Meshes are commonly used as part of instruments for in situ atmospheric measurements. This study analyses the aerodynamic effect of meshes by means of wind tunnel experiments and numerical simulations. Based on the Direct Simulation Monte Carlo method, a simple mesh parameterisation is described and applied to a number of representative flow conditions. For open meshes freely exposed to the flo...

Among the most important aspects of the atmospheric pollution problem are the anthropogenic impacts on the stratospheric ozone layer, the related trends of the total ozone content drop and the solar ultraviolet radiation enhancement at the Earth's surface level. During September 2002, the ozone hole over the Antarctic was much smaller than in the previous six years. It has split into two separa...

In this paper, a model of a leader-follower spacecraft formation in six degrees of freedom is derived and presented. The nonlinear model describes the relative translational and rotational motion of the spacecraft, and extends previous work by providing a more complete factorization, together with detailed information about the matrices in the model. In addition, mathematical models of orbital ...

Observational studies have revealed a rich low-frequency structure in the atmosphere. A review of the theories, observations, and model studies of this low-frequency atmospheric variability is presented. On time scales of weeks or longer the atmosphere appears to possess distinct oscillatory behavior in welldefined and persistent "centers of action." This behavior is also an endemic feature of ...

Observational results of the ground deformations obtained by means of tiltmeters and extensometers at two stations in Wakayama City in Kinki District, Japan, are presented and discussed with particular emphasis on the relation to meteorological and oceanic phenomena. The ground at the Oura station inclines gradually to the north-westward and a similar tendency is also discernible at the Akibasa...

The appearance of rogue waves is well known in oceanographics, optics, and coldmatter systems. Here we show a possibility for the existence of atmospheric rogue waves. Solitary waves in plasmas, and similarly in the atmosphere, have been thoroughly investigated during more than four decades [1]. Observations [2, 3] of atmospheric disturbances propagating with no appreciable change in structure ...

Canadian forests are often perceived as pristine and among the last remaining wilderness, but the majority of them are officially managed and undergo direct land use, mostly for wood harvest. This land use has modified their functions and properties, often inadvertently (e.g., age structure) but sometimes purposefully (e.g., fire suppression). Based on a review of the literature pertaining to c...

This paper presents several digital signal processor (DSP) based intelligent controllers for aircraft automatic landing systems (ALSs). Proportional-Integral-Derivative (PID) control law is adopted in the intelligent controller design. A fuzzy cerebellar model articulation controller (CMAC) is utilized to compensate for the PID control signal. Control gains are selected by evolutionary computat...

[1] Previous studies suggest that a large part of the variability in the atmospheric ratio of 13CO2/12CO2 originates from carbon exchange with the terrestrial biosphere rather than with the oceans. Since this variability is used to quantitatively partition the total carbon sink, we here investigate the contribution of interannual variability (IAV) in biospheric exchange to the observed atmosphe...