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Calculating cloud fraction profiles

Added by Kevin Helfer over 4 years ago

Dear all,

I would like to calculate cloud fraction profiles from ICON output. My idea would be to just first count all the grid points on each height level in my lat/lon selection and then those that have a non-zero liquid water content. Looking through the documentation, I found the histcount operator (https://code.mpimet.mpg.de/projects/cdo/embedded/index.html#x1-8200002.15.15), which would probably work fine. Is anybody aware of any other possibilities?

Best,
Kevin


Replies (2)

RE: Calculating cloud fraction profiles - Added by Ralf Mueller over 4 years ago

hi Kevin!

shouldn't be the cloud-fraction a regular output variable of ICON-atm? I think it depends on the physics-package you use ....

IMO it's not a good idea to exclude cells that are only partly covered (non-zero water content). Most of the cells will have some of it. So you would only count cells that are completely dry.

histcount might be a good choice, but please contact someone with more knowledge about the physics package that was used in that specific simulation (in case there is no output variable for cloud fraction).

  • For ECHAM there is a variable 'total cloud cover' (shortname:clt)
  • for NWP there is are variables 'cloud cover' (shortname:clc) and 'total cloud cover' (shortname:clct)

latest icon release

hth
ralf

RE: Calculating cloud fraction profiles - Added by Kevin Helfer over 4 years ago

Hi Ralf,

thanks for your reply! I'm working with the HDCP2 TA simulations from Matthias Brueck, and cloud fraction is not part of the output of these simulations. I didn't explicitly write it, but what I actually meant was to use a certain threshold (tbd) for the liquid water.

Kevin

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