使用 pygrib 访问 GRIB2 文件的所有参数

Question

我正在尝试使用 pygrib 读取 GRIB2 文件。我设法打开文件并毫无问题地读取数据，但我需要自动化该过程，不幸的是每个文件都包含多个非常相似的字段：

1:Total Cloud Cover:% (avg):regular_ll:unknown:level 0 214:fcst time 0-1 hrs (avg):from 201705200000
2:Total Cloud Cover:% (avg):regular_ll:unknown:level 0 224:fcst time 0-1 hrs (avg):from 201705200000
3:Total Cloud Cover:% (avg):regular_ll:unknown:level 0 234:fcst time 0-1 hrs (avg):from 201705200000
4:Total Cloud Cover:% (avg):regular_ll:unknown:level 0 10:fcst time 0-1 hrs (avg):from 201705200000
5:Total Cloud Cover:% (instant):regular_ll:unknown:level 0 244:fcst time 1 hrs:from 201705200000
6:Total Cloud Cover:% (avg):regular_ll:unknown:level 0 211:fcst time 0-1 hrs (avg):from 201705200000

这些文件的唯一区别（如 pygrib 所见）是字段 typeOfFirstFixedSurface，但我不知道该字段是什么（并且在我获得 grib2 文件的网站上找不到相关信息）。我查看了每条消息的所有键/值参数，但没有找到任何其他有用的信息可以用来区分字段....

但是，当使用Panoply 时，我会看到更多参数，例如：

float Total_cloud_cover_convective_cloud(time=1, lat=721, lon=1440);
  :long_name = "Total cloud cover @ Convective cloud layer";
  :units = "%";
  :abbreviation = "TCDC";
  :missing_value = NaNf; // float
  :grid_mapping = "LatLon_Projection";
  :coordinates = "reftime time lat lon ";
  :Grib_Variable_Id = "VAR_0-6-1_L244";
  :Grib2_Parameter = 0, 6, 1; // int
  :Grib2_Parameter_Discipline = "Meteorological products";
  :Grib2_Parameter_Category = "Cloud";
  :Grib2_Parameter_Name = "Total cloud cover";
  :Grib2_Level_Type = "Convective cloud layer";
  :Grib2_Generating_Process_Type = "Forecast";

我可以明确地使用 long_name 或 Grib_Variable_Id 字段来区分消息，但我无法使用 pygrib 访问这些“参数”。

有没有办法使用 pygrib 访问这些参数？

Answer 1

我有很多的问题来弄清楚这种特殊的格式和工具可以帮助我阅读/解析它......最终，我最终使用了IRIS，结果非常凌乱的设置。一年半前，我在 Ubuntu 机器上使用 Python 2.7 完成了这项工作。我正在粘贴安装 IRIS 和所有可能的依赖项所需执行的步骤，希望这对您有所帮助，尽管整个设置中可能有很多过时的版本...

祝你好运！

# http://scitools.org.uk/iris/docs/latest/installing.html

# necessary steps for a clean machine
#
# sudo apt-get install gcc python-dev build-essential python-setuptools libpq-dev git unzip cmake
# pip install virtualenv
# pip install virtualenvwrapper
# mkdir ~/.virtualenvs
# nano ~/.bashrc
# export WORKON_HOME=$HOME/.virtualenvs
# source /usr/local/bin/virtualenvwrapper.sh
# . ~/.bashrc
# mkvirtualenv iris

pip install numpy
pip install biggus

sudo apt-get install libblas-dev liblapack-dev libatlas-base-dev gfortran
# OR
# sudo apt-get install python-numpy python-scipy python-matplotlib ipython ipython-notebook python-pandas python-sympy python-nose

pip install scipy

# cartopy dependecies
pip install cython

# https://github.com/OSGeo/proj.4
wget http://download.osgeo.org/proj/proj-4.9.1.tar.gz
tar -xzf proj-4.9.1.tar.gz
cd proj-4.9.1/
./configure
make
make install

# OR
# sudo apt-get install libproj-dev
# sudo apt-get install libgeos-dev

# http://sourceforge.net/projects/pyke/files/pyke/
wget http://sourceforge.net/projects/pyke/files/pyke/1.1.1/pyke-1.1.1.zip/download
unzip download
cd pyke-1.1.1/
python setup.py build
python setup.py install

pip install cartopy

# netcdf4 dependecies
# https://code.google.com/p/netcdf4-python/wiki/UbuntuInstall
# wget https://www.hdfgroup.org/ftp/HDF5/current/src/hdf5-1.8.16.tar (??????????????)
sudo apt-get install libhdf5-dev

pip install h5py

sudo apt-get install python-netcdf libnetcdf-dev libnetcdf4

git clone https://github.com/Unidata/netcdf4-python.git
cd netcdf4-python
python setup.py build
python setup.py install


# other iris dependencies
pip install cf_units

sudo apt-get install libudunits2-dev

nano ~/.bashrc
# check where exactly xml file is
export UDUNITS2_XML_PATH=/usr/local/share/doc/udunits/udunits2.xml
. ~/.bashrc

pip install pillow

# gribapi
# https://software.ecmwf.int/wiki/display/GRIB/GRIB+API+CMake+installation
wget https://software.ecmwf.int/wiki/download/attachments/3473437/grib_api-1.14.4-Source.tar.gz?api=v2
tar -xzf grib_api-1.14.4-Source.tar.gz?api=v2
mkdir build; cd build
cmake ../grib_api-1.14.0-Source -DENABLE_PYTHON=ON
make -j4
ctest -j4
make install

# OR
# sudo apt-get install libgrib-api-dev
# sudo apt-get install openjpeg-tools

cp -R /usr/local/lib/python2.7/site-packages/grib_api ~/.virtualenvs/iristest/lib/python2.7/site-packages/

# aaaand, here we go, iris!
git clone https://github.com/SciTools/iris.git
cd iris
python setup.py build
python setup.py install
# rejoice!

# pip freeze output:
# Biggus==0.12.0
# Cartopy==0.13.0
# cf-units==1.0.0
# Cython==0.23.4
# h5py==2.5.0
# Iris==1.10.0.dev0
# netCDF4==1.2.2
# numpy==1.10.2
# Pillow==3.0.0
# pyke==1.1.1
# pyshp==1.2.3
# scipy==0.16.1
# Shapely==1.5.13
# six==1.10.0

Answer 2

为了安装 iris，我使用 Anaconda 发行版：

conda install -c conda-forge iris

并且所有必需的软件包都立即安装，没有问题。 我有 Anaconda 3 版本。

干杯，

佩雷