Nadine Lehmann

New! GEOTRACES Data Product 2025-Now available! 🌊

Hydrographic and marine biogeochemical data from 123 cruises covering the global ocean

*Bulk download
bodc.ac.uk/geotraces/data/dp/
*Data subsetting
geotraces.webodv.awi.de
*Data analysis, visualisation
explore.webodv.awi.de
*Atlas
egeotraces.org

Request for Proposals: Effect of Ocean Alkalinity Enhancement on Commercially and Culturally Important Species - Carbon to Sea Initiative A non-profit effort advancing ocean-based carbon dioxide removal

📣 🌊
New funding opportunity! Carbon to Sea and the Prince Albert II of Monaco Foundation invite proposals to study how ocean alkalinity enhancement (#OAE) affects key marine species. Two 24-month projects will be funded. Apply by 16 January 2026. #mCDR
➡️ www.carbontosea.org/rfp-effect-o...

Postdoctoral Research Associate at University of Liverpool Looking for a new job opportunity in academia? Check out this job opening for a Postdoctoral Research Associate on jobs.ac.uk!

Seeking a three year postdoc in the field of ocean biogeochemistry and productivity using mechanistic models and synthesis of observations. Note the short fuse for applications. Please help distribute. All nationalities welcome to apply! 🌊

www.jobs.ac.uk/job/DPG117/p...

🌟 Postdoc Opportunity in Marine Biogeochemistry at CNRS-CEREGE!

🚢 Are you a passionate researcher ready to tackle climate change? Dive into the ERC-funded Deep-C project in Aix-en-Provence, France!

⬇️

Why work at UVic? - Faculty & staff - University of Victoria Get information on the working environment at the University of Victoria.

🌊🧪 1/ Job Alert! Are you a world-leading researcher in climate change solutions? UVic’s Canada Excellence Research Chair offers 8 years of support for groundbreaking research. Join our interdisciplinary team @seos-uvic.bsky.social Learn more & apply by Aug 29: www.uvic.ca/faculty-staf...

New job! Please repost - Post doc @oxuniearthsci.bsky.social on The Security of #CarbonDioxide Drawdown During #EnhancedRockWeathering

Does downstream #carbonate formation happen? How? How much? How quick?

Apply by 12 June

my.corehr.com/pls/uoxrecru...

Includes the MODIS calcite and EHux processed products. :’(

NOAA just announced a long list of datasets that are going away🧪⚒️🌊: www.nesdis.noaa.gov/about/docume...
Download what you need asap and send comments to: ncei.info@noaa.gov

New paper just published! We combined a water mass decomposition with biogeochemical tracers to untangle advective nutrient sources from the Gulf Stream and the Labrador Current versus local recycling along the Northwest Atlantic continental shelf. Have a look: 👇🌊🧪 #AGU

doi.org/10.1029/2024GB008409

OSU is hiring! Come work at CEOAS - Open rank faculty position and director of the Oregon State Stable Isotope Laboratory. My network is small on Bluesky, please share widely! Reach out if you have questions about living in Corvallis or about CEOAS specifically.

jobs.oregonstate.edu/postings/165...

Global carbonate chemistry gradients reveal a negative feedback on ocean alkalinity enhancement - Nature Geoscience Intensive ocean alkalinity enhancement will cause a proliferation of calcifying organisms, which reduces its effectiveness as a carbon sequestration approach, according to an analysis of coccolithopho...

This looks like a pretty importamt paper for people modelling calcifiers www.nature.com/articles/s41...

"scientists from the University of Tasmania’s Institute for Marine and Antarctic Studies took a closer look at how OAE could change ocean chemistry and how this could affect marine organisms in their surrounding environment" 🌊🧪

@utas.edu.au article: bit.ly/418Lqe7

Article: doi.org/10.1038/s415...

Pelagic calcifier proliferation along surface ocean gradients in carbonate chemistry - Nature Geoscience Natural gradients across surface ocean regions show that changes in carbonate chemistry projected for ocean alkalinity enhancement could promote the proliferation of calcifying phytoplankton. This shi...

Importantly, our findings show that it is critical to consider large-scale feedbacks in the ocean system when evaluating the efficiency of ocean alkalinity enhancement.

A summary of the article can be found here: www.nature.com/articles/s41...

However, more moderate and arguable more realistic alkalinity enhancement may only mitigate for adverse acidification effects on coccolithophores, with only minor impacts on the CO2 removal potential of OAE (a reduction of less than 3% until 2100).

Based on observed relationships, we estimate that extreme alkalinity enhancement may promote the proliferation of coccolithophores, thereby reducing the CO2 removal potential of ocean alkalinity enhancement by 2-29% by 2100. 8/10

However, our results also show that on a regional and local scale other environmental drivers such as nutrient availability and the physical environment may dominate over the influence of carbonate chemistry. 7/10

This observation is supported by physiological theory from previous laboratory experiments showing a combined influences of carbon substrate availability and proton inhibition of calcification. 6/10 www.sciencedirect.com/science/arti...

We found that surface gradients similar in magnitude to OAE-induced changes in carbonate chemistry support the proliferation of calcifying over non-calcifying phytoplankton. This positive correlation was observed across biogeochemically-distinct ocean provinces, bloom areas and marginal seas. 5/10

To test this, we used global satellite data to look at the balance in the abundance of calcifying phytoplankton relative to non-calcifying phytoplankton, and how this balance correlates with natural surface gradients of environmental drivers such as carbonate chemistry, nutrients, temperature. 4/10

A key question we tried to answer was if such a shift in carbonate chemistry could lead to a proliferation of calcifying organisms like coccolithophores by facilitating calcium carbonate precipitation. By consuming alkalinity, increased calcification could directly reduce the efficiency of OAE. 3/10

OAE sequesters atmospheric CO2 by shifting the seawater carbonate equilibrium from CO2 toward bicarbonate and carbonate ions, thereby promoting an influx of CO2 from the atmosphere into the surface ocean. 2/10

Would marine calcifiers such as coccolithophores benefit from changes in carbonate chemistry under ocean alkalinity enhancement? @bachlennart.bsky.social and I tried to answer this question in a new natural analogue study out now in Nature Geoscience! @naturegeosci.bsky.social 🌊🧪 rdcu.be/d9zdH 1/10

Review article on marine carbon dioxide removal now available open access 🌊 www.annualreviews.org/content/jour...

🚨 JOB OPPORTUNITY IN HOBART! 𝗖𝗮𝗿𝗯𝗼𝗻 𝗕𝗶𝗼𝗴𝗲𝗼𝗰𝗵𝗲𝗺𝗶𝘀𝘁
Use observations from ships, moorings and floats to quantify regional variations in Southern Ocean carbon uptake and ocean acidification.

▶️ careers.utas.edu.au/en/job/500582/research-associate-carbon-biogeochemist

Applications close 2 Feb 2025

Post Doctoral RA – Coastal Biogeochemistry in Sequim, Washington | Pacific Northwest National Laboratory PNNL is hiring a Post Doctoral RA – Coastal Biogeochemistry in Sequim, Washington. Review all of the job details and apply today!

Looking for an #mCDR postdoc? Consider working with us at PNNL: careers.pnnl.gov/jobs/9956?la...

So, is anyone interested in and wants to follow people doing marine biogeochemistry?
I might have a starter pack for you!
(also, I blame @malinodalen.bsky.social for this)
bsky.app/starter-pack...

Spot anyone not there (maybe you?), say something.

Does anyone know what the best temperature, salinity, pH (maybe O2) logger is for in situ application at 10m depth in seawater?

Obviously a SeapHox is great but looking for something more affordable.
🌊

I am hiring! Want to join a collaborative project with hydrologists, ecologists, biogeochemists, and microbiologists? Come join us here in Boston. Looking for a tech and postdoc - links here for tech position: tinyurl.com/mpm82399 and here for postdoc: tinyurl.com/4vrra3mf
please share widely! 🧪🦠

👋 at #AGU23 & interested in a PhD on climate impacts on freshwater nutrient cycling (& in moving to Aotearoa New Zealand)? Please come have a chat!

Position details here: sites.google.com/view/wells-s...

Where to find me: I’ll be here all week, so pls feel free to send an email/ msg.

Good primer on Ocean Alkalinity Enhancement: www.science.org/content/arti...