iiinova — where your digital self keeps evolving

Jannes Koelling @koelling.bsky.social · 30/09/2026

Reminder for those of us who leave things to the last minute - last day to respond to the NSF request for input on ocean observing 🌊 GO-BGC funding is crucial for us to keep putting floats in the water, and for me to keep putting Lego floats in my office!

033

Jannes Koelling @koelling.bsky.social · 26/08/2026

Turns out my printed-out dissertation is useful for something after all

110

Jannes Koelling @koelling.bsky.social · 18/08/2026

Quintessentially Seattle activity of the day: picking up a bunch of beers for a workshop happy hour on my bike

020

Jannes Koelling @koelling.bsky.social · 15/07/2026

Something feeling very familiar about this England performance at the world cup..

000

Jannes Koelling @koelling.bsky.social · 12/03/2026

You know you’re American when the only examples of ground transportation you can think of are different ways of having someone drive you in a car

020

Jannes Koelling @koelling.bsky.social · 26/02/2026

Successful second edition of OSM Soccer at #OSM26 yesterday - guess we’ll need to keep it going in 2028 🌊

020

Jannes Koelling @koelling.bsky.social · 23/02/2026

Organizers clearly don’t trust the life skills of a room full of scientists #OSM26

020

Jannes Koelling @koelling.bsky.social · 02/12/2025

🌊⚽ Coming to Ocean Sciences Meeting '26 in Glasgow and looking for some non-science fun? Then fill out this interest form for the second ever edition of OSM football*: forms.gle/GbjvxnhCBDVy... Everyone's welcome, and no firm commitment required (yet 👀) *soccer for my American friends #OSM26

352

Jannes Koelling @koelling.bsky.social · 05/11/2025

There’s also this (much longer, but very helpful) science brief: oceanrep.geomar.de/id/eprint/59... which includes a nice graphic on it:

Graphic showing the ocean’s importance for producing oxygen on geological vs biological time scales

020

Jannes Koelling @koelling.bsky.social · 03/11/2025

Which brings us back to our lovely schematic. Our results highlight that ventilation occurs all along the subpolar gyre pathway, in contrast to previous studies (including my own) that focused largely on the Labrador Sea for O2 uptake/ventilation So does this mean the Lab Sea doesn’t matter? 11/🧵

240

Jannes Koelling @koelling.bsky.social · 03/11/2025

To understand why, we turned to an Argo float that tracked the circulation through the SPNA. The data shows that water is progressively modified: light water becomes SPMW, which becomes denser SPMW, which becomes LSW. The high O2 of LSW is the end result of uptake throughout this process 10/🧵

130

Jannes Koelling @koelling.bsky.social · 03/11/2025

Going back to the observational data, O2 levels increase during winter in different water masses - ocean layers defined by their density - as a result of the uptake. Surprisingly, the change is strongest in subpolar mode water (SPMW), not Labrador Sea Water (LSW), the highest O2 water mass 9/🧵

120

Jannes Koelling @koelling.bsky.social · 03/11/2025

Analyzing data from an ocean model we find similar patterns, and also see that the positive oxygen uptake is balanced by a negative transport divergence - implying that the oxygen absorbed from the atmosphere is subsequently carried away by ocean currents. 8/🧵

Map showing annual air-sea exchange , biological sources and sinks, and physical transport of oxygen in the North Atlantic from an ocean model

120

Jannes Koelling @koelling.bsky.social · 03/11/2025

This allowed us to estimate the air-sea exchange of oxygen for the whole SPNA; previous studies had only been able to sample at a single location. We find that almost the entire SPNA (green box) is an annual oxygen sink, meaning O2 flows from the atmosphere into the ocean year after year 7/🧵

Map showing annual air-sea exchange of oxygen in the North Atlantic

130

Jannes Koelling @koelling.bsky.social · 03/11/2025

Which is where our study comes in - improving our understanding of how the North Atlantic is ventilated currently To find out, we used GOBAI-O2, a data product created by @jdsharp.bsky.social with the help of an army of ocean robots that sample all over the world (@bgc-argo.bsky.social) 6/🧵

Global map showing locations of biogeochemical-Argo floats

141

Jannes Koelling @koelling.bsky.social · 03/11/2025

Why do we care about oxygen in the ocean? Well, because things living there need to breathe And unlike those of us breathing air, ocean organisms can’t always rely on there being enough O2. Without sunlight for plants to grow below ~200m, ventilation is the main O2 supply for most of the ocean 3/🧵

140

Jannes Koelling @koelling.bsky.social · 03/11/2025

Our new 🌊 paper “Progressive oxygenation of the North Atlantic Subpolar Gyre” is out @jgroceans.bsky.social (open access): agupubs.onlinelibrary.wiley.com/doi/10.1029/... We examined the breathing of one of the ocean’s lungs 🩺 and found some surprises Paper summary in schematic, more info ⬇️ 1/🧵

Schematic showing oxygen dynamics in the subpolar North Atlantic Ocean

54015

Jannes Koelling @koelling.bsky.social · 02/12/2024

Hobbes would like to remind everyone that it’s important to take breaks from work

000

Jannes Koelling @koelling.bsky.social · 21/02/2024

First installment of #OSM24 soccer 🌊⚽️

130