Every year, cut-off low (COL) pressure systems produce severe weather conditions and heavy rainfall, often leading to flooding, devastation disruption of socio-economic activities in South Africa. COLs are defined as cold-cored synoptic-scale mid-tropospheric low-pressure which occur the mid-latitudes cause persistent rainfall. As they throughout these important rainfall producing that also ass...

the weaknesses of the traditional climatic classification methods in presenting the climatic realities of caspian region and showing the new methods' merits based on multivariate statistical methods, and geographical information system in presenting the climatic regions of caspian, are among the most important ideas of conducting this study. to do so, we used the data of synoptic stations ...

A case study illustrating cloud processes and other features associated with the Ross Ice Shelf airstream (RAS), in Antarctica, is presented. The RAS is a semipermanent low-level wind regime primarily over the western Ross Ice Shelf, linked to the midlatitude circulation and formed from terrain-induced and large-scale forcing effects. An integrated approach utilizes Moderate Resolution Imaging ...

A new approach to portable photo-voltaic systems which described in this paper is of very low power (5W) and main purpose is for recharging or powering small portable electronics devices. The objects of this study are: i) the optimization of photo-voltaic cells connection with regard to portable conditions; a nonstandard topology is adopted, to compensate shadowing or nonoptimal orientation; ii...

This study examines ozone (O3) predictions from the Community Multiscale Air Quality (CMAQ) model version 4.5 and discusses potential factors influencing the model results. Daily maximum 8-h average O3 levels are largely underpredicted when observed O3 levels are above 85 ppb and overpredicted when they are below 35 ppb. Using a clustering approach, model performance was examined separately for...

This article investigates the synoptic characteristics of individual North Atlantic Oscillation (NAO) events by examining the daily evolution of the potential temperature field on the nominal tropopause (the 2-PVU surface). This quantity is obtained from the National Centers for Environmental Prediction–National Center for Atmospheric Research (NCEP–NCAR) reanalysis dataset for the winter seaso...