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Titolo:
APPLICATION OF O-18 TRACER TECHNIQUES TO ARCTIC HYDROLOGICAL PROCESSES
Autore:
COOPER LW; SOLIS C; KANE DL; HINZMAN LD;
Indirizzi:
OAK RIDGE NATL LAB,DIV ENVIRONM SCI,POB 2008,MS 6038 OAK RIDGE TN 37831 UNIV ALASKA,INST NO ENGN,WATER RES CTR FAIRBANKS AK 99775
Titolo Testata:
Arctic and alpine research
fascicolo: 3, volume: 25, anno: 1993,
pagine: 247 - 255
SICI:
0004-0851(1993)25:3<247:AOOTTT>2.0.ZU;2-9
Fonte:
ISI
Lingua:
ENG
Soggetto:
HYDROGEN ISOTOPE RATIOS; SNOWMELT RUNOFF; PRECAMBRIAN SHIELD; STORM RUNOFF; WATER; BASIN; GROUNDWATER; CALIFORNIA; GENERATION; TERRAIN;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
40
Recensione:
Indirizzi per estratti:
Citazione:
L.W. Cooper et al., "APPLICATION OF O-18 TRACER TECHNIQUES TO ARCTIC HYDROLOGICAL PROCESSES", Arctic and alpine research, 25(3), 1993, pp. 247-255

Abstract

The deltaO-18 value of streamflow at Imnavait Creek, Alaska, shifted dramatically from -30.3 parts per thousand on 14 May, the first day ofstreamflow in 1990, to -22.5 parts per thousand on 22 May, at the endof the snowmelt. These results suggested a large degree of mixing between snow (deltaO-18 value = -27.6 parts per thousand +/- 1.6 SD) and underlying soil moisture (estimated deltaO-18 value = -20.6 parts per thousand). Nevertheless, independent hydrological measurements of snowredistribution by wind, snow ablation, snow and soil moisture content, and snowmelt runoff indicate there cannot be significant mixing of meltwater with underlying ice-rich soils. An alternative explanation isthat isotopic fractionation during the phase change from solid to liquid dominates the isotopic variation in streamflow during snowmelt andprevents a straightforward application of O-18 as a conservative hydrological tracer. By contrast, under dry antecedent conditions in late summer, O-18 appeared to be a suitable tracer following rain contributions to streamflow. Streamflow increased as a result of rainfall, but stream isotopic composition did not change until at least two hours after streamflow increased, implicating a wave, or piston-like mechanismfor forcing ''old'' water into the stream channel. Analyses of the stable hydrogen and oxygen isotope composition of various hydrological components within the watershed indicate the importance of evaporation as a dominant factor in the hydrological cycle; soil moisture, streamflow, permafrost, and the snowpack all showed varying degrees of isotopic alteration as a result of evaporation. Our analyses indicate that caution would be advised for any application of stable isotopes to hydrological studies in arctic watersheds. Proportions of snowmelt mixing with underlying soil water may be subject to overestimation because isotopic fractionation as snow melts can be similar in direction and magnitude to the isotopic mixing of snowmelt and soil waters.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 30/10/20 alle ore 09:04:39