Cluster B - B02



Towards a better understanding of moisture responses to radiative forcing

Prof. Dr. S. Fiedler
GEOMAR Kiel  |    +49 431 600-4054 |    This email address is being protected from spambots. You need JavaScript enabled to view it.



The radiation budget plays a key role in climate change. This project systematically assesses the soil moisture response to the radiative forcing of atmospheric composition changes and the influence of water management using the Coupled Model Intercomparison Project Phase 6 (CMIP6) models. With a focus on the response of the soil moisture in Europe, the project separates contributions from water management, greenhouse gases, anthropogenic dust-aerosols, as well as aerosols from biomass burning and industrial pollution. It contributes to understand the possible future development of anthropogenic dust-aerosols in a warmer world.

Graphical summary

Contribution to the CRC

B02 is an essential component of a larger research project with multiple connections to various clusters. B02 collaborates with different clusters to achieve this, for joint advancements in the understanding of the hydrological cycle and its impact on atmospheric models, for observational data on precipitation and dust emissions along with input from global climate simulations. B02 aims to provide valuable insights into radiative forcing and climate response analysis, bridging the gap between regional and global perspectives.


B02's initial research delves into the analysis of the CMIP6 historical simulations, aiming to unravel the impact of anthropogenic aerosols on global atmospheric circulation and precipitation patterns. To achieve this, we examined various CMIP6 simulations, including those from the Detection and Attribution Model Intercomparison Project (DAMIP). In the CMIP6 historical simulations, we considered a comprehensive all-forcing setup. In contrast, DAMIP represents its single forcing counterpart, where only anthropogenic aerosols vary, while all other forcings remain at pre-industrial levels. We identify two distinct time periods for analysis: the Aerosol Increase (AI) phase and the Aerosol Shift (AS) phase. The AI phase was defined as the average difference between the 1970s and the 1850s, allowing us to assess changes over time. Similarly, the AS phase was characterized as the average difference between the 2000s and the 1970s, providing insights into more recent shifts in aerosol influence.

Main Results in 2022 and 2023

  • Comprehensive analyses of CMIP6 and DAMIP simulations were conducted.
  • During the AI phase, a significant surge in the anthropogenic aerosols was observed mostly over Europe and North America. In contrast, the AS phase indicated a shift in aerosol emission sources towards lower latitudes, particularly over South and East Asia. (See Figure (a) and Figure (b)).
  • These alterations in the distribution of anthropogenic aerosols had a discernible impact on the patterns of the boreal summer Inter Tropical Convergence Zone (ITCZ). During the AI phase the ITCZ exhibited an equatorward shift. In contrast, during the AS phase a poleward shift was observed.
  • This shift in the ITCZ also manifested in global summer precipitation patterns consistent with observations.
  • Our analyses, encompassing both CMIP6 all-forcing and DAMIP single-forcing simulations, underscored the significant influence of anthropogenic aerosols in modifying meridional heat transport and subsequently shaping atmospheric circulation patterns.
  • This research sheds light on the intricate relationship between aerosols and climate, highlighting the substantial impact of human activities on global climate systems.
  • In parallel, we've also established an offline dust emission model, to utilize the high-temporal frequency data generated by the CMIP6 historical simulations mentioned earlier. This model allows us to investigate how specific factors such as wind patterns and soil moisture levels influence the calculation of dust emission fluxes.

B02 Fig 1

Collaborative Research Centre (SFB) 1502 - DETECT

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Coordination Office

logomosaik slim Universität Bonn Forschungszentrum Jülich Geomar Georg-August-Universität Göttingen Deutscher Wetterdienst