Olga Penalba

Olga Penalba
Universidad de Buenos Aires | UBA · Department of Atmospheric and Ocean Sciences

About

111
Publications
22,998
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2,600
Citations
Citations since 2017
29 Research Items
1496 Citations
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2017201820192020202120222023050100150200250300
2017201820192020202120222023050100150200250300
2017201820192020202120222023050100150200250300

Publications

Publications (111)
Article
Full-text available
Rainfall in the Moist Tropical Caribbean Region (MTCR) in Costa Rica occurs practically throughout the year, with the quarters June–August (JJA) and December–February (DJF) concentrating over 70% of annual rainfall. Contrarily, in March–April and September–October, it rains below 100 mm per month. This seasonal rainfall behavior makes the region id...
Poster
Full-text available
Este trabajo analiza la relación espacio-temporal entre el Modo Anular del Sur (SAM) y los índices de precipitación (PRCPTOT, WD, R75pTOT, CWD y CDD) en el trimestre octubre-diciembre (OND), en Sudamérica, para el período 1981-2010. A partir del índice de correlación simple se estudia la relación espacio-temporal y se encuentran correlaciones negat...
Preprint
Full-text available
Rainfall in the moist Tropical Caribbean region (MTCR) in Costa Rica occurs practically throughout the year, with the quarters June–August (JJA) and December–February (DJF) concentrating over 70% of annual rainfall. On the other hand, in March–April and September–October, it rains below 100mm per month. This seasonal rainfall behavior makes the reg...
Article
Full-text available
Climate services provide information on El Niño-Southern Oscillation (ENSO) evolution and predicted seasonal precipitation, broadly used by decision makers from the agriculture sector. However, soil moisture participates in a more complex soil–atmosphere interaction at subseasonal scale. This work aims to identify the ENSO signal on subseasonal pre...
Article
Full-text available
The assessment of ENSO influence on extreme rainfall events over South America will provide useful information to climate services. This research analyzes the performance of eleven global climate models (GCMs) from the Coupled Model Intercomparison Project Phase 5 (CMIP5) using skill score metrics to simulate two climate extreme rainfall indices: m...
Article
Low streamflows caused by natural and anthropogenic forcings affect ecosystems and societies, especially on large timescales. We analysed the main basins of central-north Argentina (CNA) using centennial streamflow data. This study is focussed on describing spatial and temporal variability of hydrological drought events, and evaluating the atmosphe...
Article
The goal of this study is to provides a better understanding of the trends and dominant oscillations characterizing the co‐variability between global sea surface temperature (SST) anomalies and daily extreme rainfall in Argentina. A singular value decomposition was performed between daily extreme rainfall monthly index in Argentina and global SST w...
Article
Full-text available
The several variables involved in soil-atmosphere interaction were analyzed in South America from seven Global Climate Models (GCM) of CMIP5. Two different periods were used: 1970–2005 as climate reference for historical experiment and 2065–2100 for projections under the Representative Concentration Pathways scenario RCP 8.5. We assessed the climat...
Article
The deficit of daily precipitation, persistent over time (LDS: long dry sequences), causes economic losses in the east‐northeast of Argentina where agriculture production is the main economic activity. For this reason, an improvement in the seasonal prediction of the frequency of precipitation is required. Among several forcings influencing the reg...
Article
Full-text available
El índice de caudal estandarizado (ICE) se desarrolló siguiendo los lineamientos teóricos del índice de precipitación estandarizado (IPE) para el monitoreo y la comparación de patrones espaciales y temporales de las condiciones hidrológicas considerando como variable de entrada los caudales mensuales. Un paso fundamental para su cálculo consiste en...
Article
Full-text available
Projected changes were estimated considering the main variables which take part in soil-atmosphere interaction. The analysis was focused on the potential impact of these changes on soil hydric condition under extreme precipitation and evapotranspiration, using the combination of Global Climate Models (GCMs) and observational data. The region of stu...
Article
Full-text available
This paper performed a streamflow drought climatology considering some of the most important rivers of Southern South America, a region highly vulnerable to climatic variations, based on the analysis of monthly streamflow records. The standardized hydrological drought index (SHDI) was used in order to depict the main characteristics of droughts—num...
Article
La Plata Basin has a considerable socio‐economic value, being one of the most important agricultural and hydropower‐producing regions in the world. In this region, there is increasing evidence of a changing climate with more frequent and more intense extreme events. Despite the importance of empirical statistical downscaling for regional climate im...
Article
Surface marine meteorological observations made on board ships that navigate in the Southwestern Atlantic Ocean are regularly collected and verified at the Meteorological Department of the Naval Hydrographic Service of Argentina (DMSHN). The database that contains this information spans from 1950 to present. Due to the importance of these data at t...
Article
Full-text available
During the period 2010–2015, the semi-arid Central Andes in Argentina (CAA) experienced one of the most severe and long-lasting hydrological droughts on record. Since the snowmelt is the most important source of water, the reduced snowfall over the mountains propagated the drought signal through the streamflows in the adjacent foothills east of the...
Article
The importance of forecasting extreme wet and dry conditions from weeks to months in advance relies on the need to prevent considerable socio-economic losses, mainly in regions of large populations and where agriculture is a key value for the economies, such as Southern South America (SSA). To improve the understanding of the performance and uncert...
Article
A streamflow drought climatology was developed over the Central Andes of Argentina, a semi-arid region highly vulnerable to climatic variations, based on the analysis of daily historical streamflow records. A threshold level approach was applied on a daily basis for three different severity levels, in order to depict the main characteristics of dro...
Article
Precipitation or no precipitation persistent over time often became extreme weather conditions with greater regional economic impact. The temporal and spatial variability of these variables, together with the evapotranspiration, is crucial in the east-northeast of Argentina, where rain-fed agricultural production is carried out. In this work, the f...
Conference Paper
Full-text available
The importance of forecasting extreme wet and dry conditions from weeks to months in advance relies on the need to prevent considerable socio-economic losses, mainly in regions of large populations and where agriculture is a key value for the economies, like Southern South America (SSA). Therefore, to improve the understanding of the performance an...
Conference Paper
Full-text available
In the Central Andes of Argentina (CAA, located between 28° and 38°S), an arid to semi-arid region, irrigation and a variety of socio-economical activities are highly dependent on river streamflows. Permanent and semi-permanent rivers originate mainly from snowmelt and glacier ablation, enabling the development of large agricultural oasis and the c...
Conference Paper
Full-text available
Con el propósito de mejorar el conocimiento de la variabilidad temporal de los caudales de los ríos del centro-norte de Argentina en términos de la variabilidad de baja frecuencia, se analizaron los registros mensuales históricos de 10 estaciones de aforo durante el período 1919-2014. A fin de comparar los registros hidrológicos en cuencas con dist...
Article
Under the current global warming trend, droughts are expected to increase, with serious implications for water resources management. This study analyzed the regional aspects of droughts in terms of streamflow deficiencies over the Andean rivers of Patagonia, Argentina. Based on the variable threshold level method, the main characteristics of stream...
Article
Full-text available
The ENSO phenomenon is one of the key factors that influence the interannual variability of precipitation over Southern South America. The aim of this study is to identify the regional response of precipitation to El Niño/La Niña events, with emphasis in drought conditions. The standardized precipitation index (SPI) was used to characterize precipi...
Article
Full-text available
Extreme climate events over the La Plata basin (LPB) can produce significant impacts due to the importance of its agriculture and hydroelectric power production for the local economy. Progresses on describing, projecting and understanding extremes in LPB, in the framework of the CLARIS-LPB Europe-South America Network for Climate Change Assessment...
Article
Full-text available
Existen numerosos índices de sequía que deben ser monitoreados continuamente a fin de determinar el inicio y fin de los eventos de sequía y sus características espacio-temporales. Este trabajo describe y compara el desempeño de seis índices basados en datos de precipitación para el monitoreo de sequías en el sur de Sudamérica, con el objetivo de ob...
Article
The interaction between land surface and atmosphere plays an important role in the climate system. Soil-atmosphere feedback mechanisms are analyzed through calculating the hydric condition (HC) of the soil from the water balance. Spatial coherence between HC and the Standardized Precipitation Index (SPI) as well as the circulation patterns associat...
Conference Paper
Full-text available
Droughts are perceived as one of the costliest and least understood natural disasters, given the difficulty in defining its beginning and end, its slow development and its multiple regional aspects. Southern South America (SSA) was no exception to this hazard, whose impacts were evident in the reduction in crop yields, reduced cattle products, stre...
Article
Full-text available
This article addresses the regional impacts of climate change on precipitation and meteorological drought over Southern South America (SSA) through a CMIP5 multi-model ensemble based on 15 General Circulation Models (GCMs) forced under two different greenhouse gas concentration pathways (RCP4.5 and RCP8.5). An assessment of the biases in the repres...
Article
A singular value decomposition (SVD) analysis was performed jointly on the daily intensity of extreme rainfall (DIER) over Argentina and sea surface temperature (SST) anomalies from 17.5°N–90°S to describe and understand the influence of the large-scale variability of the SSTs on the regional extreme rainfall events for spring summer, autumn and wi...
Conference Paper
Full-text available
RESUMEN: En el presente trabajo se realiza una comparación del período de crisis hídrica 2010-2014 en la región de Cuyo con otros períodos deficitarios históricos, en función del análisis de su duración y severidad. Se obtuvo que el período seco reciente es el más importante de los últimos 40 años en todas las cuencas analizadas. En algunas de esta...
Conference Paper
Full-text available
RESUMEN: El cálculo de amenaza de sequías es una aplicación útil que puede estimarse a través del índice de precipitación estandarizado en distintas escalas temporales. La distribución espacial de los valores de amenaza posee implicancias socio-económicas y puede permitir el desarrollo de mapas de riesgo asociado a las sequías meteorológicas en la...
Article
Full-text available
This study aims to compare simulated soil moisture anomalies derived from different versions of the Global Land Data Assimilation System (GLDAS), the standardized precipitation index (SPI), and a new multisatellite surface soil moisture product over southern South America. The main motivation is the need for assessing the reliability of GLDAS varia...
Chapter
Full-text available
The aim of this study is to identify support tools for the regional monitoring of drought conditions over Southern South America (SSA). The Standardized Precipitation Index (SPI) was used to characterize rainfall variabilities through the 1961–2008 period. The SPI was calculated at two time scales (3 and 12 months), which represents short-and long-...
Article
Monthly and daily precipitation extremes over La Plata Basin (LPB) are analyzed in the framework of the CLARIS-LPB Project. A review of the studies developed during the project and results of additional research are presented and discussed. Specific aspects of analysis are focused on large-scale versus local processes impacts on the intensity and f...
Conference Paper
Full-text available
La interacción entre el suelo, la vegetación y la atmósfera juega un papel importante en el sistema climático. La humedad y la condición hídrica del suelo se determinan por la temperatura y la precipitación a nivel local. La precipitación recarga directamente la humedad del suelo y el ciclo se completa a través de la evapotranspiración, que produce...
Article
Full-text available
Based on 56 rainfall stations, which cover the period 1961–2008, we analyzed the presence of trends in the drought-affected area over southern South America (SSA) at different time scales. In order to define drought conditions, we used the standardized precipitation index, which was calculated on time scales of 1, 3, 6, 9 and 12 months. The trends...
Article
CLARIS LPB database was built within the framework of the CLARIS LPB project “A Europe-South America Network for climate Change Assessment and Impact Studies in La Plata Basin” of the European Community’s Seventh Framework Programme (FP7). The main variables available in the database are rainfall, temperature, radiation, heliophany and streamflow c...
Article
The ability of 17 global circulation models to simulate daily rainfall of the Pampas region is assessed for winter and summer, key seasons for crop production in the region. Principal Component Analysis combined with k-means Cluster Analysis is employed to examine the models' representation of the relationship between daily sea level pressure of so...
Article
Full-text available
La Plata basin is one of the most important agricultural and hydropower-producing regions in the world. Extreme climate events such as cold and heat waves and frost events have a significant socioeconomic impact. This work analyzes the influence of the surface circulation in southern South America on daily maximum temperature T-MAX and daily minimu...
Conference Paper
Full-text available
El incremento en la demanda de los recursos hídricos superficiales exige una mejor estimación de las características de las sequías hidrológicas. Uno de los parámetros de interés para el análisis de las deficiencias en los caudales es la cantidad anual de días con caudales bajos, y su variabilidad temporal asociada. Los días con caudales bajos –de...
Article
Full-text available
The impact of climate change on drought main characteristics was assessed over Southern South America. This was done through the precipitation outputs from a multi-model ensemble of 15 climate models of the Coupled Model Intercomparison Project Phase 5 (CMIP5). The Standardized Precipitation Index was used as a drought indicator, given its temporal...
Article
Daily station precipitation totals are used to develop a gridded dataset for the region (14°–40°S, 45°–70°W) on a 0.5° × 0.5° latitude/longitude grid, primarily for comparison with regional climate model (RCM) simulations. The gridded dataset covers the period 1961–2000. Much of the paper discusses the quality control of the basic station precipita...
Article
Full-text available
For the first time in serveral years, the El Nino-Southern Oscillation did not dominate regional climate conditions around the globe. A weak La Ni a dissipated to ENSOneutral conditions by spring, and while El Nino appeared to be emerging during summer, this phase never fully developed as sea surface temperatures in the eastern conditions. Neverthe...
Article
La Plata Basin is one of the most important agriculture and hydropower producing regions worldwide, where temporal and spatial variability of precipitation have a significant socio-economic impact. The aim of this work is to analyze the dependence of the daily precipitation in the south of La Plata Basin region on the large-scale circulation in Sou...
Article
This work proposes to employ the number of dry days (days without precipitation) as a variable of study, and to analyse their spatial and temporal variability in Argentina. Climatological aspects of dry days, such as their annual mean values and its seasonal cycle, were discussed and compared with precipitation features in the country. Linear trend...
Article
AbstractA Singular value decomposition (SVD) analysis was performed jointly on the daily intensity of extreme rainfall (DIER) over Argentina and the sea surface temperature (SST) of all the oceans from 17.5°N to 90°S in order to identify the large‐scale variability of the SSTs related to extreme rainfall, in the period 1962–2005. The main objective...
Article
Full-text available
The ability of four regional climate models to reproduce the present-day South American climate is examined with emphasis on La Plata Basin. Models were integrated for the period 1991–2000 with initial and lateral boundary conditions from ERA-40 Reanalysis. The ensemble sea level pressure, maximum and minimum temperatures and precipitation are eval...
Conference Paper
Full-text available
El Índice de Precipitación Estandarizado (IPE) es uno de los índices de sequía más utilizados a nivel mundial. Este índice se estima en base al ajuste de la distribución gamma a las frecuencias de precipitaciones mensuales para cada localidad, y posteriormente realiza una transformación a fin de estandarizar el índice. Los cambios temporales en los...
Conference Paper
Full-text available
El primer paso en el cálculo del Índice de Precipitación Estandarizado es determinar la función de densidad de probabilidad que describe las observaciones de precipitación. Dada la gran variedad de regímenes de precipitación presentes en el Sudeste de Sudamérica (SESA), se analizó qué tan flexible es la distribución de probabilidades gamma para rep...
Conference Paper
Due to the increasing demand on surface water resources, it is necessary an assessment of the rainfall deficit conditions. Particularly, northeastern Argentina is part of the La Plata Basin, environment of great economic and demographic significance, and the impacts of droughts on hydrology and agriculture are immediate. The main goal of this resea...
Article
The aim of this research is to validate the spatio-temporal variability of droughts in Southern South America (south of 20°S) depicted by the VAMOS atlas of extremes, trough the Standardized Precipitation Index (SPI). In the study region, droughts are a recurring climatic phenomenon, with periodicities that vary regionally. Monitoring of these extr...
Article
Full-text available
Extreme precipitation (wet or dry) over La Plata Basin (LPB) can cause intense damage in several sectors as agriculture and hydroelectricity, and also has an impact on urban areas due to flooding and landslides. Extreme temperatures (cold incursions or heat waves) have impact on agriculture and health. The frequency and intensity of extremes can va...
Article
Full-text available
The main objective of WP3 is to improve the description of past climate variability in the LPB in order to provide an observational basis for quantifying past climate variability (WP4 and WP6), evaluating climate scenarios (WP4, WP5 and WP6) and providing high-quality data to WP7 for impact model calibration (WP8 and WP9).
Article
Full-text available
Several large-scale climate patterns influenced climate conditions and weather patterns across the globe during 2010. The transition from a warm El Nino phase at the beginning of the year to a cool La Nina phase by July contributed to many notable events, ranging from record wetness across much of Australia to historically low Eastern Pacific basin...
Article
The study of the temporal-spatial variability of dry sequences and the probability of their occurrence are particularly important in understanding the impact of climate change on droughts.This paper analyses the different properties of dry sequences, focussing on extreme condition, analysing their degree of spatial coherence, and their temporal var...
Article
Full-text available
La regionalización de diferentes variables climáticas ha sido llevada a cabo en diversas zonas del mundo, dado que para distintos propósitos es conveniente dividir espacialmente la climatología de una variable en un número de áreas cuasi-homogéneas. El objetivo de este trabajo es la obtención de una regionalización objetiva de las distintas variabi...
Chapter
Full-text available
Debido a la creciente demanda en los recursos hídricos superficiales, es necesaria una evaluación de las condiciones deficitarias en las precipitaciones sobre Argentina, dado que sus impactos en el abastecimiento de agua y la agricultura son inmediatos. Por lo tanto, se presenta un análisis de la variabilidad temporal de los períodos secos ocurrido...
Conference Paper
The impact of climate variability on the environment and the economic activities mainly depends on changes in the frequency of occurrence of extreme events. Relatively small changes in the mean can be related to substantial changes in the frequency of extreme events. The objective of this work is to study daily extreme rainfall and temperature even...
Conference Paper
Full-text available
Within the framework of the EU FP6 project CLARIS (A Europe-South America Network for Climate Change Assessment and Impact Studies in South America), four regional modelling groups have coordinated simulations of South American present climate (1992-2000). The models' domains cover the entire continent and are driven by ERA40 reanalysis with an hor...
Article
The Pampas covers Argentina's most productive agricultural land, extending more than 1600 km in the heartland of the country. The impact of climate adversities on agricultural activities makes it necessary to determine to what extent climate spatial and temporal variability is responsible for crop yields and to generate elements to monitor, estimat...
Article
During the past few decades there has been considerable effort devoted to obtaining a better understanding of natural climate variability on interannual to interdecadal timescales. To determine the mechanisms governing these climatic variations, it is essential to characterize the large-scale interactions between the ocean and the overlying atmosph...
Article
Cultivation of grain crops constitutes one of the most important agricultural activities in Argentina. They have been, and continue to be, subject to a wide scope of studies in the areas of economics, agronomics and agrometeorology. The agricultural activities involve a broad range of decision making in which various factors have significant influe...
Chapter
Full-text available
During the second half of the twentieth century, Southeastern South America experienced a positive trend in annual precipitation. Since Argentina is a country whose economy mostly relies on rain-fed agriculture, this trend has favoured the extension of the agricultural frontier, increasing the availability of productive lands. However, this precipi...
Article
Full-text available
This paper classifies daily geopotential height anomalies at the 1000 hPa and 500 hPa levels for the period 1979-2001, and examines the capability of these atmospheric patterns to discriminate between the occurrence and non-occurrence of rainfall in the core crop-producing region located in the Argentine Humid Pampas. The resulting optimal classifi...
Article
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In this study we examine the performance of eight of the IPCC AR4 global coupled climate models used in the WCRP CMIP3 Multimodel Dataset, as well as their ensemble mean, in simulating annual indices of extreme temperature and precipitation climate events in South America. In this first part we focus on comparing observed and modeled mean values an...
Article
Full-text available
We analyzed trends, interdecadal variability, and the quantification of the changes in the frequency of daily rainfall for two thresholds: 0.1mm and percentile 75th, using high quality daily series from 52 stations in the La Plata Basin (LPB). We observed increases in the annual frequencies in spatially coherent areas. This coherence was more marke...
Article
Full-text available
The goal of the CLARIS project was to build an integrated European–South American network dedicated to promote common research strategies to observe and predict climate changes and their consequent socio-economic impacts taking into account the climate and societal peculiarities of South America. Reaching that goal placed the present network as a p...
Article
Full-text available
Projections of changes in climate extremes are critical to assessing the potential impacts of climate change on human and natural systems. Therefore, especial care should be put on the validation of those extremes derived for present climate in both spatial and temporal variability. We analyze historical simulations of three such indicators as deri...