Code for generating marine heatwave (MHW) metrics from observational data for: Kajtar, J.B., N.J. Holbrook, V. Hernaman, A catalogue of marine heatwave metrics and trends for the Australian region. J. South. Hemisph. Earth Syst. Sci., 71 (2021) 284–302. https://doi.org/10.1071/ES21014.
Marine heatwaves are calculated following the Hobday et al. (2016) definition, using the marineHeatWaves python module (https://github.com/ecjoliver/marineHeatWaves). Marine heatwave categories follow the definition given by Hobday et al. (2018).
This code has been written to generate MHW metrics for the marine region around Australia (100°E-170°E, 50°S-0°). The metrics are computed from daily observational sea surface temperature (SST) data, using NOAA 0.25° daily Optimum Interpolation Sea Surface Temperature (OISST) over the period 1982-2020. Marine heatwaves are computed with respect to the 1983-2012 climatology. The marine heatwave data are provided on a grid point basis across the domain. Area-averaged SST timeseries and marine heatwave metrics are also provided for five case study regions: the Western Australia coast, Torres Strait, Great Barrier Reef, Tasman Sea, and South Australian Basin.
| Directory | Description |
|---|---|
| code | Code for computing MHW metrics |
| marineHeatWaves | Customised MHW detection code |
| post-processing | Code for post-processing data |
| data | Output and source data |
Python code for computing MHW metrics. Data source paths must first be specified in each of the scripts. The raw observed daily sea surface temperature data (NOAA OISST) is not provided here, but more information about the data and how to access can be found at: https://doi.org/10.25921/RE9P-PT57.
| File | Description |
|---|---|
| compute_australian_mhw_stats.py | Compute MHW metrics across the Australian region. |
| store_aus_case_study_regions.py | Store area-averaged SST timeseries, for further processing. |
| plot_fig_case_studies.py | Processing and plotting of case study region MHW metrics. Code for generating Figs. 5-9. |
Marine heatwaves detection code, available at: https://github.com/ecjoliver/marineHeatWaves. The code provided here has been slightly adapted, but the original module should also work.
MATLAB code for post-processing of MHW metrics.
| File | Description |
|---|---|
| area_average.m | Function to compute an area-average |
| area_make.m | Function to compute a cell area array, used in area_average.m |
| findrange.m | Function to find a range in an array |
| pp_mhw_stats.m | Post-processing of MHW field data |
| pp_mhw_strongest.m | Post-processing of strongest and longest detected MHWs |
Various source and output data produced by the code.
| File | Description |
|---|---|
| oni.data.txt | Observed Oceanic Nino Index (ONI) data, provided by NOAA/PSL |
| sst_ts.aus.NOAA_OISST.AVHRR.v2-1_modified.nc | Area-averaged daily SST timeseries for case study regions |
| mhw_cats.aus.NOAA_OISST.AVHRR.v2-1_modified.nc | MHW metrics: annual field data |
| mhw_stats.processed.aus.NOAA_OISST.AVHRR.v2-1_modified.nc | MHW metrics: post-processed data for producing figures |
| mhw_strongest.processed.aus.NOAA_OISST.AVHRR.v2-1_modified.nc | MHW metrics: post-processed data of the strongest and longest MHWs |
Hobday, A.J., L. V. Alexander, S.E. Perkins-Kirkpatrick, D.A. Smale, S.C. Straub, E.C.J. Oliver, J.A. Benthuysen, M.T. Burrows, M.G. Donat, M. Feng, N.J. Holbrook, P.J. Moore, H.A. Scannell, A. Sen Gupta, T. Wernberg, A hierarchical approach to defining marine heatwaves, Prog. Oceanogr. 141 (2016) 227–238. https://doi.org/10.1016/j.pocean.2015.12.014.
Hobday, A.J., E.C.J. Oliver, A. Sen Gupta, J.A. Benthuysen, M.T. Burrows, M.G. Donat, N.J. Holbrook, P.J. Moore, M.S. Thomsen, T. Wernberg, D.A. Smale, Categorizing and naming marine heatwaves, Oceanography. 31 (2018) 162–173. https://doi.org/10.5670/oceanog.2018.205.
Kajtar, J.B., N.J. Holbrook, V. Hernaman, A catalogue of marine heatwave metrics and trends for the Australian region. J. South. Hemisph. Earth Syst. Sci., 71 (2021) 284–302. https://doi.org/10.1071/ES21014.
We acknowledge support from the Australian Government’s National Environmental Science Program (NESP) Earth Systems and Climate Change (ESCC) Hub, and the Australian Research Council’s Centre of Excellence for Climate Extremes. The research was conducted under ESCC Hub Project 5.8: ‘Marine and coastal climate services for extremes’. We acknowledge the input and support of project leader Kathleen L. McInnes and the whole Project 5.8 team. JBK and NJH acknowledge further support from the NESP Phase 2 Climate Systems Hub.
NOAA High Resolution SST data were provided by the NOAA National Centers for Environmental Information. We thank them for making this data publicly available. We acknowledge the compuational resources provided by the National Computational Infrastructure (NCI), which is supported by the Australian Government. We acknowledge Eric Oliver for the use of his marineHeatWaves python module, freely available at https://github.com/ecjoliver/marineHeatWaves.