciadri,J. Stoesz,S. Hagelin,S.,F. Lascaux,INAF - Osservatorio Astrofisico di Arcetri
Physics , 2010, DOI: 10.1117/12.856904
Abstract: A characterization of the optical turbulence vertical distribution and all the main integrated astroclimatic parameters derived from the CN2 and the wind speed profiles above Mt. Graham is presented. The statistic includes measurements related to 43 nights done with a Generalized Scidar (GS) used in standard configuration with a vertical resolution of ~1 km on the whole 20-22 km and with the new technique (HVR-GS) in the first kilometer. The latter achieves a resolution of ~ 20-30 m in this region of the atmosphere. Measurements done in different periods of the year permit us to provide a seasonal variation analysis of the CN2. A discretized distribution of the typical CN2 profiles useful for the Ground Layer Adaptive Optics (GLAO) simulations is provided and a specific analysis for the LBT Laser Guide Star system ARGOS case is done including the calculation of the 'gray zones' for J, H and K bands. Mt. Graham confirms to be an excellent site with median values of the seeing without dome contribution equal to 0.72", the isoplanatic angle equal to 2.5" and the wavefront coherence time equal to 4.8 msec. We provide a cumulative distribution of the percentage of turbulence developed below H* where H* is included in the (0,1 km) range. We find that 50% of the whole turbulence develops in the first 80 m from the ground. The turbulence decreasing rate is very similar to what has been observed above Mauna Kea.
Optical turbulence vertical distribution with standard and high resolution at Mt. Graham  [PDF]
E. Masciadri,J. Stoesz,S. Hagelin,F. Lascaux
Physics , 2010, DOI: 10.1111/j.1365-2966.2010.16313.x
Abstract: A characterization of the optical turbulence vertical distribution (Cn2 profiles) and all the main integrated astroclimatic parameters derived from the Cn2 and the wind speed profiles above the site of the Large Binocular Telescope (Mt. Graham, Arizona, US) is presented. The statistic includes measurements related to 43 nights done with a Generalized Scidar (GS) used in standard configuration with a vertical resolution Delta(H)~1 km on the whole 20 km and with the new technique (HVR-GS) in the first kilometer. The latter achieves a resolution Delta(H)~20-30 m in this region of the atmosphere. Measurements done in different periods of the year permit us to provide a seasonal variation analysis of the Cn2. A discretized distribution of Cn2 useful for the Ground Layer Adaptive Optics (GLAO) simulations is provided and a specific analysis for the LBT Laser Guide Star system ARGOS (running in GLAO configuration) case is done including the calculation of the 'gray zones' for J, H and K bands. Mt. Graham confirms to be an excellent site with median values of the seeing without dome contribution epsilon = 0.72", the isoplanatic angle theta0 = 2.5" and the wavefront coherence time tau0= 4.8 msec. We find that the optical turbulence vertical distribution decreases in a much sharper way than what has been believed so far in proximity of the ground above astronomical sites. We find that 50% of the whole turbulence develops in the first 80+/-15 m from the ground. We finally prove that the error in the normalization of the scintillation that has been recently put in evidence in the principle of the GS technique, affects these measurements with an absolutely negligible quantity (0.04").
Estimating actual, potential, reference crop and pan evaporation using standard meteorological data: a pragmatic synthesis
T. A. McMahon, M. C. Peel, L. Lowe, R. Srikanthan,T. R. McVicar
Hydrology and Earth System Sciences (HESS) & Discussions (HESSD) , 2013,
Abstract: This guide to estimating daily and monthly actual, potential, reference crop and pan evaporation covers topics that are of interest to researchers, consulting hydrologists and practicing engineers. Topics include estimating actual evaporation from deep lakes and from farm dams and for catchment water balance studies, estimating potential evaporation as input to rainfall-runoff models, and reference crop evapotranspiration for small irrigation areas, and for irrigation within large irrigation districts. Inspiration for this guide arose in response to the authors' experiences in reviewing research papers and consulting reports where estimation of the actual evaporation component in catchment and water balance studies was often inadequately handled. Practical guides using consistent terminology that cover both theory and practice are not readily available. Here we provide such a guide, which is divided into three parts. The first part provides background theory and an outline of the conceptual models of potential evaporation of Penman, Penman–Monteith and Priestley–Taylor, as well as discussions of reference crop evapotranspiration and Class-A pan evaporation. The last two sub-sections in this first part include techniques to estimate actual evaporation from (i) open-surface water and (ii) landscapes and catchments (Morton and the advection-aridity models). The second part addresses topics confronting a practicing hydrologist, e.g. estimating actual evaporation for deep lakes, shallow lakes and farm dams, lakes covered with vegetation, catchments, irrigation areas and bare soil. The third part addresses six related issues: (i) automatic (hard wired) calculation of evaporation estimates in commercial weather stations, (ii) evaporation estimates without wind data, (iii) at-site meteorological data, (iv) dealing with evaporation in a climate change environment, (v) 24 h versus day-light hour estimation of meteorological variables, and (vi) uncertainty in evaporation estimates. This paper is supported by a Supplement that includes 21 sections enhancing the material in the text, worked examples of many procedures discussed in the paper, a program listing (Fortran 90) of Morton's WREVAP evaporation models along with tables of monthly Class-A pan coefficients for 68 locations across Australia and other information.
Estimating actual, potential, reference crop and pan evaporation using standard meteorological data: a pragmatic synthesis
T. A. McMahon,M. C. Peel,L. Lowe,R. Srikanthan
Hydrology and Earth System Sciences Discussions , 2012, DOI: 10.5194/hessd-9-11829-2012
Abstract: This guide to estimating daily and monthly actual, potential, reference crop and pan evaporation covers topics that are of interest to researchers, consulting hydrologists and practicing engineers. Topics include estimating actual evaporation from deep lakes and from farm dams and for catchment water balance studies, estimating potential evaporation as input to rainfall-runoff models, and reference crop evapotranspiration for small irrigation areas, and for irrigation within large irrigation districts. Inspiration for this guide arose in response to the authors' experiences in reviewing research papers and consulting reports where estimation of the actual evaporation component in catchment and water balance studies was often inadequately handled. Practical guides using consistent terminology that cover both theory and practice are not readily available. Here we provide such a guide, which is divided into three parts. The first part provides background theory and an outline of conceptual models of potential evaporation of Penman, Penman-Monteith and Priestley-Taylor, and discussions of reference crop evaporation and then Class-A pan evaporation. The last two sub-sections in this first part include techniques to estimate actual evaporation from (i) open-surface water and (ii) landscapes and catchments (Morton and the advection-aridity models). The second part addresses topics confronting a practicing hydrologist, e.g. estimating actual evaporation for deep lakes, shallow lakes and farm dams, lakes covered with vegetation, catchments, irrigation areas and bare soil. The third part addresses six related issues (i) hard-wired evaporation estimates, (ii) evaporation estimates without wind data, (iii) at-site meteorological data, (iv) dealing with evaporation in a climate change environment, (v) 24-h versus day-light hour estimation of meteorological variables, and (vi) uncertainty in evaporation estimates. This paper is supported by supplementary material that includes 21 appendices enhancing the material in the text, worked examples of many procedures discussed in the paper, a program listing (Fortran 90) of Morton's WREVAP evaporation models along with tables of monthly Class-A pan coefficients for 68 locations across Australia and other information.
Levy-Kolmogorov scaling of turbulence  [PDF]
W. Chen,H. B. Zhou
Mathematics , 2005,
Abstract: The Kolmogorov scaling law of turbulences has been considered the most important theoretical breakthrough in the last century. It is an essential approach to analyze turbulence data present in meteorological, physical, chemical, biological and mechanical phenomena. One of its very fundamental assumptions is that turbulence is a stochastic Gaussian process in small scales5. However, experiment data at finite Reynolds numbers have observed a clear departure from the Gaussian. In this study, by replacing the standard Laplacian representation of dissipation in the Navier-Stokes (NS) equation with the fractional Laplacian, we obtain the fractional NS equation underlying the Levy stable distribution which exhibits a non-Gaussian heavy trail and fractional frequency power law dissipation. The dimensional analysis of this equation turns out a new scaling of turbulences, called the Levy-Kolmogorov scaling, whose scaling exponent ranges from -3 to -5/3 corresponding to different Levy processes and reduces to the limiting Kolmogorov scaling -5/3 underlying a Gaussian process. The truncated Levy process and multi-scaling due to the boundary effect is also discussed. Finally, we further extend our model to reflecting the history-dependent fractional Brownian motion.
VALIDATION OF THE VERTICAL PROFILES OF THREE METEOROLOGICAL MODELS USING RADIOSONDES FROM ANTOFAGASTA, PARANAL AND LLANO DE CHAJNANTOR  [cached]
L. Cortu00E9s,M. Curu00E9
Revista mexicana de astronomía y astrofísica , 2011,
Abstract: Esta investigación presenta una evaluación de tres modelos meteorológicos, el Global Forecast System (GFS), el European Centre for Medium-Range Weather Forecasts (ECMWF) y el modelo mesoescalar WRF (Weather Research and Forecasting) para tres sitios localizados en el norte de Chile. El Aeropuerto Cerro Moreno, el Observatorio Paranal y el Llano de Chajnantor estan ubicados a 25, 130 y 283 km de la ciudad de Antofagasta, respectivamente. Los resultados para los tres sitios, demuestran que la correlación más baja y los errores más altos se producen en superficie, donde el modelo ECMWF es el que presenta los mejores resultados en estos niveles para las dos horas analizadas. Esto podría ser por el hecho de que el modelo ECMWF cuenta con 91 niveles verticales, en comparación de los 64 y 27 niveles verticales que poseen los modelos GFS y WRF, respectivamente, por lo que puede representar mejor los procesos en la Capa Límite Planetaria (CLP). En relación a la tropósfera media-alta, los tres modelos presentan buenos resultados.
Detection of meteorological inconsistencies by GPS  [cached]
L. Balestri,M. Boccolari,S. Fazlagic,S. Pugnaghi
Annals of Geophysics , 2003, DOI: 10.4401/ag-3393
Abstract: GPS observations, distances from satellites to receivers and meteorological conditions in neutral atmosphere are known to obey a constraint, which provides a residual or in other words a quality index. A method is discussed which provides a residual epoch by epoch in near real time. In general, distribution of residuals during several consecutive epochs belonging to the same satellites, allows estimates of a mean and a standard deviation of mean. Under normal meteorological conditions distribution of residuals appears to be consistent with zero mean as expected. However, consecutive residuals sometimes appear to have a mean different from zero by more than three standard deviations of mean. Such signifi cant consecutive epochs provide a warning of existing inconsistencies among GPS observations, distances from satellites to receivers as obtained by orbital information, meteorological conditions above receivers (as obtained by ground measurements or by extrapolation of meteorological analysis). A procedure has been set up which warns about these inconsistencies in near real time.
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