Kuni Inoue
Lamont-Doherty Earth Observatory
"New Diagnostic Applications of Fourier Analyses to the Assessments of Tropical Waves: Assessments of Vertical Velocity Profiles and Moist Static Energy Budgets"
Abstract: In this talk, I will demonstrate some new diagnostic applications of Fourier analyses to the assessments of atmospheric waves in the tropics. It has been widely recognized that a significant portion of tropical convective precipitation is organized in an aggregated convective system over a wide range of spatial and temporal scales. In daily-to-intraseasonal time-scales, precipitation is often organized by waves that propagate eastward or westward along the equator. There exist different kinds of tropical waves (including the Madden-Julian Oscillations, Kelvin waves, equatorial Rossby waves, etc.), each of which is regulated by different mechanisms, and it has been still a challenge to simulate those different kinds of waves in general circulation models (GCMs) with conventional convective parameterizations. Because those waves are a primary source of tropical precipitation, the lack of the ability to simulate them may cause some undesirable biases in the GCMs. There have been many theoretical studies which attempt to explain the mechanisms of the tropical waves. In most of them, vertical velocity profiles and/or moist static energy (MSE) budgets, which are mutually interwound, play crucial roles. In this talk, I will propose a novel diagnostic framework for assessing the vertical velocity profiles and MSE budgets in the Fourier space. Since most of the past theoretical studies are based on linear wave theories, our diagnoses may be directly compared to those studies, in hoping that they reveal the causes of the deficiency of the skill for conventional GCMs to simulate tropical wave phenomena. Our diagnostic methodology may have a wide range of applicability. I will generalize our methodology so that it may be applied to other phenomena than tropical waves.
Bio: Dr. Inoue is a postdoctoral researcher at the Lamont-Doherty Earth, and also a NASA Postdoctoral Fellow at GISS. Before joining the LDEO and the GISS, he was a postdoctoral research associate at the Geophysical Fluid Dynamical Laboratory (GFDL) in Princeton. He finished his PhD at the University of Wisconsin-Madison in the department of the Atmospheric and Oceanic Sciences. His main research interest is the interaction between large-scale circulations and moist convection in the tropics. He analyzed the thermodynamics in tropical convective phenomena among a wide range of time-scales, from sub-daily to intraseasonal scales. He uses satellite observations, re-analysis data, field campaign data, and outputs of GCMs as tools for his research.
