👩🎓 PhD position at the National Oceanography Centre 👨🎓
🔍 Project: Heat, Freshwater and Oxygen Budgets in the Eastern Subpolar North Atlantic: Implications for UK continental shelf and European Weather.
🤝Team: Tiago, Neil, Lidia, & Bieito @bfcastro.bsky.social
🌊 Info: www.o-snap.org/phd-at-noc-uk/
What supplies nutrients to the surface layer of subtropical gyres is a long standing question in oceanography
Recent work by Kate Oglethorpe shows that horizontal nutrient fluxes by mesoscale eddies are as (if not more) important than vertical fluxes:
agupubs.onlinelibrary.wiley.com/doi/10.1029/...
Yep you're right! But net zero is compatible (and driven) with a significant release of young physosynthetic oxygen to the atmosphere. Which we are breathing! So I think both things make sense and we should be advocating for the importance that that has
The ocean is not a net source of oxygen to the atmosphere. But... primary producers at the surface need to release a non-negligible fraction of the oxygen they produce to air in order to compensate for the upwelling of oxygen depleted waters. I think makes our both viewpoints compatible:)
There is no need to burry organic matter in the sea floor to lock carbon away from the atmosphere. Organic matter remineralised within the water column is locked in as inorganic carbon, until circulation and mixing bring it back to the surface. The same goes for oxygen, the other way round
Most of respiration happens at the surface, but a non negligible fraction of respiration (10-20%?) occurs in the ocean interior. There, oxygen is depleted from water and can't get back in straight away. Therefore, there is a net release of oxygen to air. Maybe it is 10-20%×50%=5-10%. But not zero!
I disagree on the net zero claim. The bulk of the ocean is depleted in oxygen (oxygen concentration is below atmospheric equilibrium). This is because photosynthesis happens close to the surface, where oxygen leaves to the atmosphere.
Earth system models are plagued by uncertainties in the response of microbes to climate change. We leveraged metabolic insights from genome scale models when coupled to an ocean model in this new exciting work 🌊
www.science.org/doi/full/10....
Researchers modeled the paths of 100,000 particles of water backward in time over multiple decades to learn more about the origins of Subantarctic Mode Waters.
Thanks @aguadvances.bsky.social and @eos.org for sharing our work on the sources and formation process of sub-Antarctic Mode Waters!
@aguadvances.bsky.social
[7/7] Our results shed new light on the intricate nature of SAMWs, helping to predict and understand their role in slowing down future climate change.
[6/7] Subtropical source waters release heat into the atmosphere, whilst Antarctic waters absorb heat. Because of their different relative contribution to Indian and Pacific SAMWs, these SAMW pools play a different role in the climate system, as sources and sinks of atmospheric heat, respectively.
[5/7] Subtropical waters are the main precursor of Indian Ocean SAMWs (70%) but contribute a smaller amount (<40%) to Pacific SAMWs, which are mainly sourced from the upwelled CDW.
[4/7] We found that both subtropical and Antarctic sources contribute to SAMW formation and strong inter‐basin contrasts in their contributions, between the Indian and Pacific SAMW pools.
[3/7] We performed a flow-tracking experiment with a Southern Ocean model (B-SOSE) to address a long standing question about SAMWs: the extent to which they originate from southward‐flowing subtropical waters vs northward‐flowing Antarctic waters sourced by Circumpolar Deep Water (CDW) upwelling.
[2/7] Sub-Antarctic Mode Waters (SAMWs) form in the Southern Ocean, north of the Antarctic Circumpolar Current. These water masses are critical for the climate system, absorbing -and holding away from the atmosphere- vast amounts of anthropogenic heat and carbon dioxide.
[1/7] Check our latest paper investigating the sources, pathways and drivers leading to the formation of Sub-Antarctic Mode Waters!
agupubs.onlinelibrary.wiley.com/doi/epdf/10....
📣 Exciting opportunity! We're hiring a #postdoctoral fellow in #gutmicrobiome research to explore the activity and function of the gut microbiome in situ and its regulation by the immune system.🦠🔬
Post based at @sotonbiosciences.bsky.social
Apply here 👇
jobs.soton.ac.uk/Vacancy.aspx...
About ten days left for this job! Don't miss the chance!
The Greenland Sea is undergoing dramatic changes due to climate change, which has altered deep water production in the Northern Hemisphere. This is not just a regional issue—it has global consequences, especially for ocean circulation and carbon absorption.🧪🌊
WE ARE HIRING. Interested in ocean mixing? Come work with us in the ARIA-funded POLEMIX project to create and deploy a float-based mixing observing system in the subpolar North Atlantic. Applications here: jobs.soton.ac.uk/Vacancy.aspx...
@sotonoceanearth.bsky.social @noc.ac.uk
Graphical abstract for the study.
Fernández Castro et al. (2024) find that mesoscale eddies play a dominant role in mixing heat and salt in the North Atlantic, helping us to better understand the Atlantic Meridional Overturning Circulation and its future behavior.
🔗 doi.org/10.1029/2023...
#AGUPubs
Great to have you onboard @gaelforget.net!
POLEMIX will deploy a mixing observing system in the North Atlantic and feed the observations into ocean models to disentangle the fate of freshwater and its impacts on dense water formation. Hiring soon! @sotonoceanearth.bsky.social @nocmarinephys.bsky.social @imev-mer.fr @mitpress.bsky.social
Sea ice in the Arctic and around Antarctica cool our climate, drive ocean circulation across the planet, and provide a unique habitat for polar ecosystems.
Sea ice amounts have now fallen to their lowest since we started measuring them. This is not good.
🌊🥼❄️🧪
www.bbc.co.uk/news/article...
Great views of sea ice in the Greenland Sea
Soon on our way to the Fram strait thanks to a NERC-funded Seedcorn grant and our colleages at U Bergen. We will investigate organic matter transport and export along the East Greenland margin. @sotonoceanearth.bsky.social
We are leading a new project which could transform our understanding of how the ocean ‘breathes’ - storing heat and greenhouse gases from the atmosphere 🌊
It will use sensors onboard high-tech floats to provide unprecedented detail on ocean mixing.
Read more 👉 brnw.ch/UoS_News_Oce...
Two postdoc positions in my group are opening: First is part of SOCCOM3 (3 years, NSF funded, S. Ocean carbon/oxygen/nutrient budgets), Second is part of InMOS (4.25 yrs, Schmidt Sciences / OBVI funded, long-term oxygen/carbon flux and inventory constraints). More info: bushinskyoceanlab.org/people/