Snow is important too: disentangling the role of the cryosphere in the water cycle of a tropical Andean catchment
| Autor: | Fyffe, C., Potter, E., Miles, E., Shaw, T., McCarthy, M., Orr, A., Loarte, E., Medina, K., Llacza, A., Jacome, G., Fatichi, S., Hellström, R., Baraer, M., Mateo, E., Pellicciotti, F. |
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| Jazyk: | angličtina |
| Rok vydání: | 2023 |
| Zdroj: | XXVIII General Assembly of the International Union of Geodesy and Geophysics (IUGG) |
| DOI: | 10.57757/iugg23-4655 |
| Popis: | The Peruvian Andes contains the largest mass of glaciers in the tropics and previous work identified glacier melt as a key contributor to sustaining dry season water resources. Snow, however, has been neglected to date, and modelling and hydro-chemical analyses have been unable to resolve the snow cover dynamics nor fully distinguish between the separate contributions of snow and glaciers to runoff. To provide these insights we run the fully distributed, hourly glacier-hydrological model TOPKAPI-ETH from 2008-2018 over the upper Rio Santa catchment in the Cordillera Blanca. The model parameters are derived from ground-based data and evaluated against independent snow cover and glacier mass balance estimates from remote sensing, alongside gauged runoff. Glacier melt is important in the dry season and in the Blanca (eastern) side of the catchment, where even the catchments with the smallest glacier-covered area benefit from dry season runoff. However, our results highlight the underappreciated importance of snow for discharge. Snowmelt is a strikingly consistent contributor to runoff temporally and spatially: its proportional contribution is largest at the beginning of the dry season and lowest at the beginning of the wet season. Off-glacier snowfall is significant in the wet season. However, this melts quickly, so that accumulation is limited to high elevations and the dry season snow-cover reduces to on-glacier areas. Snow cover durations are in the order of hours to days, contrasting with the seasonal snowpack typical of mid-latitude climates. Paradoxically ephemeral snow cover provides a reliable source of runoff in the tropical Andes. The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) |
| Databáze: | OpenAIRE |
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