Journal of the Atmospheric Sciences: Recent submissions

Now showing items 3281-3300 of 13215

    • Theoretical Formulation of Collision Rate and Collision Efficiency of Hydrodynamically Interacting Cloud Droplets in Turbulent Atmosphere 

      Wang, Lian-Ping; Ayala, Orlando; Kasprzak, Scott E.; Grabowski, Wojciech W. (American Meteorological Society, 2005)
      A methodology for conducting direct numerical simulations (DNSs) of hydrodynamically interacting droplets in the context of cloud microphysics has been developed and used to validate a new kinematic formulation capable of ...

    • Bimodality of the Planetary-Scale Atmospheric Wave Amplitude Index 

      Christiansen, Bo (American Meteorological Society, 2005)
      The evidence for multiple flow regimes in the planetary-scale atmospheric wave amplitude index (WAI) is studied using the 56 winters from the NCEP reanalysis data. The regimes are identified by bimodality in the probability ...

    • Diagnosed Three-Dimensional Axisymmetric Structure of the Mulhall Tornado on 3 May 1999 

      Lee, Wen-Chau; Wurman, Joshua (American Meteorological Society, 2005)
      On 3 May 1999, an unusually large tornado that caused F4-level damage and killed several people was intercepted by the Doppler on Wheels (DOW) mobile radar near Mulhall, Oklahoma, from a range of 4 to 9 km, resulting in ...

    • Small-Scale Drop Size Variability: Impact on Estimation of Cloud Optical Properties 

      Knyazikhin, Y.; Myneni, R. B.; Marshak, A.; Wiscombe, W. J.; Larsen, M. L.; Martonchik, J. V. (American Meteorological Society, 2005)
      Most cloud radiation models and conventional data processing techniques assume that the mean number of drops of a given radius is proportional to volume. The analysis of microphysical data on liquid water drop sizes shows ...

    • The Origin of High Ice Crystal Number Densities in Cirrus Clouds 

      Hoyle, C. R.; Luo, B. P.; Peter, T. (American Meteorological Society, 2005)
      Recent measurements with four independent particle instruments in cirrus clouds, which formed without convective or orographic influence, report high number densities of ice particles (as high as nice = 50 cm?3) embedded ...

    • Collision Rates of Cloud Droplets in Turbulent Flow 

      Franklin, Charmaine N.; Vaillancourt, Paul A.; Yau, M. K.; Bartello, Peter (American Meteorological Society, 2005)
      Direct numerical simulations of an evolving turbulent flow field have been performed to explore how turbulence affects the motion and collisions of cloud droplets. Large numbers of droplets are tracked through the flow ...

    • Convective Structures in a Cold Air Outbreak over Lake Michigan during Lake-ICE 

      Zurn-Birkhimer, Suzanne M.; Agee, Ernest M.; Sorbjan, Zbigniew (American Meteorological Society, 2005)
      The Lake-Induced Convection Experiment provided special field data during a westerly flow cold air outbreak (CAO) on 13 January 1998, which has afforded the opportunity to examine in detail an evolving convective boundary ...

    • Shear Instability in a Shallow Water Model with Implications for the Venus Atmosphere 

      Iga, Shin-ichi; Matsuda, Yoshihisa (American Meteorological Society, 2005)
      The shear instability problem in the spherical shallow water system is investigated for three types of wind profiles that are observed at the upper cloud level in Venus. Destabilized Kelvin modes are obtained for all ...

    • The Effects of Stratification on Flow Separation 

      Ambaum, Maarten H. P.; Marshall, David P. (American Meteorological Society, 2005)
      Separation of stratified flow over a two-dimensional hill is inhibited or facilitated by acceleration or deceleration of the flow just outside the attached boundary layer. In this note, an expression is derived for this ...

    • Tropical Zonal Momentum Balance in the NCEP Reanalyses 

      Dima, Ioana M.; Wallace, John M.; Kraucunas, Ian (American Meteorological Society, 2005)
      The seasonal cycle of the zonal-mean zonal momentum balance in the Tropics is investigated using NCEP reanalysis data. It is found that the climatological stationary waves in the tropical upper troposphere, which are ...

    • The GCM Response to Current Parameterizations of Nonorographic Gravity Wave Drag 

      McLandress, Charles; Scinocca, John F. (American Meteorological Society, 2005)
      A comparison is undertaken of the response of a general circulation model (GCM) to the nonorographic gravity wave drag parameterizations of Hines, Warner and McIntyre, and Alexander and Dunkerton. The analysis is restricted ...

    • The Vorticity–Velocity Gradient Cofactor Tensor and the Material Invariant of the Semigeostrophic Theory 

      Viúdez, Álvaro (American Meteorological Society, 2005)
      A new derivation and interpretation of the semigeostrophic (SG) material invariant in the theory of geophysical flows is introduced. First, a generalized three-dimensional equation of the SG dynamics is established and the ...

    • Why Rolls are Prevalent in the Hurricane Boundary Layer 

      Foster, Ralph C. (American Meteorological Society, 2005)
      Recent remote sensing observations show that the hurricane boundary layer flow, although energetic, is not a region of homogeneous turbulence. In fact, the observations convincingly demonstrate that a large fraction of the ...

    • Radiative Impacts on the Growth of Drops within Simulated Marine Stratocumulus. Part I: Maximum Solar Heating 

      Hartman, Christopher M.; Harrington, Jerry Y. (American Meteorological Society, 2005)
      The effects of solar heating and infrared cooling on the vapor depositional growth of cloud drops, and hence the potential for collection enhancement, is investigated. Large eddy simulation (LES) of marine stratocumulus ...

    • A Polarized Delta-Four-Stream Approximation for Infrared and Microwave Radiative Transfer: Part I 

      Liou, K. N.; Ou, S. C.; Takano, Y.; Liu, Q. (American Meteorological Society, 2005)
      The delta-four-stream polarized (vector) thermal radiative transfer has been formulated and numerically tested specifically for application to satellite data assimilation in cloudy atmospheres. It is shown that for thermal ...

    • Coupling Diffuse Sky Radiation and Surface Albedo 

      Pinty, Bernard; Lattanzio, Alessio; Martonchik, John V.; Verstraete, Michel M.; Gobron, Nadine; Taberner, Malcolm; Widlowski, Jean-Luc; Dickinson, Robert E.; Govaerts, Yves (American Meteorological Society, 2005)
      New satellite instruments have been delivering a wealth of information regarding land surface albedo. This basic quantity describes what fraction of solar radiation is reflected from the earth?s surface. However, its concept ...

    • Radiative Impacts on the Growth of Drops within Simulated Marine Stratocumulus. Part II: Solar Zenith Angle Variations 

      Hartman, Christopher M.; Harrington, Jerry Y. (American Meteorological Society, 2005)
      The effects of solar heating at a variety of solar zenith angles (Θo) on the vapor depositional growth of cloud drops, and hence the potential for collection enhancement, is investigated. A large eddy simulation (LES) model ...

    • A Stochastic Model for the Angular Momentum Budget of Latitude Belts 

      Egger, Joseph (American Meteorological Society, 2005)
      The stochastic model of Weickmann et al. for the global angular momentum budget is modified to become applicable to latitude belts. In particular, a Langevin equation is added for the flux divergence of angular momentum ...

    • Baroclinic Multiple Zonal Jets on the Sphere 

      Lee, Sukyoung (American Meteorological Society, 2005)
      Multiple zonal jets are investigated with a two-level primitive equation model on the sphere in which both baroclinicity and planetary radius are varied. As in the case for a two-layer quasigeostrophic model on a ?-plane ...

    • Prediction Rules for Regime Changes and Length in a New Regime for the Lorenz Model 

      Yadav, Rama Shankar; Dwivedi, Suneet; Mittal, Ashok Kumar (American Meteorological Society, 2005)
      Despite the widespread use of the Lorenz model as a conceptual model for predictability studies in meteorology, only Evans et al. seem to have studied the prediction of occurrence of regime changes and their duration. In ...