During MOSAiC, one spring biological sample was named “Ridgey McRidgeFace” — and it made it into the final paper (doi.org/10.1038/s43247-026-03364-8). RMRF was a young ridge of thin first-year ice sampled in late March. The real challenge? Explaining what RMRF actually stands for.

Our graphic shows Arctic sea-ice ridges aren’t just rubble—they’re biomass hotspots. In summer, they can hold up to ~80–100% of ice-algal biomass despite covering much less area. Their complex structure creates diverse microhabitats for microbial life. doi.org/10.1038/s432... 🎨 Frida Cnossen

There are many colorblind-friendly, perceptually uniform colormaps (e.g., cmocean, @fabiocrameri.ch), yet many papers at @agu.org still use rainbow variants. Not just aesthetics — they can create artificial structures (see plot). Better options exist.

Some papers follow me into my nightmares. This study about the shape of pressure ridges claims that most of them are cusped (like an arrow tip). Not only is this counterintuitive, but when I checked the dataset used in the study, most ridges appeared to be either trapezoidal or irregular.

Can a portable device measure the full thickness of sea-ice pressure ridges? New preprint led by Polona Itkin @oceanseaicenpi.bsky.social tests ground-based electromagnetic induction (GEM) across all seasons. doi.org/10.5194/egus...

A blog post from Megan Lenss about our new paper on Antarctic sea-ice algae: ic3.uit.no/news/hidden-...

New nice preprint led by Dmitry Divine (@oceanseaicenpi.bsky.social) on #Arctic sea ice ridge volume in the Fram Strait, derived from moored sonar observations from 2012–2019: doi.org/10.5194/egus...

A new thesis about the inclusion of air bubbles into the mushy layer model of sea ice by Joseph Fishlock from the University of Oxford @ox.ac.uk: ora.ox.ac.uk/objects/uuid...

Back from the CONTRASTS expedition (July–Sept)! We studied 3 types of Arctic sea ice, revisiting each site 4 times. I wrote a short overview here: en.wikipedia.org/wiki/CONTRAS...

CONTRASTS Expedition - Wikipedia

en.wikipedia.org

Unique concept for observing Arctic sea ice successfully implemented: AWI scientists were able to study different types of sea ice in parallel during the Polarstern expedition “CONTRASTS.” 🧊 www.awi.de/en/about-us/... Photo: Evgenii Salganik

Great to see a data paper from the Nansen Legacy cruises (2018–2022), led by Dmitry Divine (@oceanseaicenpi.bsky.social), including sea ice density measurements that clearly show strong seasonality: doi.org/10.1002/gdj3.70001

Our new data paper about under-ice observations from a remotely operated vehicle (ROV) during MOSAiC led by Philipp Anhaus from @awi.de: www.nature.com/articles/s41...

A new study led by Niels Fuchs uses hydrological models to predict the locations of melt ponds: doi.org/10.1029/2025GL115033

Our new study is out: The Arctic Beaufort Gyre is projected to weaken or vanish in most CMIP6 models under future climate change. The gyre would thus stop storing freshwater in its centre, with possibly large impacts on the Arctic and beyond. Read: agupubs.onlinelibrary.wiley.com/doi/full/10....

The Arctic Beaufort Gyre in CMIP6 Models: Present and Future

CMIP6 models generally simulate a too strong, large, and northward-extending Beaufort Gyre (BG) during the historical period Among the least unrealistic models, most simulations project a decline...

agupubs.onlinelibrary.wiley.com

Ice Mass Balance (IMB) buoys are unique in their ability to distinguish between ice surface and bottom melt, which relates to the way solar energy is distributed. Models still do a poor job of capturing this. You can find the updated Wiki article here: en.wikipedia.org/wiki/Ice_mass_balance_buoy

If you are into Arctic sea ice thermodynamics, here is our new dataset of 82 CRREL ice mass balance buoys deployed in 1997–2024 with estimates of snow and ice thickness and their interface evolution: doi.org/10.5281/zenodo.15096485

If you are into modeling of sea ice physical properties (salinity, brine volume, or density), we combined coring datasets to have a seasonal evolution for first- and second-year level ice: doi.org/10.5281/zeno... The coring datasets have many more parameters, including isotopes and nutrients.

In summer we typically track sea ice melt, assuming its height above the waterline decreases. In our new study, we show that sea ice freeboard may increase during the advanced melt in June and July due to the rapid decrease of ice density. Read more: doi.org/10.5194/tc-19-1259-2025

Last day at the Norwegian Polar Institute. Thanks for the good memories.

Yesterday, you showed Zack's beautiful work to your colleague; today, he no longer works at NOAA. Huge support. We all live in an evolving dystopia.

Zack Labe@zacklabe.com · last yr.

Last Tuesday, I was set to give a talk on 'climate change in the Northeast' at a retirement home but had to cancel due to hourly job threats. After nearly two weeks of overwhelming uncertainty, today it happened. I was fired from my dream of working at NOAA. I'm so sorry to everyone also affected.

Shocking. It is hard to overestimate the importance of all the wonderful research and observations from NOAA @climate.noaa.gov and other US-based agencies. Huge support to Zack and others who are affected.

Zack Labe@zacklabe.com · last yr.

I really cannot believe my childhood career dream might end like this. Feeling so small and lost.

Fate of #Arctic sea ice melt | In a new study led by @madm-ice.bsky.social, we followed the #MOSAiC ice floe and calculated the budget of freshwater sources and sinks from snow and ice melt in summer 2020. Read more: doi.org/10.5194/tc-19-619-2025

Impressive airborne measurements of ice ridge spacing led by Thomas Krumpen:

Nature Climate Change@natclimate.nature.com · 2y ago

Nature Climate Change January issue is now online Content includes 💻 Internet image search & climate views 🌀 cyclone risk to ecosystems 📉 the Global Stocktake technical dialogue 🦠 Microbial carbon use efficiency in soil models 🧊 smoother Arctic sea ice & much more www.nature.com/nclimate/vol...

Academic journals may need stricter guidelines for introductions. Broad overviews with ambiguous claims and irrelevant references are way too common. Worse, unjustified citations of colleagues and co-authors further devalue citations, as if they can get less valuable than now.

If only they could have asked the author. The sea-ice density part is not much better. Half-based on a 1978 study published in Russian and not publicly available.

Robbie Mallett@robbiemallett.bsky.social · 2y ago

New paper out on satellite-based snow depth estimates. doi.org/10.1038/s415... As flattered as I am to have an equation named after me, I would have preferred the authors to have cited the paper in which I wrote this equation (rather than the URL of some random CCI report).

The only problem with Fabio's color maps is that they are so beautiful it is hard to choose one.

Fabio Crameri@fabiocrameri.ch · 3y ago

Scientific colour maps 8.0 · Perceptually uniform · Perceptually ordered · Colour-blind friendly · Readable as B&W print · Widely compatible · Versioned & citable fabiocrameri.ch/colourmaps #useBatlow #Dataviz #SciArt #EduSky #OpenSource 1/n

Our sea ice and ocean sections of Norwegian Polar Institute on Bluesky:

Oceans & Sea Ice NPI@oceanseaicenpi.bsky.social · 2y ago

Hello Bluesky! We are scientists from the #SeaIce and #Oceanography sections within the Research Department at the Norwegian Polar Institute, located in Tromsø, Norway. Follow us here on @bsky.app for updates and insights into polar #research in the #Arctic and #Antarctic carried out by us.

Quote from WMO sea ice nomenclature: "Ice ridge concentration: Concentration (aerial coverage) of hummocked ice of all kinds in an ice area in tenths." Should it be areal instead of aerial? @wmo-global.bsky.social, we can do better.

A great new study led by Thomas Krumpen about the decrease of ridge density based on airborne observations since the 1990s:

Lars Kaleschke@seaice.de · 2y ago

Sea ice paper alert, congratulations to my colleagues! Krumpen, T., von Albedyll, L., Bünger, H.J. et al. Smoother sea ice with fewer pressure ridges in a more dynamic Arctic. Nat. Clim. Chang. (2025). doi.org/10.1038/s415... #Arctic #climate 🌊 🥼❄️ rdcu.be/d5rtv

Presenting our work on sea-ice ridge thermodynamics during winter and summer at @agu.org was a pleasure. You can check out our #AGU24 talk here: www.youtube.com/watch?v=gUFi...

Seasonal evolution of sea ice ridges presented at AGU24

YouTube video by Evgenii Salganik

youtube.com