Heating rate application
area for Phase 2 of I3RC
Frank Evans and Lazaros
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.
3D heating rate fields (monochromatic or broadband),
surface downwelling and upwelling fluxes (monochromatic or broadband).
Averaging for vertically integrated maps and
domain average profiles will be done at the comparison center.
Broadband calculations are optional.
Periodic boundary conditions
Monochromatic set of experiments:
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
Surface: Lambertian surface albedo=0.20
for both monochromatic and broadband (assumed spectrally invariant).
For each experiment set, run:
Two accuracies: high (as much as computationally
feasible), low (10 times less computer time)
Two cloud fields
Two solar zenith angles (0 and 60 degrees)
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.
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:
All the above files can also be dowloaded
by anonymous http to i3rc.gsfc.nasa.gov:
login name: anonymous
password: your e-mail address
cd Cu or cd Sc
Details about the input
files (including format)
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:
Cu cloud field (case 4)
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
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:
||0.67 2.13 11.0
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:
||0.67 2.13 11.0
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
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
For each cloud
field (case) and for both accuracies (high and low) perform the following
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.
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
Experiment 8: As Experiment 4,
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
+++++++++++++++ high Y
0 deg |
+++++++++++++++ low Y
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 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:
is the radiative quantity contained in the file. RQ
takes the following values: RQ index
(heating rate or flux convergence)
the cloud field case. For phase II the cloud field cases have been assigned
the following numbers:
LES Cu cloud
"accu"=H (for high accuracy runs)
or L (low accuracy runs).
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
"[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
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:
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:
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)
is the radiative quantity of interest (heating rate)
open (11, file='I3RC_Fc_4_L_HR_6.KIAE', status='unknown')
write (11, '(f8.5)') rq(ix,iy,iz)
Output format for flux files should be
like the one produced by the following sample Fortran code:
parameter (nx=64, ny=64)
is the radiative quantity of interest
open (11, file='I3RC_Fu_4_H_HR_5.KIAE', status='unknown')
write (11, '(f8.2)') rq(ix,iy)
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
See above for the meaning of "case"
Include only the error results in %. Output
format should be like the one produced by the following sample Fortran
(11, file='I3RC_errors_4_L_HR_6.UMBC2', status='unknown')
write (11, '(f10.2,f10.4)') (error(iq,ir), ir=0,nerr)
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.
Again, same procedure as in Phase I. Please
submit via anonymous http following the instructions below:
user ID: anonymous
Password: your e-mail address
Please notify Lazaros
Oreopoulos whenever you upload results.
For questions contact Lazaros