Meteorology; Climatology; Numerical weather prediction; Atmospheric water cycle; Stable water isotopes
Dahinden Fabienne, Aemisegger Franziska, Wernli Heini, Schneider Matthias, Diekmann Christopher J., Ertl Benjamin, Knippertz Peter, Werner Martin, Pfahl Stephan (2021), Disentangling different moisture transport pathways over the eastern subtropical North Atlantic using multi-platform isotope observations and high-resolution numerical modelling, in
Atmospheric Chemistry and Physics, 21, 16319-16347.
Diekmann Christopher J., Schneider Matthias, Knippertz Peter, Vries Andries J., Pfahl Stephan, Aemisegger Franziska, Dahinden Fabienne, Ertl Benjamin, Khosrawi Farahnaz, Wernli Heini, Braesicke Peter (2021), A Lagrangian Perspective on Stable Water Isotopes During the West African Monsoon, in
Journal of Geophysical Research: Atmospheres, 126(19), e2021JD034.
Aemisegger Franziska, Vogel Raphaela, Graf Pascal, Dahinden Fabienne, Villiger Leonie, Jansen Friedhelm, Bony Sandrine, Stevens Bjorn, Wernli Heini (2021), How Rossby wave breaking modulates the water cycle in the North Atlantic trade wind region, in
Weather and Climate Dynamics, 2(1), 281-309.
Christner Emanuel, Aemisegger Franziska, Pfahl Stephan, Werner Martin, Cauquoin Alexandre, Schneider Matthias, Hase Frank, Barthlott Sabine, Schädler Gerd (2018), The Climatological Impacts of Continental Surface Evaporation, Rainout, and Subcloud Processes on δ D of Water Vapor and Precipitation in Europe, in
Journal of Geophysical Research: Atmospheres, 123(8), 4390-4409.
This project will use observations and numerical simulations of atmospheric water vapourisotopologues to increase the process understanding of the coupling between atmosphericwater and circulation in different climatic regions. Novel observational data are essential forfurther improving numerical weather and climate models and to this end water vapourisotopologues can make a unique contribution. Their ratios provide information about thesource conditions of atmospheric water and the involved transformation processes, in particularin clouds. There has recently been large progress in modelling and observing these ratios,such that a combined analysis is now feasible at high resolution and on a global scale.The aim of this project is to establish tropospheric water vapour isotopologues as an observational tool for testing the model representation of atmospheric moisture pathways, thereby contributing to key challenges in present-day climate research. To achieve statistical robustness, we will generate an unprecedented amount of free tropospheric {H2O, dD}-pairs (dD is the standardised ratio between HD16O and H216O). For the first time a validated observational dataset will be available that covers large areas and long time periods. At the same time, a high-resolution meteorological model with isotopologue representation will be used for analysing moisture sources and pathways and their associated isotopologue signals. This combined observational-modeling approach will provide unique opportunities for modelevaluation and for advancing the understanding of the involved processes. The potential of the isotopologues will be demonstrated in three different climatologically interesting regions. In Europe our approach will provide valuable insight into the key relationship between moisture sources and isotopologue signals in highly variable weather conditions. Over the subtropical North Atlantic the isotopologues will be used for tracing mixing between the marine boundary layer and the free troposphere, whose discrepant treatment in models is thought to be one important reason for a large cloud feedback uncertainty in climate models. Over West Africa the isotopologues serve to evaluate the model representation of the West African monsoon, particularly the associated horizontal moisture transport, terrestrial moisture recycling and the diurnal variations related to vertical mixing. Of particular interest will be the role of organised convection in influencing the monsoon circulation and the associated water pathways. Together these results will help to identify and better understand deficits in existing weather and climate models and provide a new framework to guide future model improvement.