Wavelike Structures in the Turbulent Layer During the Morning Development of Convection at Dome C, Antarctica

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Wind and turbulence in the urban boundary layer analysis from acoustic remote sensing data and fit to analytical relations

Mittlere saisonale Profile der Windgeschwindigkeit, Standardabweichung der Vertikalgeschwindigkeit und der Turbulenzintensität aus SODAR-Messungen in drei unterschiedlich großen Städten, Moskau, Hannover und Linz, werden mit analytischen Annäherungen für die Prandtl- und die Ekman Schicht verglichen. Typische Eigenschaften für diese Profile in Städten sind eine stärkere Zunahme desWindgeschwindigkeitsprofils mit der Höhe, höhere Turbulenzintensitäten und die Zunahme der Turbulenz mit der Höhe. Der analytische Ansatz, welcher von ETLING (2002) für die Beschreibung des Windprofils in der gesamten Grenzschicht vorgeschlagen wird, wird in der Prandtl Schicht durch eine Korrekturfunktion zur Berücksichtigung der atmosphärischen Stabilität erweitert. Die erweiterte Profilbeschreibung ermöglicht die beste Annäherung an städtische Windprofile in den untersten 500 m über Grund

Stable Surface-Based Turbulent Layer During the Polar Winter at Dome C, Antarctica: Sodar and In Situ Observations

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Summertime low-level jet characteristics measured by sodars over rural and urban areas

This work is devoted to the study of nocturnal low-level jet streams (LLJ) at altitudes up to 400 m agl, with the help of Doppler sodars. The objective was twofold: firstly, to study the origin and behavior of LLJ in a mid-latitude region, and secondly, to compare the LLJ characteristics over urban and rural areas. To this end, simultaneous measurements of wind velocity profiles over the center of Moscow city and over a nearby countryside were carried out. The sodar data on wind speed and direction collected continuously during 27 days in July 2005 were analyzed together with in situ data from a meteorological mast. A good correlation between the height of the LLJ core and the inversion height was found. Empirical distributions of the maximum speed of the jet streams, the height of the jet core, and the wind turning across the stream were obtained. The relationships between the LLJs characteristics and some surface layer parameters were found. Over the urban area the jet streams appeared less frequently and at heigher altitudes than over the countryside

Sodar Observation of the ABL Structure and Waves over the Black Sea Offshore Site

Sodar investigations of the breeze circulation and vertical structure of the atmospheric boundary layer (ABL) were carried out in the coastal zone of the Black Sea for ten days in June 2015. The measurements were preformed at a stationary oceanographic platform located 450 m from the southern coast of the Crimean Peninsula. Complex measurements of the ABL vertical structure were performed using the three-axis Doppler minisodar Latan-3m. Auxiliary measurements were provided by a temperature profiler and two automatic weather stations. During the campaign, the weather was mostly fair with a pronounced daily cycle. Characteristic features of breeze circulation in the studied area, primarily determined by the adjacent mountains, were revealed. Wave structures with amplitudes of up to 100 m were regularly observed by sodar over the sea surface. Various forms of Kelvin–Helmholtz billows, observed at the interface between the sea breeze and the return flow aloft, are described