PICTURE OF THE MONTH Vertically Pointing Airborne Doppler Radar Observations of Kelvin–Helmholtz Billows
نویسندگان
چکیده
A train of Kelvin–Helmholtz billows in a deep stratiform cloud over a mountain range is documented using data from a high-resolution vertically pointing airborne Doppler radar. The billows had a spacing of 2–2.5 km and a small aspect ratio. The formation and decay of the billows appear to be related to flow acceleration over a mountain.
منابع مشابه
Vertically pointing airborne Doppler radar observations of Kelvin-Helmholtz billows
A train of Kelvin–Helmholtz billows in a deep stratiform cloud over a mountain range is documented using data from a high-resolution vertically pointing airborne Doppler radar. The billows had a spacing of 2–2.5 km and a small aspect ratio. The formation and decay of the billows appear to be related to flow acceleration over a mountain.
متن کاملFinescale Vertical Structure of a Cold Front as Revealed by an Airborne Doppler Radar
In the afternoon of 24 May 2002, a well-defined and frontogenetic cold front moved through the Texas panhandle. Detailed observations from a series of platforms were collected near the triple point between this cold front and a dryline boundary. This paper primarily uses reflectivity and Doppler velocity data from an airborne 95-GHz radar, as well as flight-level thermodynamic data, to describe...
متن کاملRelease of potential shearing instability in warm frontal zones
Potential shearing instability (PSHI) exists in the atmosphere when the Richardson number in a stably stratified shear layer would be less than 4 if the layer were lifted to saturation. Sometimes the air entering a warm frontal zone near the position of the surface warm front is initially unsaturated, its Richardson number is greater than a, but PSHI exists over a deep layer. This paper present...
متن کاملUse of Wind-Shear Displays for Doppler Radar Data
The usefulness of displaying vertical wind shear on a radar range height indicator is demonstrated. Fine structure in the pattern of shear is shown to be helpful for inferring general flow patterns and the occurrence of billows due to shearing (Kelvin–Helmholtz) instability. Corresponding author address: Prof. Keith A. Browning, Joint Centre for Mesoscale Meteorology, Department of Meteorology,...
متن کاملDifferential Diffusion in Breaking Kelvin–Helmholtz Billows
Direct numerical simulations are used to compare turbulent diffusivities of heat and salt during the growth and collapse of Kelvin–Helmholtz billows. The ratio of diffusivities is obtained as a function of buoyancy Reynolds number Reb and of the density ratio R (the ratio of the contributions of heat and salt to the density stratification). The diffusivity ratio is generally less than unity (he...
متن کامل