ALCF-MODEL(1)

NAME
alcf-model - Extract model data at a point or along a track.

SYNOPSIS
alcf model <type> point: { <lon> <lat> } time: { <start> <end> } [options] [--] <input> <output>
alcf model <type> track: <track> [options] [--] <input> <output>

DESCRIPTION
Arguments following -- are treated as literal strings. Use this delimiter if the input or output file names might otherwise be interpreted as non-strings, e.g. purely numerical file names.

ARGUMENTS

○   type: Input data type (see Types below).

○   input: Input directory.

○   output: Output directory.

○   lon: Point longitude (degrees East).

○   lat: Point latitutde (degrees North).

○   start: Start time (see Time format below).

○   end: End time (see Time format below).

○   track: <file>, track: { <file>... }: One or more track NetCDF files (see Files below). If multiple files are supplied and time_bnds is not present in the files, they are assumed to be multiple segments of a discontinous track unless the last and first time of adjacent tracks are the same.

○   options: See Options below.

OPTIONS

njobs: <n>
    Number of parallel jobs. Default: number of CPU cores.

-r  Process the input directory recursively.

--track_lon_180
    Expect track longitude between -180 and 180 degrees. This option is no longer needed as the conversion is automatically. [deprecated]

override_year: <year>
    Override year in the track. Use if comparing observations with a model statistically and the model output does not have a corresponding year available. The observation time is converted to the same time relative to the start of the year in the specified year. Note that if the original year is a leap year and the override year is not, as a consequence of the above 31 December is mapped to 1 January. The output retains the original year as in the track, even though the model data come from the override year. Default: none.

track_gap: <interval>
    If the interval is not 0, a track file is supplied, the time_bnds variable is not defined in the file and any two adjacent points are separated by more than the specified time interval (seconds), then a gap is assumed to be present between the two data points, instead of interpolating location between the two points. Default: 21600 (6 hours).

TYPES

amps
    Antarctic Mesoscale Prediction System (AMPS).

era5
    ERA5.

icon
    ICON.

icon_intake_healpix
    ICON through Intake-ESM on HEALPix grid.

jra55
    JRA-55.

merra2
    Modern-Era Retrospective Analysis for Research and Applications, Version 2 (MERRA-2).

nzcsm
    New Zealand Convection Scale Model (NZCSM).

nzesm
    New Zealand Earth System Model (NZESM). [Experimental]

um  UK Met Office Unified Model (UM).

TIME FORMAT
YYYY-MM-DD[THH:MM[:SS]], where YYYY is year, MM is month, DD is day, HH is hour, MM is minute, SS is second. Example: 2000-01-01T00:00:00.

FILES
The track file is a NetCDF file containing 1D variables lon, lat, time, and optionally time_bnds. time and time_bnds are time in format conforming with the CF Conventions (has a valid units attribute and optional calendar attribute), lon is longitude between 0 and 360 degrees and lat is latitude between -90 and 90 degrees. If time_bnds is provided, discontinous track segments can be specified if adjacent time bounds are not coincident. The variables lon, lat and time have a single dimension time. The variable time_bnds has dimensions (time, bnds).

EXAMPLES
Extract MERRA-2 model data in M2I3NVASM.5.12.4 at 45 S, 170 E between 1 and 2 January 2020 and store the output in the directory alcf_merra2_model.

    alcf model merra2 point: { -45.0 170.0 } time: { 2020-01-01 2020-01-02 } M2I3NVASM.5.12.4 alcf_merra2_model

COPYRIGHT
Copyright © 2019–2024 Peter Kuma, Adrian J. McDonald, Olaf Morgenstern, Richard Querel, Israel Silber and Connor J. Flynn.

BUG REPORTING
Report bugs to Peter Kuma (peter@peterkuma.net).

SEE ALSO
alcf(1), alcf-auto(1), alcf-calibrate(1), alcf-compare(1), alcf-convert(1), alcf-download(1), alcf-lidar(1), alcf-plot(1), alcf-simulate(1), alcf-stats(1)