We report on a development of a long-range airborne UV high spectral resolution lidar, intended for the detection and characterisation of clear air turbulence (CAT). The detection of turbulence is based on the measurement of density fluctuations associated with the movement of turbulent air masses. These density fluctuations are measured by the variations in the molecular backscatter coefficien...

The main challenges in predicting the weather are insufficient computational power and gaps in our understanding of the complex dynamics of atmospheric phenomena. There are comparatively straightforward solutions to these problems: enough teraflops, the right equations. But what happens when you have neither? This is the problem facing aviation turbulence forecasters, who are charged with the t...

Occurrences of clear air turbulence in the stratosphere at altitudes of 45,000 to 68,000 f t are analyzed in terms of observed variability in vertical temperature gradients and balloon ascensional rates based on nearby radiosonde data. While the magnitudes of both parameters are positively correlated with the probability of encountering turbulence, the temperature gradient variability has a hig...

in this paper, inflow turbulence effects on the flow wake parameters around a naca0012 airfoil at zero incidence angle and reynolds number of 38,700 were investigated. various turbulence promoter networks were used to achieve turbulence intensity of 5% and 6%. experiments have been conducted for three different turbulence intensities in which mean velocity parameters, turbulence intensity, freq...

Clear-air turbulence (CAT) is hazardous to aircraft and projected intensify in response future climate change. However, our understanding of past CAT trends currently limited, being derived largely from outdated reanalysis data. Here we analyze globally during 1979–2020 a modern data set using 21 diagnostics. We find clear evidence large increases around the midlatitudes at cruising altitudes. ...

Abstract Clear-air turbulence (CAT) has a large impact on the aviation sector. Our current understanding of how CAT may increase with climate change in future is largely based simulations from CMIP3 and CMIP5 global models (GCMs). However, these have now been superseded by high-resolution CMIP6 GCMs, which for first time grid lengths at individual patches start to be resolved. Here we use multi...

The note presents preliminary information on the power spectral data obtained during Project TOPCAT in Australia. Measurements of moderately severe clear air turbulence were obtained from a Canberra aircraft flying at altitudes of 26000 to 33000 ft in the vicinity of the subtropical jet stream. In some respects, particularly at long wavelengths, the spectra are dissimilar to those found for low...