PCMDI Published Content
Published August 7, 2026 | Version v9
Dataset Open

The System for Classification of Low-Pressure Systems (SyCLoPS) Dataset (Based on ERA5)

Authors/Creators

  • 1. ROR icon University of California, Davis

Description

This is the ERA5 System for Classification of Low-Pressure Systems (SyCLoPS) dataset version 9. SyCLoPS is an LPS classifier built upon the TempesteExtremes (TE) software. Details of SyCLoPS algorithms are described in the paper titled The System for Classification of Low-Pressure Systems (SyCLoPS): An All-in-One Objective Framework for Large-scale Data sets published on J. Geophys. Res. Atm.: [https://doi.org/10.1029/2024JD041287]. Please cite this paper if you use this dataset.

Important: The most up-to-date SyCLoPS codes are now kept on GitHub: [https://github.com/yepkids/SyCLoPS] 

SyCLoPS user manual: [https://climate.ucdavis.edu/syclops.php]
See Chapter 3 of the manual for instructions on how to load and use the output classified catalog

In the list of datasets below, "classified" refers to the output LPS catalogs with classification. "Input" refers to the input LPS catalogs that contains the parameters used for classification. "3hr" and "6hr" describes the detection time interval (temporal frequency).

Updates in this version:

  1. Reflects changes in the recent SyCLoPS v1.2 release (see GitHub page). Changes are summarized below:
  2. 2025 data is included.
  3. Introduced the new classification "Hybrid TC," mainly designed to recover missing TC detections in the North Atlantic. Details will be discussed in our next paper manuscript. Stay tuned for preprint.
  4. Added columns of LPS translation distance/speed ("distance") and moving direction ("direction").
  5. Improved data structure: Changed "0" and "1" flags to boolean data type. Minimized data bytes for a more compact file size.
  6. We removed the high-altitude branch and simplified the dry LPS branch (renamed to land LPS branch) in the classification. Please see an updated classification worflow below in the preview.

The following files can be obtained from version 4:

  1. The labeled size blobs of each year: "size_blobs_1979_2022.tar.gz"
  2. The labeled precipitation blobs of each year: "preci_blobs_1979_2022.tar.gz"

    For more recent size and precipitation blob files, and integrated kinetic energy (IKE) and weighted area mean precipitation calculated for each LPS node, please contact Yushan Han (yshhan@ucdavis.edu)

Other SyCLoPS-related data products:

  1. SyCLoPS HighresMIP LPS catalogs: Link
  2. SyCLoPS HighresMIP TC-only catalogs: Link

Please contact Yushan Han (yshhan@ucdavis.edu) if you have questions about the SyCLoPS framework. Please contact Paul Ullrich (paullrich@ucdavis.edu) if you have any questions about the TE software.

See below for a flowchart of the classification process. See the SyCLoPS manual for more details.

Files

SyCLoPS_flowchat_v1.2.png

Files (2.1 GB)

Name Size
md5:5989d154923fd31f316bb63fb95a4dd7
327.9 MB Download
md5:eb87ee5e6571ec2e99213a9b1efa9aa9
206.8 MB Download
md5:825b2470da6649a1119b272e71fdbdcc
215.5 kB Preview Download
md5:90975c85ef0a256ebcd1ecbe4fdda114
1.0 GB Download
md5:b03b2d8b546ebeb07518028cc14c6bdb
588.6 MB Download

Additional details

Software

Repository URL
https://github.com/yepkids/SyCLoPS

References

  • Ullrich, P. A., & Zarzycki, C. M. (2017). Tempestextremes: A framework for scale-insensitive pointwise feature tracking on unstructured grids. Geoscientific Model 1154 Development , 10 (3), 1069–1090.
  • Ullrich, P. A., Zarzycki, C. M., McClenny, E. E., Pinheiro, M. C., Stansfield, A. M., & Reed, K. A. (2021). Tempestextremes v2.1: A community framework for feature detection, tracking and analysis in large datasets. Geoscientific model development discussions, 2021 , 1–37.
  • Han, Y., & Ullrich, P. A. (2025). The system for classification of low-pressure systems (SyCLoPS): An all-in-one objective framework for large-scale data sets. Journal of Geophysical Research: Atmospheres, 130, e2024JD041287.