Aircraft turbulence is one of the most dangerous meteorological phenomena that can affect aviation safety. This study focused on associated to mountain lee waves in vicinity Adolfo Suárez Madrid-Barajas airport (Spain). Sixty-eight events are selected simulate with Weather Research and Forecasting (WRF-ARW) HARMONIE-AROME numerical weather prediction models. To characterize associated, vertical...

Ever since they were placed in use for aircraft detection, radars have detected "angels." An "angel" is a radar reflection from a location in the atmosphere that does not contain a known discrete target. Such reflections have been variously attributed to birds or insects too distant to see by eye, or to local fluctuations in the refractive index of the air. For quite some time heated scientific...

We present the first evidence of the direct influence of gas turbulence on the shear instability of a planar air-water mixing layer. We show with two different experiments that increasing the level of velocity fluctuations in the gas phase continuously increases the frequency of the instability, up to a doubling of frequency for the largest turbulence intensity investigated. A modified spatiote...

Numerical study of two dimensional supersonic hydrogen-air mixing layer is performed to investigate the effect of turbulence and chemical additive on ignition distance. Chemical reaction is treated using detail kinetics. Advection upstream splitting method is used to calculate the fluxes and one equation turbulence model is chosen here to simulate the considered problem. Hydrogen peroxide is us...

A multiscale computational framework is designed for simulating atmospheric convection and clouds. In this multiscale framework, large eddy simulation (LES) is used to model the coarse scales of 100 m and larger, and a stochastic, one-dimensional turbulence (ODT) model is used to represent the fine scales of 100 m and smaller. Coupled and evolving together, these two components provide a multis...

[1] A refined theoretical analysis of the clear-air Doppler radar (CDR) measurement process is presented. The refined theory builds on the Fresnel-approximated (as opposed to Fraunhofer-approximated) radio wave propagation theory, and turbulence statistics like locally averaged velocities, local velocity variances, local dissipation rates, and local structure parameters are allowed to vary rand...

Polar mesosphere summer echoes (PMSE) are very strong radar echoes primarily studied in the VHF wavelength range from altitudes close to the polar summer mesopause. Radar waves are scattered at irregularities in the radar refractive index which at mesopause altitudes is effectively determined by the electron number density. For efficient scatter, the electron number density must reveal structur...

Polar mesosphere summer echoes (PMSE) are very strong radar echoes primarily studied in the VHF wavelength range from altitudes close to the polar summer mesopause. Radar waves are scattered at irregularities in the radar refractive index which at mesopause altitudes is solely determined by the electron number density. 5 For efficient scatter, the electron number density must reveal structures ...