In this paper an attempt is made to explain the period-doubling of wind-generated gravity-capillary waves as observed in the experimentofChoi (1977). It is conjectured that period-doubling is closely related to the phenomenon of second-harmonic resonance. In order to obtain a simple dynamical model, results of McGoldrick (1970) and Simmons (1969) are extended to include the effect of wind input...

The potential for using high-resolution meteorological data from two operational numerical weather analyses (NWA) to diagnose and predict persistent contrail formation is evaluated using two independent contrail observation databases. Contrail occurrence statistics derived from surface and satellite observations between April 2004 and June 2005 are matched to the humidity, vertical velocity, wi...

Linear mountain wave theory is used to derive the general formulas of the gravity wave momentum flux (WMF) and its vertical divergence that develop in directionally sheared flows with constant vertical shear. Height variations of theWMF and its vertical divergence are studied for a circular bell-shapedmountain. The results show that the magnitude of the WMF decreases with height owing to variab...

Results are presented from wind tunnel simulations of gaseous pollutant dispersion in the atmospheric convective boundary layer (CBL) capped by a temperature inversion. The experiments were performed in the thermally stratified wind tunnel of the University of Karlsruhe, Germany. In the tunnel, the case of horizontally evolving, sheared CBL is reproduced. This distinguishes the employed experim...

The deposition of energy into the solar wind beyond 1 AU is thought to result from the dissipation of low frequency magnetohydrodynamic (MHD) turbulence via kinetic processes at spatial scales comparable to the ion gyroradius. Beyond 1 AU, solar wind turbulence is comprised of both a decaying component generated in the corona and turbulence generated dynamically in situ by processes such as str...

Data-intensive scientific applications require rapid access to local and geographically distributed data, however, there are significant I/O latency bottlenecks associated with storage systems and widearea networking. LambdaRAM is a high-performance, multi-dimensional, distributed cache, that takes advantage of memory frommultiple clusters interconnected by ultra-high-speed networking, to provi...

[1] Routine radiation and meteorological data at South Pole Station are used to investigate historical discrepancies of up to 50 W m 2 in the monthly mean surface energy budget and to investigate the behavior of turbulent heat fluxes under stable atmospheric temperature conditions. The seasonal cycles of monthly mean net radiation and turbulent heat fluxes are approximately equal, with a differ...

Destruction and fatalities from recent tornado outbreaks in North America have raised considerable concerns regarding their climatic and geographic variability. However, regional characterization of tornado activity in relation to large-scale climatic processes remains highly uncertain. Here, a novel Bayesian hierarchical framework is developed for elucidating the spatiotemporal variability of ...

This paper describes several flow visualization experiments carried out in Mach 3 and Mach 8 turbulent shear flows. The experimental technique was based on laser scattering from particles of H2O or CO2 condensate that form in the wind tunnel nozzle expansion process. The condensate particles vaporize extremely rapidly on entering the relatively hot fluid within a turbulent structure, so that a ...

By combining substrate-free structures with anodic bonding technology, we present a simple and efficient micro-electro-mechanical system (MEMS) thermal shear stress sensor. Significantly, the resulting depth of the vacuum cavity of the sensor is determined by the thickness of silicon substrate at which Si is removed by anisotropic wet etching process. Compared with the sensor based on a sacrifi...