South America East Research Articles

Skill and sources of skill in seasonal streamflow hindcasts for South America made with ECMWF’s SEAS5 and VIC

The first aim of the present paper is the determination of the magnitude, annual variation and spatial distribution of skill in seasonal hindcasts of runoff and discharge in the entire continent of South America. We evaluated 35 years of hindcasts generated with the Variable Infiltration Capacity (VIC) hydrological model forced with SEAS5 hindcasts. Initial conditions of terrestrial water and so-called pseudo-observations were computed with a reference (i.e. historic) simulation. Skill was determined with monthly temporal resolution for the entire annual cycle and mostly using the pseudo-observations for verification. The second aim of the paper is the explanation of skill in terms of its sources, namely meteorological forcing and the initial conditions. Therefore, two sets of restricted hindcasts, which isolate the sources of skill, were analysed. The SEAS5 precipitation hindcasts exhibit significant skill even at the longest lead times (7 months). Beyond the first lead month we found significant skill in 13–43 % of the grid cells, depending on target and lead month. Levels of skill are higher in the full hindcasts (significant skill in 31–89 % of the grid cells). At the continental scale more of the skill is caused by the forcing than by the initial conditions. The runoff hindcasts are skilful in large parts of the continent. In a 1000 km wide band along the north coast of the continent and in southeast South America, most of the skill is due to the forcing. A typical feature of these regions is an increase of skill with lead time during specific parts of the year, which is against the common tendency. In Argentina and north Chile most of the skill in the runoff hindcasts can be attributed to the initial conditions of soil moisture. Verification with real observations of discharge broadly confirmed the skill pattern obtained with pseudo-observations.

Characteristics of Ocean Waves in the Southern Ocean and Seasonal Prediction of Difficulty for the Vessels Crossing the Westerlies

In this study, the European Centre for Medium-Range Weather Forecasts reanalysis v5 (ERA5) wave height reanalysis data and sea-level pressure data from two seasonal prediction systems were used to study the wave characteristics of the Southern Ocean and the seasonal prediction of difficulty for the vessels crossing the westerlies. The results show that significant wave height, extreme wave height, and extreme wave processes were all much stronger in austral winter than in austral summer, making it more difficult for vessels to cross the westerlies in winter. Furthermore, the difficulty of crossing the westerlies has increased over the last 40 years, except in areas east of South America. We found that the monthly frequency of crossing the westerlies between 100° E and 75° W could be accurately estimated point by point using the monthly mean sea-level pressure difference between 30° S and 65° S. With a 1-month lead, the multi-model forecasts gave a fairly accurate forecast of such sea-level pressure difference signal between 150° E to 60° W for target months from May to December. Based on these assessments, we could estimate the difficulty of crossing the westerlies in some specific months in advance using a seasonal prediction system. We also found that the seasonal prediction system produced inaccurate predictions of sea-level pressure at high latitudes, which is the main barrier to further accurately estimating the difficulty of crossing the westerlies. These findings may provide support for predicting difficulty for the vessels crossing the westerlies with a 1-month lead and can provide planning for the route and the allocation of material reserves.

Climate, sea-level and anthropogenic processes controlling the environmental evolution of shallow lakes in the southeastern Pampa plain (South East South America) during the last 12 ka

The evolution of both Lake Hinojales-San Leoncio (37°23′S; 57°23′W) and Tobares (37°30′S; 57°28′W) was reconstructed using pollen, non-pollen palynomorphs, plant macrofossil remains and associated fauna, diatoms and mollusks. This is the first paleolimnological reconstruction covering the hydroclimatic variability over the last 12 ka for the southeastern Pampa plain. At the onset of the Holocene (12-11 ka), shallow clear brackish-to-hypersaline water bodies subject to episodic expansion/retraction cycles developed in the area under wet climatic conditions. During the Early Holocene, unstable environments were inferred due to intercalated episodes of total desiccation, associated with a drop in rainfall that promoted drier conditions than those previously inferred. The Middle Holocene (only represented in Lake Hinojales-San Leoncio) was characterized by the development of a brackish-saline lake with a deeper water column, under drier climatic conditions than those recorded previously. The temporal persistence of this saline paleolake might have been influenced by the marine transgressive-regressive cycle dated between 6000 and ca. 2000 yr BP in the coastal area close to the lake. From nearly 2500 to ca. 600 cal yr BP there was a gradual change from brackish to freshwater-brackish water conditions, as a consequence of a regional increase in rainfall together with the decrease in sea level that promoted the establishment of modern humid to sub-humid climatic conditions prevailing today in the Pampa plain. The last 35 cal yr BP represented the onset of modern eutrophic conditions within the lake, which are concomitant with the agriculture intensification in the region. The regional changes in the different biological proxies analyzed here, support the hypothesis of a predominance of external climatic triggers over intrinsic limnological processes as main causes of paleoenvironmental changes modulating the evolution of lakes. The main environmental forces affecting these lakes seem to be indirectly related to precipitation during the Early Holocene, sea level changes during the Middle Holocene and the recent (Anthropocene) human impacts related to the intensification of farming activities.

Recent geomorphological changes in the Paraiba do Sul delta, South America East Coast

The Paraiba do Sul River delta, a South America east coast system, presents deposits recording complex sedimentary dynamics in the deltaic plain during the Little Ice Age (LIA). The use of optically stimulated luminescence (OSL) dating, sediment grain-size characterization, and morpho-chronological analysis showed that from ∼450 to 100years (LIA period), both in lower to upper deltaic plain, remodeling occurred in conjunction with the coastline regression. The freshwater and sediment influx increases due to the moisture enhancements during the LIA resulted in the intensification of the fluvial dynamic, channel downcutting on the marine terrace, and sedimentary environments remodeling. Further, the base-level changes occasioned by the coastline regression strengthen the geomorphological dynamics associated with the recent changes in the Paraiba do Sul delta. Currently, the coastal erosion problem found in the area seems to reflect the coupling between climate dynamic (rainfall rates decrease) and multiple-scale anthropic intervention. Results show a high sensitivity of humid tropical deltaic systems to short-time climate events, further contribute to broadening discussions on the complexity of this delta system’s morphosedimentary evolution during the Late Holocene.

The damselfly genus Megaloprepus (Odonata: Pseudostigmatidae): Revalidation and delimitation of species-level taxa including the description of one new species.

As the longest-winged odonate species of the extant world, Megaloprepus caerulatus (Drury, 1782) has received attention by many entomologists. While the behavior and ecology of this species has been subject of intense studies, biogeography and species status throughout its distributional range in old-growth Neotropical forests are less well known. For tropical forests, this information is a sine qua non when estimating the impact of degradation and climate change. Recent population genetic analyses, quantitative morphometric, and traditional taxonomic studies rediscovered a complex composed of cryptic species within the genus Megaloprepus Rambur, 1842up until now still regarded as a monotypic genus. Here we introduce one new species Megaloprepus diaboli sp. nov. from the southern Pacific coast of Costa Rica and from the central Caribbean coast of Honduras and Guatemala. The holotype is from the Corcovado National Park, Costa Rica (N82855.62 W833513.92), and was deposited at the National Museum of Costa Rica. Aside from M. caerulatus, two formerly described and later refused species within the genus were reevaluated and consequently raised to species status: Megaloprepus latipennis Selys, 1860 is found in the northeastern regions of Mesoamerica and Megaloprepus brevistigma Selys, 1860 in South America east of the Andes. Morphological descriptions of selected specimens (holotype of M. diaboli, lectotype of M. latipennis, and the mature males of M. brevistigma and M. caerulatus) are provided. Diagnostic features of the four species are illustrated, discussed, and summarized in a key to adult males.

Survey on the tribe Tigridieae (Iridaceae) in the Campos of Southeast South America

Survey on the tribe Tigridieae (Iridaceae) in the Campos of Southeast South America (SESA Grasslands). Iridaceae is one of the largest families of monocots and is an important constituent of grassland ecosystems across the globe. The tribe Tigridieae is exclusive to the Americas, with an important center of diversity in the Andean region, in the Campos of Southeast South America, in Mexico and in the southern United States. In this study, a survey of the Iridaceae-Tigridieae native to the Grassland Ecosystems of Southeast South America (=SESA Grasslands) is carried out. The SESA was divided into four regions: Campos, Campos de Altitude, Chaco Húmedo and Pampa. The Iridaceae-Tigridieae are represented by a total of 65 species (including ten subspecies), distributed in ten genera. The genus Cypella with 30 species and eight subspecies is the most diverse, followed by Calydorea (13 species), Herbertia (11 species) and Gelasine (four species and two subspecies). A total of 87% of the taxa occurring in the SESA are endemic, most of them exclusive to the Campos region, which includes 54 taxonomic entities, of which 41 taxa are endemic The Campos de Altitude region is represented by 15 taxa, including six endemic species. The Pampa region includes six taxonomic entities, being one of them endemic. The Chaco Húmedo region comprises five species, none of which are exclusive to the latter region. Key words: Bulbous, Grasslands, High Grasslands, Humid Chaco, Geographic distribution, diversity, Pampa.

Tinea Imbricata among the Indigenous Communities: Current Global Epidemiology and Research Gaps Associated with Host Genetics and Skin Microbiota.

Tinea imbricata is a unique fungal skin disease that mostly affects indigenous populations in Southeast Asia, Oceania, and Central and South America. The control and management of this disease among these communities are challenging given their remote locations, certain traditional practices, and severe malnutrition status. To date, there are only a handful of reports published globally, which highlights the need for a more holistic approach in addressing this skin disease. Several bodies of evidence and reports have shown that host genetic factors have a profound influence on the pathogenesis of tinea imbricata, while skin microbiota is touted to have a role in the pathogenesis of the disease. However, there are limited studies of how host genetics and skin microbiota impact disease susceptibility in the host. To improve the understanding of this disease and to find possible long-term effective treatment among the affected indigenous communities, a comprehensive literature review is needed. Hence, this review paper aims to present the current status of tinea imbricata among the indigenous communities, together with published findings on the possible underlying reasons for its specific distribution among these communities, particularly on the ways in which host skin microbiota and host genetics affect occurrence and disease patterns. This information provides valuable insights for future research by highlighting the current knowledge gaps in these areas.

Distribution patterns of Triatominae (Hemiptera: Reduviidae) in the Americas: an analysis based on networks and endemicity.

Triatominae, commonly known as kissing bugs, are a group of approximately 150 species of hematophagous reduviids, some of which are vectors of Trypanosoma cruzi, the etiological agent of the Chagas disease. Distributional patterns of triatomines have been studied based on macroecological and historical biogeographic approaches, but the definition of distributional patterns and areas of endemism are yet to be defined based on objective criteria. We used two methods to identify biogeographic units in the Triatominae: the endemicity analysis based on an optimality criterion (NDM/VNDM software) and a network approach aimed to simplify and highlight the underlying structure in species distributions (Infomap Bioregions). Information on species distributions was obtained from a data paper, comprising 21 815 records for 135 triatomine species occurring in the Americas. The resulting areas of each method were clustered using a meta consensus criterion based on dissimilarities and interpreted as recurrent areas. The NDM areas show a nested structure, presenting greater restrictions to the inclusion of species in a given area, requiring broad sympatry. In contrast, bioregions emphasize spatial patterns with better-delimited areas and species occurrences do not need to be highly congruent. When areas were clustered based on their species composition two clear patterns arose from both methods: (i) areas within the southern Amazon and southeast South America, especially in the Chacoan subregion, formed a cluster, and (ii) areas north of the Amazon, Pacific, Mesoamerica, Mexican transition zone and Nearctic formed another cluster. Moreover, within each of these two clusters, there was a latitudinal gradient of the areas in the Americas showing spatial similarity between the areas found in both methods. Results of both methods show well-bound areas separating the triatomine fauna in the Brazilian subregions, resulting in the recognition of areas corresponding to the biomes Chaco, Pampa, Cerrado, and Caatinga, and, to a lesser extent, the Atlantic Forest.

A comparison of satellite cloud motion vectors techniques to forecast intra-day hourly solar global horizontal irradiation

Solar forecasting provides valuable information for grid management. Satellite-based forecasting tools account for the short-term intra-day time horizons, typically outperforming numerical weather predictions up to 4–5 h ahead. The method consist of three separated stages, namely, cloud motion estimation, motion extrapolation and satellite-to-irradiation conversion. In this work we compare different satellite-based proposals for hourly irradiation forecast up to 5 h ahead using a 2-years data set. The widely-used Lorenz’s block matching technique and four optical flow (OF) algorithms are assessed, both at image and irradiation levels. All the methods are locally optimized to obtain their peak performance. It is found that the OF algorithm which combines an L1 data penalty term on the optical flow equation with total variation regularization (TVL1) outperforms the rest. Different image extrapolation approaches and spatial smoothing are also tested. It is found that changing the extrapolation technique does not have much impact in the overall performance and that important gains can be obtained by optimally smoothing the predicted images previous to solar irradiation conversion. By doing this, all methods outperform the exigent convex persistence benchmark, achieving positive forecasting skills. The tests are performed using GOES-East satellite images of south-east South America, and the methods’ optimal parameters are given.

Western Disorientations: The Vanishing East of South America and Eastern Europe

In this paper I utilise Edward Said’s framework of Orientalism in order to investigate how the regions that the European explorers have mistakenly or negligently identified in their imaginaries as “the East” are brought into the colonial order through an a priori assumption of their inferiority to the West. I turn to South America and Eastern Europe as the two frontiers which make these operations visible. Through the analysis of primary sources such as travel journals and letters from Spanish explorers and conquistadors during the age of encounters, as well as the writings the English and French travellers made during their visits to Eastern Europe during the Enlightenment, I demonstrate how the Western European Orientalist imaginaries remain persistent through the ages despite the geographical explorations and geopolitical changes, and instead of disappearing, migrate to create the new orients as the realms of European otherness.

Ecotourism as Leisure and Labor in the Experience of the “Great” Outdoors

Ecotourism as an international concept promotes foreign and domestic tourism to locations in forests, oceans, and other forms of the natural world. National parks and other preserved ecosystems are popular destinations, usually located in the so-called developing countries or Global South countries, such as South and Southeast Asia, Central and South America, and Africa. This paper examines the construction of labor and leisure as forms of experience of the “Great” Outdoors for both ecotourists and local peoples. We argue that ecotourism is a form of colonial/racialized/gendered gaze, in which power imbalances are reflected in people’s experiences of ecotourism as labor and leisure. We use case studies in Indonesia and India, based on our long standing field research in each respective country.

From the Atlantic coast to the lowland forests: Stable isotope analysis of the diet of forager–horticulturists in southern Brazil

AbstractIn this study, we analyze the diet of forager–horticulturalist societies of southeast South America through different isotopic markers (δ13Ccollagen, δ13Capatite, and δ15N). The economy of these populations was based on hunting, fishing, gathering, and, to a greater or lesser extent, horticulture, showing a different emphasis on each one of these options. The samples analyzed here were recovered from different environments, including the Atlantic coast, the highlands of the Brazilian plateau, and the lowland forests of the upper valleys of the Uruguay and Paraná rivers, within a general east–west sampling transect. Most of the samples correspond to individuals recovered from the Guarani and Itararé‐Taquara archeological units. We have also included a smaller sample of foragers clustered in the so‐called Vieira Tradition, perhaps with some food production, and two individuals buried in shell mounds (“sambaquis”) of the south Brazilian Atlantic coast (“Coastal Tradition”), whose economy was strongly based on marine resources and wild plants. The results indicate that, regardless of the archeological unit in question, the individuals recovered from the seashore settlements show a diet based mostly on marine protein, with a minor contribution of other resources, except in a Guarani sample, where a significant intake of maize is observed. The individuals recovered in the highlands of the Brazilian plateau (“Itararé‐Taquara”) present the highest incidence of plant consumption of the entire sample analyzed, within a C3 monoisotopic pattern, probably strongly influenced by the consumption of the araucaria pine nut, and no isotopic signals related to maize intake. Guarani samples recovered from sites located in tropical forests in the interior of the continent show an unquestionable and systematic impact of maize on the diet, in addition to an important consumption of C3 animal proteins. The individuals assigned to the so‐called Vieira Tradition show a diet based on C3 protein and both C3 and C4 lipids and carbohydrates. The latter could be related to a small consumption of maize. These results demonstrate the multidirectionality of subsistence strategies in southeastern South America during the late Holocene.

Travelers' Diarrhea: Resolved and Unresolved Issues

Relevance. Travel diarrhea is the most common health problem in travelers, affecting up to 70% of travelers, especially when traveling to developing countries. Research and development of scientific and practical approaches to the prevention, risk assessment and treatment of travelers' diarrhea continues to be the focus of attention of specialists in the field of epidemiology, infectious diseases and travel medicine around the world.Aim of the study: systematization and synthesis of new data on various clinical and epidemiological aspects of travelers' diarrhea.Conclusion. Analysis of modern scientific literature has made it possible to identify the risks for travelers associated with the direction of travel and the state of their own health. The highest risk of developing traveler's diarrhea (from 20% to 90%) is recorded in people visiting the countries of the Middle East, South and Southeast Asia, Central and South America, and Africa. There is a high risk of developing traveler's diarrhea in children under 4 years of age. The causative agents of acute bacterial intestinal infections can account for up to 80% -90% of all cases of travelers' diarrhea. In most cases, travelers' diarrhea is mild. Seeking medical care is observed from 5% to 15% of cases. For etiotropic therapy, the use of azithromycin, ciprofloxacin and other drugs is recommended. Recommendations for self-management of traveler's diarrhea have been formulated. Pre-trip travel advice will help reduce the risks of travelers' diarrhea.

A Triple Collocation-Based Comparison of Three L-Band Soil Moisture Datasets, SMAP, SMOS-IC, and SMOS, Over Varied Climates and Land Covers

Soil moisture plays an important role in the hydrologic water cycle. Relative to in-situ soil moisture measurements, remote sensing has been the only means of monitoring global scale soil moisture in near real-time over the past 40 years. Among these, soil moisture products from radiometry sensors operating at L-band, e.g., SMAP, SMOS, and SMOS-IC, are theoretically established to be more advantageous than previous C/X-band products. However, little effort has been made to investigate the inter-product differences of L-band soil moisture retrievals and provide insights into the optimal use of these products. In this regard, this study aims to identify the relative strengths and weaknesses of three L-band soil moisture products across diverse climate zones and land covers at the global scale using triple collocation analysis. Results show that SMOS-IC exhibits significantly improved soil moisture estimation skills, relative to the original SMOS product. This demonstrates the paramount importance of retrieval algorithm development in improving global soil moisture estimates—given both SMOS-IC and SMOS are using the same L-band brightness temperature information. Relative to SMOS-IC, SMAP is superior across 69% of global land surface in terms of error variances. However, SMOS-IC tends to outperform SMAP over temperate/arid regions including in the east of North America, South America, western Africa, northern China, and central Australia. Additionally, considerable performance degradation of all the L-band data products is observed over unvegetated areas. This may suggest that improving soil moisture retrieval accuracy over arid and semi-arid regions should be a key priority for future L-band soil moisture development, and model-based (e.g., GLDAS) soil moisture products appear to provide more accurate soil moisture estimates over these regions.

A Synoptic Evolution Comparison of the Smallest and Largest MCSs in Subtropical South America between Spring and Summer

AbstractSubtropical South America (SSA) east of the Andes Mountains is a global hotspot for mesoscale convective systems (MCSs). Wide convective cores (WCCs) are typically embedded within mature MCSs, contribute over 40% of SSA’s warm-season rainfall, and are often associated with severe weather. Prior analysis of Tropical Rainfall Measuring Mission (TRMM) Precipitation Radar (PR) data identified WCCs in SSA and associated synoptic conditions during austral summer. As WCCs also occur during the austral spring, this study uses the 16-year TRMM PR dataset and ERA5 reanalysis to compare anomalies in environmental conditions between austral spring (SON) and summer (DJF) for the largest and smallest WCCs in SSA. During both seasons, large WCCs are associated with an anomalous mid-level trough that slowly crosses the Andes Mountains and a northerly South American low-level jet (SALLJ) over SSA, though the SON trough and SALLJ anomalies are stronger and located farther northeastward than in DJF. A synoptic pattern evolution resembling large WCC environments is illustrated through a multi-day case during the RELAMPAGO field campaign (10-13 November 2018). Unique high-temporal resolution soundings showed strong mid-level vertical wind shear associated with this event, induced by the juxtaposition of the northerly SALLJ and southerly near-surface flow. It is hypothesized that the Andes help create a quasi-stationary trough/ridge pattern such that favorable synoptic conditions for deep convection persist for multiple days. For the smallest WCCs, anomalously weaker synoptic-scale forcing was present compared to the largest events, especially for DJF, pointing to future work exploring MCS formation under weaker synoptic conditions.

Obstructive uropathy secondary to nasal type NK/T-cell lymphoma relapse: report of two cases

Introduction: Extranodal natural killer (NK)/T- cell represents only 0.3% of all non-Hodgkin lymphomas in North America and has a higher relative frequency in Southeast Asia and South America. NK/T- cell, nasal type lymphoma usually appears in the nasal cavity, but can also affect soft tissues, skin, gastrointestinal tract, and testes. Besides, most relapses are locoregional. Acute kidney injury (AKI) due to obstructive uropathy, as the initial presentation of relapsing NK/T- cell, nasal type lymphoma, has not been previously described. Case description: We present two cases of Mexican women with AKI due to obstructive uropathy caused by a relapsing NK/T-cell, nasal type lymphoma. Conclusions: In a patient with a history of NK/T- cell, nasal type lymphoma, presenting with AKI, we should rule out obstructive uropathy caused by a relapsing lymphoma. Relapse should be suspected even in the absence of oliguria and transvaginal bleeding.

Centennial hydroclimatic and anthropogenic processes of South East South America modulate interannual and decadal river discharge

The Río de la Plata (RdlP) mud depocenter is an outstanding centennial ultra-high-resolution information source of hydroclimatic variability and terrigenous export because sedimentation attains values of 13 mmyr−1. Thus, our main objective was to inter-compare and correlate the direct hydroclimatic observations to the proxy record from the RdlP mud depocenter. We correlated continental input and marine productivity proxies to the instrumental historical hydroclimatic observations, and determined the associated periodicity and coherences of such environmental processes by means of wavelet analyses. We discuss the results in the context of both natural climate variability and anthropogenic impacts within the RdlP drainage basin. To this end, we performed a 210Pb and 14C mixed age-depth model and μXRF scanning (every 2 mm), and used Ti/Al and Ba/Al as proxies for continental input and marine productivity changes. We incorporated instrumental observations, i.e., rainfall, river discharges and climate variability modes (CVM) such as: El Niño Southern Oscillation (ENSO), Pacific Decadal Oscillation (PDO) and Atlantic Multidecadal Oscillation (AMO). The statistical correlation analyses indicated a consistent correspondence between both proxies and rainfall anomalies for the warm season within the lower Paraná drainage basin. Such rainfall anomalies are dominated at inter-annual, decadal and multi-decadal scales by ENSO, PDO and AMO modes of variability, respectively, which together modulated river flow. Thus, centennial hydrological and proxy variability appear to be mainly modulated by the CVM. In this sense the present study is in close agreement and complementary to previous worldwide studies by showing similar results for RdlP drainage basin. We further identified a strong change in the proxy data after 1970s; i.e., the highest continental input and marine productivity record, and we related it to the combined effect of climatic variability and anthropogenic impact. Such a period is related to a dominance of positive ENSO (El Niño events) and PDO, and negative AMO, leading to increased rainfall and runoff over the drainage basin, together with intensified agricultural practices. The strong intensification of agricultural activities, mostly soy beans, together with increasing rainfall and runoff led to increased soil erosion and sediment transport, whose final fate is the RdlP mud depocenter.

Hydroclimatic trends during 1950–2018 over global land

Global hydroclimatic changes from 1950 to 2018 are analyzed using updated data of land precipitation, streamflow, and an improved form of the Palmer Drought Severity Index. The historical changes are then compared with climate model-simulated response to external forcing to determine how much of the recent change is forced response. It is found that precipitation has increased from 1950 to 2018 over mid-high latitude Eurasia, most North America, Southeast South America, and Northwest Australia, while it has decreased over most Africa, eastern Australia, the Mediterranean region, the Middle East, and parts of East Asia, central South America, and the Pacific coasts of Canada. Streamflow records largely confirm these precipitation changes. The wetting trend over Northwest Australia and Southeast South America is most pronounced in austral summer while the drying over Africa and wetting trend over mid-high latitude Eurasia are seen in all seasons. Coupled with the drying caused by rising surface temperatures, these precipitation changes have greatly increased the risk of drought over Africa, southern Europe, East Asia, eastern Australia, Northwest Canada, and southern Brazil. Global land precipitation and continental freshwater discharge show large interannual and inter-decadal variations, with negative anomalies during El Nino and following major volcanic eruptions in 1963, 1982, and 1991; whereas their decadal variations are correlated with the Interdecadal Pacific Oscillation (IPO) with IPO’s warm phase associated with low land precipitation and continental discharge. The IPO and Atlantic multidecadal variability also dominate multidecadal variations in land aridity, accounting for 90 % of the multidecadal variance. CMIP5 multi-model ensemble mean shows decreased precipitation and runoff and increased risk of drought during 1950–2018 over Southwest North America, Central America, northern and central South America (including the Amazon), southern and West Africa, the Mediterranean region, and Southeast Asia; while the northern mid-high latitudes, Southeast South America, and Northwest Australia see increased precipitation and runoff. The consistent spatial patterns between the observed changes and the model-simulated response suggest that many of the observed drying and wetting trends since 1950 may have resulted at least partly from historical external forcing. However, the drying over Southeast Asia and wetting over Northwest Australia are absent in the 21st century projections.

Last interglacial (MIS 5e) sea-level proxies in southeastern South America

Abstract. Coastal southeast South America is one of the classic locations where there are robust, spatially extensive records of past high sea level. Sea-level proxies interpreted as last interglacial (Marine Isotope Stage 5e, MIS 5e) exist along the length of the Uruguayan and Argentinian coast with exceptional preservation especially in Patagonia. Many coastal deposits are correlated to MIS 5e solely because they form the next-highest terrace level above the Holocene highstand; however, dating control exists for some landforms from amino acid racemization, U∕Th (on molluscs), electron spin resonance (ESR), optically stimulated luminescence (OSL), infrared stimulated luminescence (IRSL), and radiocarbon dating (which provides minimum ages). As part of the World Atlas of Last Interglacial Shorelines (WALIS) database, we have compiled a total of 60 MIS 5 proxies attributed, with various degrees of precision, to MIS 5e. Of these, 48 are sea-level indicators, 11 are marine-limiting indicators (sea level above the elevation of the indicator), and 1 is terrestrial limiting (sea level below the elevation of the indicator). Limitations on the precision and accuracy of chronological controls and elevation measurements mean that most of these indicators are considered to be low quality. The database is available at https://doi.org/10.5281/zenodo.3991596 (Gowan et al., 2020).

Comparing organisational and alternative regional citizenships: the case of ‘Entrepreneurial regional citizenship’ in ASEAN

ABSTRACT Researchers have increasingly investigated emerging regional citizenships outside the European Union, including in Southeast Asia, South America and West Africa. Their accounts have, however, largely focused on efforts by regional organisations to promote a regional identity and enhance mobility. This article applies a broader comparative framework disaggregating regional citizenship into six constitutive elements. The approach enables a more comprehensive analysis of the nature and shape of emerging organisational citizenship regimes, the identification of potentially significant alternatives, and more systematic comparisons of both across global regions. It is applied first in identifying a duties-centric, top-down and developmental conception of citizenship implicit in recent communications to ‘ASEAN citizens’ by the Association of Southeast Asian Nations. That conception is compared to alternatives, including one implicit in Amitav Acharya’s model of participatory regionalism, and one drawn from field work among regionally networked, digitally focused social entrepreneurs within ASEAN states. The latter indicate a conception which is duties centric but also foregrounds entrepreneurs’ potential for agency and leadership in regional development. We close with a discussion of different practical challenges, related to different elements of citizenship, each conception faces, and the potential for alternatives such as entrepreneurial regional citizenship to influence emergent organisational regimes.