Wie heiß wird es in der Sahara, wie kalt in der Antarktis? 🌡️ Klimamodelle berechnen die Temperatur-Landkarte der Erde. Aber wie gut sind diese? Eine Studie von Dr. @lukasbrunner.bsky.social zeigt: Im Schnitt sind die Temperatur-Landkarten der Klimamodelle deutlich genauer und zuverlässiger geworden.
Hier geht's zur Pressemitteilung der @uni-hamburg.de über unser gerade erschienenes Papier zum Vergleich von globalen Klimamodellen in den letzten 3 Jahrzehnten. 🧑🎓
www.uni-hamburg.de/newsroom/pre...
Many thanks also to all the institutions, data, and infrastructure providers involved!!
@uni-hamburg.de @univie.ac.at @ethz.ch @ecmwf.int @awi.de MPI-M @esrah.uni-hamburg.de @usyseth.bsky.social y #OpenScience #SciComm
Thanks so much to all the people that helped with this, in particular my co-authors Rohit Ghosh, Leopold Haimberger, Cathy Hohenegger, Dian Putrasahan, Thomas Rackow @trackow.bsky.social , Reto Knutti @retoknutti.bsky.social and Aiko Voigt @aikovoigt.bsky.social 🙏🧪🧑🎓
Root-mean-square distance (RMSD) to the full reference range for all 176 models individually.
We provide an extensive supplement to reveal model differences, also within model generations and spatial resolved the full database is on Zenodo.
doi.org/10.5281/zeno...
Model performance as a function of model resolution. RMSD to the full reference range as a function of model resolution for all 165 CMIP and 11 km-scale models.
We find a clear improvement in model performance with spatial resolution, but note that several other factors (representation of processes, tuning) are also crucial.
Difference between maximum and minimum RMSD divided by the mean RMSD. The RMSD is calculated for each model using each of the 10 different reference datasets in turn. Difference in RMSD when using one of two references: ERA-Interim or its successor ERA5.
Using a single reference as ground truth for the evaluation of the model temperature we find that
❗For the latest models the reference choice can determine up to 40% of the model bias
❗Models from different generations are systematically closer to certain references
Paper: doi.org/10.1038/s432...
Fraction of Earth’s land surface area for which the models' 20-year mean surface temperature falls within the range of the 10 reference. Two models are highlighted: IFS-FESOM from nextGEMS cycle 4 and from EERIE phase 1.
We find that km-scale models have the *potential* to match cross-evaluated references (some versions of IFS outperform several reference datasets) but in many cases, they still need considerable work to realize their full potential.
Fraction of Earth’s land surface area for which the models' 20-year mean surface temperature falls within the range of the 10 references and area-weighted root-mean-square distance (RMSD) relative to the reference range.
We investigate the global pattern of surface air temperature from
- 176 fully coupled climate models
- developed in 5 model generations (CMIP2 to the latest km-scale models)
- and 3 decades
- compared to 10 observational references
🚨 New paper: Three decades of simulating global temperature patterns with coupled global climate models
💡 Some of the latest km-scale models perform similarly to obs
💡 Reference choice starts to dominate for the latest models
💡 Resolution matters but is not everything
www.nature.com/articles/s43...
Hier ist noch die Info zu der ganzen Vortragsreihe, mit super spannenden weiteren Themen: www.zfw.uni-hamburg.de/oeffentliche...
Letzte Woche durfte ich im Rahmen der Ringvorlesung zur Klimakrise der @uni-hamburg.de einen Vortrag zu den naturwissenschaftlichen Grundlagen der Klimakrise geben. Vielen Dank fürs Dabeisein und für die spannenden Fragen! Zum Nachschauen 👇
youtu.be/IuTXbtR1fFw
#SystemChangeNotClimateChange
Vielen Dank für das Interesse und die angeregte Diskussion an alle die (online) dabei waren!
Der Vortrag ist zum nachsehen jetzt auch auf YouTube 💻
Die zugehörigen Slides auf meiner Homepage: lukasbrunner.github.io/outreach
youtu.be/IuTXbtR1fFw
Am kommenden Dienstag gebe ich im Rahmen der Ringvorlesung zur Klimakrise an der @uni-hamburg.de einen Vortrag zu den physikalischen Grundlagen der Klimakrise. Der Vortrag ist öffentlich, also gerne vorbeikommen!
Freue mich auf den Austausch! #climatecomms
www.zfw.uni-hamburg.de/oeffentliche...
Comparing global km-scale climate models to the resolution of coarser CMIP6 models.
The video shows precipitation flux and accumulated precipitation for 2025, ending with a quantification of the difference in resolutions.
Animation: Michael Böttinger (DKRZ)
Method & paper: bsky.app/profile/luka...
See also the amazing visualization made by DKRZ based on our work 👇👇
bsky.app/profile/luka...
Here's also my thread on the main findings: /profile/lukasbrunner.bsky.social/post/3lrsdhwkev22y
Here is the thread to the original publication:
bsky.app/profile/luka...
Amazing visualization of our recent sub-grid variability work by Michael Böttinger (DKRZ) 🤩.
It shows the local detail in global precipitation resolved by km-scale models. From 0:50 in direct comparison to CMIP6-type 100km. From 2:07 the sub-grid variability is shown. 🤓🧪
youtu.be/fzA92tSF4ZM?...
Local downpour near Oberstdorf, Germany ⛰️
Vor einigen Wochen durfte ich im Rahmen des Formats Vorlesung für Alle der @uni-hamburg.de einen Vortrag zu Temperaturextremen geben. Die Aufzeichnung ist jetzt auf YouTube 👇 Danke für die Einladung und das Interesse!
youtu.be/0KGi4Y6J2Ls?...
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...
Text reading "start a climate conversation" superimposed over the global warming stripes.
Today is #ShowYourStripes Day!
Created by @edhawkins.org, the warming stripes show temperature each year: blue for cool, white for avg, red for hot.
Athletes are wearing them, knitters are knitting them, and cities are putting them on trams.
Find + share your "stripes" here: showyourstripes.info
Annually the impact of climate change is pretty clear even locally. And even on a daily basis the signal starts to emerge!
For regular updates on daily Hamburg temperatures in a long term context, check out my bot @weather-climate.bsky.social (still 🚧)
2025 so far: bsky.app/profile/weat...
Book cover: Welt ohne Morgen by Tom Roth
Scary but fitting read for the occasion 🫣
Temperature anomaly relative to 1951-2010 in Hamburg, Germany
#ShowYourStripes day #SystemChangeNotClimateChange
The first 3 eps of TOTALLY COOKED have landed!
Check it out for weather & climate in a factual, relatable & often humorous way.
Available below, & where you get your podcasts.
Like, follow & share.
Let's tackle the climate crisis together.
#totallycooked
www.21centuryweather.org.au/engage/total...
The repository is hierarchical. Click on the rightmost tab, there you can select one of the two models, and then again one of the two resolutions. At the lowest level, there is a green 'Download' button.
Here's a direct link to the high-resolution IOCN results: www.wdc-climate.de/ui/entry?acr...
@cenunihh.bsky.social climate visualization lab has created this nice animation of the resolution effect on climate extremes! 🤩 Comparison of CMIP6-like 100km and the new 10km for the example of TXx (hottest day in the year).
Details in the paper: doi.org/10.1088/1748...
youtu.be/R5laSSVHUAk?...
