Climate Dynamics

, Volume 33, Issue 4, pp 495–507

Effects of the low-frequency zonal wind variation on the high frequency atmospheric variability over the tropics

  • K. P. Sooraj
  • Daehyun Kim
  • Jong-Seong Kug
  • Sang-Wook Yeh
  • Fei-Fei Jin
  • In-Sik Kang
Article

DOI: 10.1007/s00382-008-0483-6

Cite this article as:
Sooraj, K.P., Kim, D., Kug, JS. et al. Clim Dyn (2009) 33: 495. doi:10.1007/s00382-008-0483-6

Abstract

Recently, there is increasing evidence on the interaction of atmospheric high-frequency (HF) variability with climatic low-frequency (LF) variability. In this study, we examine this relationship of HF variability with large scale circulation using idealized experiments with an aqua-planet Atmospheric GCM (with zonally uniform SST), run in different zonal momentum forcing scenarios. The effect of large scale circulation changes to the HF variability is demonstrated here. The HF atmospheric variability is enhanced over the westerly forced region, through easterly vertical shear. Our study also manifests that apart from the vertical wind shear, strong low-level convergence and horizontal zonal wind shear are also important for enhancing the HF variance. This is clearly seen in the eastern part of the forcing, where the HF activity shows relatively maximum increase, in spite of similar vertical shear over the forced regions. The possible implications for multi-scale interaction (e.g. MJO–ENSO interaction) are also discussed.

Keywords

ENSO/MJO interactionScale interactionHigh-freqeuncy variabilityAqua-planet experimentsState-dependent noise

Copyright information

© Springer-Verlag 2008

Authors and Affiliations

  • K. P. Sooraj
    • 1
  • Daehyun Kim
    • 1
  • Jong-Seong Kug
    • 2
  • Sang-Wook Yeh
    • 3
  • Fei-Fei Jin
    • 2
  • In-Sik Kang
    • 1
  1. 1.Climate Environment System Research CenterSeoul National UniversitySeoulSouth Korea
  2. 2.School of Ocean and Earth Sciences and TechnologyUniversity of HawaiiHonoluluUSA
  3. 3.Korea Ocean Research and Development InstituteAnsanSouth Korea