View in EDS

Subsurface manifestation of marine heat waves in the southwestern Indian Ocean

Saved in:
Bibliographic Details
Title: Subsurface manifestation of marine heat waves in the southwestern Indian Ocean
Authors: C. B. Welch, N. Malan, D. Mawren, T. Morris, J. Sprintall, J. C. Hermes
Source: Ocean Science, Vol 21, Pp 1695-1708 (2025)
Publisher Information: Copernicus GmbH, 2025.
Publication Year: 2025
Subject Terms: Environmental sciences, Geography. Anthropology. Recreation, GE1-350
Description: Marine heat waves (MHWs) are extreme events of prolonged, anomalously warm ocean temperatures. Globally, marine heat waves are increasing in frequency and intensity and are responsible for long-term impacts on marine ecosystems, which have devastating socio-economic consequences. A key gap in our understanding of MHWs is how they manifest in the subsurface. This paper uses satellite sea surface temperature (SST) data and in situ subsurface temperature observations from expendable bathythermographs (XBTs) to investigate the anomalous water temperature characteristics associated with surface-identified MHWs in the southwestern Indian Ocean (SWIO) and how they progress through the water column. We find that (1) regions of high eddy activity in the Mozambique Channel and southeast of Madagascar, where eddy kinetic energy is high and SST variability is low, are primarily characterised by the occurrence of abrupt and intense MHWs and that (2) the frequency, duration and intensity of these events are largely associated with mesoscale activity. In these eddy corridors, surface-detected MHW case studies demonstrate a strong, deep-reaching subsurface temperature anomaly signal with a maximum intensity below the surface. The majority of these MHWs are associated with anticyclonic eddies, which provide a possible mechanism for the deep extent of the surface MHWs. Improving our understanding of the interaction between mesoscale features and subsurface MHW characteristics will benefit the prediction of MHWs and management of the regions' biodiversity.
Document Type: Article
Other literature type
File Description: application/pdf
Language: English
ISSN: 1812-0792
DOI: 10.5194/os-21-1695-2025
Access URL: https://os.copernicus.org/articles/21/1695/2025/
https://doaj.org/article/d06568c752804bd3b88dfeacc4d3f210
Rights: CC BY
Accession Number: edsair.doi.dedup.....724a9cf5d7bc1dfd7370c4f2a4df24d5
Database: OpenAIRE
Description
Abstract:Marine heat waves (MHWs) are extreme events of prolonged, anomalously warm ocean temperatures. Globally, marine heat waves are increasing in frequency and intensity and are responsible for long-term impacts on marine ecosystems, which have devastating socio-economic consequences. A key gap in our understanding of MHWs is how they manifest in the subsurface. This paper uses satellite sea surface temperature (SST) data and in situ subsurface temperature observations from expendable bathythermographs (XBTs) to investigate the anomalous water temperature characteristics associated with surface-identified MHWs in the southwestern Indian Ocean (SWIO) and how they progress through the water column. We find that (1) regions of high eddy activity in the Mozambique Channel and southeast of Madagascar, where eddy kinetic energy is high and SST variability is low, are primarily characterised by the occurrence of abrupt and intense MHWs and that (2) the frequency, duration and intensity of these events are largely associated with mesoscale activity. In these eddy corridors, surface-detected MHW case studies demonstrate a strong, deep-reaching subsurface temperature anomaly signal with a maximum intensity below the surface. The majority of these MHWs are associated with anticyclonic eddies, which provide a possible mechanism for the deep extent of the surface MHWs. Improving our understanding of the interaction between mesoscale features and subsurface MHW characteristics will benefit the prediction of MHWs and management of the regions' biodiversity.
ISSN:18120792
DOI:10.5194/os-21-1695-2025