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Ítem Acceso Abierto Extreme Droughts in the Peruvian Amazon Region (2000–2024)(MDPI, 2025-06-10) Martínez Castro, Daniel; Takahashi, Ken; Espinoza, Jhan Carlo; Vichot-Llano, Alejandro; Octavio Andrade, Miguel; Silva Vidal, YaminaDroughts in the Amazon region are expected to increase in frequency and intensity, which would negatively affect the tropical forest, leading to a positive climate–forest feedback loop that could potentially result in the collapse of this ecosystem. In this study, extreme drought conditions were identified in the Peruvian Amazon region for the period 2000–2024 using the maximum cumulative water deficit (MCWD) index, which is related to the tropical forest water stress. The ERA5, CHIRPS, and MSWEP datasets were used to estimate precipitation, while ERA5 data were used for evapotranspiration. This study focuses on the specificities of droughts and the differences across study areas. Six study areas were specified, three of them located in the Loreto department (northern Peruvian Amazon), another centered in Moyobamba city (western Peruvian Amazon), another in Ucayali, in the central Peruvian Amazon, and the other in Madre de Dios (southern Peruvian Amazon). It was found that the drought events are more frequent and intense in the central and southern regions of the basin. Based on the combined effect of the regional severity of the drought and its spatial extent, estimated from averaging across study areas and precipitation datasets, we identified the hydrological years of 2023-24, 2022-23, 2009-10, and 2004-05 as extreme droughts and 2015-16 and 2006-07 as moderate droughts.Ítem Acceso Abierto Surface energy exchanges and stability conditions associated with convective intense rainfall events on the central Andes of Peru(Elsevier, 2025-06-15) Flores Rojas, José Luis; Guizado-Vidal, David A.; Valdivia Prado, Jairo Michael; Silva Vidal, Yamina; Villalobos-Puma, Elver; Suárez Salas, Luis; Mata-Adauto, Zenón; Abi Karam, HugoThis 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 (Qₕ) and latent (Qₑ) 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 Qₕ and Qₑ, respectively, necessitating focused calibration and updates in satellite-derived data. Key observations include significant increases in Qe and horizontal momentum flux (𝜏) 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.Ítem Acceso Abierto A nationwide dataset of stable isotopes in meteoric and terrestrial water across Peru(Springer, 2025-07-12) Romero, Carol; Apaéstegui Campos, James EmilianoWater Stable Isotopes (δ18O, δ2H) are valuable tools for tracing sources and interactions in the water cycle, providing important information dedicated to understanding physical mechanisms related to global climate. Despite their significance, the topic of isotopic research in South America has been hindered by limited data. To address this gap, we launched a national-level water stable isotope dataset covering different water sources in Peru (WSI-PeruDB). The dataset contains curated in-house data and incorporates previously published records from various locations collected between 2000 and 2021. The WSIPeruDB dataset is composed of 489 water collection sites and allows a comprehensive use of the dataset by implementing standardized metadata templates containing essential geographical information such as latitude, longitude, and altitude (from sea level to 5000 m a.s.l), and sampling information such as sample type (e.g. groundwater, precipitation, river, spring, and others) and sampling frequency (e.g. biweekly, daily, monthly). The WSIPeruDB dataset is publicly available on Zenodo, facilitating access and use for the scientific community.Ítem Acceso Abierto Influence of local topographic structures on the atmospheric mechanisms related to the Andean-Amazon rainiest zone(Elsevier, 2025-03-16) Gutierrez-Villarreal, Ricardo A.; Junquas, Clémentine; Espinoza, Jhan Carlo; Baby, Patrice; Armijos Cardenas, Elisa NataliaThe Andes-Amazon transition region features critically important ecological services on the local, regional and global scales. This region is among the rainiest zones in the world, with rainfall rates of up to 7000 mm/year. However, the physical mechanisms leading to the existence of these “precipitation hotspots” remain poorly known. Here, we attempt to disentangle the controlling atmospheric mechanisms exerted by local topographic structures that started to uplift about 5–10 million years ago in response to the Nazca Ridge subduction, in the vicinity of the Quincemil hotspot, the most intense of them. We first use the Weather Research and Forecasting model to conduct sensitivity tests to planetary boundary layer parameterizations at 5 km horizontal grid spacing during the austral summer of 2012–13. After finding the most suitable configuration in terms of the diurnal cycle of rainfall intensity and extent, we further perform topographic sensitivity tests by reducing the Fitzcarrald Arch lowlands and, on top of it, by removing the Camisea mountain. The Fitzcarrald Arch deflects moisture flux towards Quincemil, while the Camisea mountain induces local vortical circulations that increase moisture transport, convergence and rainfall over Quincemil, ultimately controlling its location and intensity by up to 40 %. When reducing the height of the Andes in half, we find that it sustains the development of precipitation hotspots, accounting for up to 60 % of rainfall, by providing a mechanical forcing to increase regional-scale moisture fluxes. Such mechanisms dominate during nighttime, when rainfall peaks in the region, and might explain the existence of the rainiest zone in the Andes-Amazon transition.Ítem Acceso Abierto Multi-time scale analysis of the water level minima in Lake Titicaca over the past 103 years(Frontiers Media, 2025-05-06) Sulca Jota, Juan Carlos; Vuille, Mathias; Takahashi, Ken; Roundy, Paul; Dong, Bo; Mayta, Victor; Tacza, Jose; Apaéstegui Campos, James EmilianoLowest events in Lake Titicaca’s water level (LTWL) significantly impact local ecosystems and the drinking water supply in Peru and Bolivia. However, the hydroclimatic mechanisms driving extreme lake-level lowstands remain poorly understood. To investigate these low lake-level events, we analyzed detrended monthly LTWL anomalies, sea Surface temperature (SST) datasets covering the period 1921–2023. ERA5 reanalysis covers the period 1940–2023. A multiple linear regression model was developed to compute detrended LTWL anomalies, excluding multidecadal and residual components. Interdecadal Pacific Oscillation (IPO) and Pacific Decadal Oscillation (PDO) índices were also analyzed for the same period. Results indicate that 25% of all LTWL minima events have a short duration of <5 months, while the remaining 75% of all events have a long duration of more than 9 months, respectively. All long-lived LTWL minima events are associated with reduced moisture flow from the Amazon basin toward Lake Titicaca, but the large-scale forcing varies with the phase change of the decadal component in the 11–15 years band of the PDO (PDO11–15 years). Under warm PDO11–15 years phases, LTWL minima are driven by an enhanced South American low-level jet (SALLJ) caused by warm SST anomalies over the eastern Pacific Ocean. Warm SST anomalies over tropical North Atlantic and central Pacific cold events, which reinforce the cold PDO11–15 years phases, driving long-lived LTWL minima through the reduction of SALLJ. Conversely, long-lived LTWL minima events under neutral PDO11–15 years phases are caused by westerly flow anomalies confined to the Peruvian Altiplano. Therefore, PDO and IPO do not drive long-lived LTWL minima events because their relationship does not remain consistent over time. In conclusion, long-lived LTWL minima events exhibit a regional nature and are not driven by the PDO or IPO, as LTWL shows no consistent relationship with these decadal SST modes over time.Ítem Acceso Abierto Dynamics and patterns of land cover change in the Piura River Basin (Peruvian Pacific slope and coast) in the last two decades(Frontiers Media, 2025-05-15) Castillón, Fiorela; Rau, Pedro; Bourrel, Luc; Frappart, FrédéricLand use and land cover (LULC) changes in the Piura River Basin, Peru, were analyzed from 2001 to 2022 using global MODIS and ESA-CCI datasets harmonized into six major land cover classes (Forest, Non-Forest Vegetation, Cropland, Bare Soil, Water and Urban) for comparative analysis. Pearson correlation analyses with hydroclimatic variables, including precipitation (PP), maximum (Tx) and minimum (Tn) temperatures, and El Niño Southern Oscillation (ENSO) indices (Eastern Pacific, Central Pacific, and Coastal El Niño), complemented the intensity analysis to explore environmental drivers. The analyses focused on the lower-middle and upper basin regions during wet (December-May) and dry (June-November) seasons. MODIS detected more dynamic LULC transitions, with 32.8% of pixels showing changes, compared to 6.8% detected by the ESA-CCI product. These differences reflect the distinct sensitivities of MODIS and ESA-CCI products to short-term fluctuations and long-term variations, respectively. Specifically, MODIS identified higher annual change intensities and more frequent transitions, especially in the upper basin, whereas ESA-CCI provided a more conservative view of land cover trends. Both datasets consistently indicated a decline in cropland areas and an increase in bare soil, suggesting agricultural degradation and potential desertification processes. Correlation analyses revealed significant relationships between vegetation dynamics and climatic variables, notably ENSO events, precipitation, and temperature extremes, highlighting how hydroclimatic factors drive vegetation variability. The upper basin experienced notable urban expansion and deforestation dynamics linked to temperature fluctuations and intensified El Niño events, particularly after 2011. These findings underscore the critical influence of climatic extremes and human activities on vegetation dynamics, emphasizing the need for integrated, adaptive management strategies to mitigate desertification in lowlands and enhance forest conservation in highlands.Ítem Acceso Abierto A description of existing operational ocean forecasting services around the globe(Copernicus Publications, 2025-06-02) Cirano, Mauro; Alvarez-Fanjul, Enrique; Capet, Arthur; Ciliberti, Stefania; Clementi, Emanuela; Dewitte, Boris; Dinápoli, Matias; Serafy, Ghada El; Hogan, Patrick; Joseph, Sudheer; Miyazawa, Yasumasa; Montes Torres, Ivonne; Narvaez, Diego A.; Regan, Heather; Simionato, Claudia G.; Smith, Gregory C.; Staneva, Joanna; Tanajura, Clemente A. S.; Thupaki, Pramod; Urbano-Latorre, Claudia; Veitch, JenniferPredicting the ocean state in support of human activities, environmental monitoring, and policymaking across different regions worldwide is fundamental. To properly address physical, dynamical, ice, and biogeochemical processes, numerical strategies must be employed. The authors provide an outlook on the status of operational ocean forecasting systems in eight key regions including the global ocean: the West Pacific and Marginal Seas of South and East Asia, the Indian Seas, the African Seas, the Mediterranean and Black Sea, the North East Atlantic, South and Central America, North America (including the Canadian coastal region, the United States, and Mexico), and the Arctic. The authors initiate their discussion by addressing the specific regional challenges that must be addressed and proceed to discuss the numerical strategy and the available operational systems, ranging from regional to coastal scales. This compendium serves as a foundational reference for understanding the global offering, demonstrating how the diverse physical environment – ranging from waves to ice – and the biogeochemical features besides ocean dynamics can be systematically addressed through regular, coordinated prediction efforts.Ítem Restringido The Earth alignment principle for artificial intelligence(Nature Research, 2025-03-28) Gaffney, Owen; Luers, Amy; Carrero-Martinez, Franklin; Oztekin-Gunaydin, Berna; Creutzig, Felix; Dignum, Virginia; Galaz, Victor; Ishii, Naoko; Larosa, Francesca; Leptin, Maria; Takahashi, KenAt a time when the world must cut greenhouse gas emissions precipitously, artificial intelligence (AI) brings large opportunities and large risks. To address its uncertain environmental impact, we propose the ‘Earth alignment’ principle to guide AI development and deployment towards planetary stability.Ítem Acceso Abierto ENSO Diversity Regulation of the Impact of MJO on Extreme Snowfall Events in the Peruvian Andes(Wiley, 2025-03-25) Sulca Jota, Juan CarlosExtreme snowfall events (ESEs) in the Peruvian Andes (10°–18.4° S, > 4000 m) result in considerable economic losses. Despite their importance, how El Niño-Southern Oscillation (ENSO) diversity modulates the impact of the Madden–Julian Oscillation (MJO) on ESEs in the Peruvian Andes remains unexplored. Daily ERA5 reanalysis data from 1981 to 2018 were analysed. This study examines 16 ESEs. A bandpass filter with a 20–90-day range was applied to isolate the intraseasonal component of the daily anomalies. Additionally, time series data from the real-time multivariate MJO (RMM) index and Eastern and Central ENSO (E and C) indices were utilised. Composites were performed to describe the atmospheric circulation patterns related to ESEs in the Peruvian Andes under neutral, El Niño and La Niña conditions in the central and eastern Pacific Ocean. Under non-ENSO conditions, the MJO alone does not trigger ESEs in the Peruvian Andes during the DJF season. The absence of a well-organised convection system over the Peruvian Andes prevents ESEs. Conversely, during the JJA season, MJO Phases 5, 6 and 7 induce ESEs in the southern Peruvian Andes by enhancing moisture flux from the east through the equatorward propagation of an extratropical Rossby wave train that crosses South America and reaches the Altiplano region. In terms of ENSO diversity, the combined effects of the Central La Niña and MJO Phases 6 + 7 induce ESEs across the Western Cordillera of the southern Peruvian Andes during the DJF season. During austral winter, the interaction between the Central El Niño and MJO Phases 8 + 1, Eastern El Niño and MJO Phases 2 + 3, and Eastern La Niña and MJO Phases 8 + 1 induce ESEs across the Peruvian Andes.Ítem Restringido The South American Climate During the Last Two Millennia(Oxford University Press, 2024-12-11) Flores-Aqueveque, V.; Arias, P. A.; Gómez-Fontealba, C.; González-Arango, C.; Apaéstegui Campos, James Emiliano; Evangelista, H.; Guerra, L.; Latorre, C.Paleoclimate reconstructions are essential for understanding the dynamics of the climate system and its past variations. By utilizing climate-dependent proxies, these reconstructions provide a comprehensive perspective on climatic variations that extend far beyond the limited scope of instrumental records, spanning centuries to millennia. Particularly, proxy-based reconstructions for the last two millennia provide valuable insights into natural climate variability during the preindustrial era and the anthropogenic influence on current climate change. As a result, paleoclimate studies are also critical for interpreting climate projections in the context of anthropogenic forcing. South America, with its vast and diverse climate conditions, is a region rich in high-resolution paleoclimate records, including marine, lacustrine, and fjord sediments, speleothems, ice cores, tree rings, glacial and aeolian deposits, archaeological evidence, and historical documents, among others, all of which capture past climate changes. However, despite numerous paleoclimate reconstructions conducted across the continent and significant advances in understanding its past climate, substantial research gaps remain. These gaps are particularly evident in understudied regions and poorly understood phenomena, hindering a comprehensive understanding of climate variability at both regional and continental scales. To advance paleoclimatic research in South America, future efforts should prioritize (a) the collection of high-resolution records from key locations, (b) the integration of diverse proxies and innovative methodologies, (c) enhancing our understanding of climate-proxy relationships, and (d) developing new proxy calibrations. Collaboration with local communities and indigenous peoples and adopting interdisciplinary approaches will be vital in driving the field forward.Ítem Acceso Abierto Estimación de lluvias extremas mediante un enfoque de análisis regional y datos satelitales en Cusco, Perú(Instituto Mexicano de Tecnología del Agua, 2024-09-01) Aragón, Luis; Lavado-Casimiro, Waldo; Montesinos, Cristian; Zubieta Barragán, Ricardo; Laqui, WilberLa frecuencia y magnitud de los eventos climáticos extremos de precipitación han aumentado de forma significativa en varios países del mundo, incluido Perú. Estos hechos causan pérdidas económicas y humanas, especialmente en países en vías de desarrollo. La información y metodologías que permitan prevenir o diseñar estrategias para afrontarlas son escasas o inexistentes. El objetivo de esta investigación fue analizar la capacidad del producto satelital IMERG (Integrated MultisatellitE Retrievals) del satélite GPM (Global Precipitation Measurement) y datos observados a partir de estaciones meteorológicas mediante un enfoque mixto para estimar la distribución de lluvias extremas en la región del Cusco, ubicado al sur del Perú. Este enfoque mixto aprovechó las ventajas que ofrecen ambas fuentes de información, como es la solidez de los datos observados a lo largo de varios años y la resolución temporal horaria del producto satelital. La metodología se basó en una curva de crecimiento de cada región homogénea, factor de corrección y parámetros que estiman la función intensidad y duración para toda la región Cusco. Los resultados se evaluaron mediante validación cruzada entre los valores de precipitación diaria obtenidos del producto IMERG, enfoque mixto y precipitación observada para periodos de retorno de 2, 5, 10, 20, 50, 100, 200, 500 y 1 000 años. Los resultados sugieren que la combinación de datos observados de lluvia y del satélite IMERG puede ser una alternativa para estimar lluvias extremas en la región Cusco.Ítem Acceso Abierto Atmospheric aerosols and air quality in the 2022 dry season in Huancayo-Perú(Universidade Federal do Rio de Janeiro, 2024-05-15) Angeles Vasquez, Roberto; Angeles Suazo, Julio Miguel; Abi Karam, Hugo; Flores Rojas, José Luis; Suarez Salas, Luis; Lavado-Meza, Carmencita; Angeles Suazo, Nataly; Boza Ccora, Fernando; De la Cruz-Cerron, Leonel; Zarate Quiñones, RosaThis work presents results of Aerosol Optical Depth (AOD) and Direct Radiative Force (DRF) at the top of the atmosphere (TOA), obtained during monitoring campaigns carried out at the Huancayo Observatory of the Geophysical Institute of Peru (OH-IGP ) in April and August 2022. In these campaigns, a Sun CIMEL photometer was used to measure the microphysical and optical properties of aerosols at wavelengths ranging from 340 to 1020 nm, and a low-cost Purple-air sensor to quantify the concentration of material particulate (PM), in fine and coarse modes. The AOD results indicated values in the range 0.06-0.22. The daily averages of PM2.5 and PM10 did not exceed Peru’s current Environmental Quality Standards (50 μg/m³ and 100 μg/m³). The air quality index (AQI) calculated for PM2.5 and PM10 was classified as good. On some days during the campaigns, the air quality was classified as moderate. These results contribute to a better understanding of the current climatic conditions of the Peruvian Altiplano.Ítem Acceso Abierto Latitudinal and temporal distribution of aerosols and precipitable water vapor in the tropical Andes from AERONET, sounding, and MERRA‑2 data(Nature Research, 2024-01-09) Cazorla, María; Giles, David M.; Herrera, Edgar; Suárez Salas, Luis; Estevan, Rene; Andrade, Marcos; Bastidas, ÁlvaroThe aerosol and precipitable water vapor (PW) distribution over the tropical Andes region is characterized using Aerosol Robotic Network (AERONET) observations at stations in Medellin (Colombia), Quito (Ecuador), Huancayo (Peru), and La Paz (Bolivia). AERONET aerosol optical depth (AOD) is interpreted using PM₂.₅ data when available. Columnar water vapor derived from ozone soundings at Quito is used to compare against AERONET PW. MERRA-2 data are used to complement analyses. Urban pollution and biomass burning smoke (BBS) dominate the regional aerosol composition. AOD and PM₂.₅ yearly cycles for coincident measurements correlate linearly at Medellin and Quito. The Andes cordillera’s orientation and elevation funnel or block BBS transport into valleys or highlands during the two fire seasons that systematically impact South America. The February–March season north of Colombia and the Colombian-Venezuelan border directly impacts Medellin. Possibly, the March aerosol signal over Quito has a long-range transport component. At Huancayo and La Paz, AOD increases in September due to the influence of BBS in the Amazon. AERONET PW and sounding data correlate linearly but a dry bias with respect to soundings was identified in AERONET. PW and rainfall progressively decrease from north to south due to increasing altitude. This regional diagnosis is an underlying basis to evaluate future changes in aerosol and PW given prevailing conditions of rapidly changing atmospheric composition.Ítem Acceso Abierto Hydrometeors Distribution in Intense Precipitating Cloud Cells Over the Earth’s During Two Rainfall Seasons(Springer, 2024-01-25) Kumar, Shailendra; Flores Rojas, José Luis; Moya Álvarez, Aldo Saturnino; Martínez Castro, Daniel; Silva Vidal, YaminaIn the present study, we used attenuated corrected radar refectivity factor (Zₑ) and rain-drop size distribution (DSD) to investigate the hydrometeors distribution in the intense precipitating cloud cells (PCCs) from precipitation radar (PR) onboard on Global Precipitation Measurement (GPM). The DSD parameters consist of two variables, namely, mass-weighted mean diameter (Dₘ) in mm and normalized scaling parameters for hydrometeors concentration (Nw) in mm⁻¹ m⁻³. We defned two types of PCCs, which are the proxies for the intense rainfall events. First PCC is termed as Cumulonimbus Towers (CbTs), which consist of Zₑ> =20 dBZ at 12 km altitude, and its base height must be less than 3 km altitude. We also defned intense convective clouds (ICCs), which consist of Zₑ>30 (40) dBZ at 8 km (3 km), respectively, and are termed as ICC8 and ICC3, respectively. The spatial distribution reveals that continental areas consist of a higher frequency of CbTs and ICC8s compared to oceanic areas, whereas ICC3s are uniformly distributed over tropical land and oceanic areas. The DSD parameters reveal that intense PCCs have larger hydrometeors (Dₘ), whereas weaker (less Zₑ) vertical profles consist of higher concentration (Nw) of smaller hydrometeors (Dₘ). Land consists of larger hydrometeors (Dₘ) compared to oceanic areas, and diferences are higher in liquid phase regimes compared to mixed phase regimes. The vertical profles of Zₑ, Dₘ and Nw are showing the higher regional diferences among the diferent land-based areas, compared to various tropical ocean basins. Western Himalaya Foothills and Sierra De Cordoba consist of the strongest vertical profles with the largest Dₘ on the Earth’s áreas during JJAS and DJFM months, respectively.Ítem Acceso Abierto 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.Ítem Acceso Abierto Chemical composition and trajectories of atmospheric particles at the Machu Picchu Peruvian Antarctic scientific station (62.09° S, 58.47° W)(Universidad Autónoma de México, 2024-04-25) Álvarez-Tolentino, Daniel; Suárez Salas, Luis; Pomalaya-Valdez, José; Barja, BorisAntarctica is a remote and relatively pristine region, but the regional transport of aerosols may be a source of pollution, especially in the Antarctic Peninsula. Few studies have characterized atmospheric aerosols and evaluated the contribution of their emission sources. The Peruvian Antarctic research station Machu Pichu (ECAMP, by its Spanish acronym) is located on King George Island in the Antarctic Peninsula. During February 2020, atmospheric particulate mass (PM ₁₀ and PM ₂.₅) was sampled and analyzed to characterize its elemental composition and was supplemented by measurements of equivalent black carbon and aerosol size distributions. Chemical elements were analyzed by inductively coupled plasma mass spectrometry (ICP-MS), multivariate techniques, and enrichment factors. The most abundant elements in PM ₁₀ and PM ₂.₅ were Na, Fe, Mg, and Si, with the most important local sources being marine (Na, Mg, Mn, Ca) and crustal (Fe, Al, P). Sources of weathering (Ba and Si) from glacial thawing and sources of combustion linked to the use of oil (V) and emission of black carbon were recorded. Air mass back-trajectory analysis using the HYSPLIT model helped identify external sources of particulate matter in the air masses reaching the ECAMP site. Overall, this study supports the growing evidence of the anthropogenic impact of distant and local sources on the white continent.Ítem Acceso Abierto Analysis of vertical flow velocity and suspended sediment concentration profiles in Tumbes River during El Niño and La Niña events. [Análisis de los perfiles verticales de velocidad de flujo y de concentración de sedimentos en suspensión medidos en el río Tumbes durante El Niño y La Niña](LACCEI, Latin American and Caribbean Consortium of Engineering Institutions, 2024-07) Mendoza Sulcaray, Renzo Dampier; Campaña Toro, Roberto Luis; Armijos Cárdenas, Elisa Natalia; Morera Julca, Sergio ByronLa región de Tumbes, ubicada en el norte de Perú, se ve afectada por los fenómenos climáticos de El Niño y La Niña. El Niño provoca una intensa precipitación, lo que resulta en altos flujos de agua y generación de sedimentos. En cambio, La Niña conlleva déficits de precipitación, resultando en flujos líquidos más bajos y cargas de sedimentos menores en comparación con El Niño. El objetivo de este estudio es analizar los perfiles verticales de velocidad de flujo y la concentración de sedimentos en suspensión medidos en la estación hidrométrica El Tigre en el río Tumbes, ubicado a 50 km río arriba del estuario del Océano Pacífico, durante los períodos de inundación en los eventos de El Niño de 2017 y La Niña de 2018. Los perfiles verticales de velocidad de flujo, medidos utilizando un medidor de corriente de efecto Doppler, se modelaron aplicando la distribución teórica de velocidad del tipo log-wake. Se ajustaron parámetros como la velocidad de corte, la distancia desde el lecho donde teóricamente la velocidad del perfil de flujo se vuelve cero y el parámetro de estela. Los perfiles verticales de concentración de sedimentos en suspensión se modelaron utilizando la distribución teórica resultante de la distribución parabólico-lineal del coeficiente de mezcla de fluidos. Se ajustaron parámetros, incluyendo el diámetro medio de los sedimentos en suspensión y la concentración de sedimentos en suspensión de referencia cerca del lecho. El estudio concluyó que los perfiles verticales de velocidad de flujo y concentración de sedimentos en suspensión registrados durante el evento de El Niño de 2017 y el evento de La Niña de 2018 coincidieron razonablemente con la distribución teórica de velocidad del tipo log-wake y la distribución teórica de concentración de sedimentos en suspensión resultante de la distribución parabólico-lineal del coeficiente de mezcla de fluidos. Utilizando los modelos ajustados, se estimó que los tamaños medios de los sedimentos en suspensión calculados para el evento de El Niño de 2017 (62 a 132 µm) fueron aproximadamente 2 veces mayores que los calculados para La Niña de 2018 (25 a 67 µm), y que las concentraciones de sedimentos en suspensión de referencia en el lecho calculadas para el evento de El Niño de 2017 (254 a 1766 mg/l) fueron aproximadamente 7 veces mayores que las calculadas para La Niña de 2018 (95 a 250 mg/l).Ítem Acceso Abierto Modern anthropogenic drought in Central Brazil unprecedented during last 700 years(Nature Research, 2024-02-26) Misailidis Stríkis, Nicolas; Silva Melo Buarque, Plácido Fabrício; Cruz, Francisco William; Bernal, Juan Pablo; Vuille, Mathias; Tejedor, Ernesto; Simões Santos, Matheus; Harumi Shimizu, Marília; Ampuero, Angela; Du, Wenjing; Sampaio, Gilvan; Reis Sales, Hamilton dos; Campos, José Leandro; Toshie Kayano, Mary; Apaéstegui Campos, James Emiliano; Fu, Roger R.; Cheng, Hai; Edwards, R. Lawrence; Chavez Mayta, Victor; Silva Francischini, Danielle da; Zezzi Arruda, Marco Aurélio; Felipe Novello, ValdirA better understanding of the relative roles of internal climate variability and external contributions, from both natural (solar, volcanic) and anthropogenic greenhouse gas forcing, is important to better project future hydrologic changes. Changes in the evaporative demand play a central role in this context, particularly in tropical areas characterized by high precipitation seasonality, such as the tropical savannah and semi-desertic biomes. Here we present a set of geochemical proxies in speleothems from a well-ventilated cave located in central-eastern Brazil which shows that the evaporative demand is no longer being met by precipitation, leading to a hydrological deficit. A marked change in the hydrologic balance in central-eastern Brazil, caused by a severe warming trend, can be identified, starting in the 1970s. Our findings show that the current aridity has no analog over the last 720 years. A detection and attribution study indicates that this trend is mostly driven by anthropogenic forcing and cannot be explained by natural factors alone. These results reinforce the premise of a severe long-term drought in the subtropics of eastern South America that will likely be further exacerbated in the future given its apparent connection to increased greenhouse gas emissions.Ítem Acceso Abierto Urban heat island and increase in temperature on urban roads in Huancayo/Peru [Isla de calor urbano e incremento de temperatura en vías urbanas en Huancayo/Perú](LACCEI, Latin American and Caribbean Consortium of Engineering Institutions, 2024-07) Angeles Vasquez, Roberto; Angeles Suazo, Julio; Flores Rojas, José Luis; Boza Ccora, Fernando; Angeles Suazo, Nataly; Suarez Salas, Luis; Abi Karam, HugoLa rápida urbanización de las ciudades está cambiando el clima local, lo que genera altas temperaturas y entornos urbanos densos y difíciles, carentes de agua y vegetación[1]. La presente contribución estima la intensidad de Isla de Calor Urbano Superficial (ICUS) durante el periodo 2001 – 2022 para el Área Metropolitana de Huancayo (AMH), Perú. Se cuantificó formación de la Isla de Calor Urbano Superficial, a partir de 2 métodos: el primero es el método de Streutker, el cual ajusta la temperatura superficial del suelo (LST) (superficie urbana y rural) a una superficie Gaussiana. El segundo, método de cuantil propuesto por José Flores, usa la diferencia entre el cuantil 0.95 de LST del área urbana y la mediana del LST del área rural. Ambos métodos usan data de sensoramiento remoto de LST a 0.05⁰ de resolución, obtenido del sensor MODIS a bordo del satélite TERRA y AQUA. Para el AMH, durante los periodos diurnos, la intensidad de ICUS en marzo y julio representan el máximo y mínimo incremento. El periodo nocturno, presentó valores máximo y mínimo en agosto y diciembre respectivamente. En general se consiguió mostrar las principales causas del incremento de temperatura superficial es el pavimento asfaltado, donde la temperatura puede ser hasta 60 °C. Por ello es importante proponer medidas de mitigación como construcciones y pavimentos sostenible que ayuden a mitigar el incremento de temperatura superficial. Así como la importancia de considerar la Floresta o plantaciones vegetales en un diseño o zonificación urbana.Ítem Acceso Abierto GC Insights: Lessons from participatory water quality research in the upper Santa River basin, Peru(Copernicus Publications, 2024-06-27) Rangecroft, Sally; Clason, Caroline; Dextre, Rosa Maria; Richter, Isabel; Kelly, Claire; Turin, Cecilia; Grados-Bueno, Claudia V.; Fuentealba, Beatriz; Camacho Hernandez, Mirtha; Morera Julca, Sergio Byron; Martin, John; Guy, John AdamHere we share four key lessons from an interdisciplinary project (Nuestro Rio) that gathered community perspectives on local water quality in the Santa River basin (Peru) utilising a digital technological approach where we collected data via a novel photo elicitation app, supported by a field work campaign. The lessons explored in this article provide insights into challenges and opportunities for researchers considering developing technological tools for encouraging participation and engagement in marginalised communities.