Aqua planet experiment by Neale and Hoskins (2000)

A method to perform an aqua planet experiment (planetary surface is covered by watar) proposed by Neale and Hoskins (2000) is described.

Following physical processes are used in this experiment.

• Radiation (model for the Earth's atmosphere)
• Vertical diffusion (Mellor and Yamada, 1974, level 2)
• Cumulus parameterization: Relaxed Arakawa-Schubert scheme (Moorthi and Suarez, 1992)
• Large scale condensation

1. Overview
2. Preparation of a directory for an experiment
3. Create initial data file
4. Preparation of additional data
5. Create SST data file
6. Run the experiment
7. Visualization of result
8. Final remark
9. References

Overview

This experiment requires data of distribution of sea surface temperature. So, the experiment is performed with the following 4 steps:

• Preparation of directory for experiments
• Preparation of initial condition
• Preparation of additional data (sea surface temperature) for experiments
• Execution of experiments

Preparation of a directory for an experiment

Let us move to the top directory of dcpam5 src tree (assuming dcpam5-YYYYMMDD in the following example). Here, we perform an experiment in ../dcpam5-exp/ape-nh01-exp directory. Please create the directory and enter there as follows:

$ mkdir -p ../dcpam5-exp/ape-nh01-exp
$ cd ../dcpam5-exp/ape-nh01-exp

Then, pleaase create the directories for executable files and configuration files as follows:

$ mkdir bin
$ mkdir conf

Finally, executable files and configuration files are copied as follows:

$ cp ../../dcpam5-YYYYMMDD/src/main/dcpam_main bin
$ cp ../../dcpam5-YYYYMMDD/src/main/init_data  bin
$ cp ../../dcpam5-YYYYMMDD/src/main/sst_data   bin
$ cp ../../dcpam5-YYYYMMDD/exp_setup_files/*.conf conf

Note that you can perform an experiment in any directory by using executable files and configuration (NAMELIST) files.

Create initial data file

Create initial data file "init_T21L22.nc" using "init_data" and "init_data_ape_nh01_T21L22.conf"

$ ./bin/init_data -N=./conf/init_data_ape_nh01_T21L22.conf

 *** MESSAGE [init_data] ***  Run: Initial data generation
 *** MESSAGE [init_data] ***  -- version = $Name: dcpam5-20120413 $$Id: exp-ape-nh01.rd,v 1.9 2012-02-23 23:05:23 takepiro Exp $
 *** MESSAGE [namelist_util] ***  ----- Initialization Messages -----
 *** MESSAGE [namelist_util] ***    MaxNmlArySize = 256
 *** MESSAGE [namelist_util] ***  -- version = $Name: dcpam5-20120413 $$Id: exp-ape-nh01.rd,v 1.9 2012-02-23 23:05:23 takepiro Exp $
 *** MESSAGE [timeset] ***  NAMELIST group "timeset_nml" is loaded from "./conf/init_data_ape_nh01_T21L22.conf".
                       : 
 *** MESSAGE [initial_data] ***    PsAvr   = 101080.
 *** MESSAGE [initial_data] ***    QVapAvr = 0.
 *** MESSAGE [initial_data] ***    Ueq     = 0.
 *** MESSAGE [initial_data] ***
 *** MESSAGE [initial_data] ***  -- version = $Name: dcpam5-20120413 $$Id: exp-ape-nh01.rd,v 1.9 2012-02-23 23:05:23 takepiro Exp $
 *** MESSAGE [HistoryClose] ***  "init_T21L22.nc" is closed

 ############## CPU TIME SUMMARY ################
 others                 0.400020E-01
 ------------------------------------------------
        TOTAL TIME =    0.400020E-01

Preparation of additional data

This experiment requires additional data of ozone distribution. Those data are prepared at following site.

• sample data

Please download "O3_NH01_T021.nc" from above site, and place those files at experimental directory.

Create SST data file

Next, create SST data "sst_T21.nc" using "sst_data" and "sst_data_ape_nh01_T21.conf".

$ ./bin/sst_data -N=./conf/sst_data_ape_nh01_T21.conf

 *** MESSAGE [sst_data] ***  Run: SST data generation
 *** MESSAGE [sst_data] ***  -- version = $Name: dcpam5-20120413 $$Id: exp-ape-nh01.rd,v 1.9 2012-02-23 23:05:23 takepiro Exp $
 *** MESSAGE [namelist_util] ***  ----- Initialization Messages -----
 *** MESSAGE [namelist_util] ***    MaxNmlArySize = 256
 *** MESSAGE [namelist_util] ***  -- version = $Name: dcpam5-20120413 $$Id: exp-ape-nh01.rd,v 1.9 2012-02-23 23:05:23 takepiro Exp $
 *** MESSAGE [timeset] ***  NAMELIST group "timeset_nml" is loaded from "./conf/sst_data_ape_nh01_T21.conf".
                       :
 *** MESSAGE [surface_data] ***    SoilHeatCap      = 2100000.
 *** MESSAGE [surface_data] ***    SoilHeatDiffCoef = 1.2
 *** MESSAGE [surface_data] ***  -- version = $Name: dcpam5-20120413 $$Id: exp-ape-nh01.rd,v 1.9 2012-02-23 23:05:23 takepiro Exp $
 *** MESSAGE [HistoryClose] ***  "sst_T21.nc" is closed

 ############## CPU TIME SUMMARY ################
 others                 0.400000E-02
 ------------------------------------------------
        TOTAL TIME =    0.400000E-02

Run the experiment

At the last, run a experiment using "dcpam_main" and "dcpam_ape_nh01_T21L22.conf". Resolution is T21L22, time step is 20 minutes. Integration time is 7 days. A restart data file, a restart data file of surface data, and some history data files are output.

$ ./bin/dcpam_main -N=./conf/dcpam_ape_nh01_T21L22.conf | tee ape-nh01.log

If initial data, surface data, settings of experiments want to be changed, edit "init_data_ape_nh01_T21L22.ocnf", "sst_data_ape_nh01_T21.conf", "dcpam_ape_nh01_T21L22.conf" in "conf" directory.

Visualization of result

Zonal mean temperature distribution after integration for 2 days is shown below.

This figure is drawn by using Gphys, as follows:

Please type irb. 

$ irb

Following prompt of irb is shown. 

irb(main):001:0>

Type following lines. Please note that the left-most number is line number, and it has not been typed. 

1: require "numru/ggraph"
2: include NumRu
3: gphys = GPhys::IO.open('Temp.nc', 'Temp')
4: DCL.gropn(1)
5: DCL.sgpset('lcntl', false) ; DCL.uzfact(0.7)
6: GGraph.tone( gphys.mean('lon').cut('time'=>2) )
7: GGraph.color_bar
8: DCL.grcls

Type quit to exit irb. 

Above figure shows spin-up phase of the atmosphere, because the Earth's atmosphere does not reach quasi-equilibrium in 5 days.

Final remark

If you would like to keep the results of the numerical experiment, please create a sub directory ("data01" for example), move the files, and keep the current directory neatly.

$ mkdir data01
$ mv *.nc *.log data01/

You can output the results of the numerical experimet concurrently with the execution. Please refer to "Change output settings" in Change experimental setup and try to configure "FilePrefix" variable in NAMELIST "&gtool_historyauto_nml".

References

• Mellor, G. L., and T. Yamada, 1974: A hierarchy of turbulence closure models for planetary boundary layers, J. Atmos. Sci., 31, 1791--1806.
• Moorthi, S., and M. J. Suarez, 1992: Relaxed Arakawa-Schubert: A parameterization of moist convection for general circulation models, Mon. Wea. Rev., 120, 978--1002.
• Neale, R. B., and B. J. Hoskins, 2000: A standard test for AGCMs including their physical parameterizations: I: The proposal, Atmos. Sci. Lett., doi:10.1006/asle.2000.0019.

DCPAM Development Group / GFD Dennou Staff