Water vapor isotopic composition measurements at Dome C, East Antarctica, from 2018 to today: Isotopic signature of moisture intrusions

• Main Authors: Ollivier, I., Landais, A., Lauwers, T., Leroy Dos Santos, C., Jossoud, O., Prie, F., Jacob, R., Casado, M., Fourre, E., Steen-Larsen, H., Stenni, B., Agosta, C.
• Format: Conference Object
• Language: English
• Published: 2023
• Subjects: Antarctic; Austral; East Antarctica; Antarc*; Antarctica; EPICA; ice core; Ice Sheet
• Online Access: https://gfzpublic.gfz-potsdam.de/pubman/item/item_5020686

Dome C is located on the high Antarctic plateau, at 3233m above sea level, and 1200km away from the coastline. At this location, the EPICA ice core was retrieved from the ice sheet and allowed the reconstruction of past climatic information 800,000 years back in time. Amongst several atmospheric parameters, the past local temperature was inferred from the stable water isotope record measured in the ice.To interpret this record, it is necessary to understand how it was formed in such a dry and cold environment. This includes understanding the water cycle dynamics in Antarctica, from evaporation to precipitation and moisture pathways, as well as the processes affecting the record after deposition of the precipitation, such as snow-atmosphere exchanges.During the austral summer 2018-2019, a Picarro laser spectrometer was installed on site to monitor continuously the isotopic composition of the atmosphere. It provided measurements for all austral summers since then and allowed the detection of two major atmospheric river events, including a rare event during the onset of the cold Antarctic winter. To go beyond the limitations of the Picarro instrument when measuring at very low humidity levels, as encountered during the wintertime at Dome C, a new laser spectrometer dedicated to low humidity measurements has been developed and installed it in parallel to the Picarro instrument during the summer season 2022-2023. Here we present the results of the atmospheric isotopic composition during four consecutive austral summers and the comparison of the two laser instruments during the most recent period.