Interannual-to-multidecadal Hydroclimate Variability and its Sectoral Impacts in northeastern Argentina

This study examines the joint variability of pre- cipitation, river streamflow and temperature over northeast- ern Argentina; advances the understanding of their links with global SST forcing; and discusses their impacts on water re- sources, agriculture and human settlements. The leading pat- terns of variability, and their nonlinear trends and cycles are identified by means of a principal component analysis (PCA)complemented with a singular spectrum analysis (SSA). In- terannual hydroclimatic variability centers on two broad fre- quency bands: one of 2.5?6.5 years corresponding to El Niño Southern Oscillation (ENSO) periodicities and the second of about 9 years. The higher frequencies of the precipita- tion variability (2.5?4 years) favored extreme events after 2000, even during moderate extreme phases of the ENSO. Minimum temperature is correlated with ENSO with a main frequency close to 3 years. Maximum temperature time se- ries correlate well with SST variability over the South At- lantic, Indian and Pacific oceans with a 9-year frequency. Interdecadal variability is characterized by low-frequency trends and multidecadal oscillations that have induced a tran- sition from dryer and cooler climate to wetter and warmer decades starting in the mid-twentieth century. The Paraná River streamflow is influenced by North and South Atlantic SSTs with bidecadal periodicities.The hydroclimate variability at all timescales had signif- icant sectoral impacts. Frequent wet events between 1970 and 2005 favored floods that affected agricultural and live- stock productivity and forced population displacements. On the other hand, agricultural droughts resulted in soil mois- ture deficits that affected crops at critical growth stages. Hy-drological droughts affected surface water resources, caus- ing water and food scarcity and stressing the capacity for hydropower generation. Lastly, increases in minimum tem- perature reduced wheat and barley yields.Fil: Lovino, Miguel Angel. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Müller, Omar Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; ArgentinaFil: Müller, Gabriela V.. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; ArgentinaFil: Sgroi, Leandro Carlos. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; ArgentinaFil: Baethgen, Walter. Columbia University; Estados Unido

Regional model simulations of the 2008 drought in southern South America using a consistent set of land surface properties

This work discusses the land surface-atmosphere interactions during the severe drought that took place in 2008 in southern South America. The drought was among the most severe in the last fifty years both in terms of intensity and extent. Once precipitation returned to normal values, it took about two months for the soil moisture content and vegetation to recover. The land surface effects were examined by contrasting long term simulations using a consistent set of satellite-derived annually varying land surface biophysical properties against simulations using the conventional land cover types in the coupled system Weather Research and Forecasting Model/Noah Land Surface Model (WRF/Noah). The new land cover data set is based on ecosystem functional properties that capture changes in vegetation status due to climate anomalies and land use changes.The results show that the use of realistic information of vegetation states enhances the model performance reducing the precipitation biases over the drought region as well as over areas of excessive precipitation. The precipitation bias reductions are traced back to the corresponding changes in greenness fraction, leaf area index, stomatal resistance and surface roughness. The simulation of temperature shows a larger bias over the domain´s central part, which is attributable to a doubling of the stomatal resistance that reduces the evapotranspiration rate and leads to a temperature increase. However, the temperature pattern using the novel data set shows improvements towards the eastern part of the domain. The overall results suggest that an improved representation of the surface processes contributes to the predictability of the system.Fil: Müller, Omar Vicente. Universidad Nacional del Litoral; ArgentinaFil: Berbery, Ernesto Hugo. University of Maryland; Estados UnidosFil: Alcaraz Segura, Domingo. Universidad de Granada; EspañaFil: Ek, Michael B.. National Oceanic And Atmospheric Administration

Análisis de la predicción de precipitaciones mediante correlaciones canónicas en el NE de Argentina

La previsión de la variabilidad climática es de vital importancia para la economía de una zona agrícola-ganadera como la región del Nordeste de Argentina. Numerosas investigaciones demuestran que las variaciones extremas de precipitación en Sudamérica, tales como excesos de precipitación y sequías, están relacionadas a eventos El Niño o La Niña. Otros trabajos muestran la influencia de las temperaturas del Atlántico en las variaciones de precipitación en algunas regiones de Sudamérica.El objetivo del presente trabajo es la aplicación y evaluación de la capacidad predictiva de un método estadístico de pronóstico de precipitaciones a largo plazo sobre el Nordeste de Argentina, a partir de las temperaturas de superficie del océano Pacífico Sur y el océano Atlántico Sur. El método consiste en el análisis de correlaciones canónicas de funciones ortogonales empíricas de los campos de temperaturas de superficie del mar y precipitación. Luego, se realiza un análisis de las posibilidades ciertas de la predicción estadística en la zona de interés, mediante el estudio de los pronósticos para periodos húmedos, normales y secos. Las correlaciones muestran que los mejores resultados se obtienen para prima vera y verano. Particularmente, se destaca la predicción de periodos húmedos cuando se utilizan las temperaturas del océano Pacífico, debido a que en general están asociados a la ocurrencia de un evento El Niño en los meses previos. Los veranos secos tienen un pronóstico adecuado utilizando las temperaturas del océano Atlántico. Es decir, la predicción estadística resulta útil sólo para ciertas estaciones delaño. No obstante, en dichas estaciones el método logra estimar las condiciones con 5 a 7 meses de antelación.Fil: Müller, Omar Vicente. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Unidad de Investigaciones Hidroclimáticas; Argentin

Evaluation of WRF model forecasts and their use for hydroclimate monitoring over Southern South America

Weather forecasting and monitoring systems based on regional models are becoming increasingly relevant for decision support in agriculture and water management. This work evaluates the predictive and monitoring capabilities of a system based on WRF Model simulations at 15-km grid spacing over the La Plata basin (LPB) in southern South America, where agriculture and water resources are essential. The model's skill up to a lead time of 7 days is evaluated with daily precipitation and 2-m temperature in situ observations for the 2-yr period from 1 August 2012 to 31 July 2014. Results show high prediction performance with 7-day lead time throughout the domain and particularly over LPB, where about 70% of rain and no-rain days are correctly predicted. Also, the probability of detection of rain days is above 80% in humid regions. Temperature observations and forecasts are highly correlated (r > 0.80) while mean absolute errors, even at the maximum lead time, remain below 2.7°C for minimum and mean temperatures and below 3.7°C for maximum temperatures. The usefulness of WRF products for hydroclimate monitoring was tested for an unprecedented drought in southern Brazil and for a slightly above normal precipitation season in northeastern Argentina. In both cases the model products reproduce the observed precipitation conditions with consistent impacts on soil moisture, evapotranspiration, and runoff. This evaluation validates the model's usefulness for forecasting weather up to 1 week in advance and for monitoring climate conditions in real time. The scores suggest that the forecast lead time can be extended into a second week, while bias correction methods can reduce some of the systematic errors.Fil: Müller, Omar Vicente. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Lovino, Miguel Angel. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; ArgentinaFil: Berbery, Ernesto H.. University of Maryland. Department of Atmospheric and Oceanic Science; Estados Unido

How have daily climate extremes changed in the recent past over northeastern Argentina?

Changes in climate extremes affect socioeconomics and natural systems in northeastern Argentina (NEA) and may increase its vulnerability leading to unprecedented disasters. This study investigates the long-term changes and interannual variability of daily temperature and precipitation climate extremes and assesses to what extent global reanalyses reproduce the observed variability in the recent past. Datasets include quality-controlled observations (1963–2013) and ERA-Interim and NCEP2 reanalyses (1979–2011). Climate extremes are characterized spatially and temporally by 15 indices proposed by the Expert Team on Climate Change Detection and Indices. The leading modes of the area-averaged index time series were obtained by means of a Singular Spectrum Analysis, while the spatial distribution of mean changes was estimated by fitting nonparametric linear trends to each index time series. The results show that temperature extremes are changing towards warmer conditions. The number of warm days has been increasing since 1990 while the number of cold days has been decreasing. Warm and cold nights show a significant signal of warming that seems to be stabilizing in recent decades. Heat waves almost double the frequency and duration of cold waves, and the duration of heat waves increased while cold spells decreased in last decades. Longer heat waves are related to longer dry spells. On the other hand, the number of frost days remained stable although they exhibit high interannual and decadal variability. As well, intense precipitation events in most of the region increased steadily since 1970. The annual maximum amount of 1-day and 5-day precipitation events increased from the 1970s to the 2000s, stabilizing in recent years. The ERA-Interim and NCEP2 reanalyses represent climate extremes with different success. ERA-Interim can recognize temperature extremes in time and space, while the older NCEP2 presents systematic positive errors and has some difficult to replicate the interannual variability of the number of summer days. Both reanalyses reproduce dry spells and the annual maximum 5-day precipitation with large biases, which are particularly noticeable at each observation station. Although reanalyses would be expected to add information for climate extremes in areas of scarce observations like northeastern Argentina, they still need to be used with great caution and only as a complement to observations, especially in studies focusing on precipitation extremes.Fil: Lovino, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; ArgentinaFil: Müller, Omar Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; ArgentinaFil: Berbery, Ernesto H.. University of Maryland; Estados UnidosFil: Muller, Gabriela Viviana. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentin

Evaluation of historical CMIP6 model simulations and future projections of temperature and precipitation in Paraguay

This study evaluates the ability of 19 models of CMIP phase 6 (CMIP6) to simulate Paraguay’s climate features. Historical multi-member simulations of single models and their multi-model ensembles are bias-corrected and evaluated with statistical metrics. Future projections of precipitation and temperature are generated with the ensembles for three integrated scenarios of socio-economic development and greenhouse gas emissions (SSP1–2.6, SSP2–4.5, and SSP5–8.5). The 19 models simulate well the observed mean temperature. The bias-corrected multi-model ensemble reaches the highest skill scores and accurately reproduces the mean spatial field and annual cycle. The bias-corrected multi-model ensemble of precipitation represents the annual cycle weakly, missing the sharp onset and decay of the South American Monsoon. Some individual models and the multi-model ensemble correctly reproduce the west-east gradient, although they underestimate its pronounced spatial variability. Ensembles of future simulations project that by 2100, the annual mean temperature will increase for the three scenarios. On average, the increases are almost 1.7 °C in the sustainable development and low emissions scenario (SSP1–2.6), 3 °C in the middle-of-the-road development and medium emissions scenario (SSP2–4.5), and 5.5 °C in the fossil-fueled development and high emissions scenario (SSP5–8.5). Models project a slight decrease in annual precipitation towards the northwest (less than 50 mm) and an increase towards the southeast (more than 200 mm). Paraguay’s humid eastern part is projected to have a small growth in temperature and an increase in precipitation. In contrast, the western arid Chaco region would experience a substantial increase in temperature, while rainfall would slightly decrease.Fil: Lovino, Miguel Angel. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Centro de Estudios de Variabilidad y Cambio Climático; ArgentinaFil: Pierrestegui, Maria Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Centro de Estudios de Variabilidad y Cambio Climático; ArgentinaFil: Müller, Omar Vicente. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Centro de Estudios de Variabilidad y Cambio Climático; ArgentinaFil: Berbery, Ernesto Hugo. University of Maryland; Estados UnidosFil: Muller, Gabriela Viviana. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Santa Fe; Argentina. Universidad Nacional del Litoral. Facultad de Ingeniería y Ciencias Hídricas. Centro de Estudios de Variabilidad y Cambio Climático; ArgentinaFil: Pasten, Max. Universidad Nacional de Asunción; Paragua

The "Woundosome" Concept and Its Impact on Procedural Outcomes in Patients With Chronic Limb-Threatening Ischemia

This editorial assembles endovascular specialists from diverse clinical backgrounds and nationalities with a global call to address key challenges to enhance revascularization in chronic limb-threatening ischemia (CLTI) patients.- Dedicated below-the-ankle (BTA) angiography and revascularization is underutilized in ischemic foot treatment. Existing guidelines do not address comprehensive BTA vessel analysis. CLTI trials also often lack data on in-line arterial flow to the ischemic lesion and BTA vessel evaluation, hindering outcome assessment.- Dedicated multi-planar angiographic evaluation of the distal microcirculation is key: Direct arterial flow or good-quality collaterals are crucial in influencing wound healing and need to be assessed diligently to the level of the distal ischemic wound territory, termed “woundosome.”- An important primary emphasis of future trials should be on validating technologies and strategies for assessing tissue perfusion before, during, and after revascularization undertaken to heal tissue loss in CLTI patients. This will allow determination of a potentially significant delta in tissue perfusion prior to and following intervention at the “woundosome” level. Once changes in arterial perfusion have been identified as positively correlated to wound healing, these could serve as a much-needed novel primary technical outcome measure for patients with tissue loss undergoing surgical, hybrid, or endovascular revascularization

Association of mechanical bowel preparation with oral antibiotics and anastomotic leak following left sided colorectal resection: an international, multi-centre, prospective audit.

This is the peer reviewed version of the following article: , (2018), Association of mechanical bowel preparation with oral antibiotics and anastomotic leak following left sided colorectal resection: an international, multi‐centre, prospective audit. Colorectal Dis, 20: 15-32. doi:10.1111/codi.14362, which has been published in final form at https://doi.org/10.1111/codi.14362. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Use of Self-Archived VersionsINTRODUCTION: The optimal bowel preparation strategy to minimise the risk of anastomotic leak is yet to be determined. This study aimed to determine whether oral antibiotics combined with mechanical bowel preparation (MBP+Abx) was associated with a reduced risk of anastomotic leak when compared to mechanical bowel preparation alone (MBP) or no bowel preparation (NBP). METHODS: A pre-planned analysis of the European Society of Coloproctology (ESCP) 2017 Left Sided Colorectal Resection audit was performed. Patients undergoing elective left sided colonic or rectal resection with primary anastomosis between 1 January 2017 and 15 March 2017 by any operative approach were included. The primary outcome measure was anastomotic leak. RESULTS: Of 3676 patients across 343 centres in 47 countries, 618 (16.8%) received MBP+ABx, 1945 MBP (52.9%) and 1099 patients NBP (29.9%). Patients undergoing MBP+ABx had the lowest overall rate of anastomotic leak (6.1%, 9.2%, 8.7% respectively) in unadjusted analysis. After case-mix adjustment using a mixed-effects multivariable regression model, MBP+Abx was associated with a lower risk of anastomotic leak (OR 0.52, 0.30-0.92, P = 0.02) but MBP was not (OR 0.92, 0.63-1.36, P = 0.69) compared to NBP. CONCLUSION: This non-randomised study adds 'real-world', contemporaneous, and prospective evidence of the beneficial effects of combined mechanical bowel preparation and oral antibiotics in the prevention of anastomotic leak following left sided colorectal resection across diverse settings. We have also demonstrated limited uptake of this strategy in current international colorectal practice