Driving UM-SCM with reanalysis / model data Vaughan Barras ACCESS Model Development Group

Dynamically constrained simulations Previous experience constraining GCMs dynamically with reanalyses, allowing other model components to evolve   18 O in hydrological cycle  eg: Melbourne Uni Network of Isotopes in Precipitation 3 rd IOP (Jun 11, 2005) See also: Noone (2006) (WGNE Rep. 36; WMO/TD-No. 1347) Yoshimura et al., 2008 (JGR, 113, D19108) Barras and Simmonds, (submitted to JGR)

Use in SCMs? …yes…provided it is set up carefully and SCM used appropriately. Idealised cases (equilibrium, constant forcings) Idealised cases (equilibrium, constant forcings) Targeted studies (Intercomparisons) Targeted studies (Intercomparisons) Intensive Observational Campaigns (IOPs) Intensive Observational Campaigns (IOPs) TWP-ICE, TOGA-COARE, GABLS, DYCOMS, RICO, Cabauw,… TWP-ICE, TOGA-COARE, GABLS, DYCOMS, RICO, Cabauw,… Alternative namelist generation? Alternative namelist generation? NWP forcings NWP forcings Useful - depending on what is under investigation Useful - depending on what is under investigation Complicated setup… Complicated setup…

genesis Software to create SCM namelists at a user-defined location from reanalyses / model input.Uses: Testing of parameterisations under a range of scenarios Testing of parameterisations under a range of scenarios IOPs can be subjective in the conditions they represent IOPs can be subjective in the conditions they represent Based on approximate ‘real-world’ conditions (reanalyses) Based on approximate ‘real-world’ conditions (reanalyses) Extract model conditions for detailed testing Extract model conditions for detailed testing Efficiency enables creation of ensemble namelists Efficiency enables creation of ensemble namelists Variable initial conditions, major forcing fields. Variable initial conditions, major forcing fields.

how it works Download global NetCDF fields of p msl, , U, V, T, q for desired period Download global NetCDF fields of p msl, , U, V, T, q for desired period ERA40 ERA40 JRA25 (q > level 12 = 0.0) JRA25 (q > level 12 = 0.0) NCEP (genesis converts RH to q) NCEP (genesis converts RH to q) UM dumps from STASH (sub-periods of longer runs) Use ‘Trans’ option in xconv to interpolate to  grid. User specifies lat / lon User specifies lat / lon Define ‘files.inp’ and ‘dates.dat’ files Define ‘files.inp’ and ‘dates.dat’ files Simple list of input file names and dates matching inputs Simple list of input file names and dates matching inputs Command line execution Command line execution Can be scripted Can be scripted

genesis --help gale/vjb> genesis Usage: genesis genesis [options] genesis [options] -d verbose, debug mode -d verbose, debug mode -h help -h help -t no. of time increments (def=150) -t no. of time increments (def=150) -l no. of levels of input data (def=20) -l no. of levels of input data (def=20) -x no. of longitudes (def=29) -x no. of longitudes (def=29) -y no. of latitudes (def=17) -y no. of latitudes (def=17) -X user defined longitude (eg: 243.7) -X user defined longitude (eg: 243.7) -Y user defined latitude (eg: 65.0) -Y user defined latitude (eg: 65.0) -D use date file (def = false) -D use date file (def = false) -O use offset file (def = false) -O use offset file (def = false) -E ERA40 data (def = false) -E ERA40 data (def = false) -J JRA data (def = false) -J JRA data (def = false) -N NCEP data (def = false) -N NCEP data (def = false) -U UM data (def = false) -U UM data (def = false) You also need a few files in the run directory for this to work. You also need a few files in the run directory for this to work. a) files.inp - a file listing the *.nc file names in order: ps,z,u,v,t,q a) files.inp - a file listing the *.nc file names in order: ps,z,u,v,t,q b) offset.dat (optional) - list of offset parameters from b) offset.dat (optional) - list of offset parameters from ncdump hdr [scale, add] ncdump hdr [scale, add] - if geopotential needs converting only (m2/s2 >> m) - if geopotential needs converting only (m2/s2 >> m) then use -O with offset file set to 1 0 for each. then use -O with offset file set to 1 0 for each. c) dates.dat (optional) - a list of dates/times corresponding to data records. c) dates.dat (optional) - a list of dates/times corresponding to data records. [generate using datetraj - yyyymmdd hhhh] [generate using datetraj - yyyymmdd hhhh]

details Read NetCDF fields Read NetCDF fields Finds nearest neighbour grid points for interpolation Finds nearest neighbour grid points for interpolation Calculates advective tendencies (T, q) Calculates advective tendencies (T, q) Linear interpolation of fields (horizontally) Linear interpolation of fields (horizontally) Could incorporate other interpolation methods if desired Could incorporate other interpolation methods if desired Derivation of geostrophic wind profiles Derivation of geostrophic wind profiles Assign dates / times to records Assign dates / times to records Intermediate output field (*.scm) Intermediate output field (*.scm) Initial profiles (P_IN, UI, VI, QI, THETA) Initial profiles (P_IN, UI, VI, QI, THETA) Increments (U_INC, V_INC, T_INC, Q_STAR) Increments (U_INC, V_INC, T_INC, Q_STAR) Output ‘namelist.scm’ Output ‘namelist.scm’ Still needs to be checked before running!

Example – CASES 99 U V T q NWP forcing profiles compared with hi-res soundings from CASES 99

Example – CASES 99 U*U* T sfc ERA40 forced UM-SCM runs  = 6hr  = 48hr

however… Still requires user to set up cases carefully. SCM6.3 has constant Ū g SCM6.3 has constant Ū g Restricted to short runs where synoptic circulation isn’t rapidly changing (midlats can be a problem in this regard, tropics ok) Restricted to short runs where synoptic circulation isn’t rapidly changing (midlats can be a problem in this regard, tropics ok) Variable setting in SCM7.1, enables longer simulations Variable setting in SCM7.1, enables longer simulations No inclusion of ‘w’ No inclusion of ‘w’ SCMs sensitive to these settings, best if user defined / derived by model continuity SCMs sensitive to these settings, best if user defined / derived by model continuity Not comparable to observations, but… Not comparable to observations, but… Genesis can provide framework for parameterisation sensitivity studies, not restricted by IOP location. Genesis can provide framework for parameterisation sensitivity studies, not restricted by IOP location. Enables targeting of problem regions / conditions Enables targeting of problem regions / conditions [debugging…]