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The Equatorial Mode, characterized by the anomalous warming of the sea surface temperature (SST) in the eastern equatorial Atlantic region, leads the interannual variability of the tropical Atlantic during the boreal summer causing impacts both in tropical and extratropical regions. However, this pattern and its teleconnections, are not stationary; and the origin of such changes continues to be subject of enquiry and debate.With this premise, in the present work, we evaluate the possible influence of a displacement of the ITCZ (Intertropical Convergence Zone), mediated by a radiative perturbation, on the pattern of the Equatorial Mode and its connection with the Pacific. More particularly, we examine two perturbation experiments that reduce the incident shortwave radiation in two latitude bands: NEXT in the northern extratropics and STRO in the southern tropics. The analysis is carried out from a multi-model perspective, using the data of 8 CMIP5 coupled climate models from the Extratropical-Tropical Interaction Model Intercomparison Project (ETIN-MIP).Our results suggest that the strengthening of the ITCZ over the Atlantic equatorial band, is capable of generating changes in the mean state of the equatorial Atlantic, as well as conditions of enhanced variability on the interannual scale. In addition, it is found that the westward shift of the SST warm anomalies in the Equatorial Mode and the existence of a more variable mean state in the equatorial Atlantic and Pacific, are key in the intensification of the Atlantic-Pacific connection.

The impact of ENSO (El Niño Southern Oscillation) events on the development of tropical cyclones in the Eastern Tropical North Atlantic is highlighted, focusing on decadal variations of the interannual relationship at the Senegalese coast, which is the main cyclone development region (MDR). The enhancement of North Atlantic tropical cyclones by the Atlantic Niño and the Pacific El Niño Southern Oscillation (ENSO) is diagnosed. An approach based on composites of anomalous positive or negative years in terms of cyclone activity is used. Based on 20yr-correlations between the number of cyclones that are born in the MDR and ENSO index, we have selected two different periods of study (period1 (P1): 1954-1973; and period2 (P2): 1986-2005). Results show an increase in the SST impact in cyclone generation from P1 to P2 and intensification of cyclones number over the Senegalese coasts. Likewise, the spatial distribution of the dynamic and thermodynamic parameters used in this composite study shows strong variations between the two periods. Our findings suggest that decadal changes in climatological conditions have a significant effect on the MDR. Additionally, the changes in the interannual signal appear to be related to the concomitant action of interannual SST anomalies over the whole tropical basins.

El Niño-Southern Oscillation (ENSO) influence on European precipitation (Pcp) has been deeply analyzed. Most of the previous studies focus on the atmospheric response in wintertime during the peak of the ENSO episode, showing boreal summer a season with a marginal ENSO signal. Furthermore, the stationarity of the ENSO teleconnection with Europe has not been considered in many works, which could mask possible nonstationary impacts in other seasons like summer. In this research we find a strong influence of eastern Pacific-like ENSO on the leading variability mode of European summer Pcp, showing a dipole-like configuration and linking El Niño with drier(wetter) conditions in northern(southern) Europe. This relationship is not limited to the total cumulative Pcp, but also to the low and extreme Pcp. This impact on European rainfall is found from the 1960s to the 1990s, a 30 years-long period when the position of the extratropical northern jet stream, which acts as a waveguide, favors the teleconnection pathway to Europe. Strikingly, the ENSO events behind this teleconnection reach their peak in summer. However, we show that the resultant Pcp in Europe also depend on the ENSO characteristic of the previous seasons, which could be used for predictability purposes.

Observational studies have reported that tropical Atlantic interannual variability impactson ENSO in different seasons and periods: Atlantic Ni ̃nos (AN) in boreal summer duringnegative phases of the Atlantic Multidecadal Variability (AMV); and tropical north Atlantic(TNA) in boreal spring during positive AMV. Nevertheless, this relation is not clear for thewhole observational record. This paper is an step forward towards understanding of tropicalAtlantic impacts on ENSO: how and when do they occur? Using observations and a pool ofpreindustrial control simulations from the CMIP5 initiative we investigate the backgroundocean and atmospheric conditions promoting these tropical interbasin connections.Periodswith a negative AN-ENSO connection appear characterized by a shallower thermoclineover the western Pacific and deeper in the east, together with an increase in interannualSST variability over the tropics. Periods with a negative TNA-ENSO connection appearcharacterized by a steeper thermocline in the Pacific and positive interhemispheric SSTgradient in the the Atlantic. A decrease in tropical Pacific atmospheric and ocean variabilitycharacterizes these periods.

Tropical interbasin teleconnections at inter-annual time scales are receiving much attention in the last years. However, their controlling factors and long-term changes are still under debate. In this work, we investigate whether selected features in the climatology, the position of the ITCZ and strong tropical convection, can influence the teleconnections between the tropical Atlantic and Pacific basins at inter-annual timescales.For investigation, we contrast a CGCM control simulation with an experiment in which the climatological position of the ITCZ is shifted in latitude by artificially reducing the shortwave radiation incident in a region of the south Atlantic sector. The perturbation magnitude and sign are such that the local model’s biases in Atlantic SST are reduced. The experiment shows stronger interannual variability over the tropical Atlantic and Pacific oceans, a westward extension of the Atlantic Niño pattern, and enhanced interannual teleconnections between equatorial Atlantic and Pacific.We examine the mechanisms at work for these changes. We find several factors as major contributors to enhance the tropical interbasin teleconnections. One is the modified Walker circulation resulting from the westward extension of SST anomalies during the Atlantic Niño and concurrent westward displacement of convection. The other factors are the enhancement of the precipitation at the equator and the shallowing of thermocline in the Pacific, which make the latter basin more sensitive to both local and remote perturbations.On the contrary, the North Tropical Atlantic – equatorial Pacific teleconnection is weakened in the experiment, despite the strongest impact of the NTA anomalies in the north tropical Pacific winds. due to the opposite effect on divergence exerted by the off equatorial winds related to NTA and the equatorial winds related to the concomitant warming in the eastern and central equatorial Pacific.

ENSO exhibits different flavors with worldwide impacts. However, the associated teleconnections with subtropical South America (SSA) are still controversial and modelling studies are needed. Here, we analyze the Southern Hemisphere (SH) circulation anomalies and the impacts over SSA during the austral summer due to different El Niño patterns (Canonical and El Niño Modoki). The analysis is performed considering reanalysis data and two different Atmospheric General Circulation Models (SPEEDY and UCLA - AGCM). Results from reanalysis show that positive precipitation anomalies develop over SSA during Canonical El Niño events. These anomalies are induced through an increase of upper level cyclonic vorticity advection and a stronger low-level southward moisture transport. However, in El Niño Modoki events, rainfall anomalies are observed over SSA only for the strongest events. Both models are able to reproduce the precipitation signal over SSA in the Canonical El Niño case, although the underlying physical mechanism depends on the model. In SPEEDY, the increased rainfall is due to an increase of the moisture transport toward SSA, while in UCLA - AGCM it is related to both, an increase of the low-level moisture transport toward SSA and the increase of upper level cyclonic vorticity advection. The precipitation signal associated with El Niño Modoki is more controversial. While UCLA - AGCM suggests a rainfall increase over SSA, SPEEDY, in agreement with observations, does not show any statistically significant signal. However, the upper level circulation anomalies reproduced by UCLA – AGCM are more consistent with reanalysis than those from SPEEDY, which makes UCLA – AGCM to be more reliable. This result suggests increased rainfall over SSA during El Niño Modoki.

Although many important crops originated in Amazonia, the general patterns of their evolutionary histories are still obscure. Currently a major global food crop, manioc originated in southwestern Amazonia and was dispersed throughout the lowland Neotropics before the European conquest. However, little is known about the origin of the bitter and sweet landraces, nor the routes by which these were dispersed in Brazil and beyond. We used a non-systematic Brazil-wide sample of 494 manioc landraces from 11 geographic regions, and ten nuclear microsatellite markers to analyze the genetic diversity of sweet and bitter manioc. Bayesian simulations highlighted the bitter–sweet divergence and also suggested the existence of two groups of sweet manioc (circum-Cerrado and general Brazil) and two groups of bitter manioc (upper Negro River and general Brazil), while the relationships among geographic regions were depicted with clustering analysis. Overall we suggest that: (1) manioc was initially domesticated to be sweet, was then dispersed from southwestern Amazonia into both the Amazon basin and the Cerrado; (2) that bitter manioc arose from the general Brazilian sweet manioc landraces, almost certainly in Amazonia, where bitter manioc became most important and was dispersed both throughout Amazonia and along the Brazilian coast, but especially to the upper Negro River, where it became most diverse. Our study adds insights to the knowledge about how native Amazonian crops have been managed across their history of domestication.

State-of-the-art general circulation models show important systematic errors in their simulation of sea surface temperatures (SST), especially in the tropical Atlantic. In this work the spread in the simulation of climatological SST in the tropical Atlantic by 24 CMIP5 models is examined, and its relationship with the mean systematic biases in the region is explored. The modes of intermodel variability are estimated by applying principal component (PC) analysis to the SSTs in the region 70°W–20°E, 20°S–20°N. The intermodel variability is approximately explained by the first three modes. The first mode is related to warmer SSTs in the basin, shows worldwide connections with same-signed loads over most of the tropics, and is connected with lower low cloud cover over the eastern parts of the subtropical oceans. The second mode is restricted to the Atlantic, where it shows negative and positive loads to the north and south of the equator, respectively, and is connected to a too weak Atlantic meridional overturning circulation (AMOC). The third mode is related to the double intertropical convergence zone bias in the Pacific and to an interhemispheric asymmetry in the net radiation at the top of the atmosphere. The structure of the second mode is closer to the mean bias than that of the others in the tropical Atlantic, suggesting that model difficulties with the AMOC contribute to the regional biases.

Vegetative canopy architecture, and plant population density, has a direct influence on the growth and production of crops. The objective of this study was to evaluate the growth of four cassava cultivars of contrasting canopies, in four population densities, during two vegetative cycles. A randomized complete block design was used in a subdivided plot scheme, with two replications, with the population densities in the plots and harvesting times in the subplots. ‘Branca de Santa Catarina’ (BSC), ‘IAC 13’, ‘IAC 14-18’ and ‘Fibra’ were collected every four months, beginning at 120 and ending at 720 days after planting (DAP). Primary data on dry matter and leaf area were calculated. The total dry mass (Wt), leaf area ratio (La), leaf area index (L), relative growth rate (Rw), and net assimilation rate (Ea) were calculated based on the primary data. All cultivars accumulated more total dry mass (Wt) at lower planting densities. The plants reached a higher leaf area ratio (La) 120 days after planting. In the second vegetative cycle, the four cultivars, independently of the population, presented a reduction of assimilate translocation to the leaves. Relative growth rate (Rw) of the cultivars varied strongly with the plant population only in the second cycle. ‘IAC 14-18’ showed greater dependence on spacing, and ‘Fibra’ less dependence. Growth (Rw) and assimilatory (Ea) rates decreased at the end of the first cycle, then increased slowly until the end of the second cycle of vegetation.

12 pages, 4 figures.-- Data availability Annual catch data from FAO major fishing areas are available from the Sea Around Us Project (http://www.seaaroundus.org/data/#/fao). Hadley Centre Sea Ice and Sea Surface Temperature data set (HadISST) are available from the Met Office Hadley Centre observations datasets (https://www.metoffice.gov.uk/hadobs/hadisst/). National Centers for Environmental Prediction (NCEP) reanalysis data are available from the NOAA/OAR/ESRL PSL website (https://psl.noaa.gov/). GFDL COBALT and FishMIP simulation data (EcoOcean, BOATS and Macroecological) are accessible through the Potsdam-Institute for Climate Impact Research Earth System Grid Federation (ESGF) data node (https://esg.pik-potsdam.de/search/isimip/). Code availabilityS4CAST originally published MATLAB® code is open access and available from the Zenodo repository (doi:10.5281/zenodo.15985) in the URL https://zenodo.org/record/15985. The rest of MATLAB scripts used in this analysis can be made available upon request from the corresponding author (i.gomara@ucm.es). Updated S4CAST versions can be requested to the TROPA-UCM research group (brfonsec@ucm.es), Tropical Pacific upwelling-dependent ecosystems are the most productive and variable worldwide, mainly due to the influence of El Niño Southern Oscillation (ENSO). ENSO can be forecasted seasons ahead thanks to assorted climate precursors (local-Pacific processes, pantropical interactions). However, owing to observational data scarcity and bias-related issues in earth system models, little is known about the importance of these precursors for marine ecosystem prediction. With recently released reanalysis-nudged global marine ecosystem simulations, these constraints can be sidestepped, allowing full examination of tropical Pacific ecosystem predictability. By complementing historical fishing records with marine ecosystem model data, we show herein that equatorial Atlantic Sea Surface Temperatures (SSTs) constitute a superlative predictability source for tropical Pacific marine yields, which can be forecasted over large-scale areas up to 2 years in advance. A detailed physical-biological mechanism is proposed whereby Atlantic SSTs modulate upwelling of nutrient-rich waters in the tropical Pacific, leading to a bottom-up propagation of the climate-related signal across the marine food web. Our results represent historical and near-future climate conditions and provide a useful springboard for implementing a marine ecosystem prediction system in the tropical Pacific, This research was funded by the EU H2020 project TRIATLAS (no. 817578), the Universidad Complutense de Madrid project FEI-EU-19-09 and the Spanish Ministry of Economy and Competitiveness project PRE4CAST (CGL2017-86415-R)., With the funding support of the ‘Severo Ochoa Centre of Excellence’ accreditation (CEX2019-000928-S), of the Spanish Research Agency (AEI)

Identificador de proyecto: CGL2015-72164-EXP, Along the coasts of Northwestern Africa, friction of the predominant winds results in an upward motion of sea water from intermediate depths toward the ocean surface. This phenomenon is known as "coastal upwelling" and it has a huge economic and social relevance. Cold upwelled water is rich in nutrients and yields very productive marine ecosystems. Therefore, knowing the changes of the upwelling intensity is of great importance. Unfortunately, prior to the 1950s, the scarcity of wind observations along these coasts difficulties the estimation of the coastal upwelling intensity, making the climatic history of this system uncertain. Since the late 18th century, a lot of ships have circumnavigated the African continent. Most of them took observations of wind direction that have come to the present day in form of records preserved in the ships' logbooks. In this study, we make use of these historical observations to calculate the intensity of the coastal upwelling. We have found that coastal upwelling in Northwest Africa is highly variable at decadal scale and we provide a strong evidence of a large change in the upwelling intensity that occurred around 1900., Departamento de Sistemas Físicos, Químicos y Naturales, Universidad Pablo de Olavide, Departamento de Física de la Tierra y Astrofísica, Universidad Complutense, IGEO, Instituto de Geociencias (CSIC, UCM)

Heavy metals are one of the most hazardous pollutants in marine environments because of their bioaccumulation and biomagnification capabilities. Among them, cadmium (Cd) has been considered as one of the most dangerous for marine organisms. Here we incubated Ammonia cf. parkinsoniana specimens, a benthic foraminiferal taxon used in previous experiments, for up to 48 h in natural seawater with different concentrations of Cd to unravel the physiological change. We document a reduced pseudopodial activity of the Cd-treated specimens at concentrations &gt, 10&ndash, 100 ppb in comparison with the control specimens. Moreover, confocal images of Cd-treated specimens using Nile Red as a fluorescent probe reveal an enhanced intracellular neutral lipid accumulation in the form of lipid droplets at 6 h and 12 h. This bioassay experiment allows for the direct evaluation of Cd-dose to A. cf. parkinsoniana-response relationships under laboratory controlled conditions and provides complementary information to field observations as well as to water quality guidelines and thresholds.

The impact of ENSO (El Niño Southern Oscillation) events on the cyclogenesis of the eastern tropical North Atlantic is highlighted, focusing on decadal variations of the interannual relationship at the Senegalese coast, which is the main cyclone development region (MDR). SST anomalies in the Equatorial Pacific associated with ENSO events affect vertical wind shear over the eastern Atlantic, by inducing strong subsidence of dry air over the eastern Atlantic which tends to inhibit deep convection and thus be unfavorable to cyclonic activity. Based on 20yr- correlations between the number of cyclones that are born in the MDR and ENSO index, we have selected two different periods of study (period1: 1950-1969; and period2: 1996-2015).The results show that period2 presents the highest scores of negative correlations between ENSO and tropical Atlantic cyclogenesis. Although there is an intensification of ENSO events during period2 compared to period1, we have found that decadal changes in climatology have a more significant effect on the MDR than the interannual changes. Additionally, the changes in the interannual signal appear to be related to the concomitant action of interannual SST anomalies over the whole tropical basins.

The Northwest Africa (NWA) upwelling region is located along the Senegalese and Mauritanian coast, between 10°N and 25°N and in a very narrow longitudinal band. In this region, most of the upwelled waters are due to alongshore surface winds through Ekman pumping.The rapid increase in the upper ocean upwelling in this region along the 20th century and the contradictions found about future projections put forward the need for a better understanding of model’s ability to simulate Ekman induced upwelling processes.In this work we assess intermodel variability to better understand the causes of different responses and spread among a set of CMIIP5 models. Results suggest that the seasonal cycle of NWA upwelling is qualitatively well simulated by CMIP5 models, although models tend to show strong biases for the permanent upwelling latitudes (north of 20°N) and the seasonal upwelling area (around 15°N in boreal spring). The maximum vertical temperature gradient shown by CMIP5 models is higher than that of SODA reanalysis and prevents cold waters from deeper layers to reach the surface, thus making coastal upwelling less effective in affecting sea surface temperatures.Most of the intermodel variance is explained by the two first EOF modes of intermodel variability. The first mode shows a latitudinal structure, with a maximum in the permanent upwelling season, while. the second one is more seasonal. Both modes are very related to changes in the North-West Africa land-sea surface pressure gradient. In the case of the leading mode, incoming solar radiation differences between the North African desert and the ocean are the cause of the pressure gradients. For the second mode pressure changes in the Atlantic Ocean are driven by ITCZ shifts in response to interhemispheric differential warming.

European Geosciences Union (EGU) General Assembly 2020, 4-8 May 2020, Observational studies have reported that interannual variability of sea surface temperature in two tropical Atlantic regions can act as ENSO predictors in different seasons and periods: boreal summer Atlantic Nino (AN) in negative phases of the Atlantic Multidecadal Variabil- ˜ ity (AMV); and boreal spring tropical north Atlantic (TNA) in positive AMV. The robustness of the AMV role in the interbasin connection remains an open question due to the short observational record. Using observations and pre-industrial climate model simulations, we demonstrate for the first time that latitudinal displacements of the Atlantic ITCZ act as a switch for the type of inter-basin teleconnection. During periods in which the Atlantic ITCZ is further equatorward (northward) AN (TNA) impacts ENSO. This ITCZ location can be 1 affected by several factors, including the inter-hemispheric SST gradients associated with AMV.Coupled models success in capturing the AN-ENSO connection. Nevertheless, they have difficulties in reproducing the TNA-ENSO connection because they overestimate rainfall in the southern tropical Atlantic. The TNA-ENSO connection occurs sporadically during periods when the ITCZ is shifted further northward in association with strong heat transports by the AMOC. Weaker AMOC periods in coupled models don't present the TNA-ENSO connection. State-of-the-art models still need to improve for correctly representing tropical Atlantic impact on ENSO

Heavy metals are known to cause deleterious effects on biota because of their toxicity, persistence and bioaccumulation. Here, we briefly document the ultrastructural changes observed in the miliolid foraminifer Pseudotriloculina rotunda (d'Orbigny in Schlumberger, 1893) and in the perforate calcareous species Ammonia parkinsoniana (d'Orbigny, 1839) induced by exposure to one of three heavy metals (zinc, lead, or mercury). The exposure of these two benthic foraminiferal species to the selected heavy metals appears to promote cytological alterations and organelle degeneration. These alterations include a thickening of the inner organic lining, an increase in number and size of lipid droplets, mitochondrial degeneration, and degradation vacuoles and residual body proliferation. Some of these alterations, including the thickening of the inner organic lining and the proliferation of lipids, might represent defense mechanisms against heavy metal-induced stress.

International audience; A recent study has brought to light the co‐existence of two distinct Atlantic Equatorial Modes during negative phases of the Atlantic Multidecadal Variability: the Atlantic Niño and Horse‐Shoe (HS) mode. Nevertheless, the associated air‐sea interactions for HS mode have not been explored so far and the prevailing dynamic view of the Atlantic Niño has been questioned. Here, using a forced ocean model simulation, we find that for both modes, ocean dynamics is essential to explain the equatorial SST variations, while air‐sea fluxes control the off‐equatorial SST anomalies. Moreover, we demonstrate the key role played by ocean waves in shaping their distinct structure and timing. For the positive phase of both Atlantic Niño and HS, anomalous westerly winds trigger a set of equatorial downwelling Kelvin waves (KW) during spring‐summer. These dKWs deepen the thermocline, favouring the equatorial warming through vertical diffusion and horizontal advection. Remarkably, for the HS, an anomalous north‐equatorial wind stress curl excites an upwelling Rossby wave (RW), which propagates westward and is reflected at the western boundary becoming an equatorial upwelling KW. The uKW propagates to the east, activating the thermocline feedbacks responsible to cool the sea surface during summer months. This RW‐reflected mechanism acts as a negative feedback causing the early termination of the HS mode. Our results provide an improvement in the understanding of the TAV modes and emphasize the importance of ocean wave activity to modulate the equatorial SST variability. These findings could be very useful to improve the prediction of the Equatorial Modes.

Isolates of Sphaceloma manihoticola, the asexual stage of Elsinoe brasiliensis, were collected from several regions of south-central Brazil. The isolates were obtained from samples of leaves, stems, and petioles of cassava (Manihot esculenta) and the weedy Euphorbia heterophylla (“amendoim bravo”) by directly plating infected tissue onto acidified potato dextrose agar. For pathogenicity studies, 19 isolates were inoculated onto each of two cassava cultivars, MBRA 703 as a susceptible cultivar and MBRA 12 as a resistant cultivar to S. manihoticola. MBRA 703, with the greatest pathogenicity to 58% (11) of the isolates, showed an intermediate pathogenic reaction to 16% (3) of the isolates, and was less pathogenic to 26% (5) of the isolates. MBRA 12, with a less pathogenic reaction to 63% (12) of the isolates, showed an intermediate pathogenic reaction to 16% (3) of the isolates, and was highly pathogenic to 21% (4) of the isolates. The isolates were verified as belonging to the genus Sphaceloma based on their morphological characteristics, including conidia and hyphae of monoconidial isolate. Conidia of isolates were small, thin-walled, ellipsoid to (rarely) globose, commonly with one or two gut-tules. Conidiophores were phialides, hyaline to slightly pigmented 0-to-1 septate; conidiophores from the weedy specie were phialides, hyaline to brown 0-to-2 septate producing hyaline conidia. The isolates also were verified as belonging to the genus Sphaceloma by using a poly-merase chain reaction (PCR) assay, which detected a 645-bp band in all isolates except two (1 and 6) for which the PCR product had 600 bp. Digestion of the amplified product with the enzymes MspI and CfoI allowed differences to be detected in restriction patterns among isolates. A homogeneous banding pattern was obtained for 17 of the isolates but a different restriction pattern was obtained for isolates 1 and 6 of E. heterophylla. This suggests the possibility of another species within this group of isolates. The results indicate the presence of pathogenic variation among isolates of the fungus and an isolate-host interaction, because statistically significant differences were observed between the two cassava cultivars in response to inoculation with the isolates of S. manihoticola.

Microscopy techniques have been widely applied to observe cellular ultrastructure. Most of these techniques, such as transmission electron microscopy, produce high‐resolution images, but they may require extensive preparation, hampering their application for in vivo examination. Other approaches, such as fluorescent and fluorogenic probes, can be applied not only to fixed specimens but also to living cells when the probes are nontoxic. Fluorescence‐based methods, which are generally relatively easy to use, allow visual and (semi)quantitative studies of the ultrastructural organization and processes of the cell under natural as well as manipulated conditions. To date, there are relatively few published studies on the nearly ubiquitous marine protistan group Foraminifera that have used fluorescent and fluorogenic probes, despite their huge potential. The aim of the present contribution is to document the feasible application of a wide array of these probes to foraminiferal biology. More specifically, we applied fluorescence‐based probes to study esterase activity, cell viability, calcium signaling, pH variation, reactive oxygen species, neutral and polar lipids, lipid droplets, cytoskeleton structures, Golgi complex, acidic vesicles, nuclei, and mitochondria in selected foraminiferal species.

As solar energy will be an increasingly important renewable energy source in the future years, the study of how climate change affects both temporal and spatial variability is very important. In this paper, we study future changes of the solar radiation resource in the Iberian Peninsula (IP) through a set of simulations from ESCENA project until mid-century. The evaluation of the simulations against observations indicates contrasting biases for the different regional climate models (RCMs) in terms of solar irradiation amount and its interannual variability. We propose a diagnostic for the quality of solar energy resource, in which the gridpoints are classified in four categories depending on the combination of solar irradiation amount and variability. The observed large percentage of points in the optimal category (high irradiation/low variability) in the IP is captured by the RCMs in general terms. The analysis of scenarios indicates a future increase in solar irradiation, although not all scenarios agree in the geographical distribution of this increase. In most projections, a shift is projected from the category with optimal resource quality towards the category with high irradiation/high variability, pointing to a certain quality loss in the solar resource. This result is not general, as a few scenarios show an opposite result. The exceptions are not linked to a particular GCM or emissions scenario. Finally, results from a first approximation to the issue of the ability of solar energy to cover power demand peaks in summer show important differences between regions of the IP. The spatially-averaged correlation of solar irradiation and summer surface temperatures for the whole IP is rather high, which is a positive result as the strong interconnections of the power grid within the IP could allow a distribution of solar power surpluses in certain regions for such high-temperature episodes.

This study sought to quantify and characterize cassava waste as fuel. The wastes from three cultivars were collected to study and were divided into three distinct parts of the cassava plant: seed stem, thick stalks, and thin stalks. Physical and chemical analyzes were carried out to determine the elemental composition of the waste: volatile matter; fixed carbon; ash; moisture; lignin; cellulose; hemicellulose; ash composition and higher heating value were determined. We conducted a thermogravimetric analysis in oxidizing and inert atmospheres to study the behavior of the waste as fuel. The root productivity obtained ranged from 7.7 to 13.0 t ha−1 yr−1 on a dry basis (db), and the ratio between waste and roots varied from 0.36 to 0.91. The physical and chemical properties of cassava waste are analogous to those of woody biomass regarding the elemental composition, the higher heating value, and thermogravimetric analysis. Ash content varied from 2.5% to 3.5%, reaching around 6.0% in samples unwashed. Approximately 60% of the ashes are alkali oxides, especially P2O5, K2O, and CaO, which have low melting points. The alkali index calculated suggests that there is a strong tendency that the combustion process leads to ash fouling and the formation of ash deposits.

Made available in DSpace on 2018-11-26T16:32:44Z (GMT). No. of bitstreams: 0 Previous issue date: 2016-03-01 Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) Growing Cassava ( Manihot esculenta ) in Mato Grosso, Brazil: Genetic Diversity Conservation in Small-Scale Agriculture. Cassava (Manihot esculenta Crantz) is a tropical species that stands out as a food source for developing countries. Within an ethnobotanical and socioeconomic context, this study aimed to compare the level of genetic diversity of cassava maintained by small farmers in three municipalities of the Cuiaba Lowland in the state of Mato Grosso, Brazil: Caceres, Porto Estrela, and Santo Antnio do Leverger. This region, which is included in the center of origin of cassava, is currently undergoing profound socioeconomic changes that can have negative impacts in the on farm conservation of cassava agrobiodiversity. We characterized 211 genotypes collected in 40 households in 10 communities, using 14 microsatellite loci. High levels for the observed (H (O) = 0.587) and expected (H (E) = 0.525) heterozygosities were found, whereas most of the genetic diversity was concentrated within communities (92%). A genetic differentiation was found between the municipality of Santo Antnio do Leverger and the municipalities of Caceres and Porto Estrela, not only due to a higher geographic distance among them, but also due to soil, climatic, and cultural factors. A different number of local varieties was observed in each municipality, while the number of unique varieties in each municipality was high, 83%, 84%, and 61%, respectively, representing an important aspect for the in situ conservation of this crop. Although local names provided by farmers were phenotypically coherent, intravarietal variability among local varieties sharing the same name was high (97%). Santo Antnio do Leverger was considered as a priority area for in situ conservation. Nevertheless, in view of the decline in local traditional agriculture systems and socioeconomic transformations in this region, public policies providing support and incentives to farmers are necessary. Univ Sao Paulo, ESALQ, Dept Genet, Piracicaba, SP, Brazil Univ Estadual Paulista, Dept Ecol, Rio Claro, SP, Brazil Univ Estadual Mato Grosso UNEMAT, Fac Ciencias Agr & Biol, MT, Dept Ciencias Biol, Campus Caceres, Caceres, MT, Brazil Inst Agron Campinas, Secao Hort, Campinas, SP, Brazil Univ Estadual Paulista, Dept Ecol, Rio Claro, SP, Brazil FAPESP: 2008/03822-3

Lack of cultivar adapted to the planting area, as the ideal harvest period undertakes the productive potential of cassava. The study was conducted to evaluate the influence of different harvest seasons on total production of fresh and dry weight of four cassava cultivars. The used cultivars were: Branca de Santa Catarina (BSC), IAC 13, IAC 14-18 and Fiber that they were planted on 09/20/11 at the headquarters of the Regional Center Valley Paranapanema Paulista Agency for Agribusiness Technology (APTA), in Assis, Sao Paulo. The experimental design was completely randomized in 4x6 (four cultivars and six harvest seasons) factorial schemes with four replicates, being 4, 8, 12, 16, 20 and 24 months after planting (MAP) the harvest season, totaling 24 treatments and 48 installments. The total production of fresh biomass (FB) and dry matter (DM) in tons per hectare of 12 plants per harvest season was evaluated. Regarding the production of FB as DM among cultivars was not observed significant differences between them. However, the cultivars showed accumulation of FB linearly. The best time to harvest in order to higher accumulation of DM occurred at 12 and 24 months, corresponding to the end of the first and second round of cassava cultivation, respectively. Key words: Manihot esculenta Crantz, precocity, production potential.