Contributions of Convectively Coupled Equatorial Rossby Waves and Kelvin Waves to the Real-Time Multivariate MJO Indices

Roundy, Paul E.; Schreck III, Carl J.; Janiga, Matthew A.
January 2009
Monthly Weather Review;Jan2009, Vol. 137 Issue 1, p469
Academic Journal
The real-time multivariate (RMM) Madden–Julian oscillation (MJO) indices have been widely applied to diagnose and track the progression of the MJO. Although it has been well demonstrated that the MJO contributes to the leading signals in these indices, the RMM indices vary erratically from day to day. These variations are associated with noise in the outgoing longwave radiation (OLR) and wind data used to generate the indices. This note demonstrates that some of this “noise” evolves systematically and is associated with other types of propagating modes that project onto the RMM eigenmodes. OLR and zonal wind data are filtered in the wavenumber–frequency domain for the MJO, convectively coupled equatorial Rossby (ER) waves, and convectively coupled Kelvin waves. The filtered data are then projected onto the RMM modes. An example phase space associated with these projections is presented. Linear regression is then applied to isolate the wave signals from random variations in the same bands of the wavenumber–frequency domain, and the regressed data are projected onto the RMM EOFs. Results demonstrate the magnitudes of the contributions of the systematically evolving signals associated with these waves to variations in the RMM principal components, and how these contributions vary with the longitude of the active moist deep convection coupled to the waves.


Related Articles

  • Association of Convection with the 5-Day Rossby-Haurwitz Wave. King, Malcolm J.; Wheeler, Matthew C.; Lane, Todd P. // Journal of the Atmospheric Sciences;Sep2015, Vol. 72 Issue 9, p3309 

    The seasonality, regionality, and nature of the association between tropical convection and the 5-day wavenumber-1 Rossby-Haurwitz wave are examined. Spectral coherences between daily outgoing longwave radiation (OLR), a proxy for convection, and 850-hPa zonal wind over the period January...

  • Laterally-Propagating Rossby Waves in the Easterly Acceleration Phase of the Quasi-Biennial Oscillation. Dunkerton, Timothy J. // Atmosphere -- Ocean (Canadian Meteorological & Oceanographic Soc;Mar1983, Vol. 21 Issue 1, p55 

    It is shown that oscillating mean flow solutions exist in the one-dimensional Holton-Lindzen (1972) model in thepresence of a single Kelvin wave, mean flow diffusion, and an easterly zonal force per unit mass that is constant in height and time except ut those points in the time-height...

  • Wave fluxes of equatorial Kelvin waves and QBO zonal wind forcing derived from SABER and ECMWF temperature space-time spectra. Ern, M.; Preusse, P. // Atmospheric Chemistry & Physics;2009, Vol. 9 Issue 12, p3957 

    The quasi-biennial oscillation (QBO) of the zonal mean zonal wind is a dynamical phenomenon of the tropical middle atmosphere. Influences of the QBO can even be found at mid and high latitudes. It is widely accepted that the phase descent of alternating tropical easterlies and westerlies is...

  • Horizontal and Vertical Structures of the Northward-Propagating Intraseasonal Oscillation in the South Asian Monsoon Region Simulated by an Intermediate Model. Hae-Kyung Lee Drbohlav; Bin Wang // Journal of Climate;Aug2007, Vol. 20 Issue 16, p4278 

    The structures and mechanism of the northward-propagating boreal summer intraseasonal oscillation (BSISO) in the southern Asian monsoon region are simulated and investigated in a three-dimensional intermediate model (3D model). The horizontal structure of the intraseasonal variability in the 3D...

  • The Shift of the Northern Node of the NAO and Cyclonic Rossby Wave Breaking. Wang, Yi-Hui; Magnusdottir, Gudrun // Journal of Climate;Nov2012, Vol. 25 Issue 22, p7973 

    Several studies have found an eastward shift in the northern node of the North Atlantic Oscillation (NAO) during the winters of 1978-97 compared to 1958-77. This study focuses on the connection between this shift of the northern node of the NAO and Rossby wave breaking (RWB) for the period...

  • The role of the QBO in the inter-hemispheric coupling of summer mesospheric temperatures.  // Atmospheric Chemistry & Physics Discussions;2010, Vol. 10 Issue 10, p23403 

    No abstract available.

  • Three-Dimensional Structure and Evolution of the MJO and Its Relation to the Mean Flow. Adames, Ángel F.; Wallace, John M. // Journal of the Atmospheric Sciences;Jun2014, Vol. 71 Issue 6, p2007 

    The two leading principal components of the daily 850- minus 150-hPa global velocity potential in the Interim European Centre for Medium-Range Weather Forecasts (ECMWF) Re-Analysis (ERA-Interim) (1979-2011) data are used as time-varying Madden-Julian oscillation (MJO) indices. Regression maps...

  • An Operational Tracking Method for the MJO Using Extended Empirical Orthogonal Functions. Dey, A.; Chattopadhyay, R.; Sahai, A. K.; Mandal, R.; Joseph, S.; Phani, R.; Abhilash, S. // Pure & Applied Geophysics;Jun2019, Vol. 176 Issue 6, p2697 

    Several methods are available to track the intraseasonal oscillation, namely the Madden–Julian oscillation (MJO) and monsoon intraseasonal oscillation (MISO). However, no methods to track both the modes in a uniform framework for real-time application exist. A new method to track the...

  • Ozone Variations Derived by a Chemical Transport Model. Eleftheratos, K.; Isaksen, I.; Zerefos, C.; Nastos, P.; Tourpali, K.; Rognerud, B. // Water, Air & Soil Pollution;Jun2013, Vol. 224 Issue 6, p1 

    The results of a comparison between monthly mean ozone column variations calculated from the chemical transport model Oslo CTM2 and those derived from solar backscatter ultraviolet (SBUV) satellite observations are presented for the period 1998-2009. Monthly mean total ozone derived from...


Read the Article


Sorry, but this item is not currently available from your library.

Try another library?
Sign out of this library

Other Topics