Kanngießer, F., Fiedler, S. Intercomparison case study of data-driven reconstructions of a cloud-obscured Saharan dust plume in Europe. Sci Rep 16, 17165 (2026). doi.org/10.1038/s41598-026-55422-y

Abstract:
On 15 March 2022 an intense, but partially cloud-obscured, Saharan dust plume was transported towards Europe by an atmospheric river. Ten-year statistics of dust plumes co-occurring with cloud cover over Europe highlights that regionally up to 100% of dust plumes are obscured by clouds, which poses challenges for reconstructing dust plumes from satellite images. The European dust case on 15 March 2022 is used to investigate whether data-driven machine-learning techniques for restoring the spatial extent of dust plumes in SEVIRI satellite images can be alleviated by exploiting the rich ground-based data sets in Europe. Satellite images were paired with different combinations of ground-based observation data, stemming from ground-based remote sensing, weather reports and measurements of particulate matter, using a k-nearest neighbours approach. Combining ceilometer and photometer data with satellite images added the most value for restoring the dust plume extent and are recommended for future reconstructions of cloud-obscured dust plumes.

Abstract:
In this thesis, I studied how decadal SST variability affects precipitation over Europe and the Sahel using atmosphere model OpenIFS. I found that the simulated European extreme precipitation is improved with higher horizontal resolution, but not with shorter time step. The European winter precipitation variability is dominated by internal atmospheric variability rather than SST forcing.  In contrast, Sahel precipitation responds strongly to AMV and IPV, with different impacts over the western and eastern Sahel. 

Abstract:
Climate change has intensified weather extremes in the semi-arid Sahel, one of the world’s most vulnerable regions. However, the cause of the most dramatic changes, from the Sahel droughts of the 1970s and 1980s to wetter conditions in recent decades, remains contested. Here we use ensembles of climate model simulations to show that these changes were primarily driven by anthropogenic aerosols. Aerosol-induced slowdown of the Hadley Cell, the atmospheric circulation that drives tropical convection globally, caused the droughts. The subsequent reduction of aerosol emissions over the North Atlantic land regions enhanced meridional heating gradient, convection, and rainfall over the Sahel. Conversely, the impact of greenhouse gases is markedly weaker, 3.5 to 5.3 times less than that of aerosols. The discovery of a dominant role for the aerosol-induced heating gradient, rather than absolute concentrations, provides a framework for advancing regional climate risk assessments generally.

Monteiro, E.A., Tran, G., Gidden, M.J. & Mengis, N.: Carbon-climate feedback responses to spatial aerosol model implementation variations. npj Clim Atmos Sci 9, 69 (2026). https://doi.org/10.1038/s41612-026-01343-6

Abstract:
Aerosols have played an important role in defining the climate over the historical period, due to their net cooling effect in the atmosphere. However, as their emissions are expected to decrease in upcoming decades, they will be associated with reduced cooling, i.e. future warming, of the planet. Despite their importance and high uncertainty associated with their radiative forcing, aerosols inclusion in simple climate models, impact models and carbon-based climate assessment metrics requires simplifications and assumptions. Typically, interactions between physical and biogeochemical processes are disregarded by such. By varying the spatial implementation of aerosols in an intermediate complexity model we explore the variability in Earth system responses under an ambitious mitigation scenario due to aerosols-radiation interactions. When aerosols are implemented disregarding their spatial distribution, surface air temperature is higher by almost 0.1 °C when compared to a regionally heterogeneous implementation, corresponding to an uncertainty of ca. 200 GtCO₂ of remaining carbon budgets. The main processes driving these responses are the land surface temperature and its effect on soil respiration, as well as changed ocean heat fluxes due to differences in incoming shortwave radiation at the surface. The spatial distribution of aerosols triggers important climate-carbon feedbacks, which should be specifically considered when assessing climate evolution and simulated Earth system responses. Even if aerosol-cloud interactions aren’t explored, the results already indicate that aerosols should be deliberately accounted for in simple models and assessment tools, as their triggered feedbacks will be instrumental in defining pathways for temperature stabilisation and evaluating, for example, remaining carbon budgets.