Logo Repositorio Institucional

Por favor, use este identificador para citar o enlazar este ítem: http://dspace.ucuenca.edu.ec/handle/123456789/31453
Título : Paleo-ENSO revisited: ecuadorian lake Pallcacocha does not reveal a conclusive El Niño signal
Autor: Schneider, Tobias
Hampel , Henrietta
Mosquera Guaman, Pablo Andres
Tylmann, Wojciech
Grosjean, Martin
Palabras clave : Andes
Climate Change
Enso
Holocene
Limnogeology
Paleolimnology
Area de conocimiento FRASCATI amplio: 1. CIENCIAS NATURALES Y EXACTAS
Area de conocimiento FRASCATI detallado: 1.5.10 RECURSOS HIDRICOS
Area de conocimiento FRASCATI específico: 1.5 CIENCIAS DE LA TIERRA Y EL AMBIENTE
Area de conocimiento UNESCO amplio: 05 - CIENCIAS FISICAS, CIENCIAS NATURALES, MATEMATICAS Y ESTADISTICAS
Area de conocimiento UNESCO detallado: 0521 - CIENCIAS AMBIENTALES
Area de conocimiento UNESCO específico: 052 - MEDIO AMBIENTE
Fecha de publicación : 2018
Fecha de fin de embargo: 28-dic-2050
Volumen: volumen 168 número 0
Fuente: Global and Planetary Change
metadata.dc.identifier.doi: 10.1016/j.gloplacha.2018.06.004
Tipo: ARTÍCULO
Abstract: 
Information about decadal to millennial variability of El Niño Southern Oscillation (ENSO) is fundamental for the assessment of ENSO responses to natural and anthropogenic forcings. Despite a growing number of ENSO reconstructions, the overall picture of Holocene ENSO variability is inconsistent. Here, we revisit the iconic Holocene ENSO sediment record of Lake Pallcacocha, Ecuador (Rodbell et al., 1999). We asked: (i) How coherent are the records of clastic layers (flood layers) in the sediments of Lake Pallcacocha and adjacent Lake Fondococha? (ii) What are the synoptic-scale atmospheric conditions that lead to intense precipitation and, potentially, to alluvial activity promoting the deposition of clastic layers in these lakes? (iii) Is intense precipitation in this area associated with El Niño, or not? We analyzed clastic layers in Late-Holocene sediments from multiple cores in Lakes Pallcacocha and Fondococha from Cajas National Park, southern Ecuadorian Andes. Additionally, we investigated precipitation data from 13 nearby meteorological stations to test if intense precipitation (percentiles P0.95, P0.99, P0.995) is predominantly related to El Niño conditions or not (based on 15 different ENSO indices). Our results show that the absolute flood frequencies (clastic layers per 100 years) differ substantially from lake to lake. This indicates that the frequency of clastic layers reflects different sensitivities (thresholds of precipitation) of the catchments to alluvial activity. 210Pb ages suggest that neither the 1982/83 nor the 1997/98 very strong El Niños produced clastic layers comparable to those found in the late Holocene. Daily precipitation records from meteorological stations close to Lake Pallcacocha including a high-altitude station from the western slope of the Andes did not show unusually high precipitation during the super El Niño 2015/16. We further find that intense precipitation in this area occurs at roughly equal probability under El Niño, La Niña and neutral conditions. Although the spectral properties of the late Holocene clastic layers in Lake Pallcacocha fall into the typical ENSO frequency band, we do not find evidence in the recent sediments and the meteorological data that would support a diagnostic link between alluvial activity in Lake Pallcacocha and strong El Niño events. Our data do not support the idea that the (late) Holocene flood record of Lake Pallcacocha is a conclusive paleo-El Niño record
Resumen : 
Information about decadal to millennial variability of El Niño Southern Oscillation (ENSO) is fundamental for the assessment of ENSO responses to natural and anthropogenic forcings. Despite a growing number of ENSO reconstructions, the overall picture of Holocene ENSO variability is inconsistent. Here, we revisit the iconic Holocene ENSO sediment record of Lake Pallcacocha, Ecuador (Rodbell et al., 1999). We asked: (i) How coherent are the records of clastic layers (flood layers) in the sediments of Lake Pallcacocha and adjacent Lake Fondococha? (ii) What are the synoptic-scale atmospheric conditions that lead to intense precipitation and, potentially, to alluvial activity promoting the deposition of clastic layers in these lakes? (iii) Is intense precipitation in this area associated with El Niño, or not? We analyzed clastic layers in Late-Holocene sediments from multiple cores in Lakes Pallcacocha and Fondococha from Cajas National Park, southern Ecuadorian Andes. Additionally, we investigated precipitation data from 13 nearby meteorological stations to test if intense precipitation (percentiles P0.95, P0.99, P0.995) is predominantly related to El Niño conditions or not (based on 15 different ENSO indices). Our results show that the absolute flood frequencies (clastic layers per 100 years) differ substantially from lake to lake. This indicates that the frequency of clastic layers reflects different sensitivities (thresholds of precipitation) of the catchments to alluvial activity. 210Pb ages suggest that neither the 1982/83 nor the 1997/98 very strong El Niños produced clastic layers comparable to those found in the late Holocene. Daily precipitation records from meteorological stations close to Lake Pallcacocha including a high-altitude station from the western slope of the Andes did not show unusually high precipitation during the super El Niño 2015/16. We further find that intense precipitation in this area occurs at roughly equal probability under El Niño, La Niña and neutral conditions. Although the spectral properties of the late Holocene clastic layers in Lake Pallcacocha fall into the typical ENSO frequency band, we do not find evidence in the recent sediments and the meteorological data that would support a diagnostic link between alluvial activity in Lake Pallcacocha and strong El Niño events. Our data do not support the idea that the (late) Holocene flood record of Lake Pallcacocha is a conclusive paleo-El Niño record
URI : http://dspace.ucuenca.edu.ec/handle/123456789/31453
https://www.scopus.com/inward/record.uri?partnerID=HzOxMe3b&scp=85048719722&origin=inward
URI Fuente: http://www.sciencedirect.com/science/journal/09218181
ISSN : 0921-8181
Aparece en las colecciones: Artículos

Ficheros en este ítem:
Fichero Descripción Tamaño Formato  
documento.pdf
  Until 2050-12-28
document9.65 kBAdobe PDFVisualizar/Abrir     Solicitar una copia


Este ítem está protegido por copyright original



Los ítems de DSpace están protegidos por copyright, con todos los derechos reservados, a menos que se indique lo contrario.

 

Centro de Documentacion Regional "Juan Bautista Vázquez"

Biblioteca Campus Central Biblioteca Campus Salud Biblioteca Campus Yanuncay
Av. 12 de Abril y Calle Agustín Cueva, Telf: 4051000 Ext. 1311, 1312, 1313, 1314. Horario de atención: Lunes-Viernes: 07H00-21H00. Sábados: 08H00-12H00 Av. El Paraíso 3-52, detrás del Hospital Regional "Vicente Corral Moscoso", Telf: 4051000 Ext. 3144. Horario de atención: Lunes-Viernes: 07H00-19H00 Av. 12 de Octubre y Diego de Tapia, antiguo Colegio Orientalista, Telf: 4051000 Ext. 3535 2810706 Ext. 116. Horario de atención: Lunes-Viernes: 07H30-19H00