CER v2
CER v2 is the Central Europe Refined analysis, version 2, published by Bart, Schmidt et al. in Meteorologische Zeitschrift (2025). It is a long-term, high-resolution regional precipitation analysis for the Berlin-Brandenburg metropolitan region, produced by dynamically downscaling ERA5 with WRF.
Why it sits alongside the Galapagos work
The two projects use the same machinery on climates that could hardly be less alike, and the contrast is the useful part.
The Galapagos analysis addresses a tropical maritime archipelago where the controlling question is whether the model can sit on the right side of a regime boundary — stratocumulus under an inversion against deep convection. Berlin-Brandenburg is mid-latitude continental, comparatively flat, and its precipitation is driven by frontal systems and summer convection over a landscape with weak topographic forcing.
What transfers is the method and, more importantly, the discipline: the physics options are choices to test rather than defaults to inherit, since a configuration tuned for one regime has no obligation to work in another. What does not transfer is any particular configuration, which is exactly the point.
What the multi-decadal length buys
A long record is what makes the analysis useful for anything about extremes or trends. Short simulations characterise a mean state and say little about the tail, and the tail is where applied questions live — design values, drought duration, the return period of an intense summer rainfall event over a city with sealed surfaces.
That is also where the analysis connects to the urban climate work: an intense convective event over Berlin interacts with an urban surface that sheds water rather than absorbing it, so the same rainfall means something different than it would over farmland.
Berlin-Brandenburg is a comparatively dry region for central Europe, which makes both drought and convective extremes worth resolving properly — and makes a gridded, physically consistent multi-decadal analysis more informative than the station network alone can be.
See also: regional climate modeling, dynamical downscaling, urban climate, and the group context.