Detection of changes in glacial run‐off in alpine basins: examples from North America, the Alps, central Asia and the Andes

Casassa, Gino; López, P.; Pouyaud, Bernard; Escobar, Fernando

doi:10.1002/hyp.7194

Cited by 102 publications

(123 citation statements)

References 25 publications

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“…Compared to watersheds of SF lakes, GSF watersheds have a higher percent cover by perennial ice and snow (p < 0.001) as well as by bedrock and talus (p ) 0.06). Across the 26 lakes in this study, NO 3 -concentrations were higher in the GSF compared to the SF lakes (nonparametric one-way ANOVA, p < 0.0001; Figure 2). The average NO 3 -concentration of the GSF lakes was 114…”

Section: Resultsmentioning

confidence: 71%

“…Across the 26 lakes in this study, NO 3 -concentrations were higher in the GSF compared to the SF lakes (nonparametric one-way ANOVA, p < 0.0001; Figure 2). The average NO 3 -concentration of the GSF lakes was 114…”

Section: Resultsmentioning

confidence: 71%

“…NO 3 --N was quantified using the cadmium reduction method on a Lachat QuikChem 8500 flow injection analyzer with a limit of quantification of 1 µg N L -1 . Matrix interferences were tested by spiking an aliquot of sample from each lake with 50 µg NO 3 --N L -1 ; percent recovery ranged from 78 to 98% across samples. Soluble reactive phosphorus (SRP) was measured using the ascorbic acid method with a limit of quantification of 1 µg P L -1 .…”

Section: Methodsmentioning

confidence: 99%

“…In the southern Rocky Mountains of North America, an area with relatively high atmospheric reactive N (Nr) deposition (4-8 kg N ha -1 yr -1 ), meltwaters from ice and rock glaciers have elevated nitrate concentrations (13). Lake-water NO 3 -concentrations are also high in this area, but because of relatively high Nr deposition (7,14), the extent to which meltwater from ice and rock glaciers contribute Nr remains unclear. Nitrogen is a key limiting nutrient in alpine lake ecosystems (15,16), hence an influx of nitrate-rich glacial meltwater could have profound effects on productivity and species diversity in historically N-limited alpine lakes.…”

Section: Introductionmentioning

confidence: 99%

“…Here we focus on NO 3 -concentrations in glacial meltwater and its effects on highelevation lake ecosystems in two low N deposition areas of the U.S. Rocky Mountains: the Greater Yellowstone Ecosystem (central Rockies) and Glacier National Park (northern Rockies) ( Figure 1). The selected sites in the central Rockies have a combined rate of NO 3 -and ammonium (NH 4 + ) deposition between 1.4-2.5 kg Nr ha -1 year -1 , while those in the northern Rockies are between 2.0-3.4 kg Nr ha -1 year -1 (17). Alpine glaciers receded substantially in both regions over the course of the 20th century (18)(19)(20).…”

Section: Introductionmentioning

confidence: 99%

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Melting Alpine Glaciers Enrich High-Elevation Lakes with Reactive Nitrogen

Saros

Rose

Clow

et al. 2010

Environ. Sci. Technol.

112

107

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See next page for additional authorsFollow this and additional works at: https://digitalcommons.unl.edu/geosciencefacpub Part of the Earth Sciences CommonsThis Article is brought to you for free and open access by the Earth and Atmospheric Sciences, Department of at DigitalCommons@University of Nebraska -Lincoln. It has been accepted for inclusion in Papers in the Earth and Atmospheric Sciences by an authorized administrator of DigitalCommons@University of Nebraska -Lincoln. Alpine glaciers have receded substantially over the last century in many regions of the world. Resulting changes in glacial runoff not only affect the hydrological cycle, but can also alter the physical (i.e., turbidity from glacial flour) and biogeochemical properties of downstream ecosystems. Here we compare nutrient concentrations, transparency gradients, algal biomass, and fossil diatom species richness in two sets of high-elevation lakes: those fed by snowpack melt alone (SF lakes) and those fed by both glacial and snowpack meltwaters (GSF lakes). We found that nitrate (NO 3 -) concentrations in the GSF lakes were 1-2 orders of magnitude higher than in SF lakes. Although nitrogen (N) limitation is common in alpine lakes, algal biomass was lower in highly N-enriched GSF lakes than in the N-poor SF lakes. Contrary to expectations, GSF lakes were more transparent than SF lakes to ultraviolet and equally transparent to photosynthetically active radiation. Sediment diatom assemblages had lower taxonomic richness in the GSF lakes, a feature that has persisted over the last century. Our results demonstrate that the presence of glaciers on alpine watersheds more strongly influences NO 3 -concentrations in high-elevation lake ecosystems than any other geomorphic or biogeographic characteristic. Melting Alpine Glaciers Enrich High-Elevation Lakes with Reactive Nitrogen

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Section: Resultsmentioning

confidence: 71%

Section: Resultsmentioning

confidence: 71%

Section: Methodsmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 3 more Smart Citations

Melting Alpine Glaciers Enrich High-Elevation Lakes with Reactive Nitrogen

Saros

Rose

Clow

et al. 2010

Environ. Sci. Technol.

112

107

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Light attenuation characteristics of glacially‐fed lakes

et al. 2014

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Transparency is a fundamental characteristic of aquatic ecosystems and is highly responsive to changes in climate and land use. The transparency of glacially-fed lakes may be a particularly sensitive sentinel characteristic of these changes. However, little is known about the relative contributions of glacial flour versus other factors affecting light attenuation in these lakes. We sampled 18 glacially-fed lakes in Chile, New Zealand, and the U.S. and Canadian Rocky Mountains to characterize how dissolved absorption, algal biomass (approximated by chlorophyll a), water, and glacial flour contributed to attenuation of ultraviolet radiation (UVR) and photosynthetically active radiation (PAR, 400-700 nm). Variation in attenuation across lakes was related to turbidity, which we used as a proxy for the concentration of glacial flour. Turbidity-specific diffuse attenuation coefficients increased with decreasing wavelength and distance from glaciers. Regional differences in turbidity-specific diffuse attenuation coefficients were observed in short UVR wavelengths (305 and 320 nm) but not at longer UVR wavelengths (380 nm) or PAR. Dissolved absorption coefficients, which are closely correlated with diffuse attenuation coefficients in most non-glacially-fed lakes, represented only about one quarter of diffuse attenuation coefficients in study lakes here, whereas glacial flour contributed about two thirds across UVR and PAR. Understanding the optical characteristics of substances that regulate light attenuation in glacially-fed lakes will help elucidate the signals that these systems provide of broader environmental changes and forecast the effects of climate change on these aquatic ecosystems.

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Predicting glacio‐hydrologic change in the headwaters of the Zongo River, Cordillera Real, Bolivia

Frans

Istanbulluoglu

Lettenmaier

et al. 2015

Water Resources Research

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In many partially glacierized watersheds glacier recession driven by a warming climate could lead to complex patterns of streamflow response over time, often marked with rapid increases followed by sharp declines, depending on initial glacier ice cover and rate of climate change. Capturing such “phases” of hydrologic response is critical in regions where communities rely on glacier meltwater, particularly during low flows. In this paper, we investigate glacio‐hydrologic response in the headwaters of the Zongo River, Bolivia, under climate change using a distributed glacio‐hydrological model over the period of 1987–2100. Model predictions are evaluated through comparisons with satellite‐derived glacier extent estimates, glacier surface velocity, in situ glacier mass balance, surface energy flux, and stream discharge measurements. Historically (1987–2010) modeled glacier melt accounts for 27% of annual runoff, and 61% of dry season (JJA) runoff on average. During this period the relative glacier cover was observed to decline from 35 to 21% of the watershed. In the future, annual and dry season discharge is projected to decrease by 4% and 27% by midcentury and 25% and 57% by the end of the century, respectively, following the loss of 81% of the ice in the watershed. Modeled runoff patterns evolve through the interplay of positive and negative trends in glacier melt and increased evapotranspiration as the climate warms. Sensitivity analyses demonstrate that the selection of model surface energy balance parameters greatly influences the trajectory of hydrological change projected during the first half of the 21st century. These model results underscore the importance of coupled glacio‐hydrology modeling.

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Detection of changes in glacial run‐off in alpine basins: examples from North America, the Alps, central Asia and the Andes

Cited by 102 publications

References 25 publications

Melting Alpine Glaciers Enrich High-Elevation Lakes with Reactive Nitrogen

Melting Alpine Glaciers Enrich High-Elevation Lakes with Reactive Nitrogen

Light attenuation characteristics of glacially‐fed lakes

Predicting glacio‐hydrologic change in the headwaters of the Zongo River, Cordillera Real, Bolivia

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