| 1 | Stratospheric aerosol files for LMDz can be created by running on ciclad the script |
|---|
| 2 | ./volc.sh |
|---|
| 3 | which itself prepares two more files and submit a job on ciclad which may take a day to run. |
|---|
| 4 | |
|---|
| 5 | The stratospheric AOD data originates from data prepared by Beiping Luo ETZH for CMIP6. |
|---|
| 6 | See http://www.wcrp-climate.org/wgcm-cmip/wgcm-cmip6 |
|---|
| 7 | and ftp://iacftp.ethz.ch/pub_read/luo/CMIP6/ |
|---|
| 8 | The data were provided in June 2016 and were not versioned (but were later referred as v2). |
|---|
| 9 | A new version (v3) was made available on 15 September 2017 due to a glitch in the 1970s data. |
|---|
| 10 | The new version also modified the trend in the background aerosol. |
|---|
| 11 | |
|---|
| 12 | Beiping calculated for the solar radiation 8 bands (bands 1-6 for the SW 6 bands |
|---|
| 13 | model and 7-8 for the SW 2 bands model) and likewise for the 16 bands of the RRTM LW model. |
|---|
| 14 | |
|---|
| 15 | The data are processed in IDL on ciclad for different resolutions |
|---|
| 16 | of the IPSL model and aerosol optical properties are generated for AOD, |
|---|
| 17 | omega and g per model layer (SW), and absorption AOD per model layer (LW). |
|---|
| 18 | |
|---|
| 19 | The stratospheric aerosol data extends into the troposphere but a mask is applied |
|---|
| 20 | in the LMDz model to remove tropospheric data. The data are interpolated on the vertical |
|---|
| 21 | from the CMIP6 altitude coordinate (z, resolution 0.5 km) to the model coordinate (sigma). |
|---|
| 22 | This is done using a monthly (10-year mean) climatology of the geopotential height. |
|---|
| 23 | zalt_LR_l79.nc = 10 yr climatology from a coupled IPSL-CM6.0.12 simulation |
|---|
| 24 | zalt_zonmean_LR_l79.nc = zonal mean of the above file (cdo zonmean zalt.nc zalt_zonmean.nc) |
|---|
| 25 | zalt_zonmean_LR_l79_rev.nc = same as above but ferret'ized so that can be read in idl |
|---|
| 26 | |
|---|
| 27 | |
|---|
| 28 | The data are on ciclad (currently in /data/$USER/CMIP6/VOLC/) |
|---|
| 29 | |
|---|
| 30 | Annual files: taulwstrat.2D.$year.nc and taulwstrat.2D.$year.nc |
|---|
| 31 | to be used for historical simulations |
|---|
| 32 | |
|---|
| 33 | In September 2017 the processing idl routine was to v4 changed to rely on climatological LMDz altitudes |
|---|
| 34 | that vary monthly and with latitude (based on GEOP variable Z=GEOP/RG/1000 [in km]). |
|---|
| 35 | |
|---|
| 36 | Average 1850-2014 conditions (no seasonal cycle): taulwstrat.2D.ave.nc and tauswstrat.2D.ave.nc |
|---|
| 37 | to be used for piControl, pdControl and for scenario runs (past a 10 year transition from 2014 conditions) |
|---|
| 38 | subject to changes in the protocol |
|---|
| 39 | |
|---|
| 40 | Transition 2015-2014 conditions: to be done. |
|---|
| 41 | |
|---|
| 42 | CMIP6 stratospheric aerosols are activated in LMDz with flag_aerosol_strat=2 |
|---|
| 43 | |
|---|
| 44 | Files to be renamed as taulwstrat.2D.nc and tauswstrat.2D.nc for use by LMDz |
|---|
| 45 | No additional interpolation between months is done. |
|---|
| 46 | |
|---|
| 47 | Olivier Boucher |
|---|
| 48 | 27/07/2016 |
|---|
| 49 | Revised 10/09/2017 |
|---|
| 50 | Revised 04/10/2017 |
|---|
