The lower limit on the drag coefficient under hurricane force winds is determined by the break-up of the air–sea interface due to Kelvin–Helmholtz instability and formation of the two-phase transition layer consisting of sea spray and air bubbles. As a consequence, a regime of marginal stability develops. In this regime, the air–sea drag coefficient is determined by the turbulence characteristi...

The generation and destruction of stratification in the surface mixed layer of the ocean is understood to result from vertical turbulent transport of buoyancy and momentum driven by air–sea fluxes and stresses. In this paper, it is shown that the magnitude and penetration of vertical fluxes are strongly modified by horizontal gradients in buoyancy and momentum. A classic example is the strong r...

An automated method producing a diagnostic of the severity of lee waves and their impacts on surface winds as represented in output from a high resolution linear numerical model (3D velocities over mountains (3DVOM)) covering several areas of the U.K. is discussed. Lee waves involving turbulent rotor activity or downslope windstorms represent a hazard to aviation and ground transport, and summa...

Results from the 1995 season of site-testing experiments at the South Pole are presented, in which the seeing was measured using balloon-borne microthermal probes. Our analysis shows a marked division of the atmosphere into two characteristic regions: (i) a highly turbulent boundary layer (0–220 m) associated with a strong temperature inversion and wind shear, and (ii) a very stable free atmosp...

Living marine organisms have spent most of their evolutionary time history as single cells, at scales dominated by viscous force. As life evolved toward a larger and more mobile multicelled organism, inertial forces also became important. Hence, microscale organisms in the ocean have experienced small-scale fluid motions throughout their entire existence on Earth. In this chapter we consider ho...

A strong relationship is observed between synoptic weather systems and atmospheric forcing of the ocean as estimated from buoy measurements made on the North Carolina inner shelf during August and October-November 1994 as part of the Coastal Ocean Processes (COOP) Inner Shelf Study. Synoptic variation (timescales of days to weeks) in the meteorological time series was primarily associated with ...

[1] The sea breeze is often a dominant meteorological feature at the coastline, but little is known about its estuarine impacts. Measurements at an anchored catamaran and meteorological stations along the Hudson River and New York Bay estuarine system are used to illustrate some basic characteristics and impacts of the feature. The sea breeze propagates inland, arriving in phase with peak solar...

Introduction: The unique data generated by the ESA Huygens probe [1] are the only in-situ measurements at Titan and thus will be key factors in interpretation of Cassini orbiter data and in design of future missions which might include balloons and landers. Here I summarize some recent results from the simple 'engineering' sensors on the probe: these include the constitution of the Titan surfac...

Collapse of the rotating magnetized molecular cloud core is studied with the axisymmetric magnetohydrodynamical (MHD) simulations. Due to the change of the equation of state of the interstellar gas, the molecular cloud cores experience several different phases as collapse proceeds. In the isothermal run-away collapse (n ∼< 10 H2 cm ), a pseudo-disk is formed and it continues to contract till th...

in this research, the effect of micro turbulence on the flotation rate of quartz particles was investigated. the maximum particle reynolds number (rep) was obtained at 60.25 with a particle size of -500+420 µm, impeller speed of 900 rpm, bubble surface area flux of 10.21 1/s and micro scale turbulence size of 162 µm. when the micro turbulence size was equal to the particle size, the maximum flo...