The Madden-Julian Oscillation (MJO) is a tropical atmospheric phenomenon first recognised in the early 1970s. The MJO, also commonly known as the 40-day wave, develops over the Indian Ocean and then travels east across the tropics at 5-10 m/s. With a timescale ranging from 30 to 60 days, the MJO has a frequency of 6-12 events per year. In its active stage, the MJO is associated with increased c...

CONTENTS CLIOTOP/PFRP Workshop: The Role of Squid in Pelagic Marine Ecosystems ............................... 2 Papua New Guinea Tuna-Tagging Project ................. 5 Upcoming Events .................................................. 5 Erratum ................................................................ 7 Pelagic Fisheries Science in the Pacific, 2005 and Beyond—PIFSC and PFRP ............

Using the new Argo array of profiling floats that gives unprecedented space-time coverage of the upper 2000 meters of the global ocean, we present definitive evidence of a deep tropical ocean component of the Madden-Julian Oscillation (MJO). The surface wind stress anomalies associated with the MJO force eastward-propagating oceanic equatorial Kelvin waves that extend downward to 1500 meters. T...

The effect of the Madden-Julian Oscillation (MJO) on the Northern Hemisphere wintertime stratospheric polar vortex in the period preceding stratospheric sudden warmings is evaluated in operational subseasonal forecasting models. Reforecasts which simulate stronger MJO-related convection in the Tropical West Pacific also simulate enhanced heat flux in the lowermost stratosphere and a more realis...

The finite resolution of general circulation models of the coupled atmosphere-ocean system and the effects of sub-grid-scale variability present a major source of uncertainty in model simulations on all time scales. The European Centre for Medium-Range Weather Forecasts has been at the forefront of developing new approaches to account for these uncertainties. In particular, the stochastically p...

Equatorial planetary waves are a fundamental component of the tropical climate system. Previous studies have examined their structure in the climatological-mean circulation, their role in the climatological-mean momentum balance of the tropics, and their contribution to the climatological-mean upwelling across the tropical tropopause. In this study, the authors focus on the contribution of the ...