The Tropical Madden–Julian Oscillation and the Global Wind Oscillation

Weickmann, Klaus; Berry, Edward
May 2009
Monthly Weather Review;May2009, Vol. 137 Issue 5, p1601
Academic Journal
The global wind oscillation (GWO) is a subseasonal phenomenon encompassing the tropical Madden–Julian oscillation (MJO) and midlatitude processes like meridional momentum transports and mountain torques. A phase space is defined for the GWO following the approach of Wheeler and Hendon for the MJO. In contrast to the oscillatory behavior of the MJO, two red noise processes define the GWO. The red noise spectra have variance at periods that bracket 30–60 or 30–80 days, which are bands used to define the MJO. The correlation between the MJO and GWO is ∼0.5 and cross spectra show well-defined, coherent phase relations in similar frequency bands. However, considerable independent variance exists in the GWO. A basic dynamical distinction occurs in the direction of midlatitude wave energy dispersion, being predominantly meridional during a MJO and zonal during the GWO. This is primarily a winter season feature centered over the Pacific Ocean. A case study during April–May 2007 focuses on the GWO and two ∼30-day duration orbits with extreme anomalies in GWO phase space. The MJO phase space projections for the same time were irregular and, it is argued, partially driven by mountain torques and meridional transports. The case study reveals that multiple physical processes and time scales act to create slowly evolving planetary-scale circulation and tropical convection anomalies.


Related Articles

  • Past and recent trends in the western Black Sea storminess. Valchev, N. N.; Trifonova, E. V.; Andreeva, N. K. // Natural Hazards & Earth System Sciences;2012, Vol. 12 Issue 4, p961 

    Storms are one of the most important phenomena producing coastal hazards and endangering human life and activities. In recent decades storm climate has become a subject of increased public awareness and knowledge of this issue can help the society to meet future challenges related to extreme...

  • A new Direct Torque Control (Dtc) Scheme to Position Control of Asymmetrical Two Phase Induction Motor. Rabiee, Abdorreza; Pahlavani, Mohammad Reza Alizadeh // Australian Journal of Basic & Applied Sciences;2011, Vol. 5 Issue 12, p1249 

    This paper presents a precise position control scheme for two phase induction motor based on direct torque control (DTC) strategy. In the proposed method the reference angle is accurately tracked with slight overshoot at the target positions. Even in the case of a sudden load torque variations,...

  • Observation of wave energy accumulation in the turbulent spectrum of capillary waves on the He-II surface under harmonic pumping. Abdurakhimov, L. V.; Brazhnikov, M. Yu.; Remizov, I. A.; Levchenko, A. A. // JETP Letters;May2010, Vol. 91 Issue 6, p271 

    Recent results of the experimental study of capillary turbulence on superfluid helium-4 surface are presented. For the first time wave energy accumulation was observed in the wave turbulent spectrum at high frequencies when the surface was excited by harmonic pumping. We suggest a qualitative...

  • Internal gravity waves over an oscillating sunspot. Kshevetskii, S. P.; Solov'ev, A. A. // Astronomy Reports;Sep2008, Vol. 52 Issue 9, p772 

    Internal gravity waves excited in the overlying atmosphere by the proper vertical oscillations of an entire sunspot are studied. For simplicity, the oscillations of the sunspot are introduced into the model through the lower boundary conditions, by specifying oscillations in the vertical...

  • Energetics of easterly wave disturbances over West Africa and the tropical Atlantic: a climatology from the 1979—95 NCEP/NCAR reanalyses. Diedhiou, A.; Janicot, S.; Viltard, A.; de Félice, P. // Climate Dynamics;Feb2002, Vol. 18 Issue 6, p487 

    Our purpose is to compute the main terms of the energy budget, following Reed et al. to characterize the maintenance of the easterly wave regimes. Although previous studies have been done on some well-observed cases, here, we use NCEP/NCAR reanalyses over the period 1979-1995 to produce a...

  • Normalizing Air—Sea Flux Coefficients for Horizontal Homogeneity, Stationarity, and Neutral Stratification. Geernaert, G. L. // Journal of Physical Oceanography;Sep2010, Vol. 40 Issue 9, p2148 

    Monin–Obukhov similarity (MOS) theory is routinely applied over the ocean to describe surface layer profiles of wind speed, temperature, and gas concentrations. Using this theory, fluxes are in turn estimated based on the best available parameterizations of normalized flux coefficients:...

  • Relation between low latitude Pc3 magnetic micropulsations and solar wind. Ansari, I. A. // Bulletin of the Astronomical Society of India;Dec2007, Vol. 35 Issue 4, p523 

    Pc3 geomagnetic pulsations are quasi-sinusoidal variations in the earths magnetic field in the period range 10-45 seconds. These Pulsations can be observed in a number of ways. However the application of ground based magnetometer arrays has proven to be one of the most successful methods of...

  • Seasonal Variations in Wave Energy and the Changing Beach Characteristics: A Case Study of Beaches of Karachi. Ali, Syed Shahid; Afsar, Sheeba // Journal of Basic & Applied Sciences;Dec2013, Vol. 9, p361 

    The study of beach characteristics is generally described in terms of the relationship of wind velocity, wave energy, beach profile and grain size variation of the beach sediments. Most of the coastal research is concerned with investigating the behavior of water and sediments along the...

  • Structure and characteristics of submonthly-scale waves along the Indian Ocean ITCZ. Fukutomi, Yoshiki; Yasunari, Tetsuzo // Climate Dynamics;Apr2013, Vol. 40 Issue 7/8, p1819 

    This study examines wave disturbances on submonthly (6-30-day) timescales over the tropical Indian Ocean during Southern Hemisphere summer using Japanese Reanalysis (JRA25-JCDAS) products and National Oceanic and Atmospheric Administration outgoing longwave radiation data. The analysis period is...


Read the Article


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

Try another library?
Sign out of this library

Other Topics