Preparing AQMBC Output for CMAQ

CMAQ expects BCON files to have 25 instantaneous outputs that cover from 00Z on the simulation day to 00Z on the next day. aqmbc is run on individual files, which can be a single hour or a few hours. Therefore, often the aqmbc outputs need to be combined.

This example uses single hour outputs from GEOS-CF to make CMAQ-ready BCON inputs. That is what aqmbc.cmaq.cmaqready is for. To do its jobs, cmaqready takes a date to be made, the inpaths to make it from, and the outpath to save it to.

The example below creates two days of output from 18 input files. The inputs cover 2023-04-30T21:30Z to 2023-05-03T00:30Z in 3-hour intervals. To create the inputs, modify the geoscf_example.py script to run for more hours. The outputs each cover 25 hours from 00Z to 00Z+1day. To run the example, you must have already created the inputs. After the run is complete, you will have the outputs.

Required Inputs:

• geoscf_mcx_tavg_1hr_g1440x721_v36_2023-04-30T2130Z_12US1_BCON.nc

• geoscf_mcx_tavg_1hr_g1440x721_v36_2023-05-01T0030Z_12US1_BCON.nc

• … 14 others …

• geoscf_mcx_tavg_1hr_g1440x721_v36_2023-05-02T2130Z_12US1_BCON.nc

• geoscf_mcx_tavg_1hr_g1440x721_v36_2023-05-03T0030Z_12US1_BCON.nc

Produced Outputs:

• geoscf_mcx_tavg_1hr_g1440x721_v36_2023-05-01_12US1_BCON_hourly.nc

• geoscf_mcx_tavg_1hr_g1440x721_v36_2023-05-02_12US1_BCON_hourly.nc

Import libraries

from pandas import date_range, to_timedelta
import aqmbc

User Inputs

# Use the domain name for your domain
gdnam = '12US1'

# Define the date range of interest
outdates = date_range('2023-05-01', '2023-05-02', freq='1d')

# Define a strftime templates for paths from aqmbc (intmpl) that need to be
# concatenated and interpolated to make CMAQ-ready files (outtmpl)
intmpl = f'geoscf_mcx_tavg_1hr_g1440x721_v36_%Y-%m-%dT%H%MZ_{gdnam}_BCON.nc'
outtmpl = f'geoscf_mcx_tavg_1hr_g1440x721_v36_%Y-%m-%d_{gdnam}_BCON_hourly.nc'

Daily Processing

# For each output date, concatenate input files and interpolate hourly output.
for date in outdates:
    # Define output path
    outpath = date.strftime(outtmpl)
    # Get paths for date-1day 21:30 ... date+1day 00:30 by 3-hours
    indates = date_range(date, freq='3h', periods=10) + to_timedelta('-2.5h')
    inpaths = indates.strftime(intmpl)
    # Make 1 output with 25h from 10 single-hour inputs
    aqmbc.cmaq.cmaqready(date, inpaths, outpath=outpath)