Make your own forcing data from ERA5

Introduction: There are lots of forcing data can be used to drive the model, such as ERA5, NCEP (https://psl.noaa.gov/data/gridded/data.ncep.reanalysis.html), etc. Here, we recommend ERA5 to make your own single point forcing as the NCEP and others are too big to download. The ERA5 data can be obtained in a small scale, which usually light weight to download and store.

Download the required variables from the cdsapi

First, we will use the cdsapi package to download the data. If you don’t have the package installed, you can install it using the following command:

pip install cdsapi

cat <<EOF > ~/.cdsapirc
url: {api-url}
key: {uid}:{api-key}
EOF

How to get your CDS API?

note: it will take a long time to run this script, so you can run it in the background and check the output file later.

We also can use the interface to download the data. The code below is an example of how to download the data using the interface.

ref: https://cds.climate.copernicus.eu/cdsapp#!/dataset/reanalysis-era5-single-levels?tab=form

[1]:

from pyclmuapp import get_forcing
lat=51.5
lon=0.12
zbot=30
start_year=2012
end_year=2012
start_month=1
end_month=2
get_forcing(
    lat=lat, lon=lon, zbot=zbot,
    start_year=start_year, end_year=end_year,
    start_month=start_month, end_month=end_month,
    source='cds')

2024-06-27 12:00:16,424 INFO Welcome to the CDS
2024-06-27 12:00:16,424 INFO Sending request to https://cds.climate.copernicus.eu/api/v2/resources/reanalysis-era5-single-levels

download: ./era5_data/era5_single_2012_01_51.5_0.12.nc

2024-06-27 12:00:16,539 INFO Request is completed
2024-06-27 12:00:16,541 INFO Downloading https://download-0019.copernicus-climate.eu/cache-compute-0019/cache/data4/adaptor.mars.internal-1719485113.5101933-9971-11-4b2c9802-6dcb-4b24-9e4a-2705adec9046.nc to ./era5_data/era5_single_2012_01_51.5_0.12.nc (123.8K)
2024-06-27 12:00:16,865 INFO Download rate 382.4K/s
2024-06-27 12:00:17,862 INFO Welcome to the CDS
2024-06-27 12:00:17,862 INFO Sending request to https://cds.climate.copernicus.eu/api/v2/resources/reanalysis-era5-single-levels
2024-06-27 12:00:17,958 INFO Request is completed
2024-06-27 12:00:17,958 INFO Downloading https://download-0018.copernicus-climate.eu/cache-compute-0018/cache/data8/adaptor.mars.internal-1719485668.0006976-4897-15-6013a414-d43b-4ed3-820a-8cdfd184bfe1.nc to ./era5_data/era5_single_2012_02_51.5_0.12.nc (116K)

download: ./era5_data/era5_single_2012_02_51.5_0.12.nc

2024-06-27 12:00:18,261 INFO Download rate 382.6K/s

[1]:

'/Users/user/Documents/GitHub/pyclmuapp/era5_data/era5_forcing_51.5_0.12_30_2012_1_2012_2.nc'

command line

this is same as above

[2]:

! pyclmuapp --pyclmuapp_mode get_forcing \
    --lat 51.5 --lon 0.12 --zbot 30 \
    --start_year 2012 --end_year 2012 \
    --start_month 1 --end_month 2
# will download and save in the default folder `./era5_forcing/`
# the output file will be `./era5_forcing/era5_forcing_51.5_0.12_30_2012_01_2012_2.nc`

Namespace(init=False, pwd='/Users/user/Documents/GitHub/pyclmuapp', container_type='docker', input_path=None, output_path=None, log_path=None, scripts_path=None, pyclmuapp_mode='get_forcing', has_container=True, usr_domain=None, usr_forcing=None, usr_surfdata=None, output_prefix='_clm.nc', case_name='usp_case', run_startdate=None, stop_option='ndays', stop_n='1', run_type='coldstart', run_refcase='None', run_refdate='None', iflog=True, logfile='pyclmuapp.log', hist_type='GRID', hist_nhtfrq=1, hist_mfilt=1000000000, clean=False, surf_var=None, surf_action=0, forcing_var=None, forcing_action=0, script=None, urbsurf=None, soildata=None, pct_urban=[0, 0, 100.0], lat=51.5, lon=0.12, outputname='surfdata.nc', zbot=30, start_year=2012, end_year=2012, start_month=1, end_month=2)
download: ./era5_data/era5_single_2012_01_51.5_0.12.nc
2024-06-27 12:00:31,297 INFO Welcome to the CDS
2024-06-27 12:00:31,297 INFO Sending request to https://cds.climate.copernicus.eu/api/v2/resources/reanalysis-era5-single-levels
2024-06-27 12:00:31,373 INFO Request is completed
2024-06-27 12:00:31,373 INFO Downloading https://download-0019.copernicus-climate.eu/cache-compute-0019/cache/data4/adaptor.mars.internal-1719485113.5101933-9971-11-4b2c9802-6dcb-4b24-9e4a-2705adec9046.nc to ./era5_data/era5_single_2012_01_51.5_0.12.nc (123.8K)
2024-06-27 12:00:31,674 INFO Download rate 411.9K/s
download: ./era5_data/era5_single_2012_02_51.5_0.12.nc
2024-06-27 12:00:32,532 INFO Welcome to the CDS
2024-06-27 12:00:32,532 INFO Sending request to https://cds.climate.copernicus.eu/api/v2/resources/reanalysis-era5-single-levels
2024-06-27 12:00:32,637 INFO Request is completed
2024-06-27 12:00:32,637 INFO Downloading https://download-0018.copernicus-climate.eu/cache-compute-0018/cache/data8/adaptor.mars.internal-1719485668.0006976-4897-15-6013a414-d43b-4ed3-820a-8cdfd184bfe1.nc to ./era5_data/era5_single_2012_02_51.5_0.12.nc (116K)
2024-06-27 12:00:32,908 INFO Download rate 427.7K/s

test the forcing data

[3]:

! pyclmuapp \
    --container_type docker \
    --iflog True \
    --logfile "pyclmuapp.log" \
    --usr_forcing "era5_data/era5_forcing_51.5_0.12_30_2012_1_2012_2.nc" \
    --usr_surfdata "inputfolder/surfdata.nc" \
    --RUN_STARTDATE "2012-01-01" --STOP_OPTION "ndays" --STOP_N "15" \
    --RUN_TYPE "coldstart" \
    --hist_type "GRID" --hist_nhtfrq "1" \
    --hist_mfilt "1000000000" \
    --output_prefix "_clm.nc" \
    --CASE_NAME "pyclmuapp" \
    --run_type "coldstart" --run_refcase "None" --run_refdate "None" --clean True

Namespace(init=False, pwd='/Users/user/Documents/GitHub/pyclmuapp', container_type='docker', input_path=None, output_path=None, log_path=None, scripts_path=None, pyclmuapp_mode='usp', has_container=True, usr_domain=None, usr_forcing='era5_data/era5_forcing_51.5_0.12_30_2012_1_2012_2.nc', usr_surfdata='inputfolder/surfdata.nc', output_prefix='_clm.nc', case_name='pyclmuapp', run_startdate='2012-01-01', stop_option='ndays', stop_n='15', run_type='coldstart', run_refcase='None', run_refdate='None', iflog=True, logfile='pyclmuapp.log', hist_type='GRID', hist_nhtfrq=1, hist_mfilt=1000000000, clean='True', surf_var=None, surf_action=0, forcing_var=None, forcing_action=0, script=None, urbsurf=None, soildata=None, pct_urban=[0, 0, 100.0], lat=None, lon=None, outputname='surfdata.nc', zbot=30, start_year=2012, end_year=2012, start_month=1, end_month=12)
Folder 'inputfolder' already exists.
Folder 'outputfolder' already exists.
Folder 'logfolder' already exists.
Folder 'scriptsfolder' already exists.
Folder '/Users/user/Documents/GitHub/pyclmuapp/inputfolder/usp' created successfully!
Copying the file era5_forcing_51.5_0.12_30_2012_1_2012_2.nc to the /Users/user/Documents/GitHub/pyclmuapp/inputfolder/usp
The domain file is not provided
The case is:  pyclmuapp
The log file is:  pyclmuapp.log
The output file is:  {'original': ['/Users/user/Documents/GitHub/pyclmuapp/outputfolder/lnd/hist/pyclmuapp_clm0_2024-06-27_12-00-50_clm.nc']}