We present temporal and spatial δD distributions derived from IASI obtained above the North Atlantic in the vicinity of West Africa. We show that the seasonality of δD in the North Atlantic is closely associated with the influence of the Saharan heat low (SHL). We provide an interpretation of the temporal and spatial variations in δD and show that the interactions between the large-scale subsidence, the ITCZ, and the SHL can be disentangled thanks to the added information contained in δD.

We present FTIR soundings (2005–15) of water vapor (H₂O) and its isotope ratio (δD) at Zugspitze. Significant {H₂O, δD} signatures are found for intercontinental transport events and stratospheric air intrusions to central Europe using backward trajectories and validation by lidar and in situ data. Our results show that {H₂O, δD} observations at Zugspitze can serve as indicators for moisture pathways and long-range-transport events, potentially impacting central European climate and air quality.