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Thomas Rackow 🧊

@trackow.bsky.social
834 followers 530 following 71 posts

Scientist @ecmwf.int : climate & ocean variability, kilometre-scale modelling, and its visualisation. #art and music enthusiast. #scicomm

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Thomas Rackow 🧊 @trackow.bsky.social · 2h
Yes, we do see signatures in the clouds and radiation. Now it is a bit unclear how to evaluate best; maybe first track the features and then overlay/composite them for different conditions; maybe arrange according to the prevailing wind direction. Happy to have a chat about this
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Thomas Rackow 🧊 @trackow.bsky.social · 3h
Really nice read, and great comparison to MOSAiC! Still very different scale, but this is a figure from our km-scale paper (doi.org/10.5194/gmd-...) last year, if you haven't seen it: gmd.copernicus.org/articles/18/... Anyway, great work, best wishes from Bonn!
gmd.copernicus.org
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Niklas Schnierstein @schnier.bsky.social · 07/04/2026
New paper! 🎉 How do Arctic leads (cracks in sea ice) affect the atmosphere under different conditions? Condensing plumes can act as "radiator fins", efficiently removing energy downstream; sometimes cooling the air even more than the lead initially warmed it! @agu.org @unicologne.bsky.social
doi.org
Lead Impacts on the Moist Static Energy Budget of the Low‐Level Arctic Atmosphere in Large‐Eddy Simulations Based on MOSAiC Data
Idealized leads are introduced into a set of large-eddy simulations based on Multidisciplinary drifting Observatory for the Study of Arctic Climate field campaign data during polar night Lead imp...
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Thomas Rackow 🧊 @trackow.bsky.social · 27/05/2026
Great to see the km-scale models perform well in Lukas' comparison! We bring the same models into an operational framework @ec.europa.eu, with a resolution of 5km. To get started with the latest generation, please look at platform.destine.eu/climate-dt/ @ecmwf.int @esa.int @eumetsat.int
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Thomas Rackow 🧊 @trackow.bsky.social · 19/05/2026
Happy to see the new #DestinE simulations out in the open! I’d strongly recommend trying the new Jupyter example notebooks, including lazy browsing: github.com/destination-... Looking forward to seeing what people will build and discover with this next generation of #ClimateDT simulations!
github.com
polytope-examples/climate-dt at main · destination-earth-digital-twins/polytope-examples
This repository describes the process for accessing Destination Earth DT data via the Polytope web service hosted on the LUMI Databridge. - destination-earth-digital-twins/polytope-examples
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Thomas Rackow 🧊 @trackow.bsky.social · 05/05/2026
To access the data of the 2.8km IFS simulations from anywhere, please have a look here: digital-earths-global-hackathon.github.io/catalog/ Thanks to @maengenheyster.bsky.social, we have great visual showcases of what you can expect from our simulations: youtube.com/playlist?lis... @ecmwf.int #EGU26
youtube.com
Highlights from a global 2.8 km coupled IFS-FESOM simulation - YouTube
The simulation couples ECMWF's Integrated Forecasting System (IFS) at tco3999 resolution (~2.8 km) to the FESOM ocean model (developed by the Alfred Wegener ...
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Thomas Rackow 🧊 @trackow.bsky.social · 04/05/2026
Check the program here: www.egu26.eu/session/56783 @frasergocean.bsky.social @eerie-project.eu
egu26.eu
Session CL4.14
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Thomas Rackow 🧊 @trackow.bsky.social · 04/05/2026
First day at #EGU26! We are starting with our poster session! Fraser and I will be in X5, 10:45-12:30, to present our work! Come to X5.184 and X5.189 to have a chat :) Oral presentations on the latest km-scale developments will be in the afternoon today, 16:15–18:00 in 🟨 0.31/32 @ecmwf.int
@fraser
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Thomas Rackow 🧊 @trackow.bsky.social · 21/04/2026
It has been a pleasure to work with Lukas on this, and to see the IFS-FESOM model perform so well in this aspect. We now bring the same km-scale models into an operational framework @ec.europa.eu, at an increased resolution of 5km. Stay tuned for the next runs 🌎 destine.ecmwf.int/climate-chan...
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European Research Council (ERC) @erc.europa.eu · 17/04/2026
Learn more about what you need to know before applying for an ERC grant in the 2027 competitions: • Resubmission restrictions • Application rules • Eligibility windows for #ERCStG #ERCCoG 🔗 link.europa.eu/BjTmVt
link.europa.eu
Applying for an ERC grant in the 2027 competitions: what you need to know
The ERC plans to launch the grant competitions under its 2027 Work Programme between July 2026 and June 2027, with the calls for proposals introducing several changes to the eligibility rules for appl...
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Thomas Rackow 🧊 @trackow.bsky.social · 18/12/2025
You are referring to this? Boyer, M., Quéléver, L., Brasseur, Z. et al. Penguin guano is an important source of climate-relevant aerosol particles in Antarctica. Commun Earth Environ 6, 368 (2025). doi.org/10.1038/s432...
doi.org
Penguin guano is an important source of climate-relevant aerosol particles in Antarctica - Communications Earth & Environment
Penguin colonies emit gaseous ammonia that enhances new particle formation processes in Antarctica, according to online observations of gaseous ammonia and aerosol particles from a coastal site in Ant...
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Leon Simons @leonsimons.com · 18/12/2025
"If this shift represents an excursion into a new normal, our future could be hotter faster than expected." A year after this insightful study was published, the albedo and net flux over the Northern Hemisphere mid-latitude oceans keep decreasing: www.science.org/stoken/autho...
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Swinda Falkena @swinda.bsky.social · 21/11/2025
📢 New paper on the impacts of AMOC collapse on European hydroclimate. 🌊 We find an AMOC collapse would exacerbate drought conditions across Europe, linked to reduced precipitation. In combination with climate change droughts are expected to become more frequent and severe. doi.org/10.5194/hess...
doi.org
Changing European hydroclimate under a collapsed AMOC in the Community Earth System Model
Abstract. The Atlantic Meridional Overturning Circulation (AMOC) is expected to weaken or even collapse under anthropogenic climate change. Given the importance of the AMOC in the present-day climate,...
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Alex Robel @iceclimate.bsky.social · 24/11/2025
“We have observational evidence and ocean modeling results to document that kilometer-scale seawater intrusions beneath grounded ice generate a high melt in the [grounding zone of Thwaites Glacier].” www.pnas.org/doi/full/10....
pnas.org
Contrasting melt regime in the Ice Grounding Zone of Thwaites Glacier, West Antarctica | PNAS
The contribution of Thwaites Glacier, Antarctica, to sea level rise is influenced by how quickly warm salty seawater of Circumpolar Deep Water orig...
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Dr. Aaron Thierry @thierryaaron.bsky.social · 19/06/2025
In the past year we've had a series of papers with results that've shocked #climate scientists - the globe is heating #FasterThanExpected & we don't fully know why The public discourse is not keeping up. Here's a series of 5 new studies that climate hawks & journos need to have on their radar 🧵
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Thomas Rackow 🧊 @trackow.bsky.social · 08/11/2025
Big thanks to @climateofgavin.bsky.social and the other authors for including me in this work. The data is open and available here: 📂 zenodo.org/records/1738... (7/7)
zenodo.org
Freshwater sources from Antarctica and Greenland
Freshwater sources from Greenland and Antarctica. For details see https://github.com/NASA-GISS/freshwater-forcing-workshop and https://doi.org/10.5194/egusphere-2025-1940 v7 update: See changelog at h...
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Thomas Rackow 🧊 @trackow.bsky.social · 08/11/2025
The datasets are designed to be flexible. We make recommendations for how climatological & anomalous fluxes can be implemented in models that may have different approaches to interactions with ice sheets. We hope this helps the community to move toward more physically consistent simulations. (6/7)
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Thomas Rackow 🧊 @trackow.bsky.social · 08/11/2025
By providing spatially and temporally resolved meltwater fluxes, our dataset could enable a large set of models to explore how AMOC might respond to realistic freshwater forcing, not just idealised pulses. This is a key step toward understanding future climate dynamics under continued ice loss (5/n)
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Thomas Rackow 🧊 @trackow.bsky.social · 08/11/2025
Similar to volcanic forcing, we provide year-to-year timeseries of freshwater anomalies, enabling models to reflect observed historical variability. This means better representation of events like Greenland’s 2012 melt spike or Antarctic ice loss & its evolving freshwater impact on the ocean (4/7)
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Thomas Rackow 🧊 @trackow.bsky.social · 08/11/2025
A personal highlight: we include iceberg melt patterns, a topic I’ve worked on for years and care deeply about. Icebergs don’t just melt, they drift over vast distances, cool their surroundings, and shape regional ocean properties. Capturing this spatial and vertical complexity matters. (3/7)
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Thomas Rackow 🧊 @trackow.bsky.social · 08/11/2025
We provide datasets of absolute & anomalous freshwater fluxes from Greenland/Antarctica, critical inputs for climate modelling, CMIP7 & beyond. These fluxes include runoff, sub-shelf melt, and calving, each with distinct ocean impacts. Most models haven’t accounted for them properly until now (2/7)
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Thomas Rackow 🧊 @trackow.bsky.social · 08/11/2025
Happy to see this out! Meltwater can delay future surface warming, and its interannual variations impact ocean stratification & overturning.​​ This effect is usually absent from models. Including it as forcing may lead to more realistic simulation of surface temperature and sea ice trends🧊🌊 (1/7)
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Robin Hogan @robinjhogan.bsky.social · 23/10/2025
Would you believe it: just 10 days after #EarthCARE went through the eye of Hurricane Humberto, it did the same with Hurricane Priscilla in the East Pacific on 7 October! A very different beast this one: a huge eye around 100 km across, and very lopsided, with much more rain on the southern side.
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Dr. Efi Rousi @efou.bsky.social · 08/10/2025
Read our editorial on #climate research in the Global South, and take a look at the collection of papers on #weather and climate extremes published in @natcomms.nature.com and @commsearth.nature.com www.nature.com/collections/...
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Leon Simons @leonsimons.com · 07/10/2025
I just updated this NASA CERES graph. The regional level of Absorbed Solar Radiation increased by 4.2 W/m² in 20 years!! That's more than the global greenhouse gas forcing increase since 1750! The 2 W/m² Net Flux increase indicates that there is a lot more regional warming in the pipeline.
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Jens Daniel Müller @jens-d-mueller.bsky.social · 02/09/2025
Finally, some excellent resources on the 2023 SST anomalies: @polarocean.bsky.social bsky.app/profile/pola... @trackow.bsky.social bsky.app/profile/trac... bsky.app/profile/mice... @tguinaldo.bsky.social bsky.app/profile/tgui... @profmattengland.bsky.social bsky.app/profile/prof...
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Jens Daniel Müller @jens-d-mueller.bsky.social · 02/09/2025
🌊 In 2023, the ocean carbon sink weakened for the first time in a record-hot year 🌡️🌎 Our new study in Nature Climate Change quantifies this unexpected decline and explains how it came about. 👇 doi.org/10.1038/s415...
doi.org
Unexpected decline in the ocean carbon sink under record-high sea surface temperatures in 2023 - Nature Climate Change
The ocean carbon sink strengthened in previous warm El Niño years due to reduced CO2 outgassing in the tropics. Here the authors show that the ocean carbon sink declined in 2023 despite record-high se...
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Dr. Dawn Wright @deepseadawn.bsky.social · 01/08/2025
Hope you enjoy exploring this cool 3D app of the ocean focusing on NOAA World Ocean Atlas water column measurements of temp, salinity, dissolved O2, and nutrients! #voxels #EcologicalMarineUnits www.esri.com/about/newsro... 🌊 🦑 🌎 🌍 🌏 #GISchat #geogchat #geogsky
esri.com
Explore a 3D App of the Ocean
In this 10-minute tutorial, learn how 3D scenes and interactive controls allow for greater data exploration with the 3D Ocean Explorer app.
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Nicolas Berrod @nicolasberrod.bsky.social · 09/07/2025
Enfin, la température de l'eau à la surface de la mer Méditerrannée entre la France rt l'Afrique du Nord a été historiquement élevée (tous mois confondus) en juin : jusqu'à 27 °C, soit +3,7 °C par rapport à la "normale". 3/3
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Lukas Brunner @lukasbrunner.bsky.social · 17/06/2025
New paper in ERL! We study the importance of resolution for the representation of climate extremes. We use a new generation of km-scale models to show that many important details about temperature and precipitation extremes are hidden at CMIP6-like resolutions. doi.org/10.1088/1748...
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Forum Météo Climat #FIMC2026 🌎 @forumeteoclimat.bsky.social · 06/06/2025
#FIMC2025, Sarah Keeley (@‌copernicusecmwf.bsky.social) showed how coupling ocean, sea ice, and atmosphere boosts forecast accuracy. Storms, heatwaves, even sea ice changes—what lies beneath shapes what’s above. AI is now taking it further. #CoupledForecasting #ECMWF #AI4Weather #UNOC3
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Marylou Athanase @marylouathanase.bsky.social · 03/06/2025
To celebrate the kick-off of #UNOC3 and #OOSC in Nice, we share a striking, mesmerising perspective on Mediterranean Marine Heatwaves —and their clear amplification by climate change. From @awi.de storyline simulations, visual by @jawijan.bsky.social
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Thibault Guinaldo @tguinaldo.bsky.social · 13/05/2025
If I can add something. Here we demonstrate that NATL warming was due to natural variability. The event was excepted and in line with climate projections (return period around 10 years). The processes are well known and we can explain it. www.nature.com/articles/s43...
nature.com
Internal variability effect doped by climate change drove the 2023 marine heat extreme in the North Atlantic - Communications Earth & Environment
The 2023 North Atlantic marine heatwave was driven by an extreme phase of internal atmospheric variability but would have been impossible without the doping effect of anthropogenic warming, according ...
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Michael E. Mann @michaelemann.bsky.social · 04/05/2025
Important new article in @nature.com: "...the record-shattering jump in surface ocean temperatures in 2023–2024 was an extreme event after which surface ocean temperatures are expected to revert to the expected long-term warming trend." #TruthIsBadEnough (h/t @flowinguphill.bsky.social)
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Leon Simons @leonsimons.com · 02/05/2025
If only people valued peer reviewed scientific papers and regional data more than tweets and blogs and global averages... This is barely ever addressed. Helge Goessling gave a great presentation at the EGU yesterday. More soon.
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ECMWF @ecmwf.int · 02/05/2025
It's a wrap for this year's European Geosciences Union (EGU) General Assembly, where we have been presenting developments from across #ECMWF. Our team have been involved as speakers, poster presenters and conveners, but found time to get together for this great group photo!
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Thomas Rackow 🧊 @trackow.bsky.social · 28/04/2025
Today @jens-d-mueller.bsky.social gave a great talk on the ocean carbon sink during the record-warm year 2023 & an outlook for 24. #EGU25 This relates to our joint work @awi.de @ecmwf.int that is presented Thursday morning, room 0.14. See you there: meetingorganizer.copernicus.org/EGU25/EGU25-...
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PLOS Climate @plosclimate.org · 23/04/2025
Our editors are calling for submissions to help build a robust, peer-reviewed evidence base for the forthcoming IPCC Special Report on Climate Change and Cities. Read more 👇 latitude.plos.org/2024/11/call...
latitude.plos.org
Call for papers: a new 'living' collection for the IPCC Special Report on Climate Change and Cities - Latitude
As work on the IPCC’s Special Report on Climate Change and Cities begins, PLOS Climate is calling for papers for a new…
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Marylou Athanase @marylouathanase.bsky.social · 27/04/2025
If you are attending #EGU25 and interested in the attribution of #climate extremes: consider joining our networking session on Friday noon! We will exchange on existing methods, their strengths, and how to compare them: meetingorganizer.copernicus.org/EGU25/sessio... W/ @vikkithompson.bsky.social
Leaflet of the EGU25 splinter meeting.

Title: Networking session: comparing methods for extreme event attribution.
Illustrations: plots from various attribution methods.

Time and location: Friday 02.05, 12h45-13h45, room 2.43.
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Marylou Athanase @marylouathanase.bsky.social · 27/04/2025
I will be presenting our results at #EGU25 in a poster on Wednesday. 🌀 So if you'd like to chat about the Arctic Beaufort Gyre in CMIP6 models, find me there! The poster: meetingorganizer.copernicus.org/EGU25/EGU25-... The paper: agupubs.onlinelibrary.wiley.com/doi/full/10....
agupubs.onlinelibrary.wiley.com
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...
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ECMWF @ecmwf.int · 25/04/2025
We will be at the European Geosciences Union (EGU) General Assembly next week, presenting developments from across #ECMWF. Find out which sessions we are involved in as speakers, poster presenters and conveners ➡ www.ecmwf.int/en/about/med... #EGU2025 @egu.eu
EGU flags in background. Text: "27 April - 2 May 2025. ECMWF at EGU General Assembly"
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Jan Wehner @jnwhnr.bsky.social · 07/04/2025
For a new visualization project @awi.de, I’m currently experimenting with satellite imagery, elevation data, and OSM. Exciting! @blender.org
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Jan Wehner @jnwhnr.bsky.social · 05/04/2025
Exploring ways to visualise wind together with my colleague @sbeyer.net at AWI. Here’s a glimpse: IFS-FESOM wind speed visualised as coloured particles.
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Marylou Athanase @marylouathanase.bsky.social · 31/03/2025
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....
agupubs.onlinelibrary.wiley.com
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...
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Thomas Rackow 🧊 @trackow.bsky.social · 19/03/2025
Merci!
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Thomas Rackow 🧊 @trackow.bsky.social · 19/03/2025
Link does not seem to work?
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Thomas Rackow 🧊 @trackow.bsky.social · 13/03/2025
Thank you for explaining, Jens!
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Thomas Rackow 🧊 @trackow.bsky.social · 13/03/2025
Very interesting! In the jump years, there is always an El Nino with "at least 1.5°" amplitude in the simulations. The 2023/24 one you write is 1.3° only, which we consider more moderate. Accounting for this, doesn't the recent temperature surge appear even more extreme/rare?
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Jens Terhaar @polarocean.bsky.social · 12/03/2025
Why have the sea surface temperature suddenly risen in 2023/24? 🌊 Is it true that climate models cannot simulate such SST jumps? What is common to such jumps? How will SSTs evolve over the next months and years? Are we in uncharted territory? More from our recent study in Nature is here👇
nature.com
Record sea surface temperature jump in 2023–2024 unlikely but not unexpected - Nature
Observations and climate models suggest that the global sea surface temperature jump in 2023–2024 was not unexpected and would have been nearly impossible without anthropogenic warming.
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