Observations of the New England coastal front show that the extraordinary temperature gradients are caused by ageostrophic wind deformation, that is, deformation in the vertical plane. The phenomenon is therefore an instance of rapid (non-classical) frontogenesis, a process broadly characterized by a lack of geostrophic balance between the temperature gradient and vertical wind shear. The prima...

The objective is to investigate the physical processes that occur as a tropical cyclone interacts with the environment such that intensity and structure changes occur. Specific interactions being studied are with baroclinic environments in the midlatitudes during extratropical transition. During extratropical transition, radical changes to the storm structure occur as vertical wind shear and in...

An ingredients-based approach (e.g., Johns and Doswell 1992) is used in the operational prediction of tornado threat, regardless of whether the favorable environment results from midlatitude or tropical perturbations. Since the majority of tropical cyclone (TC) tornadoes are associated with supercells (Edwards et al. 2012a; hereafter E12), the forecaster typically can focus on the same ingredie...

Topic 4.1 reviews the current status of the understanding on variability of tropical cyclone (TC) activity/intensity on intraseasonal to interannual time scales around the globe. Annually, approximately 80−90 TCs occur over the tropical oceans (Neumann 1993). The TC activities depend on thermodynamic parameters (e.g., sea surface temperature (SST), atmospheric stability, and mid-tropospheric mo...

A supercell storm with tornadogenesis in the afternoon hours of the 30th August 2003 in NW Croatia is studied. As was seen from radar and satellite material the cell developed in Slovenia and crossed into Croatia, where interacting with favorable wind patterns (indicated by high SREH and vertical wind shear) it evolved into a supercell. Macroscale forcing was found to be lacking. On the other h...

Sensitivity tests based on a spectral nudging (SN) technique are conducted to analyze the effect of large-scale environmental factors on the movement of typhoon Megi (2010). The error of simulated typhoon track is effectively reduced using SN and the impact of dynamical factors is more significant than that of thermal factors. During the initial integration and deflection period of Megi (2010),...

The accurate real-time detection of turbulent airflow patterns near airports is important for safety and comfort in commercial aviation. In this paper, a method is developed to identify Lagrangian coherent structures (LCS) from horizontal lidar scans at Hong Kong International Airport (HKIA) in China. LCS are distinguished frame-independent material structures that create localized attraction, ...

Passive microwave radiometers have a strong heritage of instruments: the Special Sensor Microwave Imager (SSM/I), the Tropical Rainfall Mapping Mission (TRMM) Microwave Imager (TMI), the Advanced Microwave Scanning Radiometer–Earth Observing (AMSR-E) and the Special Sensor Microwave Imager/Sounder (SSMI/S). These instruments measure vertically and horizontally polarized brightness temperatures ...

Vertical axis wind turbine (VAWT) blades undergo dynamic separation due to the large angle of attack variation they experience during a turbine rotation. The flow over a single blade was modeled using a sinusoidally pitching and surging airfoil in a constant free stream flow at a mean chord Reynolds number of 10. Two-dimensional, time resolved velocity fields were acquired using particle image ...

Most current general circulation models (GCMs) calculate radiative fluxes through partially cloudy grid boxes by weighting clear and cloudy fluxes by the fractional area of cloud cover (Ca), but most GCM cloud schemes calculate cloud fraction as the volume of the grid box that is filled with cloud (C ). In this paper, 1 yr of cloud radar and lidar observations from Chilbolton in southern Englan...