Heating rate application area for Phase 2 of I3RC
by
Frank Evans and Lazaros Oreopoulos

Here, we are after 3-D fields of heating rates for i3rc and CRM parameterization purposes. Cumulus and stratocumulus cloud fields same as in remote sensing  application area, as are the atmospheric optical property files. Both monochromatic (2.13 um and 11 um) and broadband experiments (optional) are requested. Optical properties are provided for the monochromatic calculations, but only physical properties are provided for the broadband calculations.

Synopsis:

Monochromatic set of experiments: Shortwave 2.13 um and longwave 11.0 um (optional)
Broadband set of experiments:  Complete shortwave (0.2 to 4.0 um) and longwave (4.0 to 100 um)
For both sets: Mie phase function with re depending on LWC + Rayleigh scattering + Aerosol profile + Molecular absorption
Surface: Lambertian surface albedo=0.20 for both monochromatic and broadband (assumed spectrally invariant).

For each experiment set, run:

Averaging for vertically integrated maps and domain average profiles will be done at the comparison center. Optical properties are provided for the monochromatic calculations, but only physical properties are provided for the broadband calculations. The broadband calculations are optional.
 

Input data

The following table organizes input files for individual downloads. Note that this table is similar  to the one in  remote sensing application area documentation file. Also note that the input files are identical to RS application except for the 0.67 um Mie files that are not included here. Cloud phase functions are given for two wavelengths and aerosol phase functions for one wavelengths. For broadband calculations the extinction profile at a desired wavelength should be infered from the extinction profile at 0.67 um. Surface reflection is lambertian for all experiments.
 

Alternatively, the input files can be downloaded in groups assembled in tar format:

• Download all files needed for running Case 4 (cu.tar.gz)
• Download all files needed for running Case 5 (stcu.tar.gz)
• Download all files needed for running both cases (both_cases.tar.gz)

http i3rc.gsfc.nasa.gov
login name: anonymous
password: your e-mail address
cd input/ftp/
cd Cu or cd Sc

Details about the input files (including format)
Cloud property files (1st row of table)
 These are properties at layer centers. The order of the columns is as follows:
 

The first three columns are grid indexes, the fourth is liquid water content, the fifth is effective radius. The remaining columns are volume extinction coefficient and single scattering albedo for 0.67, 2.13, and 11 um.

The midpoints (zm) of the verical layers (in km) are given by:
zm=1.02+(IZ-1)*0.04,                                 IZ=1,36                                              Cu cloud field (case 4)
zm=0.4125+(IZ-1)*0.025,                            IZ=1,16                                               Sc cloud field (case 5)

Horizontal grid size (in both X and Y directions) is 0.0667 km for the Cu cloud field and 0.055 km for the Sc cloud field.

Cloud Mie files (2nd row of table)
The Mie files are tables of extinction, single scattering albedo, and phase functions represented with Legendre polynomial coefficients for LWC=1 g/m^3 for several effective radii (increment of 0.5 um). Use plotmietab.f to read (subroutine READ_MIE_TABLE) and reconstruct the phase functions. It is left up to the participant to decide how to use these phase functions for obtaining cloud droplet phase functions for each gridpoint of the 3-d field (for experiments where reff varies with location).

Aerosol Mie files (3rd row of table)
These are similar to their cloud counterparts. The aerosol size distribution is a single mode lognormal size distribution with  Reff=0.130 um (median radius=) sigma=0.70. The index of refraction is independent of wavelength with value m=(1.45,-0.01).

Atmospheric extinction coefficient files (4th row of table)
The aerosol and water vapor profiles below 5 km are from ARM Southern Great Plains site Raman lidar data on 10/6/99 at 1450UTC.  Aerosol extinction profile scaled using single mode lognormal size distribution and Mie theory fit to CIMEL optical depths. McClatchey midlatitude summer atmosphere used above 5 km. Profiles of molecular absorption at 0.67, 2.13, 11.0 um, molecular scattering at 0.67 um, and aerosol extinction at 0.67 and 2.13 um.  These profiles should be combined with the cloud optical property profiles for experiments where atmospheric effects are accounted for; exact implementation is left to the participant. There is only one actual profile, but two files because the levels are chosen to match the two cloud cases. The order of the columns is as follows:
 

Atmospheric optical depth files (5th row of table)
Equivalent information to the extinction profiles, but integrated to layer optical depths for models that assume uniform optical properties in a grid cell.  The order of the columns is as follows:
 

Atmospheric sounding files (6th row of table)
The water vapor profile below 5 km is from ARM Southern Great Plains site Raman lidar data on 10/6/99 at 1450UTC.  McClatchey midlatitude summer atmosphere used above 5 km.  The order of the columns is as follows:
 

Source code files (7th row of table)
Fortran source code plotmietab.f  is  taken from Frank Evans' SHDOM distribution package. This routine reads in the cloud and aersol Mie table files and reconstructs the phase function from the Legendre coefficients.
 

DETAILED BREAKDOWN TO EXPERIMENTS
For each cloud field (case) and for both accuracies (high and low) perform the following experiments:

First set, monochromatic
Experiment 1: Rayleigh scattering + Aerosol profile + Molecular absorption,  wavelength = 2.13 um,  SZA=0 deg., Mie phase function with re depending on LWC (and thus a function of position),  Lambertian surface albedo=0.20, spectral solar flux= 80.5 W m-2 um-1 (corresponding to Landsat-7 band 7). Outputs are 3-D (X, Y, Z) field of heating rate and 2-D (X, Y) fields of downward flux at 0 km and upward flux at 30 km.
Experiment 2: As Experiment 1, SZA=60 deg, azimuth=0 deg.
Experiment 3: As Experiment 2, independent pixel approximation (no net photon exchange between columns)
Experiment 4: Optional. Molecular absorption, wavelength = 11 um,   Mie phase function with re depending on LWC (and thus a function of position),  black surface, surface temperature = T(0 km) from atmospheric sounding profile file. Outputs are 3-D (X, Y, Z) field of heating (cooling) rate and 2-D (X, Y) fields of upward flux at 0 km and donward flux at 30 km.

Second set, broadband (optional)
Experiment 5: As Experiment 1, broadband solar, Lambertian surface albedo=0.20 (spectrally invariant)
Experiment 6: As Experiment 2, broadband solar, Lambertian surface albedo=0.20 (spectrally invariant)
Experiment 7:  As Experiment 6,  independent pixel approximation (no net photon exchange between columns)
Experiment 8: As Experiment 4, broadband thermal

Heating rates are defined as net flux convergences (units Wm-3 or W m-3 um-1); upward flux=Fu(30 km), downward flux=Fd(0 km). For solar, Fd(30 km)=80.5 Wm-2 um-1 (2.13 um) and Fd(30 km)=1368 Wm-2 (broadband).

Note on azimuth convention:

                                                                                          90
                                                                          +++++++++++++++  high Y
                                                                          |                                     |
                                                                          |                                     |
                                                                          |                                     |
                                                           0 deg     |                                     |     180
                                                                          |                                     |
                                                                          |                                     |
                                                                          +++++++++++++++  low Y
                                                                                         270
                                                                          low X                       high X

The above sketch shows our azimuth convention. For example, a sun azimuth of 0 degrees means that the sun's rays are directed from 0 deg. ("West") towards 180 deg. ("East").

Note that in Phase II we do not require submission of statistics files; participants submit only fields and CPU performance files (see below).

OUTPUT FILE FORMAT AND NAME CONVENTION
Field files
Name convention for field output files follows the rules of Phase I.  Create a separate file for each experiment and output field. Use the following name convention:

I3RC_RQ_case_accu_HR_exp#.inst[n]

where:

"RQ" is the radiative quantity contained in the file.  RQ takes the following values:   RQ index
       Fu     (upward flux)                                                                                                                iq=1
       Fd     (downward flux)                                                                                                           iq= 2
       Fc    (heating rate or flux convergence)                                                                          iq= 3
"case" is the cloud field case. For phase II the cloud field cases have been assigned the following numbers:

            case=4  LES Cu cloud
           case=5 LES Sc cloud

"accu"=H (for high accuracy runs) or L (low accuracy runs).

"HR" stands for "Heating Rate"

"exp#" is the experiment number as listed above. Valid numbers are 1-8.

"inst" is the four-letter code that has been assigned to each institution participating in the experiment. The codes are listed in the participant list .

"[n]" is an index number following the institution whenever there are more than one participant or codes from the same institution. There is no number for institutions with one participant and one code.  Consult the participant list to determine whether you need to add  "[n]" to your filenames.

Examples
1) The heating rate field of experiment 3, LES Cu cloud case, low accuracy, submitted by a participant affiliated with institution MESC should have the following filename:

             I3RC_Fc_4_L_HR_3.MESC

2) The downward flux field of experiment 2, LES cloud Sc case, high accuracy, submitted by the 2nd participant of institution UMBC should be put in the following file:

             I3RC_Fd_5_H_HR_2.UMBC2
 

Output format for radiative heating files should be like the one produced by the following sample Fortran code:
-----------------------------------------------------------------
       parameter (nx=64, ny=64, nz=16)
c      rq is the radiative quantity of interest (heating rate)
       real rq(nx,ny,nz)
       open (11, file='I3RC_Fc_4_L_HR_6.KIAE', status='unknown')
       do ix=1,nx
         do iy=1,ny
            do iz=1,nz
               write (11, '(f8.5)') rq(ix,iy,iz)
            enddo
         enddo
       enddo
       close(11)
----------------------------------------------------------

Output format for flux files should be like the one produced by the following sample Fortran code:
-----------------------------------------------------------------
       parameter (nx=64, ny=64)
c      rq is the radiative quantity of interest
       real rq(nx,ny)
       open (11, file='I3RC_Fu_4_H_HR_5.KIAE', status='unknown')
       do ix=1,nx
         do iy=1,ny
            write (11, '(f8.2)') rq(ix,iy)
         enddo
       enddo
       close(11)
----------------------------------------------------------

Error files
Create a separate file for each case, each accuracy, and each experiment. This file will contain the mean pixel-level error (note: for the heating rate field we seek the column integrated heating rate error) and the error to the mean. Use the following  convention:

I3RC_errors_case_accu_HR_exp#.inst[n]

See above for the meaning of "case" , "accu", "exp#" and "inst[n]".

Include only the error results in %. Output format should be like the one produced by the following sample Fortran code:

--------------------------------------------------------------
      parameter (nqu=3, nerr=1)
      real error(nqu,0:nerr)
      open (11, file='I3RC_errors_4_L_HR_6.UMBC2', status='unknown')
      do iq=1,nqu
         write (11, '(f10.2,f10.4)') (error(iq,ir), ir=0,nerr)
      enddo
      close(11)
cc    error(iq,ir) contains the mean pixel-level error for
cc    quantity with index iq (indices can be found above
cc    in the description of the radiative quantities "RQ")
cc    when ir=0, and the error of the mean when ir=1.
----------------------------------------------------------------

UPLOADING RESULTS
Again, same procedure as in Phase I. Please submit via anonymous http following the instructions below:

http i3rc.gsfc.nasa.gov
user ID: anonymous
Password: your e-mail address
cd http-in
prompt
mput I3RC*

Please notify Lazaros Oreopoulos whenever you upload results.

For questions contact Lazaros Oreopoulos