The halt of deep convection in the Greenland Sea: A natural experiment for the study of their causes and effects

There are only a few sites where the deep ocean is ventilated from the surface. The responsible process known as deep convection is recognized to be a key process on the Earth’s climate system, but still it is scarcely observed, and its good representation by global oceanographic and climate models remains unclear. In the Arctic Ocean, the halt of deep convection in the Greenland Sea during the last three decades serves as a natural experiment to study: (1) the conditions that drive the occurrence or not of deep convection and (2) the effects of the halt of deep convection on the thermohaline properties of the deep water masses and circulation both locally and in adjacent ocean basins. Combining oceanic and atmospheric in-situ data together with reanalysis data, we observe that not only on average the winter net heat losses from the ocean to the atmosphere (Qo) have decreased during the last three decades in the Greenland Sea ( Qo (before the 1980s- after the 1980s) = 25 Wm-2) but the intensity and number of strong cooling events (Qo 800Wm-2). This last value for convection reaching 2000 m in the Greenland Sea seems critical to make the mixed layer deepening from being a non-penetrative process to one arrested by baroclinic instabilities. Besides, changes in the wind stress curl and preconditioning for deep convection have occurred, hindering also the occurrence of deep convection. Concerning the effects of the halt of deep convection, hydrographic data reveal that the temperature between 2000 meters depth and the sea floor has risen by 0.3 C in the last 30 years, which is ten times higher than the temperature increase in the global ocean on average, and salinity rose by 0.02 because import of relatively warm and salty Arctic Ocean deep waters continued. The necessary transports to explain the observed changes suggest an increase of Arctic Ocean deep water transport that would have compensated the decrease in deep water formation rate after the 1980s. The effects of these changes in adjacent basins remain unstudied, but the bottom waters seem to be upwelled towards the slope and the Jan Mayen ridge, being an exit for the Greenland Sea deep waters.0,000

Strong-mixing induced deep ocean heat uptake events in the North Atlantic.

The deceleration of the upper ocean heat storage during the last decade has resulted in an active search for the ’missing heat’ in the deep ocean. Modeling work has provided new insights into the role of the central Pacific Ocean on the present hiatus in global warming and the efficient transfer of heat to the deep ocean, but recent studies have highlighted also the large contribution of the North Atlantic basin to these processes, mainly based on ocean observations. The deep ocean heat uptake (below 300 m) in the North Atlantic is not confined to the subpolar gyre region but extends to mid-latitudes of the Eastern North Atlantic (ENA), requiring an additional process for its explanation other than deep convection considered until now. Here, using oceanographic in-situ data, we describe a mechanism of heat and salt injection to the deep ocean after years of warming and saltening at the surface occurred both in regions of mode (43º-48ºN) and deep water (74º-76ºN) formation in the ENA. The mechanism, although punctual meditated by strong winter mixing events, is between 2 and 6 times higher than the 2000-2010 ocean heat uptake at depths of mode (300-700m) and deep water (>2000m) formation, contributing significantly to the observed deep ocean heat uptake in the North Atlantic. Nutrient, hydrographic and reanalysis data indicate that the strong mixing-induced deep ocean heat uptake events at areas of mode and deep water formation in the North Atlantic are connected through the northward propagation of salty ENA mode waters triggered by the contraction of the subpolar gyre reinforced by the occurrences of blocking anomalies in the ENA. Such connection is not unique of the last decade but observed also during the 1960s. Natural climate variability seems the ultimate driver of the strong mixing-induced deep ocean heat uptake events, although the anthropogenic global warming and its forcing on the Arctic sea-ice retreat and frequency of extreme weather events could modify their effects.0,000

Hospedabilidade de espécies frutíferas a meloidogyne ethiopica.

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Monitoramento do nematoide-das-galhas em quivi no Rio Grande do Sul.

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Environmental and anthropogenic driven transitions in the demersal ecosystem of Cantabrian Sea

In the framework of global human-induced change, marine communities’ often respond to changing conditions abruptly reorganizing into new equilibria. These shifts are difficult to predict and often imply irreversible adjustments due to hysteresis. Unraveling the role of the forces leading regime shifts is a major challenge. We explored the temporal evolution of 63 fish species representing the Cantabrian bentho-demersal community in response to environmental changes and fishing pressure in the period 1983–2018, using survey data. Via multivariate analysis and non-additive modeling of a community index and the system's main stressors, two decadal-scale regimes were revealed, suggesting a non-linear response of the community to its environment. The Integrated Resilience Assessment framework elucidated the response mechanism to the candidate stressors and allowed quantifying resilience dynamics. The decline in fishing pressure in the 1990s was associated with a gradual transition of the system, while further decline during the 2000s eroded the resilience of the system towards changes in its stressors, leading to a discontinuous response expressed as an abrupt, possibly irreversible shift in the 2010s. Given the teleconnected character of marine ecosystems, this regional study endorses the scientific effort for actions facing the dynamic impacts of climate change on exploited marine ecosystems.En prensa2,27

Recent freshening and cooling of Biscay subsurface waters

The monitoring program Radiales (https://www.seriestemporales-ieo.net/) by the Spanish Institute of Oceanography, has been providing hydrographical and biogeochemical series in marine waters around Spain on a monthly basis from early 90's. The proximity of the shelf-break in front of the city of Santander (SE Bay of Biscay) allowed tracking intermediate and deep waters along the standard section perpendicular to this city for three decades (sampling was limited to 1000 meter until late 2007, then extended to 1500 m, and full-depth 2400 m since 2014). From the start of the sampling in nearly 90`s, subsurface waters showed unabated warming and salt-increase. Warming was linked to isopycnal sinking (heave) during the 90`s and early 00`s until the occurrence of very strong winter mixing in 2005 that shifted quickly the salinity down to lower East North Atlantic Central Waters (ENACW) levels (ca. 400 m). Overall, warming and salt-increase at the core of ENACW added up to 0.3ºC and 0.08 in salinity within only two and a bit decades. In 2014, the upper central waters showed freshening and cooling for the first time in the series, a process that enhanced in the following years especially in salinity that currently (2021) presents the lowest value of the overall timeseries. This shift in regional hydrography follows the large salinity drop observed in the subpolar gyre around 2012 and its subsequent expansion downstream into the subtropical gyre and subarctic seas. This regime shift implies that subsurface environmental conditions in the region have returned back to 90`s state, contrasting to the uppermost waters which continue to show large positive anomalies. The effects of this cold and freshwater inflow in the regional circulation of southern Biscay are discussed

Characterization of meloidogyne species from irrigated rice in southern Brazil.

Edição dos Proceedings do 6th International Congress of Nematology, Cape Town, South Africa, May 2014

Aplicação da metodologia de homozigose do haplótipo estendido (EHH) para genes relacionados com crescimento e deposição de gordura em bovinos da raça Nelore.

O rebanho bovino brasileiro destinado à produção de carne vem sendo selecionado há décadas, por programas de melhoramento genético, para diversas características de crescimento e, mais recentemente, de deposição de gordura. A seleção artificial resulta em alterações no genoma, que podem ser detectadas, por exemplo, por diferenças nos padrões de homozigose dos indivíduos de uma população, permitindo a identificação de regiões do genoma que controlam características sob seleção. Com o objetivo de avaliar a presença de assinaturas de seleção do genoma de bovinos Nelore que continham genes candidatos relacionados com crescimento e deposição de gordura, foram genotipados 796 indivíduos com o chip Illumina BovineHD BeadChip e, posteriormente, inferida a fase de ligação dos polimorfismos de único nucleotídeo (SNPs), formados os blocos de desequilíbrio de ligação (haplótipos) e realizada a detecção de possíveis evidências de seleção nas regiões específicas de quatro genes candidatos - somatostatina (SST), receptor da leptina (LEPR), gene da proteina de ligação de ácido graxo 4 (FABP4) e gene do hormônio do crescimento (GH1) - bem como o padrão de frequência e homozigose dos haplótipos. Foram encontradas evidências de seleção nos quatro genes, sugerindo que estão relacionados com crescimento (SST e GH1), metabolismo e deposição de gordura (LEPR e FABP4) na raça Nelore

Caracterização de haplótipos e identificação de assinaturas de seleção em bovinos da raça Nelore.

A identificação de regiões do genoma que controlam características de interesse econômico e que estejam sob seleção é possível por conta da disponibilidade da genotipagem em plataformas de altas densidades de polimorfismos de único nucleotídeo (SNPs). A busca por assinaturas de seleção avalia, principalmente, altas e não usuais frequências alélicas dos loci adjacentes às mutações favoráveis. Com o objetivo de detectar evidências de assinaturas de seleção recente no genoma de bovinos da raça Nelore, foram genotipados 796 indivíduos com o chip Illumina BovineHD BeadChip, que possui mais de 777 mil SNPs e, posteriormente, inferida a fase de ligação dos SNPs e a reconstrução dos blocos de desequilíbrio de ligação (haplótipos). A detecção de assinaturas de seleção recentes foi realizada por meio da aplicação da metodologia EHH (homozigose do haplótipo estendido). 330.262 SNPs entraram na formação dos 68.054 haplótipos identificados, cobrindo 42% do genoma, sendo que a maior parte deles apresentou até 10 kb de comprimento e foram formados por 3 marcadores. Além disso, foram detectadas regiões de possíveis assinaturas de seleção com diferentes significâncias: 2.103 (P<0,01), 269 (P<0,001) e 31 (P<0,0001).SBMA 2012

Is the social wasp fauna in the tree canopy different from the understory? Study of a particular area in the Brazilian Amazon Rainforest

Most studies about the insect community in rainforests only focus on the forest understory, and even though the rainforest canopy is one of the most fascinating and diverse environments, it remains poorly explored. Therefore, we analyzed the difference between the social wasp composition in these two strata at the ZF-2 Station in the Brazilian Amazon Rainforest, Amazonas, Manaus, using flight interception Malaise traps, in the rainforest understory and canopy. We collected ninety-two species belonging to 18 genera; Polybia was the richest genera (22 species), followed by Mischocyttarus (14) and Agelaia (13). Forty-four species were exclusively collected in the understory, twenty exclusively collected in the canopy, and twenty-eight in both strata. The understory was distinctly more diverse and more abundant than the canopy, while some rare or poorly collected species were only found in the canopy. We found a relationship between the species composition at the ZF-2 Station and the Ducke Reserve, Manaus. Therefore, we suggest using traps in canopy in the Amazon biome as an effective method for collecting a higher diversity of social wasps. © 2019 Universidade Estadual de Feira de Santana. All rights reserved