= Study CO2 cloud formation =

**Author**: J.Audouard, A. Määttänen, C. Mathé

**Date**: 07/2017

**Comments**
 Several logicals and integer must be set to .true. in callphys.def if not, default values are .false.

**callphys.def**


||= FLAGS/PARAMETERS =||= COMMENTS =||
|| co2clouds=.true.   || Call the subroutine ||
||co2useh2o=.true.    ||         Allow the use of water ice particles as CCN for CO2 ||
||meteo_flux=.true.   ||         Supply meteoritic particles ||
||CLFvaryingCO2=.true.||         Allows a subgrid temperature distribution of amplitude spantCO2 (=integer in callphys.def, typically 3) ||
||satindexco2=.true.  ||         Allows the filtering out of the sub-grid T distribution if the GW saturates in the column. Based on Spiga et al. (2012) ||
|| ||                             .true.: an index is computed for the column and the sub-grid T distribution is applied if the index remains < 0.1 ||
|| ||                             .false.: applies the sub-grid T everywhere default value is .true., only applies if CLFvaryingCO2=.true. anyway. ||
|| imicroco2=50 ||||

**traceur.def**
 add these two tracers: ccnco2_number, ccnco2_mass


**Reference papers**
 Listowski et al. (2013), https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/jgre.20149 \\
 Listowski et al. (2014), https://www.sciencedirect.com/science/article/pii/S0019103514002140?via%3Dihub \\
 Navarro et al. (2014), https://agupubs.onlinelibrary.wiley.com/doi/full/10.1002/2013JE004550