Results 81 to 90 of about 125 (108)

Doppler Lidar Observations of a Downslope Windstorm

Monthly Weather Review, 1988
Abstract During January and February 1987, the NOAA/WPL pulsed Doppler lidar was deployed in the foothills west of Boulder, Colorado, to study orographically induced flows over the Continental Divide. On 29 January 1987, the lidar, with its unique spatial and temporal data-gathering capabilities, documented a downslope windstorm affecting the Boulder ...
Paul J. Neiman, R. M. Hardesty, M. A. Shapiro, R. E. Cupp   +3 more
openaire   +1 more source

Observations and modelling of downslope windstorm in Novorossiysk

Dynamics of Atmospheres and Oceans, 2018
Abstract We present a comprehensive study of the three-dimensional structure of the Novorossiysk bora, a severe downslope windstorm on the north-eastern coast of the Black Sea. The analysis is based on observational data obtained from the Russian Hydrometeorological Service, automatic weather stations, sodar system, microwave temperature profiler and
Anna A. Shestakova, Pavel A. Toropov, Victor M. Stepanenko, Denis E. Sergeev, Irina A. Repina   +4 more
openaire   +1 more source

Examples of the role of surface friction in downslope windstorms

Meteorology and Atmospheric Physics, 1990
Numerical simulations of four mountain wave events over the Colorado Rockies were carried out with a two-dimensional hydrostatic model including a turbulent mixing parameterization in order to investigate the effect of surface friction. Surface friction was found to play a major role in modulating and even in some cases preventing the wave ...
Richard, Evelyne, Mascart, Patrick
openaire   +3 more sources

On the Sensitivity of Downslope Windstorms to the Asymmetry of the Mountain Profile

Journal of the Atmospheric Sciences, 1991
Abstract The influence of terrain asymmetry on the development and strength of downslope windstorms was examined through the numerical simulation of three basic atmospheric configurations: 1) flow beneath a mean-state critical layer, 2) flow in the presence of breaking waves and 3) flow in a two-layer atmosphere without wave breaking or a mean-state ...
Peter P. Miller, Dale R. Durran
openaire   +1 more source

Winter heat waves characteristics associated with downslope windstorm in south Brazil

International Journal of Climatology, 2023
AbstractThe air temperature anomaly was analysed in 16 consecutive winters from 2004 to 2019 in southern Brazil using reanalysis data and hourly atmospheric observations. In this study, 13 heat wave (HW) episodes were identified using the percentile methodology.
Cinara Ewerling da Rosa, Michel Stefanello, Nicolle Cordero Simões dos Reis, Douglas Stefanello Facco, Simone Teleginski Ferraz, Nathalie Tissot Boiaski, Dirceu Luis Herdies, Gervásio Annes Degrazia   +7 more
openaire   +1 more source

Impact of land surface roughness on downslope windstorm modelling in the Arctic

Dynamics of Atmospheres and Oceans, 2021
Abstract The article considers the reasons for the underestimation of the wind speed by the WRF-ARW model when simulating downslope windstorms in the Russian Arctic. Simulation results for the Tiksi windstorm, for which sensitivity tests were carried out, appeared to be weakly dependent on the initial and boundary conditions, topography resolution ...
openaire   +1 more source

Effects of Mountain Width on Downslope Windstorm Occurrence

Journal of the Atmospheric Sciences
Abstract This study demonstrates the impact of mountain width on the occurrence of downslope windstorms by deriving a solution for 2D flow past an idealized mountain range, including nonhydrostatic effects. Additionally, idealized numerical simulations were conducted to validate the solution.
Yuki Asano, Hiroyuki Kusaka
openaire   +1 more source

Downslope Windstorms. Part II: Effect of External Wind Shear

Journal of the Atmospheric Sciences, 1992
Abstract The nonlinear, two-dimensional, steady-state, mesoscale problem of a stable stratified airflow above a mountain ridge is considered. The influence of turbulence is disregarded. It is assumed that the atmosphere above this flow is neutral and perturbations of the pressure in it are small.
Lev N. Gutman, I. Apterman
openaire   +1 more source

An extreme clear air turbulence incidence associated with a strong downslope windstorm

24th Aerospace Sciences Meeting, 1986
The meteorological conditions present during an occurrence of clear-air turbulence (CAT) associated with the presence of a mountain wave are documented. The incident caused severe vertical accelerations of two passenger aircraft travelling at 33,000 ft altitude.
P. LESTER, R. BACH, JR.
openaire   +1 more source

A multi-scale simulation of an extreme downslope windstorm over complex topography

Meteorology and Atmospheric Physics, 2000
A severe localized windstorm, with near-surface winds > 60 ms−1, occurred in an isolated valley within the Alpine mountains (> 1800 m) of central Norway on 31 January 1995. A multi-scale numerical simulation of the event was performed with the Naval Research Laboratory (NRL)’s Coupled Ocean/Atmosphere Mesoscale Prediction System (COAMPS), configured ...
J. D. Doyle, M. A. Shapiro
openaire   +1 more source