To assess left ventricular structure and function at rest and during exercise in endurance athletes, 10 elite marathon runners, aged 28 to 37 years, and 10 matched nonathletes were studied by echocardiography and supine bicycle ergometry. Each athlete's best marathon time was less than 2 h 16 min. Echocardiography was performed at rest, at a 60 W work load and at an individually adjusted work l...

The three-dimensional structure of the meridional overturning circulation (MOC) in the deep Indian Ocean is investigated with an eddy-permitting ocean model. The amplitude of the modeled deep Indian Ocean MOC is 5.6 Sv (1 Sv 10 m s ), a broadly realistic but somewhat weak overturning. Although the model parameterization of diapycnal mixing is inaccurate, the model’s short spinup allows the effe...

[1] Abstract: The density structure along the ocean margins carries an integrated imprint of ocean circulation. The difference in pressure between the eastern and western margins of the ocean reflects the net meridional geostrophic transport across the ocean basin. If one assumes that the wind driven circulation is closed in the upper ocean, the wind driven component of the net geostrophic tran...

Chaotic transport and mixing in wavy cylindrical Couette flow has been studied in some detail, but previous studies have been limited to the velocity field at transition from Taylor–Couette flow to wavy flow or have used phenomenological, computational, or theoretical models of the flow. Recent particle image velocimetry measurements of wavy vortex flow provide the experimental three-dimensiona...

Changes in the Atlantic Meridional Overturning Circulation (AMOC) are moderate in most climate model projections under increasing greenhouse gas forcing. This intermodel consensus may be an artifact of common model biases that favor a stable AMOC. Observationally based freshwater budget analyses suggest that the AMOC is in an unstable regime susceptible for large changes in response to perturba...

The fundamental equations are linearized by the method of small perturbations for the conditions of hydrostatic equilibrium and geostrophic balance of meridional forces. I n a first case, Fickian momentum diffusion is used; in a second case, a shearand latitude-dependent eddy viscosity is used. A wave solution for the zonal wind oscillation, having in meridional profile the shape of a probabili...

Sulfur hexafluoride 6 is an excellent tracer of large-scale atmospheric transport, because it has slowly increasing sources mostly confined to northern midlatitudes, and has a lifetime of thousands of years. We have simulated the emissions, transport, and concentration of 6 for a 5-year period, and compared the results with atmospheric observations. In addition, we have performed an intercompar...

We present a mean field model based on the approach taken by Rempel (2005) in order to investigate the influence of stochastic fluctuations in the Reynolds stresses on meridional flow and differential rotation. The stochastic fluctuations found in the meridional flow pattern directly resemble the stochastic fluctuations of the Reynolds stresses, while the stochastic fluctuations in the differen...

The Geophysical Fluid Dynamics Laboratory (GFDL) three-dimensional general circulation/tracer model has been used to investigate the stratospheric behavior of N20 under a range of photodestruction hypotheses. A comparison of observations with these simulations shows that the atmospheric N20 lifetime lies between 100 and 130 years. For the three experiments conducted, it was found that the model...