WRF Software Testing
The testing conducted on the WRF code to insure bit-for-bit behavior on differing
processor counts runs through hundreds of short forecasts in about 30 minutes. These
simulations are very short (about 10 time steps). The purpose is to activate as many
possible physics options. If single processor vs multiple processor results differ,
then there is a strong likelihood that improper initialization of variables or
missing communications or race conditions exist. While tracking down the root cause
of the problem is extremely time consuming, physics options that exhibit clean
bit-wise reproducible results are more likely to be robust. This testing is handled
entirely with a newly developed mechanism designed to run on small desktops, or with
additional scripting on distributed cluster systems.
See https://github.com/davegill/wrf-coop/blob/master/README_user.md
===========================
WRF Test Framework
===========================
1. Overview
The WRF Testing Framework is designed to build, test, and analyze test results for
one or more versions of the WRF model. This is a docker containerized solution that
is utilized for interactive testing and is also part of the WRF automated jenkins
testing.
COMPILERS:
GNU fortran versions 8 and 9.
PARALLEL BUILD CONFIGURATIONS:
Serial (single-processor) build
OpenMP (multithreaded, shared memory) build
MPI (multiprocessor, distributed memory) build
WRF COMPILE-TIME VARIATIONS
ARW
ARW real*8
ARW Nested
ARW Moving Nest
NMM HWRF
CHEM
Idealized Fire
Idealized Super Cell
Idealized Super Cell real*8
Idealized Baroclinc Wave
Idealized 2D Hill
Idealized Single Column Model
ARW em_real RUN-TIME VARIATIONS
Adaptive Time Stepping
Digital Filtering
FDDA: Spectral nudging, obs nudging, surface and upper air nudging
Stochastic Forcing
Nesting
Vertical Nesting
Hybrid and Terrain Following Vertical Coordinates
Dry and Moist Potential Temperature
2. Physics Options Applied in WRF Tests
The following Table and associated table Key summarizes the combinations of physics
options that are tested for WRF. It is important to note that while the choice of
one physics option should not influence the choice of another physics option (i.e.,
the choice of a microphysics scheme should be independent of the cumulus scheme choice),
in practice certain options are developed and tested for a small subset of other physics
option combinations. Therefore, the following table is useful as a guide for
combinations of WRF physics options that are known to provide bit-for-bit results
between serial and MPI versions of WRF. Each row in the table represents a specific
test, and each column a specific physics option. Each of the physics combinations
listed in the tables can be considered a "safe" combination that will provide successful
short-term forecasts with bit-for-bit results when comparing single-processor output
against multi-processor output.
KEY 1: Column Labels (Tables 1-7)
----------------------------------------
NL => Test Namelist Identifier
PBL => Planetary Boundary Layer Scheme
CU => Cumulus Scheme
MP => Microphysics Scheme
LW => Longwave Radiation Scheme
SW => Shortwave Radiation Scheme
SFC => Surface Physics Scheme
LAND => Land Surface Scheme
URB => Urban Physics Scheme
SHCU => Shallow Cumulus Scheme
TOPO => Topography-Following Wind Scheme
----------------------------------------
KEY 2: Test Namelist Codes (Tables 1-7)
----------------------------------------
AD => Adaptive Time Stepping
DF => Digital Filtering
FD => FDDA
NE => Basic Nesting
VN => Vertical Nesting
----------------------------------------
TABLE 1:
WRF ARW Tests, Providing Successful 10 Time Step Forecasts,
and Bit-for-Bit Results for
Serial vs. MPI Runs and Serial vs. OpenMP Runs
NL MP CU LW SW PBL SFC LSM URB
3dtke D D D D D 1 D 0
conus D D D D D D D 0
rap 28 3 4 4 5 5 3 0
tropical D D D D D D D 0
03 3 3 24 24 4 4 1 0
03DF 3 3 4 4 4 4 1 0
03FD 3 3 4 4 4 4 1 0
06 6 6 24 24 8 2 1 0
07NE 8 14 5 5 8 1 2 2
10 10 2 1 2 4 4 7 0
11 10 2 1 2 4 4 7 0
14 3 6 3 3 4 4 3 0
16 8 14 5 5 9 2 7 0
16DF 8 14 5 5 9 2 7 0
17 4 2 3 3 2 2 2 0
17AD 4 2 3 3 2 2 2 0
18 8 6 5 5 10 10 7 0
20 4 1 1 2 12 1 2 0
20NE 4 1 1 2 12 1 2 0
38 2 14 4 4 2 2 7 0
48 3 3 24 24 4 4 1 0
49 3 1 24 24 1 91 2 0
50 3 1 24 24 1 91 4 0
51 3 1 24 24 1 91 4 0
52 17 3 24 24 4 4 1 0
52DF 17 3 4 4 4 4 1 0
52FD 17 3 4 4 4 4 1 0
60 6 11 24 24 1 1 4 0
60NE 6 11 4 4 1 1 4 0
65DF 28 7 4 4 9 2 3 0
66FD 3 1 4 4 4 4 1 0
71 8 1 4 4 1 1 2 0
78 52 1 4 4 1 1 2 0
79 2 14 4 4 5 2 7 0
cmt 6 11 4 4 1 1 2 0
kiaps1NE 16 14 14 14 11 1 4 0
kiaps2 16 14 14 14 1 91 4 1
solaraNE 8 1 4 4 5 5 2 3
NL MP CU LW SW PBL SFC LSM URB
TABLE 2:
WRF ARW Tests, Providing Successful 10 Time Step Forecasts,
and Bit-for-Bit Results for
Serial vs. MPI Runs and Serial vs. OpenMP Runs
REAL*8
NL PBL CU MP LW SW SFC LAND URB SHCU TOPO
14 4 6 3 3 3 4 3 0 0 0
17AD 2 2 4 3 3 2 2 0 0 0
NL PBL CU MP LW SW SFC LAND URB SHCU TOPO
TABLE 3:
WRF Idealized Supercell Tests, Providing Successful 10 Time Step Forecasts,
and Bit-for-Bit Results for
Serial vs. MPI Runs and Serial vs. OpenMP Runs
NL PBL CU MP LW SW SFC
02NE 0 0 1 0 0 1
03 0 0 1 0 0 1
03NE 0 0 1 0 0 1
04 0 0 2 0 0 1
NL PBL CU MP LW SW SFC
TABLE 4:
WRF Idealized B-Wave Tests, Providing Successful 10 Time Step Forecasts,
and Bit-for-Bit Results for
Serial vs. MPI Runs and Serial vs. OpenMP Runs
NL PBL CU MP LW SW SFC
1NE 0 0 1 0 0 0
2 0 0 1 0 0 0
2NE 0 0 1 0 0 0
3 0 0 2 0 0 0
NL PBL CU MP LW SW SFC