TY  - JOUR
A1  - Barthold, Frauke Katrin
A1  - Turner, Benjamin L.
A1  - Elsenbeer, Helmut
A1  - Zimmermann, Alexander
T1  - A hydrochemical approach to quantify the role of return flow in a surface flow-dominated catchment
JF  - Hydrological processes
N2  - Stormflow generation in headwater catchments dominated by subsurface flow has been studied extensively, yet catchments dominated by surface flow have received less attention. We addressed this by testing whether stormflow chemistry is controlled by either (a) the event-water signature of overland flow, or (b) the pre-event water signature of return flow. We used a high-resolution hydrochemical data set of stormflow and end-members of multiple storms in an end-member mixing analysis to determine the number of end-members needed to explain stormflow, characterize and identify potential end-members, calculate their contributions to stormflow, and develop a conceptual model of stormflow. The arrangement and relative positioning of end-members in stormflow mixing space suggest that saturation excess overland flow (26-48%) and return flow from two different subsurface storage pools (17-53%) are both similarly important for stormflow. These results suggest that pipes and fractures are important flow paths to rapidly release stored water and highlight the value of within-event resolution hydrochemical data to assess the full range and dynamics of flow paths.
KW  - EMMA
KW  - hydrochemistry
KW  - overland flow
KW  - return flow
KW  - stormflow generation
Y1  - 2016
U6  - https://doi.org/10.1002/hyp.11083
SN  - 0885-6087
SN  - 1099-1085
VL  - 31
IS  - 5
SP  - 1018
EP  - 1033
PB  - Wiley
CY  - Hoboken
ER  - 
TY  - JOUR
A1  - Wetterich, Sebastian
A1  - Schirrmeiste, Lutz
A1  - Nazarova, Larisa B.
A1  - Palagushkina, Olga
A1  - Bobrov, Anatoly
A1  - Pogosyan, Lilit
A1  - Savelieva, Larisa
A1  - Syrykh, Liudmila
A1  - Matthes, Heidrun
A1  - Fritz, Michael
A1  - Günther, Frank
A1  - Opel, Thomas
A1  - Meyer, Hanno
T1  - Holocene thermokarst and pingo development in the Kolyma Lowland (NE Siberia)
JF  - Permafrost and Periglacial Processes
N2  - Ground ice and sedimentary records of a pingo exposure reveal insights into Holocene permafrost, landscape and climate dynamics. Early to mid-Holocene thermokarst lake deposits contain rich floral and faunal paleoassemblages, which indicate lake shrinkage and decreasing summer temperatures (chironomid-based T-July) from 10.5 to 3.5 cal kyr BP with the warmest period between 10.5 and 8 cal kyr BP. Talik refreezing and pingo growth started about 3.5 cal kyr BP after disappearance of the lake. The isotopic composition of the pingo ice (delta O-18 - 17.1 +/- 0.6 parts per thousand, delta D -144.5 +/- 3.4 parts per thousand, slope 5.85, deuterium excess -7.7 +/- 1.5 parts per thousand) point to the initial stage of closed-system freezing captured in the record. A differing isotopic composition within the massive ice body was found (delta O-18 - 21.3 +/- 1.4 parts per thousand, delta D -165 +/- 11.5 parts per thousand, slope 8.13, deuterium excess 4.9 +/- 3.2 parts per thousand), probably related to the infill of dilation cracks by surface water with quasi-meteoric signature. Currently inactive syngenetic ice wedges formed in the thermokarst basin after lake drainage. The pingo preserves traces of permafrost response to climate variations in terms of ground-ice degradation (thermokarst) during the early and mid-Holocene, and aggradation (wedge-ice and pingo-ice growth) during the late Holocene.
KW  - bioindicators
KW  - cryolithology
KW  - hydrochemistry
KW  - Khalerchinskaya tundra
KW  - stable water isotopes
Y1  - 2018
U6  - https://doi.org/10.1002/ppp.1979
SN  - 1045-6740
SN  - 1099-1530
VL  - 29
IS  - 3
SP  - 182
EP  - 198
PB  - Wiley
CY  - Hoboken
ER  -