Lars Kaleschke

The #Arctic Ocean is full of life, not only polar bears live on the sea ice. 🐦🐟🐦🦐🐦🐋🐦 Enjoy this short movie made in the marginal ice zone. 2nd June 2020 ⁦@MOSAiCArctic

A warm welcome to the new members joining our group! ❄️🛰️ From left to right: Diren Senger, Moritz Mund, Caitlyn Peretzke, Jiaxing Gong. See comments for more details about their research! Thrilled to see what you all discover! Welcome to the team, Diren, Moritz, Caitlyn, and Jiaxing! 👏🧊

"Die Annäherung könnte Zufall sein " - Nein, absolut nicht! bsky.app/profile/marc...

Results indicate the absence of beryllium input from the North Atlantic during late MIS6 and MIS4. The Arctic was thus effectively decoupled from the global ocean, implying major reorganizations of deep-water circulation and chemistry. 👉 doi.org/10.1038/s432...

Could an entire ocean turn from salty to fresh? It has been proposed that the Arctic Ocean and Nordic Seas were not only episodically covered by an ice shelf during past ice ages, but disconnected from the North Atlantic and filled with freshwater.

New preprint open for discussion and under review for The Cryosphere. Mignac, D. and Martin, M. J.: Machine-learning bias correction of passive-microwave sea ice concentration against a SAR-derived product: impact on Arctic sea ice forecasts, EGUsphere [preprint], doi.org/10.5194/egus..., 2026.

Global ocean heat content (0-2000 m depth) now updated through June 2026... Do you see where this is heading? 🔥📈🌊 This graph showing anomalies is created by NOAA at www.ncei.noaa.gov/access/globa....

The October runs for dynamical El Niño models are now all out, and its a mixed bag. Some revise the event downward, some upward, but on average its still expected to peak at ~4C, albeit with the peak more likely to occur in December than November:

Well, actual sea surface temperatures have now passed 30°C (86°F) in the key Niño 3.4 monitoring region for the first time in this data record... 😱 Sign up for next week's state of the climate briefing: climatecentral-org.zoom.us/webinar/regi.... Bring your questions, like on this historic El Niño!

Eine Erklärung des aktuellen Physik-Nobelpreises vom Preisträger selbst. 😊 www.spektrum.de/magazin/neut...

Ein „Ideologe“, wie die Tageschau den neuen Vize-Landtagspräsiden in Sachsen-Anhalt nennt.

#FCKAFD #FCKCDU #FCKNZS

Abstract submissions are now open for the Joint (AC)3-MOSAiC Conference 2027: Drivers and Impacts of a Changing Arctic. 8-12 March 2027 in #Leipzig, Germany. Emerging topics in #Antarctic science are also welcome. #Arctic #Climate www.jamc27.com/index.html

New in The Guardian — Antarctic sea ice hit its winter maximum, the third-lowest level on record — featuring insight from Walt Meier, a senior research scientist at @nsidc.bsky.social and CIRES. www.theguardian.com/world/2026/s...

When it comes to future sea-level rise, Antarctica matters. Now researchers who looked at hundreds of thousands of potential emissions futures and the impact of each on the ice sheet found that Antarctica’s ice loss this century is locked in. theconversation.com/antarcticas-...

New preprint open for discussion Lambotte, A. et al.: Distinct and synergistic influences of sea ice rheology and seabed stress on simulated Arctic fast ice, EGUsphere [preprint], doi.org/10.5194/egus..., 2026.

🌊🔎 Die Wunder der #Meere live erleben: Beim Bremer Bürgerfest zur Deutschen Einheit präsentieren die regionalen Einrichtungen der #Meeresforschung vom 2.-4.10. ein buntes Prorgamm zum Eintauchen - von #Tiefsee über #Korallenriffe bis zum #Polareis. 👉 www.allianz-meeresforschung.de/veranstaltun...

New paper published today Koo, Y., Meier, W. N., and Stewart, J. S.: Pan-Antarctic evaluation of National Snow and Ice Data Center (NSIDC) sea ice drift product using high-resolution SAR and buoy data, Earth Obs., 1, 129–144, doi.org/10.5194/eo-1..., 2026.

And then there were three🛰️ ESA’s Programme Board for Earth Observation has selected ECO, Keystone and CryoRad to progress to the next phase toward Earth Explorer 12. The three concepts would investigate Earth’s energy balance, the upper atmosphere & polar ice sheets. 🔗 www.esa.int/Applications...

The progress we made in moving away from higher emissions futures should tell us that progress is possible. But it shouldn't breed complacency; the risks remain far too high and grow with each molecule of carbon emitted. The world still isn’t nearly concerned enough.

This is what a monster El Niño on an ocean already warmed by climate change looks like.

Schleswig-Holstein treibt den Wechsel von Microsoft auf Open Source voran. Nach E-Mail und Office läuft die Kieler Staatskanzlei nun weitgehend unter Linux. #Digitale Souveränität

Bremer Haltung im Bundesrat noch unklar www.butenunbinnen.de/nachrichten/...

This year's El Niño event is moving into record territory, with the daily Oceanic Niño Index (ONI) tying the record previously set during the 2015/2016 super-El Niño. My latest over at Carbon Brief: www.carbonbrief.org/...

“In science, each time you explore a new frequency domain, you make discoveries”

Wir hatten ja grad bundesweit die Woche der Klimaanpassung. Ich hab da mal was zum Thema geschrieben. Spoiler: es wird teuer und hilft nicht so wirklich.

#Europe and #Canada are talking about a closer partnership. @esa.int has been showing what that can look like for decades: Canada has been its only non-European Cooperating State since 1979.

Here is the latest combined forecast across all 14 models, compared to past strong El Nino events. It shows just how extreme and unprecedented this event is forecast to be:

Am Samstag den 12. September haben wir in vielen Städten wieder die Chance, uns für ein Demokratie Prüfverfahren für Parteien einzusetzen, zum Beispiel in #Bremen um 17:00 Uhr am Bahnhofsvorplatz! Sag es weiter, komm vorbei und bring noch jemanden mit! #AFDVerbot @pruef-demos.de

GOOD NEWS: the Arctic Report Card will continue under its independent editorial team – led by researchers at CIRES @colorado.edu and @uafairbanks.bsky.social – with new support from @agu.org. cires.colorado.edu/news/2026-ar...

Spoiler alert: The melange is not going to save us. But actually our findings are much more complex and interesting than just that. Full article in The Cryosphere here: tc.copernicus.org/articles/20/...

Last month was the all-time hottest month on record globally (albeit very close to July 2023). This was not surprising at all unfortunately... Graphic from zacklabe.com/climate-chan... using ERA5 data.

Over the coming months, warships and support vessels will carry out long-distance voyages in the Arctic Ocean. This is the first Northern Sea Route voyage for the Russia's new ice-classed patrol ship Ivan Papanin.

🌊 SOOS Update! Issue 35 is out! Explore five years of SOOS progress, the new SOOS 5-Year Report, SYNCHRONY, Antarctica InSync, new Working Group leaders, Polar Profiles, research, publications and more. 📖 Read it here: go.soos.aq/SOOSUpdateNo35

Here is an example of how relentless and excessive the heat has been in parts of Europe. Baden-Württemberg in SW Germany added a whopping 30% of hot days (>30°C) to the previous warmest year. London with 55 days w/o rain is also mad #ClimateEmergency Source: www.mtwetter.de (image modified) (2/2)

Globally, the hottest August in observed history is just about to end. In Western Europe, the summer of 2026 (June, July, August) has been the warmest as well. Compared to this year, 1976 (the famous UK summer) and 2003 (the hottest EU summer so far) look like amateurs in terms of heat (1/2)

ECMWF's HPC system has around 1 million processors and 248 Graphics Processing Units that can perform many calculations in parallel. Around 1.5 exabytes (1,500,000,000,000,000,000 bytes) of data are currently stored, equivalent to roughly 175 billion music tracks. www.ecmwf.int/en/about/med...

Klimadaten aus Galapagos-Korallen deuten darauf hin, dass El Nino durch die menschengemachte Erderwärmung signifikant steigt. #Klimakrise

A comprehensive new study finds that the El Niño events during the past 40 years are 36% stronger than those during the preindustrial era, a trend that is likely tied to climate change. www.cnn.com/2026/08/27/c... [THREAD] 1/

New from @vantortech.bsky.social. Absolutely astonishing images of the China-Nepal Gyirong Port/Rasuwagadhi border post. Literally nothing is left. (Before 19 April, After 27 Aug)

📣 Registration is now open for experts to review the First Order Draft of the Working Group I contribution to IPCC’s Seventh Assessment Report. Experts can register until 25 Sept 2026 👉https://bit.ly/4vi25cq Review period 10 Aug to 2 Oct 🔗 https://bit.ly/WGI7Fod

🐻‍❄️😍 www.bbc.com/news/article...

Die Bremer Straßenbahn AG wollte eigentlich gar keine automatisierte Verhaltenskontrolle, das System war nur gerade im Angebot. Ohne Plan und Ahnung von Persönlichkeitsrechten startete der Einsatz. Die Datenschutzaufsicht hat grundsätzliche Bedenken.

Für die Expedition scheint es auch bald ein online Log Buch zu geben (gewissermaßen einen Log Blog: www.marum.de/en/Ship-s-lo...). Auf jeden Fall ein sehr interessantes Projekt, dass hier läuft.

English lawn summer 2026 edition #drought

🚨 Preliminary daily data shows we just broke the all-time highest global sea surface temperature in this record... Download high-resolution graphic at zacklabe.com/climate-chan.... This data (extrapolar ocean) is provided by @copernicusecmwf.bsky.social ERA5. 🌊

Here are my latest numbers incorporating the August 10th C3S model updates (and the rest of the August dynamic model runs) as well as July data from (most) datasets:

🚨🚨🚨 The just released CPC El Nino forecast now calls for a peak Relative Oceanic Nino Index (RONI) of +2.7C (50th percentile) during the Oct-Dec period. This would exceed any 3-month RONI value in the entire ERSSTv6 database. 🔥🔥🔥

2nd-lowest for the 1978-2026 period as well. Interesting drop in extent the last week...