Characterizing hydrological processes within kettle holes using stable water isotopes in the Uckermark of northern Brandenburg, Germany

The last century of hydrological research has led to significant improvements in representing different hydrological processes in rainfall-runoff models. With widely available streamflow data, such models are typically calibrated against this reference time series, which can limit their predictive power. One option to improve the realism of rainfall-runoff models is by incorporating environmental tracers such as stable isotopes of water, water temperature and electrical conductivity within the modeling setup. Conventionally, stable water isotopes have been used to learn more about the dominant hydrological processes that occur within a given catchment, which generally helps improve the hydrologic model structure, but often at the cost of increased model complexity to simulate the tracer concentration along with streamflow.In this study, we develop a framework to incorporate stable water isotopes in continuous hydrological modeling, without significantly increasing model complexity. In the first step, stable water isotopes are used along with streamflow recession analysis to initialize the model state variables. After that, a Bayesian mixing model is used to infer the proportion of slow vs fast subsurface flow, and the results are used as additional constraints during the model calibration. This framework is extensively tested in a snow-dominated experimental catchment called Vallon de Nant, located in the Southwestern Swiss Alps (1189-3051 m. a.s.l.). During the presentation, we will discuss the advantages and limitations of such a modeling approach and how it can be extended to other experimental catchments.

Download Full-text

A Lagrangian perspective on stable water isotopes during the West African Monsoon

10.1002/essoar.10506628.1 ◽

2021 ◽

Author(s):

Christopher Johannes Diekmann ◽

Matthias Schneider ◽

Peter Knippertz ◽

Andries Jan de Vries ◽

Stephan Pfahl ◽

...

Keyword(s):

West African Monsoon ◽

West African ◽

Water Isotopes ◽

Stable Water Isotopes ◽

The West ◽

African Monsoon

Download Full-text

Use of stable water isotopes to identify and estimate the sources of groundwater recharge in an alluvial aquifer of Upper Jhelum Basin (UJB), western Himalayas

Hydrological Sciences Journal ◽

10.1080/02626667.2021.1985126 ◽

2021 ◽

Author(s):

Ghulam Jeelani ◽

Suhail A. Lone ◽

Amrin Un Nisa ◽

R. D. Deshpande ◽

Virendra Padhya

Keyword(s):

Groundwater Recharge ◽

Alluvial Aquifer ◽

Water Isotopes ◽

Western Himalayas ◽

Stable Water Isotopes

Download Full-text

Use of stable water isotopes to identify stages of the pingo ice core formation

Journal Ice and Snow ◽

10.15356/2076-6734-2018-4-507-523 ◽

2018 ◽

Vol 58 (4) ◽

pp. 507-523 ◽

Cited By ~ 1

Author(s):

Ju. N. Chizhova ◽

Yu. K. Vasil’chuk

Keyword(s):

Closed System ◽

Ice Core ◽

Ice Cores ◽

Water Isotopes ◽

Ice Formation ◽

Stable Water Isotopes ◽

Additional Tool ◽

Hydrological Conditions ◽

Water Saturated ◽

Average Annual Precipitation

Te isotopic characteristics of the pingo ice cores are considered. Te distribution of δ18O and δ2H values, dexc, δ18O–δ2H and δ2H–d exc relationships, and the simulation of the distribution of δ18O and δ2H values during the ice formation in a closed system, allowed drawing conclusion about the hydrological conditions and stages of the ice core growth. All pingos (Pestsovoye, Weather, Pingo-20) were formed in draining lake basins in the course of freezing of closed taliks. It is established that the water, which served as a source for the formation of the ice core, was subjected to evaporation still before the ice formation. According to our estimates, the water from which the ice of the Pestsovoye pingo was formed was heavier in values of δ18O and δ2H by 3.9 and 29.7‰, respectively, than the current average annual precipitation in the region. Similarly, for the ice of the core of the Pingo Weather it is 2.9 and 14.5‰, and 5.1 and 27.7‰ for the Pingo-20, respectively. In the ice cores of all considered pingos there is an ice formed in a closed system: in Pingo-20 it is a pure injection ice, while in the Pestsovoye and the Weser ones – the injected-segregated ice. Te frost mounds Pestsovoe and Weser grew under changing hydrological conditions: one part of the ice was formed when there was a free ﬂow of water to the freezing front (open system); the other one – when the water-saturated lenses of the closed talik were frozen (closed system). Te isotopic composition of ice being formed under conditions of a closed system reﬂects isotopic depletion during freezing and ice formation according to the Rayleigh model. It is expressed in a successive decrease in the values of δ18O and δ2H from the frst portions of ice to the last ones as the freezing continued. Te contrast values of δ18O and δ2H in diﬀerent parts of the ice being formed in the closed system may be used as an additional tool to identify direction of freezing. In a closed system, the last portions of ice have the greater contrast of the isotope values as compared to the frst portions.

Download Full-text

A pulse of mercury and major ions in snowmelt runoff from a small Arctic Alaska watershed

10.21079/11681/41203 ◽

2021 ◽

Author(s):

Thomas Douglas ◽

Matthew Sturm ◽

Joel Blum ◽

Christopher Polashenski ◽

Svetlana Stuefer ◽

...

Keyword(s):

Major Ions ◽

Atmospheric Mercury ◽

Water Isotopes ◽

Polar Regions ◽

Snowmelt Runoff ◽

Stable Water Isotopes ◽

Ephemeral Stream ◽

Arctic Alaska ◽

Open Sea ◽

Ice Leads

Atmospheric mercury (Hg) is deposited to Polar Regions during springtime atmospheric mercury depletion events (AMDEs) that require halogens and snow or ice surfaces. The fate of this Hg during and following snowmelt is largely unknown. We measured Hg, major ions, and stable water isotopes from the snowpack through the entire spring melt runoff period for two years. Our small (2.5 ha) watershed is near Barrow (now Utqiaġvik), Alaska. We measured discharge, made 10 000 snow depths, and collected over 100 samples of snow and meltwater for chemical analysis in 2008 and 2009 from the watershed snowpack and ephemeral stream channel. Our results suggest AMDE Hg complexed with Cl⁻ or Br⁻ may be less likely to be photochemically reduced and re-emitted to the atmosphere prior to snowmelt, and we estimate that roughly 25% of the Hg in snowmelt is attributable to AMDEs. Projected Arctic warming, with more open sea ice leads providing halogen sources that promote AMDEs, may provide enhanced Hg deposition, reduced Hg emission and, ultimately, an increase in snowpack and snowmelt runoff Hg concentrations.

Download Full-text

Linking Lagrangian model simulations with stable water isotope measurements in Arctic weather systems.

10.5194/egusphere-egu21-10984 ◽

2021 ◽

Author(s):

Aina Johannessen ◽

Alena Dekhtyareva ◽

Andrew Seidl ◽

Harald Sodemann

Keyword(s):

Water Cycle ◽

Lagrangian Model ◽

Water Isotopes ◽

Stable Water Isotopes ◽

Atmospheric Water ◽

Model Simulations ◽

Evaporation Source ◽

Isotope Measurements ◽

Water Isotope ◽

Eulerian Models

Transport of water from an evaporation source towards a precipitation sink is the essence of the atmospheric water cycle. However, there are significant challenges with the representation of the atmospheric water cycle in models. For example, incomplete representation of sub-grid scale processes like evaporation, mixing or precipitation can lead to substantial model errors. Here we investigate the combined use of Lagrangian and Eulerian models and in-situ observations of stable water isotopes to reduce such sources of model error. The atmospheric water cycle in the Nordic Seas during cold air outbreaks (CAOs) is confined to a limited area, and thus may be used as a natural laboratory for hydrometeorological studies. We apply Lagrangian and Eulerian models together with observations taken during the ISLAS2020 field campaign in the Arctic in spring 2020 for characterising source-sink relationships in the water cycle. During the field campaign, we observed an alternating sequence of cold air outbreaks (CAO) and warm air intrusions (WAI) over the key measurement sites of Svalbard and northern Norway. Thereby, meteorological and stable water isotope measurements have been performed at multiple sites both upstream and downstream of the CAOs and WAIs. The Lagrangian model FLEXPART has been run with the input data from the regional convection-permitting numerical weather prediction model AROME Arctic at 2.5 km resolution to investigate transport patterns. The combination of observations and model simulations allows us to quantify the connection between source and sink for different weather systems, as well as the link between large-scale transport and stable water isotopes. Findings will lead to a better understanding of processes in the water cycle and the degree of conservation of isotopic signals during transport. This study may also serve as a guideline on how to evaluate the performance of Lagrangian transport models using stable water isotope measurements, and on how to detect constraints for quantifying the transport route and evaporation source from stable water isotope measurements for future work, including an aircraft campaign planned in 2021.

Download Full-text