Browsing by Author "Valdivia Prado, Jairo Michael"
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Item Open Access Analysis of extreme meteorological events in the central Andes of Peru using a set of specialized instruments(MDPI, 2021-03-21) Flores Rojas, José Luis; Silva Vidal, Yamina; Suárez Salas, Luis; Estevan, René; Valdivia Prado, Jairo Michael; Saavedra Huanca, Miguel; Giráldez, Lucy; Piñas-Laura, Manuel; Scipión, Danny; Milla, Marco; Kumar, Shailendra; Martínez Castro, DanielA set of instruments to measure several physical, microphysical, and radiative properties of the atmosphere and clouds are essential to identify, understand and, subsequently, forecast and prevent the effects of extreme meteorological events, such as severe rainfall, hailstorms, frost events and high pollution events, that can occur with some regularity in the central Andes of Peru. However, like many other Latin American countries, Peru lacks an adequate network of meteorological stations to identify and analyze extreme meteorological events. To partially remedy this deficiency, the Geophysical Institute of Peru has installed a set of specialized sensors (LAMAR) on the Huancayo observatory (12.04º S, 75.32º W, 3350 m ASL), located in the Mantaro river basin, which is a part of the central Andes of Peru, especially in agricultural areas. LAMAR consists of a set of sensors that are used to measure the main atmosphere and soil variables located in a 30-meter-high tower. It also has a set of high-quality radiation sensors (BSRN station) that helps measure the components of short-wave (SW) (global, diffuse, direct and reflected) and long-wave (LW) (emitted and incident) irradiance mounted in a 6-meter-high tower. Moreover, to analyze the microphysics properties of clouds and rainfall, LAMAR includes a set of profiler radars: A Ka-band cloud profiler (MIRA-35c), a UHF wind profiler (CLAIRE), and a VHF wind profiler (BLTR), along with two disdrometers (PARSIVEL2) and two rain gauges pluviometers. The present study performs a detailed dynamic and energetic analysis of two extreme rainfall events, two intense frost events, and three high-pollution events occurring on the Huancayo observatory between 2018 and 2019...Item Open Access Cuantificación de lluvias usando el radar perfilador de banda Ka MIRA 35C(Universidad Nacional José Faustino Sánchez Carrión, 2018) Valdivia Prado, Jairo Michael; Mendoza Nieto, EroncioEn el presente trabajo se desarrolla un algoritmo para estimación de la lluvia a partir de datos del radar perfilador de nubes y precipitación, ubicado en el Laboratorio de Microfísica Atmosférica y Radiación – LAMAR en el Observatorio de Huancayo del Instituto Geofísico del Perú. Métodos: El algoritmo usa los datos del espectro Doppler (valores de potencia y velocidad) para calcular la distribución de tamaño de gotas de lluvia y en función de ésta se calculan los diferentes parámetros microfísicos. La intensidad de lluvia estimada es evaluada usando datos del pluviómetro de la estación meteorológica para un periodo de cinco meses. Resultados: El algoritmo es capaz de brindarnos información de la distribución del tamaño de gotas, el contenido de agua líquida y la intensidad de lluvia. Se encontró una sobrestimación de 12%, con errores de ±1.3 mm en acumulados horarios, los cuales se compensan en periodos de tiempo prolongados. Conclusiones: Estos resultados sugieren que la técnica es adecuada para estudios que involucren la cuantificación de lluvias, como algoritmos satelitales de estimación de precipitación.Item Open Access Dataset on raindrop size distribution, raindrop fall velocity and precipitation data measured by disdrometers and rain gauges over Peruvian central Andes (12.0°S)(Elsevier, 2020-04) Valdivia Prado, Jairo Michael; Contreras, Kevin; Martínez Castro, Daniel; Villalobos Puma, Elver Edmundo; Suárez Salas, Luis; Silva Vidal, YaminaThis dataset includes data obtained at the Atmospheric Microphysics and Radiation Laboratory (LAMAR) of the Huancayo Observatory (12.04° S, 75.32° W, 3313 m ASL). Two Parsivel2 and two tipping bucket rain gauges are used in this dataset which are operating together since 2018. Data is given in NetCDF format, including two types of files, one NetCDF for precipitation totals and another which contains Parsivel2 data. This data set was collected in the complex topography conditions of the tropical Andes, and its potential use is to study the microphysics of orographic rainfall, atmospheric models and rainfall estimation algorithms.Item Open Access Dataset on the first weather radar campaign over Lima, Perú(Elsevier, 2021-04) Valdivia Prado, Jairo Michael; Scipión, Danny; Milla, Marco; Prado, Josep J.; Espinoza, Juan C.; Cordova, Darwin; Saavedra Huanca, Miguel; Villalobos Puma, Elver Edmundo; Callañaupa Gutierrez, Stephany Magaly; Silva Vidal, YaminaThe first weather radar campaign over Lima, the capital of Peru, a desertic area on the western side of the Peruvian Andes, was carried out to study the occurrence of rain events in summer 2018. The weather radar was installed strategically and was able to overlook three river basins: Rimac, Chillón, and Lurin. An X-band radar (PX-1000) was used, which operates at 9.55 GHz. PX-1000 was built by the Advanced Radar Research Center (ARRC) at the University of Oklahoma (U.S.A.). The radar operated from January 26th to April 1st, 2018, at Cerro Suche located 2910 m ASL and 55 km from the city of Lima. The PX-1000 performed plan-position indicators (PPI) for elevations starting at 0° up to 20°. The data presented here were obtained using a three-dimensional constant-altitude plan position-indicator (3D CAPPI), which was generated by high resolution (250 m) nearest point algorithm.Item Open Access 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, 2024-04-04) Villalobos-Puma, Elver; Morales, Annareli; Martinez-Castro, Daniel; Valdivia Prado, Jairo Michael; Lavado-Casimiro, Waldo; Santiago, AlexzanderThe 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.Item Restricted Evaluation of GPM Dual-Frequency Precipitation Radar algorithms to estimate drop size distribution parameters, using ground-based measurement over the Central Andes of Peru(Springer, 2021-09) Del Castillo-Velarde, Carlos; Kumar, Shailendra; Valdivia Prado, Jairo Michael; Moya Álvarez, Aldo Saturnino; Flores Rojas, José Luis; Villalobos Puma, Elver Edmundo; Martínez Castro, Daniel; Silva Vidal, YaminaThe raindrop size distribution (DSD) parameters, which consists of the mass-weighted average diameter (Dm) and the scaling parameter for the concentration (Nw) are essential to estimate precipitation in numerical modelling and other research areas such as the Global Precipitation Measurement (GPM) core satellite. In the present work, we used the GPM Dual-Frequency Precipitation Radar algorithms (GPM-DPR), single (SF) and dual (DF) frequency, and in situ observations to derive the DSD parameters and evaluate the performance of algorithms under the complex orography and climate regime of the central Andes. We used data from optical disdrometer and Ka-band profiler radar over Huancayo Observatory during the austral summer monsoon. Our results indicate that the GPM-DPR algorithms have problems to correctly estimate the DSD parameters of convective rains due to the high variability in time and space of this type of rain and is the result of fixing the shape parameter (µ). The estimation of DSD parameters in stratiform rains, which are very common in the central Andes, is strongly affected by the limitation of the DF algorithm in light rain rates caused by its inability to estimate Dm < 1 mm.Item Open Access Field Campaign Evaluation of Sensors Lufft GMX500 and MaxiMet WS100 in Peruvian Central Andes(MDPI, 2022-04-22) Valdivia Prado, Jairo Michael; Guizado, David A.; Flores Rojas, José Luis; Gamarra, Delia P.; Silva Vidal, Yamina; Huamán, Edith R.The research presents the inter-comparison of atmospheric variables measured by 9 automatic weather stations. This set of data was compared with the measurements of other weather stations in order to standardize the values that must be adjusted when taken to different areas. The data of a set of a total of 9 GMX500, which measures conventional meteorological variables, and 10 WS100 sensors, which measures precipitation parameters. The automatic stations were set up at the Huancayo Observatory (Geophysical Institute of Peru) for a period of 5 months. The data set of GMX500 were evaluated comparing with the average of the 9 sensors and the WS100 was compared with an optical disdrometer Parsivel². The temperature, pressure, relative humidity, wind speed, rainfall rate, and drop size distribution were evaluated. A pair of GMX500 sensors presented high data dispersion; it was found found that the errors came from a bad configuration; once this problem was solved, good agreement was archived, with low RMSE and high correlation. It was found that the WS100 sensors overestimate the precipitation with a percentage bias close to 100% and the differences increase with the greater intensity of rain. The drop size distribution retrieved by WS100 have unrealistic behavior with higher concentrations in diameters of 1 mm and 5 mm, in addition to a flattened curve.Item Open Access Future changes of precipitation types in the Peruvian Andes(Nature Research, 2024-09-30) Llactayo, Valeria; Valdivia Prado, Jairo Michael; Yarleque, Christian; Callañaupa, Stephany; Villalobos‑Puma, Elver; Guizado, David; Alvarado‑Lugo, RobertIn 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.Item Open Access Hailstorm events in the Central Andes of Peru: insights from historical data and radar microphysics(European Geosciences Union, 2024-04-18) Valdivia Prado, Jairo Michael; Flores-Rojas, José Luis; Prado, Josep J.; Guizado, David; Villalobos-Puma, Elver; Callañaupa, Stephany; Silva Vidal, YaminaHailstorms, 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.Item Open Access El impacto de la parametrización de procesos microfísicos en la simulación de dos eventos de lluvia convectiva sobre los Andes centrales del Perú usando el modelo numérico WRF-ARW(Instituto Geofísico del Perú, 2020-09) Martínez-Castro, Daniel; Kumar, Shailendra; Flores Rojas, José Luis; Moya Álvarez, Aldo Saturnino; Valdivia Prado, Jairo Michael; Villalobos Puma, Elver Edmundo; Del Castillo Velarde, Carlos; Silva Vidal, YaminaEl presente estudio explora el impacto del método de expresar los procesos microfísicos en las nubes en la simulación numérica de eventos de lluvia convectiva sobre los Andes centrales, utilizando el modelo numérico de Investigación y Pronóstico del Tiempo (WRF, por sus siglas en inglés). Se probaron seis métodos de parametrización de los procesos microfísicos, a partir de la anidación sucesiva unidireccional de cuatro dominios (18, 6, 3 y 0.75 km de resolución). Las parametrizaciones de otros procesos físicos se mantuvieron invariables en los diferentes experimentos. Se integró durante 36 h con los datos globales del Centro Nacional de Predicción Ambiental de Estados Unidos (NCEP, por sus siglas en inglés) con condiciones iniciales de las 07:00, hora local (GMT-5). Las simulaciones se verificaron utilizando datos de satélite GOES, información del radar perfilador de nubes de banda Ka instalado en el Observatorio de Huancayo y variables meteorológicas medidas en superficie. Todas las parametrizaciones microfísicas describieron aproximadamente el comportamiento de la temperatura durante el paso del sistema, aunque en uno de los casos se subestimó la temperatura y en otros dos se subestimó la precipitación acumulada en 24 h. En particular, las configuraciones del modelo con parametrizaciones de Morrison y Lin reprodujeron la dinámica general del desarrollo de los sistemas de nubes para los dos estudios de caso. No obstante, el análisis del campo horizontal y los perfiles verticales de la masa de agua del sistema, así como los diferentes hidrometeoros muestran que la parametrización de Morrison reprodujo los sistemas convectivos de manera más consistente con las observaciones que los otros métodos.Item Restricted Multi-instrument rainfall-rate estimation in the Peruvian Central Andes(American Meteorological Society, 2020-10) Valdivia Prado, Jairo Michael; Scipión, Danny; Milla, Marco; Silva Vidal, YaminaAgriculture is one of the main economic activities in the Peruvian Andes; rainwater alone irrigates more than 80% of the fields used for agriculture purposes. However, the cloud and rain generation mechanisms in the Andes still remain mostly unknown. In early 2014, the Instituto Geofísico del Perú (IGP) decided to intensify studies in the central Andes to better understand cloud microphysics; the Atmospheric Microphysics And Radiation Laboratory officially started operations in 2015 at IGP’s Huancayo Observatory. In this work, a Ka-band cloud profiler [cloud and precipitation profiler (MIRA-35c)], a UHF wind profiler [Clear-Air and Rainfall Estimation (CLAIRE)], and a VHF wind profiler [Boundary Layer and Tropospheric Radar (BLTR)] are used to estimate rainfall rate at different conditions. The height dependence of the drop size diameter versus the terminal velocity, obtained by the radars, in the central Andes (3350 m MSL) was evaluated. The estimates of rainfall rate are validated to ground measurements through a disdrometer [second-generation Particle, Size, and Velocity (PARSIVEL²)] and two rain gauges. The biases in the cumulative rainfall totals for the PARSIVEL², MIRA-35c, and CLAIRE were 18%, 23%, and −32%, respectively, and their respective absolute biases were 19%, 36%, and 63%. These results suggest that a real-time calibration of the radars, MIRA-35c and CLAIRE, is necessary for better estimation of precipitation at the ground. They also show that the correction of the raindrop terminal fall velocity, obtained by separating the vertical wind velocity (BLTR), used in the estimation the raindrop diameter is not sufficient, especially in convective conditions.Item Open Access Multi-instrumentación para la estimación de la intensidad de lluvia en los Andes centrales de Perú(Instituto Geofísico del Perú, 2020-07) Valdivia Prado, Jairo Michael; Scipión, Danny; Milla, Marco; Silva Vidal, YaminaEn la literatura científica los mecanismos de formación de nubes y lluvias en los Andes del Perú son poco documentados. A principios del 2014, el Instituto Geofísico del Perú (IGP) decidió intensificar los estudios en los Andes centrales para un mejor entendimiento de la microfísica de las nubes y lluvias. A fines del 2015, con la instalación del radar perfilador de nubes y precipitación que opera en la banda Ka (MIRA-35c), el Laboratorio de Microfísica Atmosférica y Radiación (LAMAR) empezó oficialmente sus operaciones en el Observatorio de Huancayo del IGP. En este trabajo, se usan datos del radar MIRA-35c, el perfilador de vientos y lluvias en la banda UHF, denominado CLAIRE (CLear-AIr and Rainfall Estimation), y el perfilador de vientos en la banda VHF, denominado BLTR (Boundary Layer Tropospheric Radar) para estimar la intensidad de lluvia. Se evaluó, para el área de estudio (Andes centrales, 3314 m s. n. m.), la dependencia del diámetro de las gotas y su velocidad terminal, con la altura. Las estimaciones de la intensidad de la lluvia son validadas con mediciones en superficie a través de un disdrómetro (PARSIVEL2) y dos pluviómetros. Los errores en los totales de lluvia acumulada para el PARSIVEL2, MIRA-35c y CLAIRE fueron de 18 %, 23 % y −32 %, respectivamente, y sus respectivos errores absolutos fueron de 19 %, 36 %, y 63 %. Estos resultados sugieren que es necesaria la corrección de los datos de los radares MIRA-35c y CLAIRE para una mejor estimación de la precipitación. También se encontró que la corrección aplicada al cálculo de la velocidad terminal de las gotas, mediante la separación de la velocidad vertical del viento, y que luego es usada en la estimación del diámetro de la gota no resulto adecuada, especialmente en condiciones de lluvias convectivas.Item Open Access Observando las precipitaciones en Lima con un radar meteorológico(Instituto Geofísico del Perú, 2018-08) Valdivia Prado, Jairo Michael; Prado, Josep; Silva Vidal, Yamina; Scipión, DannyTras “El Niño Costero 2017”, el IGP desarrolló el proyecto “Modelado hidrogeodinámico (lluvias, huaicos y deslizamientos) en Chosica, Lima”, cuyo objetivo fue desarrollar una campaña de medición de lluvias usando un radar meteorológico para el modelado de lluvias y huaicos en la cuenca del río Rímac. Este proyecto; que contó con la participación de 3 direcciones del IGP: Ciencias de la Atmósfera e Hidrósfera (CAH), Ciencias de Tierra la Sólida (CTS) y el Radio Observatorio de Jicamarca; fue financiado por el Fondo para Intervenciones ante la ocurrencia de Desastres Naturales (Fondes)” del Instituto Nacional de Defensa Civil (Indeci). Para desarrollar el proyecto, el IGP, mediante colaboración con el Centro de Investigaciones Avanzadas de Radar (ARRC, por sus siglas en inglés), de la Universidad de Oklahoma, rentó un radar de doble polarización de banda X (PX-1000) para que se instale en la parte media de la cuenca del río Rímac, desde donde se monitoreó la atmósfera y los eventos meteorológicos durante los primeros meses de 2018. En el presente trabajo, mostraremos la metodología para cuantificar las lluvias a partir de los datos del radar PX-1000 usando la relación de Marshall y Palmer (1948).Item Restricted On the dynamic mechanisms of intense rainfall events in the central Andes of Peru, Mantaro valley(Elsevier, 2021-01-15) Flores Rojas, José Luis; Moya Álvarez, Aldo Saturnino; Valdivia Prado, Jairo Michael; Piñas-Laura, Manuel; Kumar, Shailendra; Karam, Hugo Abi; Villalobos Puma, Elver Edmundo; Martínez Castro, Daniel; Silva Vidal, YaminaThe present study was aimed at analysing the main atmospheric dynamic mechanisms associated with the occurrence of intense rainfall events above the Huancayo observatory (12.05°S, 75.32°W, 3313 m asl) in the central Andes of Perú (Mantaro valley) from January 2018 to April 2019. To identify the rainfall events, we used a set of instruments from the laboratory of physics, microphysics and radiation (LAMAR) composed by in-situ pluviometric observations, satellite remote sensing data (GPM), Cloud Radar (MIRA-35c), Boundary Layer Tropospheric Radar (BLTR) and downscaling model simulations with WRF (resolutions: 18 km, 6 km and 2 km) and ARPS (0.5 km) models to analyse the dynamics of the atmosphere for the synoptic, meso and local processes that control the occurrence of these rainfall events. The results showed that all intense rainfall events are associated with the presence of thermal meso-scale circulations that transport moisture fluxes through passes with gentle slopes along both sides of the Andes. The easterly moisture fluxes come in from the South America Low Level Jet (SALLJ) and the westerly moisture fluxes from the Pacific Ocean. The arrival of these moisture flows to regions within the Mantaro valley depends on their coupling with the circulations at medium and high levels of the atmosphere. At the synoptic scale, the results show that the rainfall events can be separated into two groups: the first one associated with westerly circulations (WC) at the mid and upper levels of the atmosphere, generated by the weakening and eastern displacement of the anticyclonic Bolivian high-North east low (BH-NE) system, and the second associated with easterly circulations (EC) at the mid and upper levels of the atmosphere, generated by the intensification of the BH-NE system. The observed and simulated results showed that multicell convective systems of WC events are more extensive and deeper than EC events. This situation can be explained as the convergence of moisture fluxes from opposite directions occurred within the Mantaro basin for WC events. In contrast, for EC events, the convergence develops at the east Andes mountain range, following which the multicell storm system propagates westward, driven by easterly circulations. The EC events occur mostly in the summer months, while the WC events occur mostly in the autumn and spring months. Moreover, apparently the inertia gravity waves (IGWs) formed in the Amazon basin transport moisture and energy to the central Andes plateau and intensify the convection processes.Item Open Access Radares para estudios atmosféricos en el Perú(Instituto Geofísico del Perú, 2017-11) Silva Vidal, Yamina; Scipión, Danny; Valdivia Prado, Jairo MichaelEs sabido que la precipitación es una de las variables meteorológicas más importantes en el Perú, puesto que, por un lado, es una de las principales fuentes de agua dulce para el consumo humano y la agricultura y, por el otro, debido a nuestra alta vulnerabilidad pueden causar pérdidas humanas y económicas, tal como ocurre, por ejemplo, cuando se desarrolla el fenómeno La Niña o El Niño. Es principalmente por este motivo que, desde el año 2015, la sede de Huancayo del Instituto Geofísico del Perú - IGP, cuenta con el Laboratorio de Microfísica Atmosférica y Radiación (LAMAR), el cual tiene instrumentos de última generación para medir diferentes parámetros atmosféricos en alta resolución temporal. Para el estudio de las precipitaciones se usan pluviómetros, disdrómetro, papel filtro, radares y satélite, los cuales registran información en alta frecuencia (desde segundos) y con una cobertura vertical que abarca hasta los 8-10 km de altura. La información obtenida busca responder preguntas tales como: ¿Qué tipo de precipitación es más frecuente?, ¿A qué hora ocurren las precipitaciones convectivas/estratiformes?, ¿De dónde proviene el aire que genera mayor/menor precipitación?, ¿Cuál es la estructura vertical de las nubes que generan precipitación? y ¿Cómo es la distribución del tamaño de las gotas de lluvia?, entre muchas otras.Item Open Access Rainfall characteristics in the Mantaro basin over tropical Andes from a vertically pointed profile rain radar and in-situ field campaign(MDPI, 2020-03-02) Kumar, Shailendra; Del Castillo Velarde, Carlos Manuel; Valdivia Prado, Jairo Michael; Flores Rojas, José Luis; Callañaupa Gutierrez, Stephany Magaly; Moya Álvarez, Aldo Saturnino; Martínez Castro, Daniel; Silva Vidal, YaminaInformation on the vertical structure of rain, especially near the surface is important for accurate quantitative precipitation estimation from weather and space-borne radars. In the present study, the rainfall characteristics, from a vertically pointed profile Radar in the Mantaro basin (Huancayo, Peru) are observed. In summary, diurnal variation of near-surface rainfall and bright band height, average vertical profiles of the drop size distribution (DSD), rain rate, radar reflectivity (Zₑ) and liquid water content (LWC) are investigated to derive the rainfall characteristics. Diurnal variation of rain rate and bright band height show the bimodal distribution, where frequent and higher rain rate occurred during the afternoon and nighttime, and more than 70% bright band height found between 4.3–4.7 km. The average vertical profiles of Zₑ show the opposite characteristics above and below the melting level (ML) and depend on the near-surface rain rate. For example, the average Zₑ profiles have a negative gradient above the ML, whereas below, the ML, the gradient depends on the near-surface rain rate. The rain rate and LWC show the opposite behavior, and both consist of a positive (negative) gradient below (above) the ML. The vertical growth of DSD parameters depend on the near-surface rain rate, and a higher concentration of large-sized of droplets are observed for higher near surface rain rate, however, the dominant modes of droplets are <1 mm throughout the vertical column. However, the most significant variation in DSD growth is observed for near-surface rain rate ≥20 mm/h. These findings suggest using different retrieval techniques for near surface rain estimation than the rest of the vertical profile and high rain rate events. The improved understanding of the tropical Andes precipitation would be very important for assessing climate variability and to forecast the precipitation using the numerical models.Item Restricted The GPM-DPR Blind Zone Effect on Satellite-Based Radar Estimation of Precipitation over the Andes from a Ground-Based Ka-band Profiler Perspective(American Meteorological Society, 2022-04-26) Valdivia Prado, Jairo Michael; Gatlin, Patrick N.; Kumar, Shailendra; Scipión, Danny; Silva Vidal, Yamina; Petersen, Walter A.A vertically pointing Ka-band radar (Metek MIRA-35C) installed at the Instituto Geofísico del Perú, Atmospheric Microphysics and Radiation Laboratory (LAMAR) Huancayo Observatory, which is located at an elevation of 3.3 km MSL in the Andes Mountains of Peru, is used to investigate the effects of terrain on satellite-based precipitation measurement in the Andes. We compare the vertical structure of precipitation observed by the MIRA-35C with Ka-band radar measurements from the Dual-Frequency Precipitation Radar (DPR) on board the Global Precipitation Measurement (GPM) mission core satellite using an approach based on Taylor’s hypothesis of frozen turbulence that attempts to reduce the impact of spatiotemporal offsets between these two radar measurements. From 3 April 2014 to 20 May 2018, the DPR measured precipitation near LAMAR during 15 of its 157 coincident overpasses. There were six simultaneous observations with MIRA-35C. We found that the average of the DPR’s lowest clutter-free bin is 1.62 km AGL, but the presence of precipitation worsens the situation, causing a 0.4-km-deeper algorithm-detected blind zone for the DPR at the Huancayo Observatory. In the study area, the depth of the clutter layer observed with DPR often extends above the melting layer but can be highly variable, extending even as high as 5 km AGL. These results suggest that DPR estimates of stratiform precipitation over the Andes Mountains are likely underestimated because of the terrain effects on the satellite measurements and problems in its blind zone detection algorithms, highlighting the difficulty in estimating precipitation in mountainous terrain from spaceborne radar.Item Open Access The impact of microphysics parameterization in the simulation of two convective rainfall events over the Central Andes of Peru using WRF-ARW(MDPI, 2019-08-01) Martínez Castro, Daniel; Kumar, Shailendra; Flores Rojas, José Luis; Moya Álvarez, Aldo Saturnino; Valdivia Prado, Jairo Michael; Villalobos Puma, Elver Edmundo; Del Castillo Velarde, Carlos; Silva Vidal, YaminaThe present study explores the cloud microphysics (MPs) impact on the simulation of two convective rainfall events (CREs) over the complex topography of Andes mountains, using the Weather Research and Forecasting- Advanced Research (WRF-ARW) model. The events occurred on December 29 2015 (CRE1) and January 7 2016 (CRE2). Six microphysical parameterizations (MPPs) (Thompson, WSM6, Morrison, Goddard, Milbrandt and Lin) were tested, which had been previously applied in complex orography areas. The one-way nesting technique was applied to four domains, with horizontal resolutions of 18, 6, and 3 km for the outer ones, in which cumulus and MP parameterizations were applied, while for the innermost domain, with a resolution of 0.75 km, only MP parameterization was used. It was integrated for 36 h with National Centers for Environmental Prediction (NCEP Final Operational Global Analysis (NFL) initial conditions at 00:00 UTC (Coordinated Universal Time). The simulations were verified using Geostationary Operational Environmental Satellites (GOES) brightness temperature, Ka band cloud radar, and surface meteorology variables observed at the Huancayo Observatory. All the MPPs detected the surface temperature signature of the CREs, but for CRE2, it was underestimated during its lifetime in its vicinity, matching well after the simulated event. For CRE1, all the schemes gave good estimations of 24 h precipitation, but for CRE2, Goddard and Milbrandt underestimated the 24 h precipitation in the inner domain. The Morrison and Lin configurations reproduced the general dynamics of the development of cloud systems for the two case studies. The vertical profiles of the hydrometeors simulated by different schemes showed significant differences. The best performance of the Morrison scheme for both case studies may be related to its ability to simulate the role of graupel in precipitation formation. The analysis of the maximum reflectivity field, cloud top distribution, and vertical structure of the simulated cloud field also shows that the Morrison parameterization reproduced the convective systems consistently with observations.