Alfred Wegener Institute · Bremerhaven

I build AWI's coupled climate and Earth system models.

Aerospace engineer by training. Came to AWI in 2016 for my master's thesis, stayed to couple OpenIFS to FESOM2, which became AWI-CM3. Now lead its successor AWI-ESM3, working across the Paleoclimate Dynamics and Climate Dynamics sections. PI in CAP7 and LiquidIce; advisor to EERIE and Destination Earth.

  • OpenIFS
  • FESOM2
  • OASIS3-MCT
  • LPJ-GUESS
  • PISM
  • XIOS
Ocean FESOM 2.7 Sea ice FESIM Biogeochemistry RECOM Atmosphere OpenIFS 48 Waves WAM Hydrology H-TESSEL Coupler OASIS3-MCT5 Dynamic vegetation LPJ-Guess IO server XIOS3 Runoff - Mapper Coupler SCOPE Ice sheet PISM
AWI-ESM3 components and couplers.
Simulated climates · one code base, six epochs status as of September 2026
  1. 127 kaLast InterglacialEC-Earth · M.Sc. thesis 2017done
  2. 21 kaLast Glacial MaximumAWI-ESM3 with interactive ice sheetsplanned
  3. 6 kaMid-HoloceneEC-Earth · M.Sc. thesis 2017done
  4. 1850 – 2025CMIP7 historical, transient aerosolsAWI-ESM3 · CAP7running
  5. 2100Storm-resolving projection, 9 kmAWI-CM3 · Moon et al. 2025done
  6. 2300Long-term scenario extensionsAWI-ESM3 · CAP7, LiquidIceplanned
AWI-ESM3 development and coupling
FESOM2 maintenance
Performance and scalability on HPC
CMORisation and CMIP7 data delivery
User support for the AWI model family
PI on CAP7 and LiquidIce

01Models

2019 → today

AWI-CM3

OpenIFS 43r3 atmosphere coupled to the multi-resolution FESOM2 ocean and sea ice through OASIS3-MCT. Runs from 61 km / 25–125 km CMIP-class setups up to 9 km storm-resolving projections. Described in Streffing et al. 2022.

DocumentationDescription paperSource

2024 → CMIP7

AWI-ESM3

AWI-CM3 extended to an Earth system model: OpenIFS 48r1, FESOM 2.7 with REcoM biogeochemistry, LPJ-GUESS dynamic vegetation and the PISM ice sheet via SCOPE. Running the CMIP7 historical now; designed so that the same executable can later carry glacial climates.

DocumentationCMIP7 statusSource

02Projects

PI CAP7 German contribution to CMIP7 AR7 Fast Track. AWI-CM3 and AWI-ESM3 DECK and ScenarioMIP runs, transient aerosol forcing, CMOR output. BMFTR · 2025 – 2027
PI LiquidIce Inland ice, snow and permafrost in a changing climate. Improving how AWI-ESM3 represents ice–liquid exchanges for Greenland, Svalbard, the Alps and High Mountain Asia. Horizon Europe · 2025 – 2028
Advisor EERIE European eddy-rich Earth system models. Horizon Europe
Advisor Destination Earth Climate Change Adaptation Digital Twin, km-scale IFS-FESOM. EU / ECMWF
PhD TRR 181 Energy transfers in atmosphere and ocean. Subproject L4: energy-consistent ocean–atmosphere coupling. DFG · 2021 – 2023

03Publications Full list on ORCID →

First author
  1. 2022
    Streffing, Sidorenko, Semmler, Zampieri, Scholz, Andrés-Martínez, Koldunov, Rackow, Kjellsson, Goessling, Athanase, Wang, Hegewald, Sein, Mogensen, Hohenegger, Jung (2022). AWI-CM3 coupled climate model: description and evaluation experiments for a prototype post-CMIP6 model.Geosci. Model Dev. 15, 6399–6427 · analysis scripts
  2. 2021
    Streffing, Semmler, Zampieri, Jung (2021). Response of Northern Hemisphere weather and climate to Arctic sea ice decline: resolution independence in PAMIP simulations.J. Climate 34, 8445–8457 · analysis scripts
Selected co-authored
  1. 2025
    Moon, Streffing, Hegewald, Rackow et al. (2025). Earth's future climate and its variability simulated at 9 km global resolution.Earth Syst. Dynam. 16, 1103
  2. 2025
    Rackow, Pedruzo-Bagazgoitia, Becker, Milinski, Sandu et al. incl. Streffing (2025). Multi-year simulations at kilometre scale with the Integrated Forecasting System coupled to FESOM2.5 and NEMOv3.4.Geosci. Model Dev. 18, 33–69
  3. 2022
    Smith, Eade, Andrews, Ayres, Clark et al. incl. Streffing (2022). Robust but weak winter atmospheric circulation response to future Arctic sea ice loss.Nature Communications 13, 727
All journal articles, from ORCID

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04Software

ocp-toolGenerates OASIS3-MCT input files and adapts OpenIFS land–sea masks to ocean meshes. fesom2Multi-resolution ocean and sea-ice model. Maintainer. esm_toolsModular infrastructure for building and running Earth system simulations. cmpitoolLightweight climate model performance index: how well does a model reproduce recent decades? On conda-forge. AWI-ESM/documentationHow to build, run and evaluate AWI-CM3 and AWI-ESM3. release_evaluation_tool2Evaluation framework for AWI-CM3 releases: 20+ SLURM-parallel diagnostics against ERA5, CERES, MODIS, GPCP, HadISST. Produced the figures for the 2022 and 2025 papers.

05CV & Contact

PhD thesis: Modelling the atmosphere–ocean interface with improved energetic consistency (PDF, 15 MB). Constructor University Bremen, TRR 181, defended 22 August 2023.
M.Sc. thesis: High resolution simulations for present and past climate states with the Earth system model EC-Earth. TU Braunschweig / AWI, 2017.

jan.streffing@awi.de
Alfred Wegener Institute, Klußmannstraße 3, 27570 Bremerhaven, Germany
ORCID · EPIC · GitHub · AWI

  1. 2023 –Scientific Programmer (permanent), AWI
  2. 2021 – 2023PhD Applied Mathematics, Constructor University Bremen · TRR 181
  3. 2017 – 2020Scientific Programmer, AWI Climate Dynamics
  4. 2014 – 2017M.Sc. Aerospace Engineering, TU Braunschweig · thesis at AWI from 2016
  5. 2009 – 2014B.Sc. Mechanical Engineering, TU Braunschweig