In spring 2006, US CLIVAR established the Madden-Julian Oscillation (MJO) Working Group (MJOWG). The formation of this 2-year limited lifetime WG was motivated by:

 1) The wide range of weather and climate phenomena that the MJO interacts with and influences

 2) The fact that the MJO represents an important, and as yet unexploited, source of predictability at the subseasonal time scale

 3) The considerable shortcomings in our global climate and forecast models in representing the MJO

 4) The need for coordinating the multiple threads of programmatic and investigator level research on the MJO.

   Near-term tasks involve the development of diagnostics for assessing model performance in climate simulations and extended - range/subseasonal forecast settings, as well as designing and coordinating multi-model experimentation and analysis to diagnose and improve model shortcomings and assess MJO predictability characteristics and present-day prediction skill. In addition, the WG will help to coordinate MJO-related activities across other programmatic bodies (e.g., GEWEX, International CLIVAR, Thorpex) and will explore the applications and potential user base for subseasonal predictions based on the MJO. Here we present a hierarchy of diagnostics that have been developed by the MJOWG for assessing model performance in simulating the MJO. Our goal is to publish these diagnostics, first on the world-wide web for the use of modeling centers and diagnosticians, and secondly as a peer-reviewed journal article to provide a reference regarding their usefulness in model diagnosis.


   With the publication of these diagnostics, we encourage the modeling and diagnostic communities to make use of them in their studies of the MJO in their models, and provide feedback to the MJOWG regarding their usefulness. Importantly, we will be soliciting participation in a workshop being planned for mid-late 2007 tentatively titled "New Thinking, Tools & Resources for Assessing & Improving the MJO". The workshop will focus on the multi-scale and vertical structure of the MJO, the utility of both forecast multi-scale modeling frameworks for improving MJO model representation, the vast new satellite and other resources available for studying the MJO, and application of the model diagnostics.

  For additional details, see


 * Links to codes and example data for the MJO simulation diagnostics calculation (Last update: 2008.09.08)
  - Include WK99 diagram, coherence squared and phase diagram and MJO life-cycle composite diagnostics
  - Apllicable to the model which has 360 day calendar
  - Bug
in /msd/level_1/csh/eof/ is fixed (Thanks to Cristiano in CPTEC)

   CODE      DATA

 * Links to fftpack library (if it is needed to develop the library package that suits your own system)
  - Feedback from Dr. Masahiro Sugiyama in University of Tokyo