======  N20TRAERCN_X  ======

===== Model-run description for three simulations with NorESM1-M (UNDER CONSTRUCTION)=====

**Purpose of simulation:**  Transient run for describing climate change in the 20th century (1850-2005)

**Contact person:**         Øyvind Seland (oyvind.seland@met.no)

**Data owner:    **         Mats Bentsen  (mats.bentsen@uni.no)    

**Revision Number:**        r112  

**Production computer used:** Cray XT3 in Bergen (hexagon)

**Production date:**        November - March 2010 /2011

**Ensemble runs:**          Yes, 3 members    

**Storage locations:**      NorStore (/projects/NS2345K/noresm/cases/N20TRAERCN_f19_g16_0X), where X = ensemble member, X=1,2,3 for this particular set-up  

**Storage space:**          1,6 Tb at NorStore (for each ensemble member) 

**Projects:**               EarthClim

**Publications:**            Bentsen, M., I. Bethke, J. B. Debernard, T. Iversen, A. Kirkevåg, Ø. Seland, H. Drange, C. Roelandt, I. A. Seierstad, C. Hoose, and J. E. Kristjansson (2012): The Norwegian Earth System Model, NorESM1-M. Part 1: Description and basic evaluation, Geosci. Model Dev., 6, 687-720, doi:10.5194/gmd-6-687-2013

**Papers in preparation:**  

**Simulation name(s):**     N20TRAERCN_f19_g16_0X), where X = ensemble member, where X = 1,2,3 for this set-up 
 
**Compset name used:**      N20TRAERCN

**Model type:**             Fully coupled

**Type of run:**            Hybrid

**Simulation period:**      156 years

**Initialisation **         Start from CMIP5 control simulation. Ensemble member 1: NAER1850CNOC_f19_g16_05, year 700. 2: NAER1850CNOC_f19_g16_06, year 730, 3: NAER1850CNOC_f19_g16_06, year 760

**Resolution:**             f19_g16= 1.9x2.5 degree atmosphere/land. Dipolar ocean/ice grid, ~ 1 degree

**Emission year(s):**       1850-2005 (aerosol and aerosol-precursors) 

**Greenhouse gases:**        Prescribed concentrations 1850-2005

**Emission inventories**    IPCC AR5, see references in [[http://www.geosci-model-dev.net/6/207/2013/gmd-6-207-2013.html|Kirkevåg et al. (2013)]]  

**Frequency for output:**   Monthly and selected daily 1850-1949: Monthly + daily + 6h +3h as defined by CMIP5: 1950-2005

**Active/changing forcing agents:**  Greenhouse gases: Direct and indirect (1. & 2.) effects of SO4, POM and BC. 

** Special considerations: ** An extension of the historical simulation to 2012 is done by using RCP8.5 scenario; There is a bug in the column burden for aerosols. The column burden has to be recalculated using concentrations. This was corrected before the RCP scenarios (revision 118); The CMIP 5 files for these simulations can be found at /projects/NS9034K/CMIP5/output1/NCC/NorESM1-M/historical.



**Tuning parameters which are changed relative to the host model CAM4:** 

rhminl:  0.90        lower RH threshold for formation of low stratiform clouds (0.91 in CAM4) 

critrp:  5.0 mm/day  maximum prcipitation rate for suppression of autoconversion of cloud water (0.5 mm/day in CAM4)

r3lc:    14 um       critical mean droplet volume radius for onset of autoconversion (10 um in CAM4)