Detection and spatio-temporal variation of marine heatwaves in the Gulf of Guinea, Nigeria
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Date
2019-09-04
Journal Title
Journal ISSN
Volume Title
Publisher
Academic Journals (Journal of Oceanography and Marine Science)
Abstract
Time series analyses spanning 30 years (1988 - 2017) on spatial and temporal variations in sea surface
temperatures reveal the occurrence of marine heatwaves (MHWs) within the Nigerian segment of the
Gulf of Guinea. For specific focus, three locations were also chosen along Nigeria’s coastal zone,
namely Lagos lagoon (western region), the Niger Delta (Forcados/Central region) and outer Cross River
estuary (eastern region). Daily SST data was subjected to MHW detection algorithm, and then examined
using Gaussian and Poisson distribution models to delineate the distribution of maximum intensities
and frequency of occurrence of these extreme events, respectively. Determining the likelihood
difference of maximum intensities of MHWs and the association between MHW count and occurrence
year during the period was done using Kruskal-Wallis and Kendall rank correlation tests, respectively.
Results show that the entire study area has been experiencing MHWs more frequently in recent
decades, with the northwest region having higher counts. Strong seasonality exists, as more MHWs
occurred in winter months (October to May). Peak month for MHW occurrence over the entire study
area was May. November is shared as a peak month for the three focus coastal locations, although
MHWs in Cross River and Niger Delta locations exhibited multi-modal patterns. None of the MHWs in
Lagos location was categorized as severe. This study contributes to the World Climate Research
Programme Grand Challenge on Weather and Climate Extremes.
Description
Journal of Oceanography and Marine Science, 10(2), 11-21
Keywords
Marine heatwaves, extreme events, Gulf of Guinea, Climate change, remotely-sensed SST, Ghana, ACECOR
Citation
Asuquo, F. E., & Oghenechovwen, O. C. (2019). Detection and spatio-temporal variation of marine heatwaves in the Gulf of Guinea, Nigeria. Journal of Oceanography and Marine Science, 10(2), 11-21.