Copyright©The Oceanographic Society of Japan/TERRAPUB/Springer where u∗ is the friction velocity of the air, ρa is air density. U10 is the wind speed at 10 m height above the sea surface in neutral stratification condition; CD is the drag coefficient. Many studies have shown that air-sea exchange is regulated by turbulence associated with wind and wind waves at the air-sea interface (Jähne et a...

Gravity waves can emerge as a result of the perturbation of atmospheric circulatory systems. They encompass periodic, yet geographically stationary, changes in temperature, pressure and vertical wind components. Occurrence of such waves is frequent if strong winds hit high mountains. Secondary effect of such waves may also be encountered as clear...

The propagation of Kelvin–Helmholtz (KH) shear-generated gravity waves through the summer stratosphere is investigated using ray tracing, taking into account back-reflection as well as wave dissipation due to precriticallayer breaking, radiative damping, and viscous diffusion. It is found that the transmission rate of upward– eastward waves to the mesosphere is surprisingly good, provided that ...

OBJECTIVE To evaluate nasal airflow characteristics during physiologic breathing in normal and pathologic conditions. DESIGN The choana of an anatomical human model was connected to a pump that simulated physiological pressure changes in the upper airway system. Normal ambient air was used as medium. The airstream was marked with aerosolized water particles, and was observed through an exact ...

We study the dynamics and properties of a turbulent flame, formed in the presence of subsonic, high-speed, homogeneous, isotropic Kolmogorov-type turbulence in an unconfined system. Direct numerical simulations are performed with Athena-RFX, a massively parallel, fully compressible, high-order, dimensionally unsplit, reactive-flow code. A simplified reaction-diffusion model represents a stoichi...

The noise generated by the interaction of a turbulent inflow with the leading edge of a flat plate or an airfoil is a dominant sound source, for example in rotor-stator configurations of fans and air condition units. Aeroacoustic research of this noise source often includes performing wind tunnel experiments, where the required incident turbulence is generated by passive grids or meshes. In cer...

This paper describes an artwork created in response to a question about the role of the artist in communicating climate change issues. The artwork, titled Turbulent World, incorporates turbulence and surprise as a means to visualize the potential instability of our culture and the environment due to climatic changes indicated by increased worldwide temperatures. The artwork makes use of a custo...

Turbulent-flame speeds in methane–air mixtures were measured in a Taylor–Couette apparatus with counter-rotating cylinders, used to generate turbulence that is nearly homogeneous and isotropic over many integral length and time scales. While laminar-flame propagation is found to be influenced by the Darrieus– Landau instability and heat loss to the walls of the apparatus, turbulent-flame propag...

We have demonstrated first measurements of the aerosol indirect effect using ground-based remote sensors at the Southern Great Plains (SGP) site. The response of non-precipitating, ice-free clouds to changes in aerosol loading is quantified in terms of a relative change in cloud-drop effective radius (re) for a relative change in aerosol extinction under conditions of equivalent cloud liquid wa...

An open question in cloud physics is how rain forms in warm cumulus as rapidly as it is sometimes observed. In particular, the growth of cloud droplets across the size gap from 10 to 50 m in radius has not been fully explained. In this paper, the authors investigate the growth of cloud droplets by collision– coalescence, taking into account both the gravitational mechanism and several enhanceme...