Características temporales y espaciales de los patrones de precipitaciones en la sierra norte del Perú. Un estudio de caso de las transiciones de La Niña a El Niño desde 2005 a 2010

• Autores: Krois, Joachim, Schulte, Achim, Pajares Vigo, Edwin, Cerdan Moreno, Carlos
• Formato: artículo
• Fecha de Publicación: 2013
• Institución: Pontificia Universidad Católica del Perú
• Repositorio: PUCP-Institucional
• Lenguaje: español
• OAI Identifier: oai:repositorio.pucp.edu.pe:20.500.14657/119763
• Enlace del recurso: http://revistas.pucp.edu.pe/index.php/espacioydesarrollo/article/view/10621/11093
• Nivel de acceso: acceso abierto
• Materia: Rainfall Variability; Mountain Environments; Continental Water Divide; Peru; Enso; Geografía; Variabilidad de Precipitaciones; Ambientes de Montañas; Divisoria Continental de Aguas; Perú; https://purl.org/pe-repo/ocde/ford#5.07.00

The climatic conditions of the northern Sierra of Peru are marked by the interaction of different macro- to mesoscale climatic features such as the El Niño Southern Oscillation (ENSO) or Mesoscale Convective Complexes (MCCs) and the seasonally shifting Intertropical Convergence Zone (ITCZ), but also by local scale climatic features such as inhomogeneous topography and local wind fields. The region under investigation, located in the vicinity of the South America Continental Water Divide (CWD), provides the opportunity to study interactions of western and eastern disturbances in a high mountain environment and their effects on rainfall variability. In general, rainfall variability is related to diurnal convection patterns, enhanced by valley breeze systems and modulated by local scale wind anomalies. Spillover of low-level air masses of Pacific origin passing over the Andean ridges is frequent. Although direct effects of ENSO on high Andean rainfall variability are in debate, our findings show that the majority of rain gauges used in this study follow an El Niño/dry and a La Niña/wet signal. However, high elevation areas on the western escarpment of the Andes benefit from abundant nocturnal rainfall that partly offsets the rainfall deficits during El Niño. Our data suggest that the spatial extent of this easterly wet pulse is limited to areas located above 3000 m asl. ENSO cycles contribute to rainfall variability near the CWD in the northern Sierra of Peru by modulating the seasonal rainfall regime and causing a positive temperature anomaly.