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Spatiotemporal Evolution of Marine Heatwaves Globally
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  • Hillary Scannell,
  • Cassia Cai,
  • LuAnne Thompson,
  • Daniel Bridger Whitt,
  • David John Gagne,
  • Ryan Abernathey
Hillary Scannell
Lamont-Doherty Earth Observatory
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Cassia Cai
University of Washington

Corresponding Author:[email protected]

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LuAnne Thompson
University of Washington
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Daniel Bridger Whitt
NASA Ames Research Center
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David John Gagne
National Center for Atmospheric Research
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Ryan Abernathey
Columbia University
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The spatiotemporal evolution of marine heatwaves (MHWs) is explored using a tracking algorithm termed Ocetrac that provides objective characterization of MHW spatiotemporal evolution. Candidate MHW grid points are defined in detrended gridded sea temperature data using a seasonally varying temperature threshold. Identified MHW points are collected into spatially distinct objects using edge detection with weak sensitivity to edge detection and size threshold criteria. These MHW objects are followed in space and time while allowing objects to split and merge. Ocetrac is applied to monthly satellite sea surface temperature data from September 1981 through January 2021. The resulting MHWs are characterized by their intensity, duration, and total area covered. The global analysis shows that MHWs in the Gulf of Maine and Mediterranean Sea evolve within a relatively small region, while major MHWs in the Pacific and Indian Oceans are linked in space and time. The largest and most long lasting MHW using this method lasts for 60 months from November 2013 to October 2018, encompassing previously identified MHW events including those in the Northeast Pacific (2014-2015), the Tasman Sea (2015-2016, 2017-2018), and the Great Barrier Reef (2016).
21 Jul 2023Submitted to ESS Open Archive
23 Jul 2023Published in ESS Open Archive