Continuous monitoring of surface water vapour isotopic compositions at Neumayer Station III, East Antarctica

• Published in: The Cryosphere
• Main Authors: S. Bagheri Dastgerdi, M. Behrens, J.-L. Bonne, M. Hörhold, G. Lohmann, E. Schlosser, M. Werner
• Format: Article in Journal/Newspaper
• Language: English
• Published: Copernicus Publications 2021
• Subjects: Environmental sciences; GE1-350; Geology; QE1-996.5; East Antarctica; Austral; Neumayer; Neumayer Station; Antarc*; Antarctica; The Cryosphere
• Online Access: https://doi.org/10.5194/tc-15-4745-2021; https://doaj.org/article/c89a3cb25d5b468dbfaa2ff2a9092d99

In this study, the first fully continuous monitoring of water vapour isotopic composition at Neumayer Station III, Antarctica, during the 2-year period from February 2017 to January 2019 is presented. Seasonal and synoptic-scale variations in both stable water isotopes <math xmlns="http://www.w3.org/1998/Math/MathML" id="M1" display="inline" overflow="scroll" dspmath="mathml"><mrow class="chem"><msubsup><mi mathvariant="normal">H</mi><mn mathvariant="normal">2</mn><mn mathvariant="normal">18</mn></msubsup><mi mathvariant="normal">O</mi></mrow></math> <svg:svg xmlns:svg="http://www.w3.org/2000/svg" width="28pt" height="17pt" class="svg-formula" dspmath="mathimg" md5hash="60b15d1ae8fe925bf8db6cc8d93f6fa6"><svg:image xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="tc-15-4745-2021-ie00001.svg" width="28pt" height="17pt" src="tc-15-4745-2021-ie00001.png"/></svg:svg> and HDO are reported, and their links to variations in key meteorological variables are analysed. In addition, the diurnal cycle of isotope variations during the summer months (December and January 2017/18 and 2018/19) has been examined. Changes in local temperature and specific humidity are the main drivers for the variability in δ 18 O and δ D in vapour at Neumayer Station III, on both seasonal and shorter timescales. In contrast to the measured δ 18 O and δ D variations, no seasonal cycle in the Deuterium excess signal ( d ) in vapour is detected. However, a rather high uncertainty in measured d values especially in austral winter limits the confidence of this finding. Overall, the d signal shows a stronger inverse correlation with specific humidity than with temperature, and this inverse correlation between d and specific humidity is stronger for the cloudy-sky conditions than for clear-sky conditions during summertime. Back-trajectory simulations performed with the FLEXPART model show that seasonal and synoptic variations in δ 18 O and δ D in ...