The Ekman-Taylor problem for the planetary boundary layer is solved in the case of a thermal wind which varies linearly with height. The upper boundary condition is a vanishing ageostrophic wind, while the lower boundary condition is continuity of the stress vector across the interface between the planetary boundary layer and the surface layer. The latter condition is used to determine the magn...

Interannual-to-decadal variations in the subtropical countercurrent (STCC) and low-potential vorticity (PV) water and their relations in the North Pacific Ocean are investigated based on a 60-year-long hindcast integration of an eddy-resolving ocean general circulation model. The interdecadal intensification of STCC is associated with negative PV anomalies to the north on isopycnals beneath, by...

The ability of climate models to predict extremes is determined by its ability to adequately simulate certain environmental conditions both spatially and temporally. Some of the conditions conducive to the occurrence of extreme weather can be quantified from the convective available potential energy (hereafter referred to as CAPE) and vertical shear of the horizontal wind from 0-6 kilometer (he...

This study focuses on modulation of lightning and convective vertical structure in the southern Amazon as a function of the South American monsoon V index (VI). Four wet seasons (December–March 1998– 2001) of Tropical Rainfall Measuring Mission (TRMM) Lightning Imaging Sensor (LIS) and Precipitation Radar (PR) data are examined together with two wet seasons (2000–01) of ground-based Brazilian L...

This article is a review of the basic dynamics of severe convective storms. The dynamics are in most instances described with the aid of the vorticity and divergence equations subject to the Boussinesq approximation. The behaviour of ordinary-cell convective storms in the presence of different amounts of vertical shear and its relation to the surface cold pool are explained. The role of vertica...

As the average hub height and blade diameter of new wind turbine installations continue to increase, turbines typically encounter higher wind speeds, which enable them to extract large amounts of energy, but they also face challenges due to the complex nature of wind flow and turbulence in the planetary boundary layer (PBL). Wind speed and turbulence can vary greatly across a turbine’s rotor di...

A sample of 413 soundings in close proximity to tornadic and nontornadic supercells is examined. The soundings were obtained from hourly analyses generated by the 40-km Rapid Update Cycle-2 (RUC-2) analysis and forecast system. A comparison of 149 observed soundings and collocated RUC-2 soundings in regional supercell environments reveals that the RUC-2 model analyses were reasonably accurate t...

Atmospheric wind shears control the irregularity structure in the E-region. Near 100 km altitude, where the ion collision frequency is much larger than the ion cyclotron frequency, the degree of shear turning and the direction of maximum shear gradient determine the location of the E-layer peak. The effects of speed shears on the three-dimensional structure of the E-layer are modeled using a sy...