McLean, J. D., C. R. de Freitas, and R. M. Carter (2009), Influence of the Southern Oscillation on tropospheric temperature, J. Geophys. Res., 114, D14104, doi:10.1029/2008JD011637. http://www.agu.org/pubs/crossref/2009/2008JD011637.shtml From the abstract: Change in SOI accounts for 72% of the variance in Global Tropospheric Temperature Anomalies (GTTA) for the 29-year-long MSU record and 68% of the variance in GTTA for the longer 50-year RATPAC record. The results showed that SOI accounted for 81% of the variance in tropospheric temperature anomalies in the tropics. Overall the results suggest that the Southern Oscillation exercises a consistently dominant influence on mean global temperature, with a maximum effect in the tropics, except for periods when equatorial volcanism causes ad hoc cooling. That mean global tropospheric temperature has for the last 50 years fallen and risen in close accord with the SOI of 5–7 months earlier shows the potential of natural forcing mechanisms to account for most of the temperature variation.