The authors would like thank ECMWF and NCEP for providing the data in the study. We extend our gratitude to NASA for the Grants NNX09AD08G and NNX10AU44G, which supported this research. Interpolated OLR data were provided by the NOAA/OAR/ESRL PSD, Boulder, Colorado, from their website (http://www.esrl.noaa.gov/psd/). All figures were made using the NCAR Command Language (2013).
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