ARLreader

Python only library to read the NOAA ARLs packed format for HYSPLIT (https://ready.arl.noaa.gov/HYSPLIT.php). Currently only wokring for the GDAS1 assimilation data (https://www.ready.noaa.gov/gdas1.php), which is also available from ARL (ftp://arlftp.arlhq.noaa.gov/pub/archives/gdas1). A more extensive description of the format is provided in: Things to know when working with the ARL binary fomat

Currently only GDAS1 and the profiles of GDAS0p5 are working.

Usage

Reading a 2d Field:

import ARLreader as Ar

gdas = Ar.reader('data/gdas1.apr14.w1')
print('indexinfo ', gdas.indexinfo)
print('headerinfo ', gdas.headerinfo)
for i, v in gdas.levels.items():
    print(i, ' level ', v['level'], list(map(lambda x: x[0], v['vars'])))
# load_heightlevel(day, houer, level, variable)
recinfo, grid, data = gdas.load_heightlevel(2, 3, 0, 'RH2M')

Read the profile at a given location an write it to a text file with load_profile(day, hour, (lat, lon)):

profile, sfcdata, indexinfo, ind = Ar.reader('data/gdas1.apr14.w1').load_profile(2, 3, (51.3, 12.4))
print(profile)
Ar.write_profile('testfile.txt', indexinfo, ind, (51.3, 12.4), profile, sfcdata)

Get the filename from a datetime Ar.fname_from_date(datetime.datetime(2014, 4, 3)).

Requirements

Anaconda3 can make your life easier, especially when you were mad with using different python versions. But it's free of your choice.

Installation

Installation within a new virtual environment

create a new virtual environment

conda create -n ARLreader   # you can choose other names as well, 
                            # but using the consistent name during the installation.
activate ARLreader   # activate the virtual environement

conda install python=3.6   # install python, shipped with `pip`, `setuptools`...
git clone https://github.com/martin-181/ARLreader.git   # download the code repository
cd ARLreader
pip install -r requirements.txt   # install the dependencies for ARLreader

compile ARLreader

python setup.py install

Usage

ARLreader -h   # prompt up the help

Below is the help messages for using ARLreader:

usage: ARLreader [-h] [-s START_TIME] [-e END_TIME] [--latitude LATITUDE]
                 [--longitude LONGITUDE] [--station STATION]
                 [-f GLOBAL_FOLDER] [-o PROFILE_FOLDER] [--force]

extract the GDAS1 profile from GDAS1 global binary data.

optional arguments:
  -h, --help            show this help message and exit
  -s START_TIME, --start_time START_TIME
                        start time of your interests (yyyymmdd-HHMMSS).
                        e.g.20151010-120000
  -e END_TIME, --end_time END_TIME
                        stop time of your interests (yyyymmdd-HHMMSS).
                        e.g.20151010-120000
  --latitude LATITUDE   latitude of your station. (-90, 90).
                        Default: 30.533721
  --longitude LONGITUDE
                        longitude of your station. (0, 360).
                        Default: 114.367216
  --station STATION     station name.
                        Default: wuhan
  -f GLOBAL_FOLDER, --global_folder GLOBAL_FOLDER
                        folder for saving the GDAS1 global files.
                        e.g., 'C:\Users\zhenping\Desktop\global'
  -o PROFILE_FOLDER, --profile_folder PROFILE_FOLDER
                        folder for saving the extracted profiles
                        e.g., 'C:\Users\zhenping\Desktop\wuhan'
  --force               force to download the GDAS1 global dataset (not suggested)

setup the reader for a new station

ARLreader -s 20190920-000000 -e 20190923-000000 --latitude 51.35 --longitude 12.35 --station leipzig -f /Users/zhenping/Data/global -o /Users/zhenping/Data/leipzig

Tests

python3 -m pytest -v

License

The code is partly based on a prior implementation in IDL by Patric Seifert.

Copyright 2017, Martin Radenz MIT License