Sunday, 9 January 2005
The Madden-Julian Oscillation and its effect on tropical precipitation
The Madden-Julian Oscillation (MJO) is an eastward propagating phenomenon that brings cloudiness and precipitation to the tropics in a cycle that lasts from 40 to 50 days. Precipitation data covering the years from 1974 to 2001 for over 16,000 stations between 40 degrees north and south latitude were analyzed to determine the impact of the MJO on tropical locations. Station precipitation data were also compared with OLR (outgoing longwave radiation, a measure of high-level cloudiness) data. This comparison reveals that although the OLR data capture the overall pattern of the MJO, significant differences do exist. Ongoing work involves further comparisons and analysis of precipitation and temperature data with OLR, winds and several other meteorological variables. This will help identify further dynamics of the MJO and will also help determine the impact the MJO has on local and global climates, both in the tropics and also in the extratropics.