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The Australian monsoon and its mesoscale convective systems
(1992)
The 1987 Australian monsoon was observed with satellites, rawinsondes, radar and aircraft. These data are presented, with theory filling the gaps, in illustration of its dynamics.The engine of the monsoon is its embedded mesoscale convective systems (MCSs). Ten MCSs were explored with airborne Doppler radar. They all exhibited ...
Model studies of the middle atmosphere of Venus
(1991)
Zonal winds reach in excess of 100 m/s in the middle atmosphere of Venus; the cloud-level atmosphere takes little more than 4 days to complete one rotation, while the solid planet below has a 243-day rotation period. This phenomenon, known as superrotation, is the central problem of the Venus atmosphere. The question we address ...
Cold air incursions into low-latitudes: global perspective and regional analysis over South America
(1998)
This dissertation addresses several aspects of synoptic-scale incursions of cold air (cold surges) propagating equatorward along the east side of the Andes cordillera in South America. Similar cold surges are also a well documented feature of the synoptic climatology of southeast Asia (to the east of the Himalayan Plateau) ...
Tropical dynamics near the stratospause: the two-day wave and its relatives
(1998)
The two-day wave is observed in the Upper Atmosphere Research Satellite (UARS) Microwave Limb Sounder (MLS) temperature and water vapor data. During a 3-year period (Dec. 1991-Sep. 1994), the wave signature is prominent semiannually after each solstice and is comprised of a zonal wavenumber 3 component with ${\sim}2.0$-day ...
High-drag states and lee vortices in stratified flow over topography
(1999)
Stratified flow with uniform basic wind and stability past long three-dimensional (3d) ridges is studied in the absence of surface friction and planetary rotation. The dominant control parameters for this problem are the nondimensional mountain height e=Nh0U0 and the horizontal aspect ratio beta (i.e., ratio of cross-stream ...
Numerical simulation of tropical cyclone genesis
(1980)
Past hurricane or typhoon simulation studies have concentrated on the development of the mature storm. Most of these simulations began with initial states that had closed, relatively strong cyclonic circulations and that ultimately produced hurricane disturbances during the integrations. Numerical modelers have generally not ...
An observational and numerical study of windstorms along the western side of the Washington Cascade Mountains
(1997)
This dissertation investigates western Washington Cascade windstorms by utilizing various data sources such as conventional synoptic observations, profilers on both sides of the Cascade Mountains, a WSR-88D Doppler radar located in northern Puget Sound, and non-hydrostatic model simulations down to 1 km resolution. First, the ...
A modeling study of self-aggregation and large-scale control of tropical deep convection
(1998)
The nonhydrostatic version of the Penn State University (PSU)/National Center for Atmospheric Research (NCAR) mesoscale model MM5 is used to investigate the mechanisms responsible for the superclustering of tropical deep convection. In particular, we are interested in whether mesoscale cloud clusters and super cloud clusters ...
Radiative properties, dynamics, and chemical evolution of the smoke from the 1991 Kuwait oil fires
(1994)
The oil fields in Kuwait were the scene of a massive conflagration during much of 1991 that was started by Iraqi forces during the Gulf War. At this time, approximately 4 to 5 million barrels of oil were burning each day. The climatic impacts of the fires were limited by the fact that the smoke was generally confined to the ...
Linear and nonlinear aspects of the northern hemisphere wintertime variability in the 500 hPa height field
(1993)
Low-frequency variability in the Northern Hemisphere wintertime 500 hPa height field has been investigated. The Pacific/North American pattern and the North Atlantic Oscillation stand out above the background continuum of variability in rotated EOF analysis based on the temporal covariance matrix. It is shown that these spatial ...