This repository contains climatologies, anomalies, and marine heatwave
categories for global sea surface temperature, derived from the 
European Space Agency Sea Surface Temperature Climate Change Initiative 
(ESA SSTCCI).

DIRECTORY STRUCTURE
{Input Type}/{Climatology}/{Threshold Percentile}/{Duration}

Input Type: Either "Raw" or "Detrended"

Climatology: "WMO_Climatology" (1991-2020), "Reanalysis_Climatology" 
(1993-2016), or one of several 30-year windows starting from 1982-2011 
("1982_2011_Climatology") and ending with 1995-2024 
("1995_2024_Climatology")

Threshold Percentile: Highest percentile post which that day is 
classified as an anomalous event; may be "90p", "95p", "99p"

Duration: 5 days, 10 days or 30 days

Not every possible combination of the above exists in this dataset, 
though it may be extended in the future.

Within these directories, we have the following kinds of files:
 * daily climatologies, named following the format: 
    "{day-of-year}_{Input Type}_{Threshold Percentile}_{Climatology}_SSTCCI.nc"
 * daily anomalies, named following the format:
    "{YYYYMMDD}_{Input Type}_{Threshold Percentile}_{Climatology}_anomalies_SSTCCI.nc"
 * daily categories, named following the format:
    "{YYYYMMDD}_{Input Type}_{Threshold Percentile}_{Climatology}_categories_SSTCCI.nc"

All files are NetCDF files in CF-compliant format.

The computation of anomalies and categories is based on the Hobday et 
al (2016) definition.

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DATA DESCRIPTION
DAILY CLIMATOLOGY FILES:
Dimensions: lon, lat, day of year (daily)
Temporal Coverage: 1 day of year
Spatial Coverage: Global
Variables: p10 (10th percentile), p50 (median SST), 
p{Threshold Percentile} (e.g. “p90”, “p95”, “p99”), threshCS (threshold 
for cold spells), threshHW (threshold for heatwaves)
Units for all non-dimensional variables: kelvin
Missing Value: NaN

DAILY ANOMALY AND CATEGORY FILES:
Dimensions: lon, lat, time
Temporal Coverage: 1 date as indicated in the filename as YYYYMMDD
Spatial Coverage: Global
Variable: anom (in the anomaly files) and cat (in the category files)

*** Please note that all files have been compressed and therefore have
a scale value and offset as indicated in the metadata. ***

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CODE
The code used to generate these files is under embargo and will be
released soon.

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RELATED WORK
Please cite the following manuscript if using this dataset:
Hayward, A., et al. (2025). Marine Heat waves - Multiple Analysis / Definitions (MHW-MAD)

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DOI
DOIs for the paper and dataset are forthcoming.

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CONTACT
For questions or requests, please contact:
Alex Hayward - algh at dmi dot dk
Nishka Dasgupta - nid at dmi dot dk