Big thanks to @remotereefs.bsky.social, @miked-fox.bsky.social and all our co-authors for making this work happen as part of my PhD 🌊🪸

Photo above taken by Prof. Rob Dunbar from our 2022 expedition to the Chagos Archipelgo, where this data was collected.

Upwelling delivers key oceanic subsidies to coral reef communities, supporting high biological productivity.

Changes to ocean stratification with climate change may restrict this natural phenomenon, removing a potential mechanism of temperature reprieve & nutrient delivery under a warming ocean.

We link positive phases of the Indian Ocean Dipole to anomalously deep surface mixed layer depths, showing that over the past 40yrs, positive dipole phases act to depress the surface mixed layer and effectively shut down upwelling across this archipelago.

Our loggers caught the 2019 Dipole event:

Using a machine learning statistical modelling framework, we identify the prominent atmospheric & oceanographic drivers of localized upwelling across an oceanic archipelago.

We reveal critical depths of the surface mixed layer where upwelling is enhanced or reduced on these shallow coral reefs.

Using high resolution temperature observations from 10-25 m depth over 18 months, we quantify the upwelling regime across ~200km of an oceanic archipelago in the central Indian Ocean.

We use Degree Cooling Hours (DCH) as an integrated metric of the duration and magnitude of upwelling events.

Using high resolution temperature observations from 10-25 m depth over 18 months, we quantify the upwelling regime across ~200km of an oceanic archipelago in the central Indian Ocean.

We use Degree Cooling Hours (DCH) as an integrated metric of the duration and magnitude of upwelling events.

All of this was down by a great team of marine scientists from KAUST and Bangor University. Can't wait to revisit these sites next year and continue this project for years to come! 🦑

We also did benthic surveys and collected coral samples to characterize the reef communities at each site. We've generated hundreds of gigabytes of phototransect data and tons of frozen samples... plenty to keep us busy well after the expedition has finished!