Changes of atmospheric water vapour isotopes in the Arctic at the interface with sea ice and open ocean


Contact
camilla.brunello [ at ] awi.de

Abstract

Evaporation from the increasingly ice-free Arctic ocean causes moistening of the atmosphere and serves as an unprecedent water source for the Northern Hemisphere. Atmospheric transport of moisture and its interaction with the other Arctic hydrological compartments can be tracked by primary and secondary water isotope parameters. We present observations of atmospheric humidity, δ18O, δD and d-excess, obtained from a cavity-ring-down spectrometer installed on RV Polarstern and operated continuously during the MOSAiC expedition. The dataset reveals a clear seasonal cycle of the atmospheric water vapour; positive correlation is found both with local specific humidity and air temperature. The comparison of synoptical events, characterized by abrupt isotopic fluctuations, with simultaneous observations from land-based Arctic stations indicates a strong influence of sea ice coverage on the isotopic signal. For an in-depth understanding of the isotopic changes, the observations are compared to results of an isotope-enhanced ECHAM6 atmosphere simulation. The model-data comparison assesses the capability of this state-of-the-art AGCM to capture the first-order evaporation/condensation processes and their seasonal evolution. However, a systematic overestimation of winter values and overall decreased variability of modeled values is found. Investigation of such discrepancies may help to identify deficits in the representation of the fine-scale exchange processes characterizing the central-Arctic water cycle.



Item Type
Conference (Talk)
Authors
Divisions
Primary Division
Programs
Primary Topic
Publication Status
Published
Event Details
International MOSAiC Science Conference/Workshop, 25 Apr 2022 - 29 Apr 2022, Potsdam.
Eprint ID
56277
Cite as
Brunello, C. F. , Meyer, H. , Mellat, M. and Werner, M. (2022): Changes of atmospheric water vapour isotopes in the Arctic at the interface with sea ice and open ocean , International MOSAiC Science Conference/Workshop, Potsdam, 25 April 2022 - 29 April 2022 .


Download
[thumbnail of Session_2_MOSAiC2022_Camilla_Brunello.pdf]
Preview
PDF
Session_2_MOSAiC2022_Camilla_Brunello.pdf

Download (7MB) | Preview

Share

Research Platforms

Campaigns
PS > 122/1 (MOSAiC20192020)
PS > 122/2 (MOSAiC20192020)
PS > 122/3 (MOSAiC20192020)
PS > 122/4 (MOSAiC20192020)
PS > 122/5 (MOSAiC20192020)

Funded by
BMBF 03FO869A


Actions
Edit Item Edit Item