Cosmic shear holds great promise for a precision independent measurement of Ωm, the mass density of the universe relative to the critical density. The signal is expected to be weak, so a thorough understanding of systematic effects is crucial. An important systematic effect is the atmosphere: shear power introduced by the atmosphere is larger than the expected signal. Algorithms exist to extrac...

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,...

Specifically, a flight program to measure atmospheric turbulence at high altitudes (long wavelengths) in a variety of meteorological conditions is described and some results obtained in high-altitude wind shear are discussed. Results are also presented from wind-tunnel test programs to measure fluctuating pressures associated with over-the-wing engine configurations. Two analyses, a flexible ai...

Prefrontal squall lines are mesoscale convective systems that often cannot be linked to any preexisting organizing mechanism. This suggests the possibility that they are self-forced disturbances, driven by a cooperative interaction between convective and larger scales. To investigate this hypothesis, a wave-CISK model is developed for two-dimensional disturbances in a baroclinic basic state wit...

Numerical model predictions of tropical cyclone (TC) intensity and structure suffer from deficiencies associated with initial conditions and model formulation. Here, we propose to study how errors in the HWRF model’s initial conditions impact subsequent forecasts of TC intensity and wind structure using ensemble forecasts and the ensemble-based sensitivity method. This study will utilize the se...

Numerical simulations of tropical-cyclone-like vortices are performed to analyze the effects of unidirectional vertical wind shear and translational flow upon the organization of convection within a hurricane’s core region and upon the intensity of the storm. A series of dry and moist simulations is performed using the Pennsylvania State University–National Center for Atmospheric Research Mesos...

Stratified hydrostatic fluids have linear internal gravity waves with different phase speeds and vertical profiles. Here a simplified set of partial differential equations (PDE) is derived to represent the nonlinear dynamics of waves with different vertical profiles. The equations are derived by projecting the full nonlinear equations onto the vertical modes of two gravity waves, and the result...

The principal rainband in tropical cyclones is currently depicted as a solitary and continuous precipitation region. However, the airborne radar observations of the principal rainband in TyphoonHagupit (2008) reveal multiple subrainband structures. These subbands possess many characteristics of the squall lines with trailing stratiform in themidlatitudes and are different from those documented ...

Recently, Majda and Souganidis have presented a rigorous asymptotic theory governing the large-scale renormalized ame front dynamics for a convection-reaction-di usion system involving KPP type chemistries and small scale turbulence. This theory is valid in the context of an in nitely thin reaction layer. Embid, Majda, and Souganidis have explored this rigorous theory within the context of a sh...

Although on the same theoretical basis, the current standards of major countries have set out two evidently different distributions of along-wind static equivalent wind loads, one is the same as the mean wind force and the other is the same as the first mode shape, on tall buildings. In this paper, the fluctuating static equivalent wind load is evaluated as mean, background and resonant compone...