1
artículo
Publicado 2013
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Two simultaneous extreme events affected tropical South America to the east of the Andes during the austral summer and fall of 2012: a severe drought in Northeast Brazil and intense rainfall and floods in Amazonia, both considered records for the last 50 years. Changes in atmospheric circulation and rainfall were consistent with the notion of an active role of colder-than-normal surface waters in the equatorial Pacific, with above-normal upward motion and rainfall in western Amazonia and increased subsidence over Northeast Brazil. Atmospheric circulation and soil moisture anomalies in the region contributed to an intensified transport of Atlantic moisture into the western part of Amazonia then turning southward to the southern Amazonia region, where the Chaco low was intensified. This was favored by the intensification of subtropical high pressure over the region, associated with an anom...
2
artículo
Publicado 2020
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Heavy rainfall events were observed in January along the dry southern coast of Peru, resulting in some locations breaking precipitation records of more than 30 years. Heavy rainfall during February led to 42 landslides across Peru and, by the end of summer, 77 people were reported dead, 165 wounded, and 3285 affected. More than 2600 homes were destroyed by floods and landslides. In the Bolivian Andes, an intense rainfall event triggered flash floods when 55 mm fell in Cochabamba on 20 February. This was Cochabamba’s fourth-highest daily precipitation on record and produced 2019’s biggest flood on the Rocha River.
3
artículo
Publicado 2009
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El Altiplano peruano (Departamento de Puno) es considerado una de las zonas más sensibles y perturbadas por la variabilidad climática con implicancias en las actividades del sector agropecuario, hidroeléctrico, minero, etc. En el futuro por el posible cambio climático la vulnerabilidad y las condiciones de vida en general serían afectadas, principalmente la actividad agropecuaria que es el principal sustento de la población. Tomando en cuenta estos aspectos este trabajo tiene como objetivo evaluar y tener una aproximación de los posibles cambios futuros en la precipitación y temperatura. Para esta evaluación del cambio climático futuro (período 2071 – 2100) en el Altiplano peruano se utilizaron tres modelos climáticos regionales (ETA CCS, HadRM3 y REgCM3) y se analizaron las variables de precipitación y temperatura. Inicialmente, se validó el clima presente (1961-1990) de...
4
artículo
Publicado 2019
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Amazon tropical forests and the semiarid Northeast Brazil (NEB) region have registered very severe droughts during the last two decades, with a frequency that may have exceeded natural climate variability. Severe droughts impact the physiological response of Amazon forests, decreasing the availability to absorb atmospheric CO2, as well as biodiversity and increasing risk of fires. Droughts on this region also affect population by isolating them due to anomalous low river levels. Impacts of droughts over NEB region are related to water and energy security and subsistence agriculture. Most drought episodes over Amazonia and NEB are associated with El Niño (EN) events, anomalous warming over the Tropical North Atlantic (TNA), and even an overlapping among them. However, not all the dry episodes showed a large‐scale pattern linked to a canonical EN event or warm TNA episodes. For instance...
5
artículo
Publicado 2024
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The 2022-23 hydrological year in the Lake Titicaca, Desaguadero River, and Lake Poopó hydrological system (TDPS) over the South American Altiplano constituted a historically dry period. This drought was particularly severe during the pre-wet season (October–December), when the TDPS and the adjacent Andean-Amazon region experienced as much as 60% reductions in rainfall. Consequently, Titicaca Lake water levels decreased by 0.05 m from December to January, which is part of the rising lake level period of normal conditions. Such conditions have not been seen since the El Niño-related drought of 1982-83. Using a set of hydroclimatic, Sea Surface Temperature (SST) and atmospheric reanalysis datasets, we find that this new historical drought was associated with enhanced southerly moisture flux anomalies, reducing the inflow of moisture-laden winds from the Amazon basin to the TDPS. Such an...
6
artículo
Publicado 2018
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The original concept of El Niño consisted of anomalously high sea surface temperature and heavy rainfall along the arid northern coast of Peru (Carranza 1891; Carrillo 1893). The concept evolved into the El Niño–Southern Oscillation (ENSO; Bjerknes 1969), although the original El Niño and the Southern Oscillation do not necessarily have the same variability (Deser and Wallace 1987), and the strong El Niño episode in early 1925 coincided with cold-to-neutral ENSO conditions (Takahashi and Martínez 2017). To distinguish the near-coastal El Niño from the warm ENSO phase, Peru operationally defines the “coastal El Niño” based on the seasonal Niño 1+2 SST anomaly (ENFEN 2012; L’Heureux et al. 2017). While recent attention has been brought to the concept of ENSO diversity (e.g., “central Pacific” vs “eastern Pacific” events; Capotondi et al. 2015), the coastal El Niño ...
7
artículo
The climate of South America (SA) has long held an intimate connection with El Niño, historically describing anomalously warm sea-surface temperatures off the coastline of Peru. Indeed, throughout SA, precipitation and temperature exhibit a substantial, yet regionally diverse, relationship with the El Niño–Southern Oscillation (ENSO). For example, El Niño is typically accompanied by drought in the Amazon and north-eastern SA, but flooding in the tropical west coast and south-eastern SA, with marked socio-economic effects. In this Review, we synthesize the understanding of ENSO teleconnections to SA. Recent efforts have sought improved understanding of ocean–atmosphere processes that govern the impact, inter-event and decadal variability, and responses to anthropogenic warming. ENSO’s impacts have been found to vary markedly, affected not only by ENSO diversity, but also by modes...
8
artículo
Publicado 2013
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In this study, we present the collation and analysis of the gridded land-based dataset ofindices of temperature and precipitation extremes: HadEX2. Indices were calculated based onstation data using a consistent approach recommended by the World Meteorological Organization (WMO) Expert Team on Climate Change Detection and Indices, resulting in theproduction of 17 temperature and 12 precipitation indices derived from daily maximum andminimum temperature and precipitation observations. High-quality in situ observations fromover 7000 temperature and 11,000 precipitation meteorological stations across the globe wereobtained to calculate the indices over the period of record available for each station. Monthlyand annual indices were then interpolated onto a 3.75 x 2.5 longitude-latitude grid over theperiod 1901–2010. Linear trends in the gridded fields were computed and tested for statisti...
