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XCDAT: Xarray Extended with Climate Data Analysis Tools

XCDAT: Xarray Extended with Climate Data Analysis Tools

XCDAT is an extension of xarray for climate data analysis on structured grids. It serves as a spiritual successor to the Community Data Analysis Tools (CDAT) library.

Planned Features

XCDAT aims to provide utilities for general xarray usage and climate domain specific features.

These features include:

  • Support for CF compliant, E3SM non-CF compliant, and common metadata

  • Extension of xarray’s open_dataset() and open_mfdataset() to apply common operations

    • Generate bounds for all supported axes if they don’t exist

    • Optional decoding of CF (via xarray) and non-CF time units (via xcdat)

    • Optional centering of time coordinate using time bounds

    • Optional conversion of longitudinal axes orientation

  • Robust handling of coordinates and its associated bounds

    • Name-agnostic retrieval of CF compliant coordinates and bounds using cf_xarray

    • Generating bounds for an axis or axes if they don’t exist

    • Ability to operate on both [0, 360) and [-180, 180) longitudinal axis orientations

  • Temporal averaging

    • Calculate time series averages, climatologies, and departures

    • Weighted or unweighted

    • Optional centering of time coordinates using time bounds

  • Geospatial weighted averaging over rectilinear grid

    • Optional specification of regional domain

  • Horizontal and vertical structured regridding

    • Operate on rectilinear and cuvilinear grids

  • Parallelism of XCDAT features using Dask

Feature Criteria

Features must meet the following criteria before being considered for implementation:

  1. Climate domain functionality and/or general xarray utility isn’t provided natively with xarray

  2. No other existing and actively developed xarray-based packages implement the feature

    • For example, cf_xarray already handles interpretation of CF convention attributes on xarray objects

  3. Must be generally reusable and not specific to a single use case

  4. Must be relatively simple and lightweight to implement and use

Acknowledgement

This software is jointly developed by scientists and developers from the Energy Exascale Earth System Model (E3SM) Project and Program for Climate Model Diagnosis and Intercomparison (PCMDI). The work is performed for the E3SM project, which is sponsored by Earth System Model Development (ESMD) program, and the Simplifying ESM Analysis Through Standards (SEATS) project, which is sponsored by the Regional and Global Model Analysis (RGMA) program. ESMD and RGMA are programs for the Earth and Environmental Systems Sciences Division (EESSD) in the Office of Biological and Environmental Research (BER) within the Department of Energy’s Office of Science.

License

SPDX-License-Identifier: (Apache-2.0)

See LICENSE for details

LLNL-CODE-819717

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