Predictability Aspects of Global Aqua-planet Simulations with Explicit Convection(<Special Issue>The International Workshop on High-Resolution and Cloud Modeling, 2006)

スポンサーリンク

概要

• 論文の詳細を見る

• High-resolution global simulations over zonally symmetric aqua planets are examined using Fourier analysis in the zonal direction. We highlight the tropics, where the large-scale weather consists of convectively-coupled waves so that explicit convection is an especially topical novelty. Squared differences between pairs of runs grow from initially tiny values to saturation at twice the climatological variance. For wavelengths shorter than 10^3km, differences saturate within about a day. For tropical long waves, the time to saturation indicates predictability for at least 2 weeks. This time scale is similar in middle latitude flow, which interacts with tropical waves in the 3D model, but it is also similar in 2D pseudo-equatorial vertical plane simulations of pure convectively coupled gravity waves. As a result, no simple conclusions can be drawn about whether tropical predictability is limited more by tropical chaos or by tropical-extratropical interactions. Difference growth appears to fill out the saturation energy spectrum in a "vertical" (up-magnitude) rather than "horizontal" (up-scale) manner. Up-scale growth thus occurs as a continuing amplification of large scales after small scales saturate, which begs the question of what sets the shape of the saturation (climatological) power spectra. Wind spectra are nearly power-law with a logarithmic slope of about -5/3 in the free troposphere, remarkably so in the 2D runs and clearly distinct from slope -2 (a null hypothesis of spectrally white wind divergence). A common interpretation of -5/3 slope-as indicative of a cascade, a steady conservative transfer of energy from source to sink scales by interactions that are local in log-wavelength space-is hard to apply to these moist tropical waves.

• 社団法人日本気象学会の論文
• 2008-11-25

著者

• SATOH Masaki

  Center for Climate System Research, The University of Tokyo

• MAPES Brian

  Rosenstiel School of Marine and Atmospheric Sciences, University of Miami

• Mapes Brian

  Rosenstiel School Of Marine And Atmospheric Sciences University Of Miami

• NASUNO Tomoe

  Frontier Research Center for Global Change, Japan Agency for Marine-Earth Science and Technology

• TULICH Stefan

  Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado

• Tulich Stefan

  Cooperative Institute For Research In Environmental Sciences (cires) University Of Colorado

• Satoh Masaki

  Center For Climate System Research (ccsr) The University Of Tokyo

• Nasuno Tomoe

  Frontier Res. Center For Global Change Japan Agency For Marine-earth Sci. And Technol.

• Nasuno Tomoe

  Frontier Research Center For Global Change (frcgc) Jamstec

関連論文

• Characteristics of Cloud Size of Deep Convection Simulated by a Global Cloud Resolving Model over the Western Tropical Pacific(The International Workshop on High-Resolution and Cloud Modeling, 2006)
• Cloud Vertical Structure Observed from Space and Ship over the Bay of Bengal and the Eastern Tropical Pacific(The International Workshop on High-Resolution and Cloud Modeling, 2006)
• Multi-scale Organization of Convection in a Global Numerical Simulation of the December 2006 MJO Event Using Explicit Moist Processes
• Predictability Aspects of Global Aqua-planet Simulations with Explicit Convection(The International Workshop on High-Resolution and Cloud Modeling, 2006)
• Resolution Dependency of the Diurnal Cycle of Convective Clouds over the Tibetan Plateau in a Mesoscale Model(The International Workshop on High-Resolution and Cloud Modeling, 2006)
• Equatorial Mean Zonal Wind in a Global Nonhydrostatic Aquaplanet Experiment(The International Workshop on High-Resolution and Cloud Modeling, 2006)

スポンサーリンク