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​<span style="font-size: 12pt;">Dear NCL developers</span>
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<p>My colleagues Harry Hendon and Abhik Santra at the Bureau of Meteorology want to report an issue regarding the computation of the RMM1 and RMM2 time series (eof_ts_cdata) and the expansion coefficients of olr, u200 and u850 (ceof_ts) in mjoclivar_14.ncl. </p>
<pre style="word-wrap:break-word; white-space:pre-wrap">​> eof_ts_cdata = eofunc_ts(cdata,eof_cdata,False) <br></pre>
<p>Harry and Abhik were trying to replace cdata with forecast data of a particular year to see if forecast amplitudes of RMM1 and RMM2 are realistic or not. </p>
<p>Because eofunc_ts_Wrap removes the time mean of the input data by default (i.e. 1-year time mean of forecast data for their case), their forecast MJO amplitudes were systematically biased. <br>
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<p>This problem will occur when people try to compute the MJO amplitues with a subset of a dataset.<br>
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<p>Could you please add a comment where eof_ts_cdata and ceof_ts appear in mjoclivar_14.ncl that users should compute the expansion coefficients manually rather than using eofunc_ts_Wrap if the removal of the time mean of the input data is not intended/desirable?<br>
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<p>Please let me know if what I've explained is not clear. <br>
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<p>Many thanks!<br>
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<p>Eun-Pa<br>
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<p>Research Scientist<br>
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<p>The Australian Bureau of Meteorology<br>
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<p>GPO Box 1289, Melbourne, VIC 3000, AUS<br>
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