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Related papers: Wind speed vertical distribution at Mt. Graham

200 papers

The scaling anisotropy is crucial to interpret the nonlinear interactions in solar wind turbulence. Previous observations provide diverse results and the structure function analyses are also reported to be an approach to investigate the…

Space Physics · Physics 2020-11-23 Honghong Wu , Chuanyi Tu , Xin Wang , Jiansen He , Liping Yang , Linghua Wang

The atmosphere is a nonlinear stratified fluid in which internal gravity waves are present. These waves interact with the flow, resulting in wave turbulence that displays important differences with the turbulence observed in isotropic and…

Fluid Dynamics · Physics 2015-06-23 P. Clark di Leoni , P. D. Mininni

We generate explicit height-dependent eddy viscosity coefficients in the Ekman layer from convex wind speed profiles. The solutions we obtain are parameterized in terms of the relative deflection angle between the wind directions at the top…

Fluid Dynamics · Physics 2022-06-22 Tony Lyons

We have computed wind models with time-dependent dust formation and grain-size dependent opacities, where (1) the problem is simplified by assuming a fixed dust-grain size, and where (2) the radiation pressure efficiency is approximated…

Solar and Stellar Astrophysics · Physics 2010-10-04 Lars Mattsson , Susanne Höfner

Strong stellar winds are an important feature in wind-accreting high-mass X-ray binary (HMXB) systems, providing insights into stellar evolution and their impact on surrounding environments. However, the long-term evolution and temporal…

In solar wind turbulence, the energy transfer/dissipation rate is typically estimated using MHD third-order structure functions calculated using spacecraft observations. However, the inherent anisotropy of solar wind turbulence leads to…

The common - arguably ubiquitous - large-scale variability of optical and UV lines profiles of hot, massive stars is widely interpreted as the direct consequence of structured, variable winds. Many of the variability phenomena are observed…

Solar and Stellar Astrophysics · Physics 2011-11-02 G. A. Wade

The Solar Dynamics Observatory/Helioseismic and Magnetic Imager (SDO/HMI) filtergrams, taken at six wavelengths around the Fe I 6173.3 {\AA} line, contain information about the line-of-sight velocity over a range of heights in the solar…

In this contribution we present the most relevant results obtained in the context of a feasibility study (MOSE) undertaken for ESO. The principal aim of the project was to quantify the performances of a mesoscale model (Astro-Meso-NH code)…

Instrumentation and Methods for Astrophysics · Physics 2016-08-24 E. Masciadri , F. Lascaux , A. Turchi , L. Fini

The present study addresses the following questions: How representative of the actual velocities in the solar atmosphere are the Doppler shifts of spectral lines? How reliable is the velocity signal derived from narrowband filtergrams? How…

Solar and Stellar Astrophysics · Physics 2010-02-18 B. Fleck , T. Straus , M. Carlsson , S. M. Jefferies , G. Severino , T. D. Tarbell

Recently observed minute timescale variability of blazar emission at TeV energies has imposed severe constraints on jet models and TeV emission mechanisms. We focus on a robust jet instability to explain this variability. As a consequence…

High Energy Astrophysical Phenomena · Physics 2015-06-04 Prasad Subramanian , Amit Shukla , Peter A. Becker

The thermal characterisation of a building envelope is usually best performed from on site measurements with controlled heating power set points. Occupant-friendly measurement conditions provide on the contrary less informative data.…

We develop a model for the wind properties of cool main-sequence stars, which comprises their wind ram pressures, mass fluxes, and terminal wind velocities. The wind properties are determined through a polytropic magnetised wind model,…

Astrophysics · Physics 2009-11-11 V. Holzwarth , M. Jardine

In this contribution we present the FAST, which is a comprehensive software suite that aims to streamline and automatically manage the forecast of atmospheric and astroclimatic parameters (provided respectively by Meso-Nh and Astro-Meso-Nh…

Instrumentation and Methods for Astrophysics · Physics 2024-12-09 A. Turchi , E. Masciadri , L. Fini

In this paper we present the characterization of all the principal meteorological parameters (wind speed and direction, pressure, absolute and potential temperature) extended over 25 km from the ground and over two years (2003 and 2004)…

Astrophysics · Physics 2010-12-01 K. Geissler , E. Masciadri

The Parker Solar Probe mission provides a unique opportunity to characterize several features of the solar wind at different heliocentric distances. Recent findings have shown a transition in the inertial range spectral and scaling…

Solar and Stellar Astrophysics · Physics 2022-11-30 Tommaso Alberti , Simone Benella , Giuseppe Consolini , Mirko Stumpo , Roberto Benzi

It has long been known that the high-speed stream (HSS) peak velocity at Earth directly depends on the area of the coronal hole (CH) on the Sun. Different degrees of association between the two parameters have been shown by many authors. In…

Focal ratio degradation (FRD) is a major contributor to throughput and light loss in a fibre spectroscopic telescope system. We combine the guided mode theory in geometric optics and a well-known model, power distribution model (PDM), to…

Instrumentation and Methods for Astrophysics · Physics 2019-12-25 Yunxiang Yan , Gang Wang , Weimin Sun , A-Li Luo , Zhenyu Ma , Jian Li , Shuqing Wang

Results of 2005-2007 campaign of measurement of the optical turbulence vertical distribution above Mt. Maidanak are presented. Measurements are performed with the MASS (Multi-Aperture Scintillation Sensor) device which is widely used in…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 V. Kornilov , S. Ilyasov , O. Voziakova , Yu. Tillaev , B. Safonov , M. Ibragimov , N. Shatsky , S. Ehgamberdiev

For many decades vertical winds have been observed at high altitudes of the Earth's atmosphere, in the mesosphere and thermosphere layers. These observations have been used with a simple one dimensional model to make estimates of possible…

Atmospheric and Oceanic Physics · Physics 2024-08-20 Arjun Berera , Daniel J. Brener