Experiment for the Earth

A method to perform an experiment for the Earth is described.

Following physical processes are used in this experiment.

• Radiation (...)
• Vertical diffusion (Mellor and Yamada, 1974, level 2)
• Cumulus parameterization: Convective adjustment scheme (Manabe et al., 1965)
• Large scale condensation
• Bucket model

1. Overview
2. Preparation of a directory for an experiment
3. Preparation of additional data
4. Run the experiment
5. Visualization of result
6. References

Overview

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

• Preparation of directory for experiments
• Preparation of initial condition
• Preparation of additional data for experiments
• Execution of experiments

Preparation of a directory for an experiment

Here, we perform an experiment in practice/Earth-exp directory. Please create the directory and enter there as follows:

$ cd practice
$ mkdir Earth-exp
$ cd Earth-exp

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

$ cp ../../src/main/dcpam_main ../../src/main/init_data ../../src/main/sst_data .
$ cp ../../src/sample_nml/*.nml .

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

Preparation of additional data

This experiment requires additional data, sea surface temperature, surface properties, sea ice density, and ozone distribution. Those data are prepared at following site.

• sample data

Please download "sst_amipII_bc_clim_T021.nc", "sp_for_Earth_T021.nc", "sic_amipII_bc_clim_T021.nc", and "O3_CMIP5_climatology_zonalmean_T021.nc" from above site, and place those files at experimental directory.

Run the experiment

At the last, run a experiment using "dcpam_main" and "dcpam_E_T21L22.nml". Resolution is T21L22, time step is 30 minutes. Integration time is 10 days. A restart data file, a restart data file of surface data, and some history data files are output.

$ ./dcpam_main -N=dcpam_E_T21L22.nml | tee Earth.log

If initial data, surface data, settings of experiments want to be changed, edit "init_data_T21L22.nml", "dcpam_E_T21L22.nml".

Visualization of result

Zonal mean temperature distribution after integration for 10 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.set_fig( 'itr'=> 2 )
7: GGraph.tone( gphys.mean('lon').cut('time'=>10) )
8: GGraph.color_bar
9: 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 10 days.

References

• Manabe, S., J. Smagorinsky, and R. F. Strickler, 1965: Simulated climatology of a general circulation model with a hydrologic cycle, Mon. Wea. Rev., 93, 769--798.
• Mellor, G. L., and T. Yamada, 1974: A hierarchy of turbulence closure models for planetary boundary layers, J. Atmos. Sci., 31, 1791--1806.

DCPAM Development Group / GFD Dennou Staff