Examinando por Autor "Elver Villalobos-Puma"
Mostrando 1 - 5 de 5
Resultados por página
Opciones de ordenación
Ítem Atmospheric black carbon observations and its valley-mountain dynamics: Eastern cordillera of the central Andes of Peru(Elsevier BV, 2024-08) Elver Villalobos-Puma; Luis Suarez; Stefania Gillardoni; Ricardo Zubieta; Daniel Martinez-Castro; Andrea Miranda-Corzo; Paolo Bonasoni; Yamina SilvaGlacial bodies in the Peruvian Andes Mountains store and supply freshwater to hundreds of thousands of people in central Peru. Atmospheric black carbon (BC) is known to accelerate melting of snow and ice, in addition to contributing to air pollution and the health of people. Currently there is limited understanding on the sources and temporal variability of BC in valley and mountain environments in Peru. To address this problem, this study combined surface observations of BC collected during 2022–2023 with WRF model simulations and HYSPLIT trajectories to analyze the dispersion and sources of BC in valley and high elevation environments and the associated local atmospheric circulations. Results show high BC concentrations are associated with the valley-mountain wind system that occurs on both sides of the Huaytapallana mountain range. A pronounced circulation occurs on the western slopes of Huaytapallana when concentrations of BC increase during daylight hours, which transports atmospheric pollutants from cities in the Mantaro River Valley to the Huaytapallana mountain range. Low concentrations of BC are associated with circulations from the east that are channeled by the pronounced ravines of the Andes-Amazon transition. On average, during the season of highest BC concentrations (July–November), the relative contributions of fossil fuels are dominant to biomass burning at the valley observatory and are slightly lower at the Huaytapallana observatory. These results demonstrate the need to promote mitigation actions to reduce emissions of BC and air pollution associated with forest fires and local anthropogenic activity.Ítem 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 Science and Business Media LLC, 2024-04-04) Elver Villalobos-Puma; Annareli Morales; Daniel Martinez-Castro; Jairo Valdivia; Rodolfo Cardenas-Vigo; Waldo Lavado-Casimiro; Alexzander SantiagoThe 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.Ítem Future changes of precipitation types in the Peruvian Andes(Springer Science and Business Media LLC, 2024-09-30) Valeria Llactayo; Jairo Valdivia; Christian Yarleque; Stephany Callañaupa; Elver Villalobos-Puma; David Guizado; Robert Alvarado-LugoIn high-altitude regions, such as the Peruvian Andes, understanding the transformation of precipitation types under climate change is critical to the sustainability of water resources and the survival of glaciers. In this study, we investigate the distribution and types of precipitation on a tropical glacier in the Peruvian Central Andes. We utilized data from an optical-laser disdrometer and compact weather station installed at 4709 m ASL, combined with future climate scenarios from the CMIP6 project, to model potential future changes in precipitation types. Our findings highlight that increasing temperatures could lead to significant reductions in solid-phase precipitation, including snow, graupel and hail, with implications for the mass balance of Andean glaciers. For instance, a 2 °C rise might result in less than 10% of precipitation as solid, in regard to the present day, transforming the hydrological processes of the region. The two future climate scenarios from the CMIP6 project, SSP2-4.5 and SSP5-8.5, offer a broad perspective on potential climate outcomes that could impact precipitation patterns in the Andes. Our study underscores the need to revisit and expand our understanding of high-altitude precipitation in the face of climate change, paving the way for improved water resource management strategies and sustainable glacier preservation efforts in these fragile ecosystems.Ítem Hailstorm events in the Central Andes of Peru: insights from historical data and radar microphysics(Copernicus GmbH, 2024-04-18) Jairo M. Valdivia; José Luis Flores-Rojas; Josep J. Prado; David Guizado; Elver Villalobos-Puma; Stephany Callañaupa; Yamina Silva-VidalHailstorms, while fascinating from a meteorological perspective, pose significant risks to communities, agriculture, and infrastructure. In regions such as the Central Andes of Peru, the characteristics and frequency of these extreme weather events remain largely uncharted. This study fills this gap by investigating the historical frequency and vertical structure of hailstorms in this region. We analyzed historical hailstorm records dating back to 1958 alongside 4 years of observations (2017–2021) from the Parsivel2 disdrometer and a cloud-profiling radar MIRA35c. Our findings indicate a trend of decreasing hail frequency (−0.5 events per decade). However, the p value of 0.07 suggests the need for further investigation, particularly in relation to environmental changes and reporting methods. The results show that hailstorms predominantly occur during the austral summer months, with peak frequency in December, and are most common during the afternoon and early evening hours. The analysis of radar variables such as reflectivity, radial velocity, spectral width, and linear depolarization ratio (LDR) reveals distinct vertical profiles for hail events. Two case studies highlight the diversity in the radar measurements of hailstorms, underscoring the complexity of accurate hail detection. This study suggests the need for refining the Parsivel2 algorithm and further understanding its classification of hydrometeors. Additionally, the limitations of conventional radar variables for hail detection are discussed, recommending the use of LDR and Doppler spectrum analysis for future research. Our findings lay the groundwork for the development of more efficient hail detection algorithms and improved understanding of hailstorms in the Central Andes of Peru.Ítem Surface energy exchanges and stability conditions associated with convective intense rainfall events on the central Andes of Peru(Elsevier BV, 2025-06) José Luis Flores-Rojas; David A. Guizado-Vidal; Jairo Valdivia-Prado; Yamina Silva; Elver Villalobos-Puma; Luis Suárez-Salas; Zenón Mata-Adauto; Hugo Abi KaramThis study presents an in-depth analysis of precipitation patterns, surface energy balance (SEB) components, and atmospheric vertical gradients (AVG) in the Huancayo Geophysical Observatory (HYGO) situated in an agricultural region inside the Mantaro valley within the central Andes of Peru, utilizing data from January 2018 to April 2022 and climatic-scale data from 1965 to 2018. Our findings reveal distinct daily and seasonal precipitation patterns, with peak occurrences in the late afternoon and early evening hours, and a pronounced seasonal variation aligning with dry and rainy periods. Analysis of 21 intense precipitation events linked to convective activity offers crucial insights for weather forecasting and disaster preparedness. These events were identified using in situ gauge pluviometers, the MIRA-35c vertical profiler radar and GPM-IMERG rainfall products. The turbulent energy fluxes: sensible (Q ) and latent (Q ) were estimated using the aerodynamic flux-gradient method and the ground heat flux to the surface was estimated with the scheme of Foken and Napo. Moreover, the study evaluates the efficacy of the Advanced Regional Prediction System (ARPS) model in analyzing turbulent energy fluxes during these events. A comparison with the bulk aerodynamic method indicated underestimations and overestimations by the ARPS model in predicting Q and Q , respectively, necessitating focused calibration and updates in satellite-derived data. Key observations include significant increases in Q and horizontal momentum flux ( ) before convective precipitation events, marking them as potential precursor variables. Additionally, notable decreases in water vapor mixing ratio vertical gradient (WMVG) and Richardson number (RIN), along with increases in horizontal wind gradient (HWVG), suggest changes in surface moisture fluxes and boundary layer dynamics, crucial for convective rainfall initiation. This comprehensive analysis underscores the importance of understanding atmospheric dynamics for improved prediction and preparedness strategies in the face of climatic variability.