Ken Johnson

April 2026 National Academies hybrid workshop on exploring the future of @bgc-argo.bsky.social @globaloceanbgc.bsky.social - learn more here: tinyurl.com/4985e7zx 🌊

Physical controls on heterogeneous mesopelagic biogeochemistry Communications Earth & Environment - A patchy distribution of biogeochemical properties in the ocean interior arises from the combined influence of biological and physical processes.

Surface ocean processes impact structure deep into the ocean interior. In our perspective paper, @maratimes.bsky.social, grad student Katarina Merk, and I discuss using physical perspectives to interpret subsurface biogeochemical distributions and why we as a community should care! 🌊

Frequency hopping enables cell phone tech. Hedy Lamarr is in the National Inventors Hall of Fame and her Wikipedia page is
en.wikipedia.org/wiki/Hedy_La...

If you want to adopt an @globaloceanbgc.bsky.social float, see our web page.

@bgc-argo.bsky.social @soccomproject.bsky.social

Depth (0 to 300 m) by time (2022 to 2026) plots of temperature, salinity, particulate organic carbon (POC), chlorophyll (CHL_A), oxygen, nitrate, pH at in situ temp/pressure, and computed dissolved inorganic carbon (DIC) for float 5906497 (adopted name Hedy Lamarr).

🌊BGC-Argo float of the month is 5906497 with 4 years under Antarctic sea ice, just popped out. It was adopted by the American School in Jeddah, Saudi Arabia and named “Hedy Lamarr” – the actress who co-invented and patented frequency hopping communications.  Named for her science contribution. 1/2

More funny is why we are sending an ice breaker from Alaska to the Southern Ocean. Great for float deployments, though. The ocean from Tahiti to Punta Arenas, Chile is hard to get to.

The RV Sikuliaq in port in Pape’etē, Tahiti

Home for the next few weeks. Gotta say, Tahiti is a funny place to board an icebreaker! 🌊⛴️

🌊with the wave

The 3 graphs show temperature, salinity, and oxygen from the surface to 300 m versus year from 2018 through 2025 for profiling float 5905383. The map shows the trajectory of the float from deployment in the Weddell Gyre (green square) and a loop around the Weddell sea to the present position at the red square.

What's interesting as the Thanksgiving Holiday arrives? The first @bgc-argo.bsky.social profiling floats begin to emerge from under Antarctic sea ice each year. Float 5905383 is the first @soccomproject.bsky.social float for 2025/26. It has spent 7.9 years operating under ice.
#argofloats #oneargo

And I thought we made a lot of @bgc-argo.bsky.social profiling floats!!!! We're going to have to work harder. @globaloceanbgc.bsky.social @soccomproject.bsky.social

🌊A busy day for @mbarinews.bsky.social science and @globaloceanbgc.bsky.social, the major US contribution to @bgc-argo.bsky.social.

BGC-Argo floats used to study marine heatwaves and oxygen deficient zones. Great work by Mariana Bif - University of Miami, former MBARI postdoc.

another compound is absorbing light in the UV with the spectral characteristics of thiosulfate (panel f). The float data suggest an active sulfur cycle, consistent with much recent genomic data.

The floats enable an entirely new vision into the variable metabolism of oxygen deficient regions

Nitrite comes and goes (panel e), often following organic carbon export events (panel a). That’s consistent with exported organic carbon controlling heterotrophic processes that enable complete reduction of nitrate to N2, rather than accumulation of nitrite.

But more interesting,

Time series of a BGC‐Argo float WMO#5906483 deployed in the ETNP in January 2022 (see inset map reference). (a) Mean monthly POC stocks at the upper 100 m depth. (b) Chlorophyll fluorescence concentrations at the upper 200 m depth. Dashed black lines denote the ML. (c) POC concentrations overlain by the ML. (d) Nitrate concentrations. (e) Nitrite concentrations. (f) Thiosulfate concentrations. (g) Oxygen concentrations minus a background correction from the sensor calibration offset. Continuous black lines denote the isolines where corrected O2 = 1 μmol kg^-1

🌊BGC-Argo float of the month is a sensor, not a float. Bif and Johnson (GBC; doi/10.1029/2024GB008473) show that the concentration of nitrite can be extracted from the UV spectra of ISUS or SUNA nitrate sensors.

But more..

@globaloceanbgc.bsky.social floats. @mbarinews.bsky.social

New AI approach sharpens picture of carbon export in the Southern Ocean • MBARI Applying machine learning algorithms to a trove of data collected by robotic floats has improved estimates of ocean productivity and carbon export in the Southern Ocean.

Using robots and AI to unlock the secrets of a remote ocean with @soccomproject.bsky.social 🌊🤖🌊

Applying machine learning algorithms to a trove of data collected by robotic floats has improved estimates of ocean productivity and carbon export in the Southern Ocean: www.mbari.org/news/new-ai-...

Screen shot of the article by Liniger et al. "Two decades of increase in Southern Ocean net community production revealed by BGC-Argo floats. https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2024GB008371

Graphs shown the increase in mean (a) and total (b) Annual Net Community Production over the Southern Ocean from 2004 to 2022. The spatial distribution of the ANCP increase in shown in panel (c).

🌊The Southern Ocean is warming, is productivity changing? New paper by Liniger et al. uses the nitrate sensors on 274 SOCCOM/BGC-Argo floats to compute annual NCP. It has increased significantly over the past two decades.
@mbarinews.bsky.social @soccomproject.bsky.social @bgc-argo.bsky.social‬

BGC-Argo profiling float WMO 7902313 is carried down the deck of the R/V OceanXplorer before launch. This float carries oxygen, pH, nitrate, chlorophyll and particle sensors. It will operate for 5 to 6 years, sampling from 2000 m to surface every 10 days.

A map of the 300 GO-BGC profiling float locations. All floats are part of the BGC-Argo array and were funded by the US National Science Foundation.

🌊 BGC-Argo float of the month. The 300th float of the GO-BGC project was launched in the S Atlantic. Funded by the US NSF, these floats provide essential observations of ocean metabolism - productivity, oxygen, pH... @bgc-argo.bsky.social‬ @globaloceanbgc.bsky.social #OneArgo #Argo

Global maps of dissolved oxygen and nitrate concentration, pH, and optical backscatter by particles at 300 m depth in the ocean during May, 2025. Maps created with webODV, odv.awi.de.

🌊Float of the Month. The BGC-Argo array in May 2025! With ships, it took decades to collect the data to visualize the chemistry and biology of the ocean interior. Now we can do it monthly, realtime, quality controlled. Access is easy with webODV. This is going to change things! #UNOC3 #OneArgo

Ocean monitoring: an international call to urgently strengthen the Argo program As the 3rd United Nations Ocean Conference (UNOC3) gets underway, the international community is drawing attention to the pivotal role of the Argo ocean observing program, as featured in a recent arti...

🌊 As the #UNOC3 gets underway, the international community is calling for increased support for #OneArgo, a key phase of the #Argo program, which is essential for monitoring the ocean and addressing climate challenges.

@cnrs.fr @euro-argo.eu

www.ifremer.fr/en/espace-pr...

👿 NSF in Turmoil: Radical Reorganization, Removal of Directors, Forced Layoffs
🧪
Follows take over by DOGE
#SaveNSF
science.org

MBARI expands capacity for ocean research with new state-of-the-art ship • MBARI MBARI’s marine operations team begins preparations for science missions aboard our new flagship research vessel David Packard later this year.

Welcome our newest addition to the fleet! ⛴️

We're excited to announce the arrival of our new flagship vessel, R/V David Packard, at our headquarters in Moss Landing, California. This state-of-the-art ship will expand our capacity for ocean exploration.

Learn more: www.mbari.org/news/mbari-e...

So, speaking of Universities caving to government demands and people bringing up loyalty oaths, here's a story that involves a well known oceanographer.

In 1935 Massachusetts enacted a law that required teachers in public and private schools to take a loyalty oath to teach in the state 1/n

🌊

As the float goes north, it samples cooler water that mixes deeper (its less dense) in winter, reaching depths with high NO3. This brings NO3, an essential nutrient, to the surface, fertilizing plankton, and chlorophyll blooms appear.

What does this trend mean for a warming ocean?

🌊Float of the Month, 5906440 (@globaloceanbgc.bsky.social @bgc-argo.bsky.social). Drifting north for 4 years, it shows the evolution of the bio. response to ocean phys. At low latitudes, warm water does not mix deep enough (Mixed Layer Depth, black line on NO3 plot) to bring NO3 to the surface. 1/2

A wave curls and crashes from left to right as it swells toward the shoreline in Monterey Bay. the water is blue and the foaming wave front is white.

Protecting the ocean has always been a bipartisan effort, in Congress and across multiple White House administrations. In the face of ill-conceived attacks on @noaa.gov, it's time to raise our voices. My thoughts in defense of NOAA and #OceanScience: mbayaq.co/4k8vEsx

The R/V David Packard leaving the Freire Shipyard in Vigo, Spain where she was built. The Packard is 50 m and can carry a science party of 18 and a crew of 12.

Launching an Argo float with oxygen sensor for Argo-Germany off the Straits of Gibralter.

🌊MBARIs @mbarinews.bsky.social new research vessel, R/V David Packard, has left Vigo Spain to come home. Its first science mission, deploy @bgc-argo.bsky.social floats across the Atlantic and up the Pacific. First O2 float in for @argogermany.bsky.social. More for @globaloceanbgc.bsky.social

🌊

YouTube video by OceanClimateAtUoL The Atlantic Meridional Overturning

The demo is based on this video: www.youtube.com/watch?v=eZzp...

8 panels of data showing temperature, salinity (with mixed layer depth overlaid), chlorophyll, optical backscatter (bbp), oxygen, nitrate, pH and computed dissolved inorganic carbon over 2 years and down to 400 m.

🌊🧪@bgc-argo.bsky.social Float of the Month. WMO 7900823 deployed nearly 80 south in the Ross Sea has done 2 years under ice. Here's the data plot (all data freely available @soccomproject.bsky.social). No bloom this year! Too much ice melt, no deep mixing, and no iron to feed plankton - IMO.

The global map of BGC-Argo profiling floats with multiple chemical and biological sensors. The floats sample the upper 2000 m of the water column every 10 days. Data is freely available.

It’s 10 days into the new year & @globaloceanbgc.bsky.social & @soccomproject.bsky.social have already deployed 10 new @bgc-argo.bsky.social profiling floats. 410 in the water, 70 with chem & 332 have chem/bio sensors - O2, pH, NO3, & bio-optics. They sample the upper 2 km
every 10 days. 🌊⛴️🌡🧪

Almost historical. I created the Periodic Table of Elements in the Ocean back in 1998 with my son, then age 14 who wrote the JavaScript, and daughter age 12 who chased down all references in the MLML library, to figure out how we could use the internet. Nice to see it in use. #mbari #globaloceanbgc