A new radar imaging model of ocean current features is proposed. The simulated normalized radar cross section (NRCS) takes into account scattering from “regular” surfaces (by means of resonant Bragg scattering and specular reflections) and scattering from breaking waves. The description of background wind waves and their transformation in nonuniform medium is based on solution of the wave actio...

The response of a wind-sea spectrum to sudden changes in wind directions of 180 ° and 90 ° is investigated. Numerical simulations using the third-generation wave spectral model SWAN have been undertaken at micro timescales of 30 s and fine spatial resolution of less than 10 m. The results have been validated against the wave data collected during the field campaign at Lake George, Australia. Th...

Momentum and scalar transport in the marine atmospheric boundary layer (MABL) is driven by a turbulent mix of winds, buoyancy, and surface gravity waves. To investigate the interaction between these processes, a large-eddy simulation (LES)model is developed with the capability to impose a broadband spectrum of time-varying finite-amplitude surface waves at its lower boundary. The LES model adop...

The specification of tropical cyclone atmospheric forcing for ocean response models is described with emphasis on methods that are currently actively applied in basins rich in insitu, airborne and remotely sensed meteorological data. We emphasize approaches and critical issues addressed in more detail in this workshop’s special session on Tropical Meteorology. Five alternative wind fields devel...

Context. To progress in the understanding of the solar wind and coronal dynamics, numerical modeling must include the transition region within the simulation domain, and not just as a bottom boundary. Published simulations including a transition region within the domain often do not take into account any modeling of the heat sources and sinks which generate the corona; in the rare self-consiste...

The development is presented of two low weight, motion resistant stiff floating wind turbine concepts for deployment in water depths ranging from 30 to several hundred meters in seastates with wave heights up to 30 meters supporting 3-5 MW onshore wind turbines. The floating wind turbines may be fully assembled at a coastal facility in their upright position prior to being towed to the offshore...

Breaking without air entrainment of very short wind-forced waves, or microscale wave breaking, is undoubtedly widespread over the oceans and may prove to be a significant mechanism for enhancing the transfer of heat and gas across the air-sea interface. However, quantifying the effects of microscale wave breaking has been difficult because the phenomenon lacks the visible manifestation of white...

[1] The role of microscale wave breaking in controlling the air-water transfer of heat and gas is investigated in a laboratory wind-wave tank. The local heat transfer velocity, kH, is measured using an active infrared technique and the tank-averaged gas transfer velocity, kG, is measured using conservative mass balances. Simultaneous, colocated infrared and wave slope imagery show that wave-rel...

Abstruct-Laboratory measurements of microwave scattering at grazing incidence from superposed wind and weakly nonlinear (AK<0.024) regular long waves are presented. This study is an extension of previous measurements with wind waves only. A dual polarized (VV, HH) coherent pulsed Ku-band (14 GHz) scatterometer witb temporal resolution of 3 ns was used to obtain Doppler spectra and the absolute ...

The variability of the zonal-mean zonal wind in the Southern Hemisphere is studied using EOF analysis and momentum budget diagnostics of NCEP Reanalysis data (1978-1997). The leading EOF of the zonal-mean zonal wind is well separated from the remaining EOF’s and represents the north/south movement of the mid-latitude jet. Analysis of the momentum budget shows that a positive feedback between th...