I agree that this aspect is not terribly well documented. There is a bit more on this at: http://www.cesm.ucar.edu/models/cesm1.2/cice/doc/node31.html Basically, this requires several namelist changes added to user_nl_cice. The variables histfreq and histfreq_n determine how often history files are written for each stream. histfreq is the base unit of the time period and histfreq_n is the number of base units. So histfreq = 'm','x','x','x','x' and histfreq_n = 1,1,1,1,1 which is the default implies that the first stream is one-monthly and histfreq = 'm','d','x','x','x' and histfreq_n = 1,5,1,1,1 means the first stream is one-monthly and the second stream is 5-daily. The second piece to this is telling the model what variables go on what stream. By default CICE has the first stream set to one-monthly and the default for most of the variables is to be written to the one-monthly stream. There is a separate &icefields_nml group to handle the variable selection. For example:f_hi = 'mxxxx'f_aice = 'mxxxx'Is an internal default that sends ice thickness (hi) and area (aice) to the first monthly stream. If for example one added the 5-daily stream as above, you would need to add all the variables of interest to user_nl_cice that you wanted on both streams:f_hi = 'mdxxx'f_aice = 'mdxxx'Note that if the first stream is set to 'x' for a variable, then it will not be written to any stream. For example f_hi = 'xdxxx' will not send any ice thickness to any stream despite the second stream being set to 'd'. Another thing one can do is reset the time period for the first stream. For example in Keith's case above he did:histfreq = 'y','x','x','x','x'histfreq_n = 1,1,1,1,1To redefine the first stream as one-yearly. This then requires all of the variables of interest to be added to user_nl_cice. For example:f_hi = 'yxxxx'f_aice = 'yxxxx'I will work on improving the documentation of this for CICE5.Dave