Documentation
ALCF output
The ALCF output is stored in NetCDF files. Below is a description of variables
contained in the data files. Variable names follow the
CMIP5 standard output.
Time is stored as Julian date
and can be converted to Unix time (the number of non-leap seconds since
1970-01-01 00:00 UTC) with the formula (time - 2440587.5)*86400
.
model
alcf model
output is a 2-dimensional “curtain” of model data at a given location
over a length of time or along a ship track.
Variable | Description | Dimensions | Units |
---|---|---|---|
cl | cloud area fraction in atmosphere layer | time, level | % |
cli | mass fraction of cloud ice in air | time, level | 1 |
clw | mass fraction of cloud liquid water in air | time, level | 1 |
lat | latitude | time | degrees north |
lon | longitude | time | degrees east |
orog | surface altitude | time | m |
pfull | air pressure | time, level | Pa |
ps | surface air pressure | time | Pa |
ta | air temperature | time, level | K |
time | time | time | days since -4712-01-01 12:00 |
zfull | height above reference ellipsoid | time, level | m |
cosp
alcf simulate
output is a 2-dimensional “curtain” of simulated backscatter
at a given location over a length of time or along a ship track.
Variable | Description | Dimensions | Units |
---|---|---|---|
backscatter | total attenuated backscatter coefficient | time, level, column | m-1.sr-1 |
backscatter_mol | total attenuated molecular backscatter coefficient | time, level | m-1.sr-1 |
lat | latitude | time | degrees north |
lon | longitude | time | degrees east |
pfull | air pressure | time, level | Pa |
time | time | time | days since -4712-01-01 12:00 |
zfull | height above reference ellipsoid | time, level | m |
lidar
alcf lidar
output is a 2-dimensional “curtain” of observed or simulated
backscatter at a given location over a length of time or along a ship track.
Variable | Description | Dimensions | Units |
---|---|---|---|
backscatter | total attenuated backscatter coefficient | time, range | m-1.sr-1 |
backscatter_sd | total attenuated backscatter coefficient standard deviation | time, range | m-1.sr-1 |
cbh | cloud base height | time | m |
cloud_mask | cloud mask | time, range | 1 |
lr | lidar ratio | time | sr |
time | time | time | days since -4712-01-01 12:00 |
zfull | height above reference ellipsoid | time, level | m |
stats
alcf stats
output contains histograms and summary statistics calculated
from a 2-dimensional “curtain” of observed or simulated backscatter.
Variable | Description | Dimensions | Units |
---|---|---|---|
backscatter_avg | total attenuated backscatter coefficient average | zfull | m-1.sr-1 |
backscatter_full | total attenuated backscatter coefficient | backscatter_full | m-1.sr-1 |
backscatter_hist | backscatter histogram | backscatter_full, zfull | % |
backscatter_mol_avg | total attenuated molecular backscatter coefficient average | zfull | m-1.sr-1 |
backscatter_sd_full | total attenuated backscatter coefficient standard deviation | backscatter_sd_full | m-1.sr-1 |
backscatter_sd_hist | total attenuated backscatter coefficient standard deviation histogram | backscatter_sd_full | % |
backscatter_sd_z | total attenuated backscatter coefficient standard deviation height above reference ellipsoid | m | |
cl | cloud area fraction in atmosphere layer | zfull | % |
clt | cloud area fraction | % | |
n | number of profiles | 1 | |
zfull | height above reference ellipsoid | zfull | m |