DSpace-CRIS

Now showing 1 - 3 of 3

Some of the metrics are blocked by your
consent settings
Summertime precipitation extremes and the influence of atmospheric flows on the western slopes of the southern Andes of Perú
(John Wiley and Sons Ltd, 2022)
Martínez Castro, Daniel
;
Silva Vidal, Yamina F.
;
Villalobos Puma, Elver
Although climatologically dry, the western slopes of the southern Andes of Peru (WSA) can experience precipitation extremes (PEs) during the summer (December–February) resulting in great economic and human losses. Generally, WSA has a positive upslope gradient in precipitation, meaning more rain falls at higher elevations, but observations have shown this gradient can become negative with higher rainfall near the coastal cities. In this study we analyse 2000–2019 regional atmospheric patterns associated with different upslope precipitation gradients and PEs in WSA using principal component analysis methods and surface station observations. Results show important changes in the atmospheric circulation patterns during the occurrence of PE events. A prevailing pattern of negative southerly wind anomalies and regional warming of the southeastern Pacific Ocean leads to significant increases in moisture along the coast of WSA. Eastern moisture flows associated with the presence of the Bolivian High are observed at upper levels of the atmosphere and transport water vapour from the Amazon to the western side of the Andes. Additionally, there is a blocking effect aloft in response to an intense gradient of geopotential height that attenuates the easterly circulations. These large-scale mechanisms act to concentrate high precipitable water amounts and high levels of convective available potential energy in the troposphere which favours the vertical velocities essential to trigger PEs. These results increase our knowledge of the large-scale characteristics of PEs to help with forecasting these impactful events and protecting the more than 1.8 million people living in WSA.
Some of the metrics are blocked by your
consent settings
Spatial and Temporal Distribution of Black Carbon in Peru from the Analysis of Biomass Burning Sources and the Use of Numerical Models
(Springer Science and Business Media Deutschland GmbH, 2023)
Martínez Castro, Daniel
;
Moya Álvarez, Aldo Saturnino
;
Silva Vidal, Yamina F.
Este estudio evalúa la distribución espacial y temporal del carbono negro (Black Carbon, BC) proveniente de la quema de biomasa en el Perú y países vecinos durante el periodo 2018–2020, con especial énfasis en el año 2019. Mediante simulaciones del modelo WRF-CHEM y análisis de trayectorias con el modelo HYSPLIT, se identificaron los glaciares más afectados por la deposición de BC, especialmente el glaciar Huaytapallana. Los resultados muestran un aumento significativo de incendios en el Perú a partir de julio, con picos entre agosto y septiembre, coincidiendo con mayores concentraciones de BC en la atmósfera. Se observó una fuerte correlación entre el número de focos de quema y la Profundidad Óptica de Aerosoles (AOD) registrada en el observatorio de Huancayo. Ucayali fue la región con mayor número de focos, mientras que las mayores emisiones se originaron en el sur de Loreto. El modelo mostró que el transporte de BC se produce predominantemente de norte a sur, afectando principalmente a las cordilleras de Huaytapallana, Huagoruncho y Vilcabamba, mientras que la Cordillera Blanca presentó concentraciones menores. Este análisis permite comprender mejor el impacto de las emisiones de BC en los ecosistemas glaciares del país.
Some of the metrics are blocked by your
consent settings
Dynamic atmospheric mechanisms associated with the diurnal cycle of hydrometeors and precipitation in the Andes–Amazon transition zone of central Peru during the summer season
(Springer, 2024)
Martínez Castro, Daniel
;
Santiago Martel, Alexzander
;
Villalobos Puma, Elver
The diurnal cycle of total hydrometeor availability and its associated patterns of atmospheric circulation is studied over a connected Andes–Amazon (A–A) system in the central region of Peru during the summer season. Surface precipitation depends on the amount of hydrometeors that occur in the atmosphere and its atmospheric dynamics. Hydrometeors and the precipitation efficiency index were estimated using radar of the core satellite of the GPM system (N-GPM) for the period 2014–2022. The atmospheric dynamics were analyzed using the regional Weather Research and Forecasting (WRF) model. According to the results, the Andes mountain range produces precipitation at a surface level more efficiently during the afternoon and early evening hours (12–19 LT) due to the convergence of the thermal mesoscale circulations transporting moisture fluxes from the east and west. Both generate convective multicells along the Andes mountain range. The circulation from the west intensifies during the day, causing the displacement of the chain of convective multicells towards the east and producing hydrometeors and intense precipitations in the inter-Andean valleys. The A–A transition zone is more efficient in producing precipitation during the early hours of the day (00–07 LT) due to an increase in the northern circulation associated with the low-level jets and a change in the magnitude of the horizontal winds. Northerly winds enter the A–A transition zone with increased intensity and leave with reduced intensity. This mechanism is driven by the effect of the topographical barrier and the masses of cold air located in high areas on the eastern flank of the Andes. These factors generate significant updrafts and, therefore, the formation of storm clouds with high concentrations of hydrometeors and precipitation on the surface.

INAIGEM

Browse

Filters

Settings

Sort By

Results per page

Search Results