While process technologists are obsessed to follow Moore’s curve down to nanoscale dimensions, design technologists are confronted with gigascale complexity. On the other hand, post-PC and post dotcom products require zero cost, zero energy yet software programmable novel system architectures to be sold in huge volumes and to be designed in exponentially decreasing time. How do we cope with the...

Evaluation of ECMWF ERA-40 temperature and wind in the lower tropical stratosphere since 1988 from past long-duration balloon measurements T. Christensen, B. M. Knudsen, J.-P. Pommereau, G. Letrenne, A. Hertzog, F. Vial, J. Ovarlez, and M. Piot Danish Meteorological Institute, Copenhagen, Denmark Service d’Aéronomie, IPSL/CNRS, Verrières-Le-Buisson, France Centre National d’Études Spatiales, To...

The 40-yr ECMWF Re-Analysis (ERA-40) data are analyzed to demonstrate that wave forcing at lower latitudes plays a crucial role in driving the tropical upwelling portion of the Brewer–Dobson circulation. It is shown that subtropical wave forcing is correlated with tropical upwelling on both intraseasonal and interannual time scales when transient waves are taken into account, and that tropical ...

[1] The energy input to the upper ocean Ekman layer is assessed for the Southern Ocean by examining the rotary cross spectrum between wind stress and surface velocity for frequencies between 0 and 2 cpd. The wind stress is taken from European Center for Medium-Range Weather Forecasts ERA-40 reanalysis, and drifter measurements from 15 m depth are used to represent surface velocities, with an ad...

We are now in the post-PC era, yet our mobile devices are insecure. We consider the different stake-holders in today’s mobile device ecosystem, and analyze why widely-deployed hardware security primitives on mobile device platforms are inaccessible to application developers and end-users. We systematize existing proposals for leveraging such primitives, and show that they can indeed strengthen ...

To my family in China and my wife Yun ACKNOWLEDGEMENTS I wish to thank Prof. Robert Dickinson for advising my thesis and providing support for my PhD study for the past five years. This dissertation would be impossible without his continuous encouragement and support. I am grateful to the support and help from and discussions with Prof. Albany). I also like to thank my current and past group me...

A new nonparametric method to correct model data is proposed. At any given point in space and time the correction is determined from “analogs” in a learning dataset. The learning dataset contains model data and simultaneous observations. The method is applied to the significant wave height dataset of the 45-yr European Centre for Medium-Range Weather Forecasts Re-Analysis (ERA-40). Comparison o...

Evaluation of the vertical diffusion coefficients from ERA-40 with Rn simulations D. J. L. Olivié , P. F. J. van Velthoven, and A. C. M. Beljaars Royal Netherlands Meteorological Institute, De Bilt, The Netherlands Eindhoven University of Technology, Eindhoven, The Netherlands European Centre for Medium-range Weather Forecasts, Reading, UK Received: 15 June 2004 – Accepted: 15 July 2004 – Publi...

During recent years, great interest has grown within the operational weather community on the adaptable component of observational networks. Decisions regarding where to deploy new observations of special value under threatening weather, or regarding permanent changes in observational strategies need support from sensitivity studies that determine areas where the addition of observations would ...

It has often been suggested that the period of the Quasi-Biennial Oscillation (QBO) has a tendency to synchronize with the Semi-Annual Oscillation (SAO). Using 45 years of ERA-40 data of the equatorial stratosphere up to the stratopause, we demonstrate that this synchronization is not just a tendency but indeed holds quite well in the upper stratosphere. A QBO period starts when a SAO westerly ...