Observation of Clear-Air Echoes with 3.2-cm Radars

Study of Clear Air Turbulence over Iranian Plato

This study was carried out using two sets of numerical weather forecast data and flight reports for Clear Air Turbulence (CAT) over Iranian Plato to find atmospheric flow patterns favorable to the formation of CAT. The numerical data include five months of AVN analysis with horizontal resolution of 1 degree(about 100 km) and four months forecast data of MM5 model with resolution of 50 km. Impor...

Verification of clear-air turbulence forecasts

On differentiating ground clutter and insect echoes from Doppler weather radars using archived data

Normally wind measurements from Doppler radars rely on the presence of rain. During fine weather, insects become a potential radar target for wind measurement. However, it is difficult to separate ground clutter and insect echoes when spectral or polarimetric methods are not available. Archived reflectivity and velocity data from repeated 5 scans provide alternative methods. The probability of ...

Bird Migration Echoes Observed by Polarimetric Radar

Weather surveillance radars observe clear-air radar echoes (CAE); aerial biota and irregularities in atmospheric refractive index caused the echoes. Using weak returns of atmospheric CAE, the radars have been applied to wind findings in a short radar range in a fair weather, in particular S-band radars. Long wavelength radars perform good to observe air motion, because a detectable turbulent sc...

Clear-air turbulence in a changing climate

Atmospheric turbulence causes most weather-related aircraft incidents. Commercial aircraft encounter moderate-or-greater turbulence tens of thousands of times each year worldwide, injuring probably hundreds of passengers (occasionally fatally), costing airlines tens of millions of dollars and causing structural damage to planes. Clear-air turbulence is especially difficult to avoid, because it ...