Browsing by Autor "Jhan Carlo Espinoza"

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A cold wave of winter 2021 in central South America: characteristics and impacts
(Springer Science+Business Media, 2023) José A. Marengo; Jhan Carlo Espinoza; L. Bettolli; Ana Paula Martins do Amaral Cunha; Jorge Molina‐Carpio; María de los Milagros Skansi; Kris Correa; Andrea M. Ramos; Roberto Salinas; Juan Pablo Sierra
A Novel Downscaling Approach to Improve Local-Scale Assessment of Future Precipitation Changes in the Tropical-Subtropical Andes–Lowland Transition Region
(RELX Group (Netherlands), 2025) Santiago Mendoza Paz; Mariella Carbajal; Jhan Carlo Espinoza; Kevin Campos; Patrick Willems
A reassessment of the suspended sediment load in the Madeira River basin from the Andes of Peru and Bolivia to the Amazon River in Brazil, based on 10 years of data from the HYBAM monitoring programme
(Elsevier BV, 2017) Philippe Vauchel; William Santini; Jean‐Loup Guyot; Jean‐Sébastien Moquet; Jean-Michel Martínez; Jhan Carlo Espinoza; Patrice Baby; Oscar Fuertes; Luis Noriega; Oscar Puita
Climatological patterns of heatwaves during winter and spring 2023 and trends for the period 1979–2023 in central South America
(Frontiers Media, 2025) José Marengo; Mabel Calim Costa; Ana Paula Cunha; Jhan Carlo Espinoza; Juan C. Jiménez‐Muñoz; Renata Libonati; Vitor Miranda; Isabel F. Trigo; Juan Pablo Sierra; João L. Geirinhas
In the last 40 years, trends in heat wave frequency, intensity, and duration have increased steadily around the world. These intense heat waves were characterized persistent atmospheric blocking episode, with a continuous presence of a warm air mass and lack of rain for several consecutive days, that contributed to pronounced positive temperature anomalies, reinforced by extremely low soil moisture, and warm and drought conditions. The year 2023 was the warmest year on record, and the global average temperature was +1.45°C above pre-industrial (1850–1900) values worldwide. In South America 2023 was the warmest since 1900, with 0.81°C above the 1991–2020 reference period. Central South America experienced a sequence of heatwaves series being the most intense during the autumn and spring of 2023. From August to December 2023, the meteorological services of Brazil, Argentina, Paraguay and Bolivia reported record-high maximum temperatures in this period in several stations east of the Andes and identified 7 heat waves episodes that affected all these countries. The large-scale circulation patterns show that heatwaves were characterized by an anomalously high-pressure system that facilitated the formation of a heat dome through dry, hot air columns over a warm and dry soil. Several locations experienced temperature of about 10°C above normal, and some locations reported maximum temperatures above 40°C for several days in a row. These heat waves aggravated the drought over Amazonia during the second half of 2023, during an El Niño year. Compound drought-heat favored hydrological drought, while the increased dryness amplified the risk of fires.
Decline of Fine Suspended Sediments in the Madeira River Basin (2003–2017)
(Multidisciplinary Digital Publishing Institute, 2019) Irma Ayes Rivera; Elisa Armijos Cardenas; Raúl Espinoza-Villar; Jhan Carlo Espinoza; Jorge Molina‐Carpio; José Max Ayala; Omar Gutierrez‐Cori; Jean-Michel Martínez; Naziano Filizola
The Madeira River is the second largest Amazon tributary, contributing up to 50% of the Amazon River’s sediment load. The Madeira has significant hydropower potential, which has started to be used by the Madeira Hydroelectric Complex (MHC), with two large dams along the middle stretch of the river. In this study, fine suspended sediment concentration (FSC) data were assessed downstream of the MHC at the Porto Velho gauging station and at the outlet of each tributary (Beni and Mamoré Rivers, upstream from the MHC), from 2003 to 2017. When comparing the pre-MHC (2003–2008) and post-MHC (2015–2017) periods, a 36% decrease in FSC was observed in the Beni River during the peak months of sediment load (December–March). At Porto Velho, a reduction of 30% was found, which responds to the Upper Madeira Basin and hydroelectric regulation. Concerning water discharge, no significant change occurred, indicating that a lower peak FSC cannot be explained by changes in the peak discharge months. However, lower FSCs are associated with a downward break in the overall time series registered at the outlet of the major sediment supplier—the Beni River—during 2010.
Deforestation Impacts on Amazon-Andes Hydroclimatic Connectivity
(2021) Juan Pablo Sierra; Clémentine Junquas; Jhan Carlo Espinoza; Hans Segura; Thomas Condom; Marcos Andrade; Jorge Molina‐Carpio; Laura Ticona; Valeria Mardóñez; Luis Blacutt
<title>Abstract</title> Amazonian deforestation has accelerated during the last decade, threatening an ecosystem where almost one third of the regional rainfall is transpired by the local rainforest. Due to the precipitation recycling, the southwestern Amazon, including the Amazon-Andes transition region, is particularly sensitive to forest loss. This study evaluates the impacts of Amazonian deforestation in the hydro-climatic connectivity between the Amazon and the eastern tropical Andes during the austral summer (December-January-February) in terms of hydrological and energetic balances. Using 10-year high-resolution simulations (2001–2011) with the Weather Research and Forecasting Model, we analyze control and deforestation scenario simulations. Regionally, deforestation leads to a reduction in the surface net radiation, evaporation, moisture convergence and precipitation (~ 20%) over the entire Amazon basin. In addition, during this season, deforestation increases the atmospheric subsidence over the southern Amazon and weakens the regional Hadley cell. Atmospheric stability increases over the western Amazon and the tropical Andes inhibiting convection in these areas. Consequently, major deforestation impacts are observed over the hydro-climate of the Amazon-Andes transition region. At local scale, nighttime precipitation decreases in Bolivian valleys (~ 20–30%) due to a strong reduction in the humidity transport from the Amazon plains toward Andes linked to the South American low-level jet. Over these valleys, a weakening of the daytime upslope winds is caused by local deforestation, which reduces the turbulent fluxes at lowlands. These alterations in rainfall and atmospheric circulation could impact the rich Andean ecosystems and its tropical glaciers.
Deforestation impacts on Amazon-Andes hydroclimatic connectivity
(2021) Juan Pablo Sierra; Jhan Carlo Espinoza; Clémentine Junquas; Jan Polcher‬; Miguel Saavedra; Jorge Molina‐Carpio; Marcos Andrade; Thomas Condom; Laura Ticona
&lt;p&gt;The Amazon rainforest is a key component of the climate system and one of the main planetary evapotranspiration sources. Over the entire Amazon basin, strong land-atmosphere feedbacks cause almost one third of the regional rainfall to be transpired by the local rainforest. Maximum precipitation recycling ratio takes place on the southwestern edge of the Amazon basin (a.k.a. Amazon-Andes transition region), an area recognized as the rainiest and biologically richest of the whole watershed. Here, high precipitation rates lead to large values of runoff per unit area providing most of the sediment load to Amazon rivers. As a consequence, the transition region can potentially be very sensitive to Amazonian forest loss. In fact, recent acceleration in deforestation rates has been reported over tropical South America. These sustained land-cover changes can alter the regional water and energy balances, as well as the regional circulation and rainfall patterns. In this sense, the use of regional climate models can help to understand the possible impacts of deforestation on the Amazon-Andes zone.&lt;/p&gt;&lt;p&gt;This work aims to assess the projected Amazonian deforestation effects on the moisture transport and rainfall behavior over tropical South America and the Amazon-Andes transition region. We perform 10-year austral summer simulations with the Weather Research and Forecasting model (WRF) using 3 one-way nested domains. Our finest domain is located over the south-western part of the basin, comprising two instrumented Andean Valleys (Zongo and Coroico river Valleys). Convective permitting high horizontal resolution (1km) is used over this domain. The outcomes presented here enhance the understanding of biosphere-atmosphere coupling and its deforestation induced disturbances.&lt;/p&gt;
Deforestation impacts on Amazon-Andes hydroclimatic connectivity
(Springer Science+Business Media, 2021) Juan Pablo Sierra; Clémentine Junquas; Jhan Carlo Espinoza; Hans Segura; Thomas Condom; Marcos Andrade; Jorge Molina‐Carpio; Laura Ticona; Valeria Mardóñez; Luis Blacutt
Hydroclimate of the Andes Part I: Main Climatic Features
(Frontiers Media, 2020) Jhan Carlo Espinoza; René Garreaud; Germán Poveda; Paola A. Arias; Jorge Molina‐Carpio; Mariano Masiokas; Maximiliano Viale; Lucía Scaff
The Andes is the longest cordillera in the world and extends from northern South America (11°N) to the southern tip of the continent (53°S). The Andes runs through seven countries and is characterized by a wide variety of ecosystems strongly related to the contrasting climate over its eastern and western sides and along its latitudinal extension. In fact, the tropical Andes is the most biodiverse region on Earth. Currently, this region faces the highest potential impact of climate change, which could affect food security and water supplies for about 90 million people. From a scientific and societal view, the Andes present specific challenges because of its unique landscape and the fragile equilibrium between the growing population and its environment. In this manuscript, we provide an updated review of the most relevant scientific literature regarding the hydroclimate of the Andes. This review paper is presented in two parts. Part I is dedicated to summarize the scientific knowledge about the main climatic features of the Andes, with emphasis on mean large-scale atmospheric circulation, the Andes-Amazon hydroclimate interconnections, and the regular cycles of precipitation, including the most characteristic diurnal and annual cycles of precipitation. Part II, which is also included in the research topic “Connecting Mountain Hydroclimate Through the American Cordilleras”, focuses on hydroclimate variability of the Andes at a sub-continental scale.
Hydroclimate of the Andes Part II: Hydroclimate Variability and Sub-Continental Patterns
(Frontiers Media, 2021) Paola A. Arias; René Garreaud; Germán Poveda; Jhan Carlo Espinoza; Jorge Molina‐Carpio; Mariano Masiokas; Maximiliano Viale; Lucía Scaff; P.J. van Oevelen
This paper provides an updated review of the most relevant scientific literature related to the hydroclimate of the Andes. The Andes, the longest cordillera in the world, faces major challenges regarding climate variability and climate change, which impose several threats to sustainable development, including water supply and the sustainability of ecosystem services. This review focuses on hydroclimate variability of the Andes at a sub-continental scale. The annual water cycle and long-term water balance along the Andes are addressed first, followed by the examination of the effects of orography on convective and frontal precipitation through the study of precipitation gradients in the tropical, subtropical and extratropical Andes. In addition, a review is presented of the current scientific literature on the climate variability in the Andes at different timescales. Finally, open research questions are presented in the last section of this article.
Hydroclimatology of the Upper Madeira River basin: spatio-temporal variability and trends
(Taylor & Francis, 2017) Jorge Molina‐Carpio; Jhan Carlo Espinoza; Philippe Vauchel; Josyane Ronchail; Beatriz Emma Gutierrez Caloir; Jean‐Loup Guyot; Luis Noriega
International audience
Hydrologie et production agricole dans le nord-ouest de l’Amazonie
(Association de Geographes Francais, 2016) Josyane Ronchail; Tatiana Schor; Jhan Carlo Espinoza; Manon Sabot; Heitor Pinheiro; Percy Gomez Davila; Guillaume Drapeau; Véronique Michot; Naziano Filizola; Jean-Loup Guyot
En « Amazonie des rivières », la période de basses eaux permet la mise en culture de vastes zones exondées et fertiles sur les berges des rivières et dans les plaines d’inondation. La variabilité des extrêmes hydrologiques et celle de la structure du cycle de décrue, facteurs réputés importants pour la qualité des récoltes sont explorés à la station fluviométrique de Tamshiyacu sur le fleuve Amazonas. Le riz, culture rentable dans cette région, est notre référence. Les résultats ne présentent pas les liens supposés entre résultats agricoles et durée de la saison de basses eaux ou vitesse de remontée des eaux. Néanmoins, ils montrent la baisse des étiages, l’allongement de la durée de décrue en relation avec un retard de la montée des eaux et une accélération de la remontée des eaux pendant la période 1985-2015.
On the Relationship between Suspended Sediment Concentration, Rainfall Variability and Groundwater: An Empirical and Probabilistic Analysis for the Andean Beni River, Bolivia (2003–2016)
(Multidisciplinary Digital Publishing Institute, 2019) Irma Ayes Rivera; Ana Claudia Callau Poduje; Jorge Molina‐Carpio; José Max Ayala; Elisa Armijos Cardenas; Raúl Espinoza-Villar; Jhan Carlo Espinoza; Omar Gutierrez‐Cori; Naziano Filizola
Fluvial sediment dynamics plays a key role in the Amazonian environment, with most of the sediments originating in the Andes. The Madeira River, the second largest tributary of the Amazon River, contributes up to 50% of its sediment discharge to the Atlantic Ocean, most of it provided by the Andean part of the Madeira basin, in particular the Beni River. In this study, we assessed the rainfall (R)-surface suspended sediment concentration (SSSC) and discharge (Q)-SSSC relationship at the Rurrenabaque station (200 m a.s.l.) in the Beni Andean piedmont (Bolivia). We started by showing how the R and Q relationship varies throughout the hydrological year (September to August), describing a counter-clockwise hysteresis, and went on to evaluate the R–SSSC and Q–SSSC relationships. Although no marked hysteresis is observed in the first case, a clockwise hysteresis is described in the second. In spite of this, the rating curve normally used ( SSSC = aQ b ) shows a satisfactory R2 = 0.73 (p < 0.05). With regard to water discharge components, a linear function relates the direct surface flow Qs–SSSC, and a hysteresis is observed in the relationship between the base flow Qb and SSSC. A higher base flow index (Qb/Q) is related to lower SSSC and vice versa. This article highlights the role of base flow on sediment dynamics and provides a method to analyze it through a seasonal empirical model combining the influence of both Qb and Qs, which could be employed in other watersheds. A probabilistic method to examine the SSSC relationship with R and Q is also proposed.
Recent changes in the dry-to-wet transition season in the Andean Altiplano and related atmospheric circulation patterns (1981–2022)
(Springer Science+Business Media, 2025) Pierina Milla; Jhan Carlo Espinoza; Ricardo A. Gutiérrez; Jorge Molina‐Carpio; Josyane Ronchail; Daniel Espinoza‐Romero; Clémentine Junquas
Regional hydro-climatic changes in the Southern Amazon Basin (Upper Madeira Basin) during the 1982–2017 period
(Elsevier BV, 2019) Jhan Carlo Espinoza; Anna A. Sörensson; Josyane Ronchail; Jorge Molina‐Carpio; Hans Segura; Omar Gutierrez‐Cori; Romina Ruscica; Thomas Condom; Sly Wongchuig
Regionalization of rainfall in the upper Madeira basin based on interannual and decadal variability: A multi‐seasonal approach
(Wiley, 2023) Jorge Molina‐Carpio; Irma Ayes Rivera; Daniel Espinoza‐Romero; Wilmar L. Cerón; Jhan Carlo Espinoza; Josyane Ronchail
Abstract Identifying rainfall regions associated with specific modes of variability is of practical interest for water resources management, seasonal forecasting, and mitigation of weather‐related risks. This study aims to identify homogeneous rainfall regions within the ~1 million km 2 Upper Madeira River basin—southwestern Amazon—by their interannual and decadal variability and relates this variability to ocean indices. An observed dataset of 146 ground‐based rainfall stations, distributed throughout the Andes and the Amazon, and homogenized at the monthly time‐step for the period 1980–2016, was used for the analysis. With no spatial constraints, hierarchical cluster analysis and principal component analysis (PCA) optimally grouped stations into 10 rainfall homogenous regions. The value of the regionalization for interpreting the rainfall variability was evaluated by relating the seasonal rainfall time series of the regions with ocean indices. Then, by applying PCA to seasonal rainfall series and linking the principal components to sea surface temperature and ocean indices, an insight into the main large‐scale drivers of the rainfall spatio‐temporal variability in this basin at interannual and decadal scales is provided. This analysis identified differences in the year‐round influences of the tropical Pacific and/or Atlantic oceans on the 10 homogenous regions.
The 2022-23 drought in the South American Altiplano: ENSO effects on moisture flux in the western Amazon during the pre-wet season
(Elsevier BV, 2024) Ricardo A. Gutiérrez; Jhan Carlo Espinoza; Waldo Lavado‐Casimiro; Clémentine Junquas; Jorge Molina‐Carpio; Thomas Condom; José A. Marengo
The extreme 2014 flood in south-western Amazon basin: the role of tropical-subtropical South Atlantic SST gradient
(IOP Publishing, 2014) Jhan Carlo Espinoza; José A. Marengo; Josyane Ronchail; Jorge Molina‐Carpio; Luís Noriega Flores; Jean‐Loup Guyot
Unprecedented wet conditions are reported in the 2014 summer (December-March) in Southwestern Amazon, with rainfall about 100% above normal. Discharge in the Madeira River (the main southern Amazon tributary) has been 74% higher than normal (58 000 m 3 s -1 ) at Porto Velho and 380% (25 000 m 3 s -1 ) at Rurrenabaque, at the exit of the Andes in summer, while levels of the Rio Negro at Manaus were 29.47 m in June 2014, corresponding to the fifth highest record during the 113 years record of the Rio Negro. While previous floods in Amazonia have been related to La Nia and/or warmer than normal tropical South Atlantic, the 2014 rainfall and flood anomalies are associated with warm condition in the western Pacific-Indian Ocean and with an exceptionally warm Subtropical South Atlantic. Our results suggest that the tropical and subtropical South Atlantic SST gradient is a main driver for moisture transport from the Atlantic toward south-western Amazon, and this became exceptionally intense during summer of 2014.
The Role of the Rainfall Variability in the Decline of the Surface Suspended Sediment in the Upper Madeira Basin (2003–2017)
(Frontiers Media, 2021) Irma Ayes Rivera; Jorge Molina‐Carpio; Jhan Carlo Espinoza; Omar Gutierrez‐Cori; Wilmar L. Cerón; Frédéric Frappart; Elisa Armijos Cardenas; Raúl Espinoza-Villar; José Max Ayala; Naziano Filizola
The Madeira River rises in the Andes, draining the southwestern Amazon basin and contributing up to 50% of the Amazon River sediment load. The Porto Velho station monitors the Upper Madeira basin and is located just downstream of the Jirau and Santo Antonio hydropower dams. At this station, decreasing trend ( p &lt; 0.10) of the surface suspended sediment concentration (SSSC) has been documented during the sediment peak season (December to February) for the 2003–2017 period. This study aims to evaluate the role of the rainfall variability on this documented decreasing trend. For this purpose, we applied correlation and trend analysis in water discharge, SSSC and rainfall time series over the main tributaries of the Upper Madeira basin. The decline of SSSC in December is attributed to the reduction of rainfall in the Madre de Dios sub-basin from the start of the rainy season in October. However, the SSSC negative trend ( p &lt; 0.10) in January and February is associated with a shift in the magnitude of rainfall during these months in the Andean region after 2008, and the dilution associated with base flow. These results reveal that the decline of SSSC in the Madeira River should not be evaluated just on the basis of the data downstream from the dams, but also of the processes upstream in the Andean part of the basin. In a context of drastic anthropogenic climate and environmental changes, understanding the combined influence of regional hydroclimate variability and human actions on erosion and sediment transport remains a critical issue for the conservation of the Amazon-Andes system.