# Output daily means

**URL:** <https://forum.ecmwf.int/t/output-daily-means/12151>\
**Category:** OpenIFS\
**Tags:** openifs-configuration-and-namelists, openifs-40r1, openifs-model-output\
**Created:** [29 September 2017 14:04 UTC](https://forum.ecmwf.int/t/output-daily-means/12151 "2017-09-29T14:04:54Z")\
**Posts on this page:** 2\
**Page:** 1

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**Author:** ![Victoria\_Sinclair](https://forum.ecmwf.int/letter_avatar_proxy/v4/letter/v/278dde/32.png) [@Victoria\_Sinclair](https://forum.ecmwf.int/u/Victoria_Sinclair)\
**Post date:** [29 September 2017 14:04 UTC](https://forum.ecmwf.int/t/output-daily-means/12151/1 "2017-09-29T14:04:54Z")

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Is it possible to output daily mean values rather than instantaneous values from OpenIFS? If yes, how? I am using cy40r1v1.

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**Author:** ![Glenn\_Carver](https://forum.ecmwf.int/letter_avatar_proxy/v4/letter/g/e495f1/32.png) [@Glenn\_Carver](https://forum.ecmwf.int/u/Glenn_Carver)\
**Post date:** [29 September 2017 15:42 UTC](https://forum.ecmwf.int/t/output-daily-means/12151/2 "2017-09-29T15:42:22Z")

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Hi Victoria,

Unfortunately it's not possible to output daily mean values from OpenIFS. There's no code in the model for summing individual timesteps to output each day.

I do have access to code from EC-Earth colleagues which outputs monthly means - maybe this could be modified to output daily means with some work.

If summing individual instantaneous outputs, fields with a diurnal cycle are best averaged with a 3 or 6hrly output to avoid aliassing (as I'm sure you already know - a useful reference is [Thuburn, QJRMS, 1991](http://onlinelibrary.wiley.com/doi/10.1002/qj.49711749807/full)).

&nbsp;&nbsp; Glen