Balloon-borne water vapour measurements during January and February 2004, which were obtained as part of the LAUTLOS campaign at Sodankylä, Finland, 67 N, were used to analyse the water vapour distribution in the wintertime Arctic lowermost stratosphere. A 2.5 km thick layer (or 30 K in the potential temperature scale) above the tropopause is characterized by a significant water vapour variabil...

In the design of land-based or offshore wind turbines for ultimate limit states, long-term loads associated with return periods on the order of the service life (20 years, usually) must be estimated. This requires statistical extrapolation from turbine load data that may be obtained by simulation or by field tests. The present study illustrates such extrapolation that uses field data from the B...

A technique is described for multiple-path propagation time measurements in the surface layer of the atmosphere. This is based on solving simple bi-directional ray tracing equations on successively higher penetrating paths using propagation times for a short acoustic pulse. The scattering process from turbulence is shown to be capable of providing signals from which phase comparisons can be mad...

A remarkable phenomenon in turbulent flows is the spontaneous emergence of coherent large spatial scale zonal jets. Geophysical examples of this phenomenon include the Jovian banded winds and the Earth’s polar front jet. In this work a comprehensive theory for the interaction of jets with turbulence, Stochastic Structural Stability Theory, is applied to the problem of understanding the formatio...

This paper reports on the findings of a field trial programme to investigate the effect of range-dependent meteorology on sound propagation in the atmosphere. Comparisons are made with predictions derived from a PE model utilising the rangedependent meteorology and terrain data derived from the field trail. An experiment is described in which range-dependent meteorological and acoustical data w...

Multi-decadal changes in patterns of physical phenomena and populations of marine biota occur in the Bering Sea and Eastern North Pacific Ocean. The most marked physical manifestation of these changes is a variation in modes of atmospheric pressure patterns known as a " regime shift ". The physical mechanisms that generate regime shifts are hypothesized to include such primary driving forces as...

We present a simple stochastic-dynamical approach to estimate the turbulent vertical diffusivity (D) in the lower stratosphere from routinely observed ozone profiles. First, an observed ozone profile is reconstructed using three-dimensional back-trajectories obtained from analyzed winds and initializing the trajectories with ozone values from the output of a chemistry-transport model. Assuming ...

We perform a global, three-dimensional GRMHD simulation of an accretion torus embedded in a large scale vertical magnetic field orbiting a Schwarzschild black hole. This simulation investigates how a large scale vertical field evolves within a turbulent accretion disk and whether global magnetic field configurations suitable for launching jets and winds can develop. We identify a “coronal mecha...

Information is now available regarding the vertical distribution of water vapour and helium in the lower stratosphere over southern England. The helium content of the air is found to be remarkably constant up to 2 0 km but the water content is found to fall very rapidly just above the tropopause, and in the lowest I km of the stratosphere the humidity mixing ratio falls through a ratio of 10-1....

An experimental study was conducted to quantify the characteristics of wake vortex and flow structures around a gable-Roof building model as well as the resultant pressure distribution and wind loads (both forces and moments) acting on the test model in tornadolike winds. In addition to measuring the pressure acting on the tested high-rise building model using pressure transducers and wind load...