Feature #977

Stratospheric ozone for EC-Earth

Added by Twan van Noije almost 5 years ago. Updated over 2 years ago.

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For the EC-Earth version of TM5, stratospheric ozone should be nudged to the CMIP6 ozone data set.

Test-CMIP6-O3.pdf (3.03 MB) Twan van Noije, 03/27/2017 12:07 PM


#1 Updated by Twan van Noije almost 5 years ago

  • Subject changed from Stratospheric ozone to Stratospheric ozone for EC-Earth

#2 Updated by Twan van Noije over 4 years ago

  • File Test-CMIP6-O3.pdf added
  • Status changed from New to In Progress
  • Assignee changed from Michiel van Weele to Twan van Noije

The option to nudge stratospheric ozone to mixing ratios from CMIP6 has now been implemented for the pre-industrial climatology (to be used in the CMIP6 control simulation) and the historical data set (1850-2014) in r566. Future scenarios of stratospheric ozone still need to be added.

I have tested the implementation in an offline TM5 simulation for 2010, driven by ERA-Interim and using 2009 as spin-up. The simulation produces chemical budgets and ozone mixing ratios in close agreement with a reference simulation where nudging to total colums from MSR2 with vertical profiles from the Fortuin and Kelder climatology is applied. The annual mean total ozone burden changes from 3209.0 to 3215.4 Tg. The impact on tropospheric ozone is small. The trospheric ozone burden changes by less than 1 Tg. In my budget calculations, the tropospheric burdens of ozone and the stratopheric ozone tracer applied in TM5 (O3S) change from 385.0 to 384.6 Tg and from 81.7 to 83.9 Tg, respectively. Note that these numbers will depend on the tropopause definition applied. The attached pdf shows a comparison of ozone mixing ratios at different levels from both simulations.

Some new flags have been included in the rc-file:

input.conc.o3.cmip6 : T
input.conc.o3.cmip6.dir :
input.conc.o3.cmip6.piclim : F

To run with the CMIP6 data set, input.conc.o3.cmip6 should be set to T, and input.climat.MSR to F. To run with the pre-industrial climatology, input.conc.o3.cmip6.piclim should be set to T.

The input files are the same as used to prescribe the ozone concentrations in IFS in EC-Earth3, and were prepared by Michiel van Weele. They are available from ECMWF at ec:/nm6/EC-EARTH/ECEARTH3.2b/INPUT/ece-data-cmip6-o3.tgz. The required files should be put in the directory indicated at input.conc.o3.cmip6.dir (e.g. ${PERM}/TM5_INPUT/boundary/CMIP6/O3/).

Two additional flags can be used to fix the ozone mixing ratios used in the nudging scheme to a specific year:
input.o3.fixyear :
input.o3.year :

This option works for both CMIP6 and MSR ozone. Note that fixing CMIP6 ozone to 1850 is not the same as using the CMIP6 pre-industrial ozone climatology, and that the climatology should be used for the CMIP6 control simulation.

#3 Updated by Twan van Noije over 4 years ago

  • File deleted (Test-CMIP6-O3.pdf)

#4 Updated by Twan van Noije over 4 years ago

#5 Updated by Twan van Noije almost 3 years ago

I have added the reading of the future scenario data for ozone. Ozone data have been provided for CMIP6 only for the four tier-1 scenarios of ScenarioMIP (SSP1-2.6, SSP2-4.5, SSP3-7.0 and SSP5-8.5). These have been included in the code. I have assumed that the stratospheric ozone fields for SSP3-7.0 can also be used for SSP3-7.0-LowNTCF, which will be run as part of AerChemMIP.

#6 Updated by Twan van Noije almost 3 years ago

  • Status changed from In Progress to Resolved

#7 Updated by Philippe Le Sager over 2 years ago

  • Status changed from Resolved to Closed
  • % Done changed from 0 to 100

Merged into the trunk in r964.

Also available in: Atom PDF