argopy 0.1.0

A python library for Argo data beginners and experts

Argo data python library

argopy is a python library that aims to easy Argo data access, visualisation and manipulation for regular users as well as Argo experts and operators.

Several python packages exist: we are currently in the process of merging and structuring these libraries to have a single powerfull tool.

Install

Since this is a library in active development, use direct install from this repo to benefit from the last version:

pip install git+http://github.com/euroargodev/argopy.git

Examples

Examples of data fetching, manipulation and visualisation are available on the erddap examples repository.

You can run and test live example notebooks on Binder (thanks Pangeo) here:

Usage

The primary data model used to manipulate Argo data is xarray.

Argo Data Fetcher

API usage:

    from argopy import DataFetcher as ArgoDataFetcher

    argo_loader = ArgoDataFetcher()
    argo_loader = ArgoDataFetcher(backend='erddap')
    argo_loader = ArgoDataFetcher(cachedir='tmp')

    argo_loader.region([-85,-45,10.,20.,0,1000.]).to_xarray()
    argo_loader.region([-85,-45,10.,20.,0,1000.,'2012-01','2014-12']).to_xarray()

    argo_loader.profile(6902746, 34).to_xarray()
    argo_loader.profile(6902746, np.arange(12,45)).to_xarray()
    argo_loader.profile(6902746, [1,12]).to_xarray()

    argo_loader.float(6902746).to_xarray()
    argo_loader.float([6902746, 6902747, 6902757, 6902766]).to_xarray()
    argo_loader.float([6902746, 6902747, 6902757, 6902766], CYC=1).to_xarray()

Devlopment roadmap:

We aim to provide high level helper methods to load Argo data from:

• Ifremer erddap
• local copy of the GDAC ftp folder (help wanted)
• the argovis dataset (help wanted)
• any other usefull access point to Argo data ?

At this point data are fetched in memory as xarray.DataSet. From there, it is easy to convert it to other formats like a Pandas dataframe:

ds = argo_loader.profile(6902746, 34).to_xarray()
df = ds.to_dataframe()

and to export it to files:

ds = argo_loader.region([-85,-45,10.,20.,0,1000.]).to_xarray()
ds.to_netcdf('my_selection.nc')
# or by profiles:
ds.argo.point2profile().to_netcdf('my_selection.nc')

Argo data manipulation with xarray

The argopy library provides an xarray accessor named argo to help manipulate and analyse data.

Example: Convert a collection of points to a collections of profiles:

from argopy import DataFetcher as ArgoDataFetcher
ds = ArgoDataFetcher(ds='bgc').float(5903248).to_xarray()
ds = ds.argo.point2profile()