Observing and Modeling the Isotopic Evolution of Snow Meltwater on the Southeastern Tibetan Plateau
- 주제(키워드) snow meltwater , isotopic evolution , model , isotopic exchange , temperate glacier , Tibetan Plateau
- 주제(기타) Environmental Sciences
- 주제(기타) Limnology
- 주제(기타) Water Resources
- 설명문(일반) [Pu, Tao; Kang, Shichang; He, Yuanqing; Wang, Shijin] Chinese Acad Sci, Northwest Inst Ecoenvironm & Resources, State Key Lab Cryospher Sci, Lanzhou, Peoples R China; [Wang, Ke; Kong, Yanlong; Huang, Yonghui] Chinese Acad Sci, Inst Geol & Geophys, Beijing, Peoples R China; [Shi, Xiaoyi] Zhejiang Normal Univ, Coll Geog & Environm Sci, Jinhua, Zhejiang, Peoples R China; [Kang, Shichang] CAS Ctr Excellence Tibetan Plateau Earth Sci, Beijing, Peoples R China; [Lee, Jeonghoon] Ewha Womans Univ, Dept Sci Educ, Seoul, South Korea; [Cuntz, Matthias] Univ Lorraine, AgroParisTech, INRAE, UMR Silva, Nancy, France
- 등재 SCIE, SCOPUS
- 발행기관 AMER GEOPHYSICAL UNION
- 발행년도 2020
- 총서유형 Journal
- URI http://www.dcollection.net/handler/ewha/000000174641
- 본문언어 영어
- Published As http://dx.doi.org/10.1029/2019WR026423
초록/요약
Observing the isotopic evolution of snow meltwater helps in understanding the process of snow melting but remains a challenge to acquire in the field. In this study, we monitored the melting of two snowpacks near Baishui Glacier No. 1, a typical temperate glacier on the southeastern Tibetan Plateau. We employed a physically based isotope model (PBIM) to calculate the isotopic composition of meltwater draining from natural snowpacks. The initial condition of the PBIM was revised to account for natural conditions, i.e., the initial delta O-18 stratigraphy of snow layers before melting. Simulations revealed that the initial heterogeneity of delta O-18 in snow layers as well as ice-liquid isotopic exchange were responsible for most variations of delta O-18 in snow meltwater, whereas new snow and wind drift could result in sudden changes of the isotopic composition of the meltwater. The fraction of ice involved in the isotopic exchange (f) was the most sensitive parameter for the model output. The initial delta O-18 in the snowpack is mirrored in meltwater in case of smallfand is smoothed with a large exchange fractionf. The other unknown parameter of the PBIM is the dimensionless rate constant of isotopic exchange, which depends on water percolation and initial snow depth. The successful application of the PBIM in the field might not only be useful for understanding snow melting process but might also provide the possibility of predicting the isotopic composition of snow meltwater and improve the accuracy of hydrograph separation.
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