Reconstruction of the surface marine carbonate system at the Western Tropical Atlantic

2021 ◽  
Author(s):  
Carlos Augusto Musetti de Assis ◽  
Letícia Cotrim da Cunha ◽  
Luana Queiroz Pinho ◽  
Helen Michelle de Jesus Affe ◽  
Renan Luis Evangelista Vieira ◽  
...  
Keyword(s):  
Rainy Season ◽  
Dry Season ◽  
Sea Surface ◽  
Total Alkalinity ◽  
Subsurface Water ◽  
Amazon River ◽  
Tropical Atlantic ◽  
Carbonate System ◽  
Marine Carbonate ◽  
Equatorial Upwelling

<p>The Western Tropical Atlantic is a crucial region when it comes to understanding the CO<sub>2</sub> dynamics in the tropics, as it is subject to large inputs of freshwater from the Amazon River and the ITCZ rainfall, as well as the input of CO<sub>2</sub>-rich waters from upwelling of subsurface water. This study aims to reconstruct the surface marine carbonate system from 1998 to 2018 using sea surface temperature (SST) and sea surface salinity (SSS) data from the PIRATA buoy at 8°N 38°W and describe its variability in time. Two empirical models were used to calculate total alkalinity (TA) and dissolved inorganic carbon (DIC) from SSS. From these two parameters and SST data, it was possible to calculate pH and CO<sub>2</sub> fugacity (<em>f</em>CO<sub>2</sub>) values. Only DIC, pH and <em>f</em>CO<sub>2</sub> showed a statistically significant trend in time, where DIC showed an increase of 0.717 µmol kg<sup>-1</sup> year<sup>-1</sup>, pH decreased 0.001394 pH units year<sup>-1</sup>, and <em>f</em>CO<sub>2</sub> had an increase of 1.539 µatm year<sup>-1</sup>. Two different seasons were observed when data were analyzed: a dry season from January to June, when SSTs were lower (around 27°C) and SSS was stable around 36, matching the period when the ITCZ is over the South American continent, Amazon river plume is restricted to western shelf areas and Equatorial upwelling is more active, and a rainy season from July to December, when SSTs were higher (around 28.5°C) and SSS had higher variability (from 31 to 36), matching the period when the ITCZ is at its northern range, the Amazon plume is spread eastwards through the North Brazil Current’s retroflection and the Equatorial upwelling is less intense. Along with that, TA, DIC and pH varied positively with SSS, with higher values (TA around 2350 µmol kg<sup>-1</sup>, DIC around 2025 µmol kg<sup>-1</sup> and pH around 8.060 pH units) during dry season and lower values (TA around 2300 µmol kg<sup>-1</sup>, DIC around 1990 µmol kg<sup>-1</sup> and pH around 8.050 pH units) during rainy season. On the other hand, <em>f</em>CO<sub>2</sub> varied positively with SST, with lower values (around 385 µatm) during dry, upwelling season and higher values (around 390 µatm) during rainy season, showing that both SSS and SST variability play an important role in the CO<sub>2</sub> solubility in the region.</p>

scholarly journals An objective tropical Atlantic sea surface temperature gradient index for studies of south Amazon dry-season climate variability and change

2008 ◽  
Vol 363 (1498) ◽  
pp. 1761-1766 ◽  
Author(s):  
Peter Good ◽  
Jason A Lowe ◽  
Mat Collins ◽  
Wilfran Moufouma-Okia
Keyword(s):  
Climate Change ◽  
Surface Temperature ◽  
Sea Surface Temperature ◽  
General Circulation ◽  
Southern Oscillation ◽  
Circulation Model ◽  
Dry Season ◽  
Sea Surface ◽  
Tropical Atlantic ◽  
Sst Gradient

Future changes in meridional sea surface temperature (SST) gradients in the tropical Atlantic could influence Amazon dry-season precipitation by shifting the patterns of moisture convergence and vertical motion. Unlike for the El Niño-Southern Oscillation, there are no standard indices for quantifying this gradient. Here we describe a method for identifying the SST gradient that is most closely associated with June–August precipitation over the south Amazon. We use an ensemble of atmospheric general circulation model (AGCM) integrations forced by observed SST from 1949 to 2005. A large number of tropical Atlantic SST gradient indices are generated randomly and temporal correlations are examined between these indices and June–August precipitation averaged over the Amazon Basin south of the equator. The indices correlating most strongly with June–August southern Amazon precipitation form a cluster of near-meridional orientation centred near the equator. The location of the southern component of the gradient is particularly well defined in a region off the Brazilian tropical coast, consistent with known physical mechanisms. The chosen index appears to capture much of the Atlantic SST influence on simulated southern Amazon dry-season precipitation, and is significantly correlated with observed southern Amazon precipitation. We examine the index in 36 different coupled atmosphere–ocean model projections of climate change under a simple compound 1% increase in CO 2 . Within the large spread of responses, we find a relationship between the projected trend in the index and the Amazon dry-season precipitation trends. Furthermore, the magnitude of the trend relationship is consistent with the inter-annual variability relationship found in the AGCM simulations. This suggests that the index would be of use in quantifying uncertainties in climate change in the region.

SMOS-based estimation and validation of Total Alkalinity in the Mediterranean basin

2020 ◽  
Author(s):  
Roberto Sabia ◽  
Estrella Olmedo ◽  
Giampiero Cossarini ◽  
Aida Alvera-Azcárate ◽  
Veronica Gonzalez-Gambau ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Mediterranean Sea ◽  
Mediterranean Basin ◽  
Sea Surface ◽  
Sea Surface Salinity ◽  
Total Alkalinity ◽  
Surface Salinity ◽  
Carbonate System ◽  
The Mediterranean ◽  
The Mediterranean Basin

<p>ESA SMOS satellite [1] has been providing first-ever Sea Surface Salinity (SSS) measurements from space for over a decade now. Until recently, inherent algorithm limitations or external interferences hampered a reliable provision of satellite SSS data in semi-enclosed basin such as the Mediterranean Sea. This has been however overcome through different strategies in the retrieval scheme and data filtering approach [2, 3]. This recent capability has been in turn used to infer the spatial and temporal distribution of Total Alkalinity (TA - a crucial parameter of the marine carbonate system) in the Mediterranean, exploiting basin-specific direct relationships existing between salinity and TA.</p><p>Preliminary results [4] focused on the differences existing in several parameterizations [e.g, 5] relating these two variables, and how they vary over a seasonal to interannual timescale.</p><p>Currently, to verify the consistency and accuracy of the derived products, these data are being validated against a proper ensemble of in-situ, climatology and model outputs within the Mediterranean basin. An error propagation exercise is also being planned to assess how uncertainties in the satellite data would translate into the final products accuracy.</p><p>The resulting preliminary estimates of Alkalinity in the Mediterranean Sea will be linked to the overall carbonate system in the broader context of Ocean Acidification assessment and marine carbon cycle.</p><p>References:</p><p>[1] J. Font et al., "SMOS: The Challenging Sea Surface Salinity Measurement From Space," in Proceedings of the IEEE, vol. 98, no. 5, pp. 649-665, May 2010. doi: 10.1109/JPROC.2009.2033096</p><p>[2] Olmedo, E., J. Martinez, A. Turiel, J. Ballabrera-Poy, and M. Portabella,  “Debiased non-Bayesian retrieval: A novel approach to SMOS Sea Surface Salinity”. Remote Sensing of Environment 193, 103-126 (2017).</p><p>[3] Alvera-Azcárate, A., A. Barth, G. Parard, J.-M. Beckers, Analysis of SMOS sea surface salinity data using DINEOF, In Remote Sensing of Environment, Volume 180, 2016, Pages 137-145, ISSN 0034-4257, https://doi.org/10.1016/j.rse.2016.02.044.</p><p>[4] Sabia, R., E. Olmedo, G. Cossarini, A. Turiel, A. Alvera-Azcárate, J. Martinez, D. Fernández-Prieto, Satellite-driven preliminary estimates of Total Alkalinity in the Mediterranean basin, Geophysical Research Abstracts, Vol. 21, EGU2019-17605, EGU General Assembly 2019, Vienna, Austria, April 7-12, 2019.</p><p>[5] Cossarini, G., Lazzari, P., and Solidoro, C.: Spatiotemporal variability of alkalinity in the Mediterranean Sea, Biogeosciences, 12, 1647-1658, https://doi.org/10.5194/bg-12-1647-2015, 2015.</p><p> </p><p> </p>

scholarly journals The Sensitivity of the Marine Carbonate System to Regional Ocean Alkalinity Enhancement

2021 ◽  
Vol 3 ◽  
Author(s):  
Daniel J. Burt ◽  
Friederike Fröb ◽  
Tatiana Ilyina
Keyword(s):  
Southern Ocean ◽  
Dissolved Inorganic Carbon ◽  
Ocean Model ◽  
Total Alkalinity ◽  
Surface Pattern ◽  
Carbon Uptake ◽  
Max Planck ◽  
Carbonate System ◽  
Carbon Cycle Model ◽  
Marine Carbonate

Ocean Alkalinity Enhancement (OAE) simultaneously mitigates atmospheric concentrations of CO2 and ocean acidification; however, no previous studies have investigated the response of the non-linear marine carbonate system sensitivity to alkalinity enhancement on regional scales. We hypothesise that regional implementations of OAE can sequester more atmospheric CO2 than a global implementation. To address this, we investigate physical regimes and alkalinity sensitivity as drivers of the carbon-uptake potential response to global and different regional simulations of OAE. In this idealised ocean-only set-up, total alkalinity is enhanced at a rate of 0.25 Pmol a-1 in 75-year simulations using the Max Planck Institute Ocean Model coupled to the HAMburg Ocean Carbon Cycle model with pre-industrial atmospheric forcing. Alkalinity is enhanced globally and in eight regions: the Subpolar and Subtropical Atlantic and Pacific gyres, the Indian Ocean and the Southern Ocean. This study reveals that regional alkalinity enhancement has the capacity to exceed carbon uptake by global OAE. We find that 82–175 Pg more carbon is sequestered into the ocean when alkalinity is enhanced regionally and 156 PgC when enhanced globally, compared with the background-state. The Southern Ocean application is most efficient, sequestering 12% more carbon than the Global experiment despite OAE being applied across a surface area 40 times smaller. For the first time, we find that different carbon-uptake potentials are driven by the surface pattern of total alkalinity redistributed by physical regimes across areas of different carbon-uptake efficiencies. We also show that, while the marine carbonate system becomes less sensitive to alkalinity enhancement in all experiments globally, regional responses to enhanced alkalinity vary depending upon the background concentrations of dissolved inorganic carbon and total alkalinity. Furthermore, the Subpolar North Atlantic displays a previously unexpected alkalinity sensitivity increase in response to high total alkalinity concentrations.

scholarly journals PyCO2SYS v1.7: marine carbonate system calculations in Python

2021 ◽  
Author(s):  
Matthew P. Humphreys ◽  
Ernie R. Lewis ◽  
Jonathan D. Sharp ◽  
Denis Pierrot
Keyword(s):  
Automatic Differentiation ◽  
Dissolved Inorganic Carbon ◽  
Total Alkalinity ◽  
Carbonate System ◽  
Chemical Equilibria ◽  
Ph Response ◽  
Carbonate Ion ◽  
Seawater Ph ◽  
Marine Carbonate ◽  
Carbon Dioxide Co2

Abstract. Oceanic dissolved inorganic carbon (TC) is the largest pool of carbon that interacts considerably with the atmosphere on human timescales. Oceanic TC is increasing through uptake of anthropogenic carbon dioxide (CO2), and seawater pH is decreasing as a consequence. Both the exchange of CO2 between ocean and atmosphere and the pH response are governed by a set of parameters that interact through chemical equilibria, collectively known as the marine carbonate system. To investigate these processes, at least two of the marine carbonate system's parameters are typically measured – most commonly, two from TC, total alkalinity (AT), pH, and seawater CO2 fugacity (fCO2; or its partial pressure, pCO2, or its dry-air mole fraction, xCO2) – from which the remaining parameters can be calculated and the equilibrium state of seawater solved. Several software tools exist to carry out these calculations, but no fully functional and rigorously validated tool was previously available for Python, a popular scientific programming language. Here, we present PyCO2SYS, a Python package intended to fill this capability gap. We describe the elements of PyCO2SYS that have been inherited from the existing CO2SYS family of software and explain subsequent adjustments and improvements. For example, PyCO2SYS uses automatic differentiation to solve the marine carbonate system and calculate chemical buffer factors, ensuring that the effect of every solute and reaction is accurately included in all its results. We validate PyCO2SYS with internal consistency tests and comparisons against other software, showing that PyCO2SYS produces results that are either virtually identical or different for known reasons, with the differences negligible for all practical purposes. We discuss new insights that arose during the development process, for example that the marine carbonate system cannot be unambiguously solved from the total alkalinity and carbonate ion parameter pair. Finally, we consider potential future developments to PyCO2SYS and discuss the outlook for this and other software for solving the marine carbonate system. The code for PyCO2SYS is distributed via GitHub (https://github.com/mvdh7/PyCO2SYS) under the GNU General Public License v3, archived on Zenodo (Humphreys et al., 2021), and documented online (https://PyCO2SYS.readthedocs.io).

Spatial and temporal changes in biomass, production and assemblage structure of mesozooplanktonic copepods in the tropical south-west Atlantic Ocean

2014 ◽  
Vol 95 (3) ◽  
pp. 483-496 ◽  
Author(s):  
C.O. Dias ◽  
A.V. Araujo ◽  
S.C. Vianna ◽  
L.F. Loureiro Fernandes ◽  
R. Paranhos ◽  
...  
Keyword(s):  
Atlantic Ocean ◽  
Continental Shelf ◽  
Continental Slope ◽  
Rainy Season ◽  
Temporal Variations ◽  
Dry Season ◽  
Subsurface Water ◽  
Tropical Region ◽  
The South ◽  
South West

We examined the spatial and temporal variations of coastal and oceanic epipelagic copepods (rainy–dry seasons of 2009) in a tropical area of the south-west Atlantic. Zooplankton samples were obtained at 48 stations along six transects perpendicular to the coast, in the subsurface water between the 25 and 3000 m isobaths, by horizontal hauls using a Multinet. Abundance (42–64,753 ind. m−3), biomass (0.08–113 mg C m−3) and daily copepod production (0.17–163.20 mg C m−3 d−1) showed longitudinal and latitudinal variability. The highest values were observed over the southern continental shelf during the dry season. Temoridae, Undinula vulgaris and Paracalanus quasimodo dominated the biomass and daily copepod production during the rainy season; while Calanoides carinatus, Calanopia americana, Clausocalanidae, Temoridae, Paracalanidae and Subeucalanidae dominated during the dry season. The copepod assemblages formed four different groups: rainy season–continental shelf (1), dry season–continental shelf (2), rainy season–continental slope (3) and dry season–continental slope (4). Temperature, salinity, chlorophyll-a and suspended particulate matter explained 45% of the productivity distribution of the dominant copepod species. This study is the first attempt to examine the biomass and daily copepod production in oceanic waters in the south-west Atlantic Ocean, and it showed that copepod biomass and production in a tropical region can be relatively high compared with other regions of the world's oceans.

scholarly journals Seasonal pattern in parasite infracommunities of Hoplerythrinus unitaeniatus and Hoplias malabaricus (Actinopterygii: Erythrinidae) from the Brazilian Amazon

2016 ◽  
Vol 61 (1) ◽  
Author(s):  
Raissa Alves Gonçalves ◽  
Marcos Sidney Brito Oliveira ◽  
Ligia Rigôr Neves ◽  
Marcos Tavares-Dias
Keyword(s):  
Seasonal Variation ◽  
Rainy Season ◽  
Parasite Species ◽  
Seasonal Pattern ◽  
Life Cycles ◽  
Dry Season ◽  
Amazon River ◽  
Hoplias Malabaricus ◽  
Variable Nature ◽  
Hoplerythrinus Unitaeniatus

AbstractThe present study investigated the effects of seasonal variation in parasites infracommunities of Hoplerythrinus unitaeniatus and Hoplias malabaricus from a tributary of Amazon River. For H. unitaeniatus and H. malabaricus, 11 parasite species were similar, and greatest parasite richness occurred during the rainy season. Ichthyophthirius multifiliis was the dominant parasite species for both hosts. In H. unitaeniatus, infection by Whittingtonocotyle caetei, Whittingtonocotyle jeju, Urocleidoides sp. and Anacanthorus sp. was higher during rainy season. Contracaecum sp., Procamallanus (Spirocamallanus) inopinatus, Nomimoscolex matogrossensis and Gorytocephalus spectabilis showed no seasonal pattern. For H. unitaeniatus, P. pillulare, Clinostomum marginatum and Argulus pestifer occurred only during dry season, while Trichodina sp., Dolops geayi, undetermined metacercariae and Posthodiplostomum sp. occurred only during the rainy season. In H. malabaricus, the prevalence of Urocleidoides eremitus was similar during the two seasons, but abundance was higher during the rainy season. Tetrahymena sp., C. marginatum, Dendrorchis neivai, undetermined metacercariae, Posthodiplostomum sp., Genarchella genarchella, Cystidicoloides sp., G. spectabilis, D. geayi, A. pestifer and Glossiphonidae gen. sp. occurred only during the dry season. However, Contracaecum sp. and P. (S.) inopinatus occurred during both seasons, but the prevalence of P. (S.) inopinatus was higher during the rainy season. Seasonal variation in this infection levels was due to the host’s feeding behavior and habits and the availability of infectious forms of parasites with heteroxenic life cycles. The non-seasonal fluctuation detected are likely a result of the parasites biology, highly variable nature of this tributary of Amazon River and low abundance of parasites.

scholarly journals Pengaruh Suhu Permukaan Laut (SPL) terhadap Curah Hujan di Perairan Bali menggunakan Data Citra Satelit

2021 ◽  
Vol 4 (2) ◽  
pp. 1
Author(s):  
Ni Kadek Martini ◽  
I Wayan Nuarsa ◽  
I Wayan Gede Astawa Karang
Keyword(s):  
Correlation Coefficient ◽  
Strong Correlation ◽  
Rainy Season ◽  
Regional Scale ◽  
Time Lag ◽  
Dry Season ◽  
High Variability ◽  
Sea Surface ◽  
Weather Element ◽  
Level 3

Rainfall is a weather element. Sea surface temperatures (SST) affects precipitation. SST and rainfall have a high variability which can be measured by satellite. At a regional scale, a research of the effect of SST on rainfall analyzed island rainfall, which means that there is still little research on rainfall in the waters. This study purposed to find out the variability and correlation between SST and rainfall in the Bali waters.  It used satellite MODIS and TRMM for 10 years, started from 2010 to 2019. The data used was SST MODIS and rainfall TRMM level 3 with the geographic coordinates boundaries area 114.4281o East - 115.7145o East, and 7.8168o South 8.9868o South. The method of this study was correlation analyzed with time lag between of SST and rainfall. The variability of SST in the Bali waters were ranged from 25,2 oC to 31,6 oC. Furthermore, the variability of rainfall was ranged from 0 mm to 556,92 mm. The changes patterns of SST and precipitation in Bali water were related to the season in each month. The data showed that the SST was warmer in the rainy season compared to the SST in the dry season. Besides, the rainfall increases when entering the rainy season, and the decreases when entering the dry season. The correlation between SST and rainfall in this waters area ranged from weak to strong. Correlation formed in the rainy season is negative with a correlation coefficient between -0.34 to -0.74. However, in the dry season there was a positive correlation with a correlation coefficient ranging from 0.77 to 0.92.

scholarly journals Alkalinity, inorganic carbon and CO2 flux variability during extreme rainfall years (2010-2011) in two polluted tropical estuaries NE Brazil

2018 ◽  
Vol 66 (1) ◽  
pp. 115-130 ◽  
Author(s):  
Felipe Lima Gaspar ◽  
Barbara Ramos Pinheiro ◽  
Carlos Esteban Delgado Noriega ◽  
Moacyr Araujo ◽  
Nathalie Lefèvre ◽  
...  
Keyword(s):  
Dissolved Oxygen ◽  
Rainy Season ◽  
Inorganic Carbon ◽  
Co2 Flux ◽  
Extreme Rainfall ◽  
Dry Season ◽  
Rainfall Event ◽  
Total Alkalinity ◽  
Extreme Rainfall Event ◽  
Tropical Estuaries

Abstract The susceptibility of coastal environments to shifts in the biogeochemical cycles of carbon and nutrients driven by anthropogenic pressure and climate change is a real challenge for the scientific community. This paper evaluated the effects of an extreme rainfall event over the nutrients and carbonate parameters in two polluted tropical estuaries. Surface water samples were taken seasonally along a salinity gradient in the Capibaribe and Barra de Jangadas estuaries in order to investigate the spatial and seasonal variability of dissolved nutrients, chlorophyll-a, dissolved oxygen, total alkalinity, inorganic carbon, partial pressure of CO2 (pCO2) and CO2 fluxes. The increased riverine influence caused by the fluvial flooding during the extremely rainy season augmented the nitrogen concentrations in the plumes, which also presented reduced salinity, alkalinity and dissolved oxygen values. In the Capibaribe plume it has also shifted the mean CO2 flux value of - 4.01 mmolC m-2 d-1 during the dry season, to a positive mean flux of + 5.7 mmolC m-2 d-1 during the rainy season. Within the estuaries the BOD5,20 and dissolved phosphorus values were higher during the dry season (p<0.0001), they showed positive correlation with the phytoplanktonic blooms that reached a chl-a value of 85 mg m-3 in the Capibaribe. The high alkalinity found in both estuaries, with mean values between dry and wet seasons respectively from 1808 to 1373 µmol kg-1 in the Capibaribe estuary and 1616 to 1058 µmol kg-1 in Barra de Jangadas estuary, may act as a buffer to the process of coastal acidification due to eutrophication. The increased rivers discharge lead to a greater transport of organic matter and nutrients to the coast, decreasing the oxygen availability and shifting the metabolic status of the estuarine plume to heterotrophic, whereas increased the water quality within the estuaries due the flushing promoted by the extreme rainfall event.

Interannual variability of Tropical Atlantic and its influence on drought and flood events in the Amazon Basin

2020 ◽  
Author(s):  
Katherine Lisbeth Ccoica López ◽  
Ricardo Hallak ◽  
Victor Raúl Chavez Mayta
Keyword(s):  
North Atlantic ◽  
Rainy Season ◽  
Amazon Basin ◽  
South Atlantic ◽  
Sea Surface ◽  
Tropical Atlantic ◽  
Flood Events ◽  
Drought And Flood ◽  
The North ◽  
Tropical North Atlantic

&lt;p&gt;The Tropical Pacific and Tropical Atlantic Ocean modulate the interannual precipitation over the Amazon region and the decadal and interdecadal variation as well. During El Ni&amp;#241;o Southern Oscillation (ENSO), below-average rainfall is recorded in the North and Northeast of the Basin, while deficit of precipitation is observed in the West and South. On the other hand, during La Ni&amp;#241;a years, rainfall is above of normal in the North and Northeast of Amazon Basin. However, there are also drought events, such as in 1964 and 2005, unrelated to the El Ni&amp;#241;o event, but influenced by warm conditions in the Tropical North Atlantic. In fact, the exceptional drought recorded in 2010 was influenced by a combined effect of the El Ni&amp;#241;o event during the peak of rainy season, followed by warm conditions in the Tropical North Atlantic during final of rainy season and dry season.&lt;/p&gt;&lt;p&gt;Therefore, the main aim of this study is exploring the Atlantic Sea Surface Temperature (SST) condition in modulating patterns that influence the development of drought and flood events in the Amazon Basin. First of all, the Atlantic Ocean is divided into Tropical North Atlantic (TNA), Tropical South Atlantic (TSA) and Subtropical South Atlantic (STSA), to analyze the behavior of each region separately. Atlantic Index, in each region, is the first principal component (PC1) time series, which comes from the empirical orthogonal function (EOF) analysis applied to Hadley Center Global Sea Ice and Sea Surface Temperature (HadISST) dataset for the 1870-2107 period. The Tropical North Atlantic, Tropical South Atlantic and Subtropical South Atlantic indices show the main years when drought and flood events reaching the Amazon Basin (droughts in 2005, 2010 and 2015, and floods in 2009 and 2012, mainly), and 5-years moving correlations indicate that these three ocean basin have been coupled and decoupled periodically each other in the last century.&lt;/p&gt;&lt;p&gt;The equatorial Pacific, North Atlantic and South Atlantic indices were also correlated with rainfall over the Amazon for three databases: the Tropical Rainfall Mission Measurements (TRMM), the Global Precipitation Climatology Centre (GPCC) and the HyBAm Observed Precipitation. All three databases showed the same results. An increase of the SST in Eastern Pacific influences in low precipitation over the central and west of the Amazon Basin during the rainy season (December to February), increase of the SST in Central Pacific influences for droughts over the northeast region and the TSA influences in the central Amazon. Increase of the SST in TNA and STSA influences mainly in the dry season (May to September), intensifying it. TNA is responsible for precipitation below normal over the central and west Amazon Basin, while STSA only influences in the central region of the basin. Finally, analysis of extreme events indicate that droughts and floods in the Amazon are intensified (de-intensified) if we consider warm (cold) phases of the AMO (Atlantic Multidecadal Oscillation) and the PDO (Pacific Decadal Oscillation).&lt;/p&gt;

Influence of the industrial port complex of Suape (Western Tropical Atlantic) on the biodiversity and biomass of Phaeophyceae.

2011 ◽  
Vol 39 (2) ◽  
Author(s):  
Thiago Nogueira de Vasconcelos REIS ◽  
Nathalia Cristina GUIMARÃES-BARROS ◽  
Edson Regis Tavares Pessoa Pinho de VASCONCELOS ◽  
Adilma De Lourdes Montenegro COCENTINO ◽  
Mutue Toyota FUJII
Keyword(s):  
Rainy Season ◽  
Dry Season ◽  
Tropical Atlantic

Esta pesquisa teve como objetivo principal conhecer a diversidade e distribuição espacial da biomassa de Phaeophyceae nos recifes da região portuária de Suape (Pernambuco, Brasil). O material estudado foi coletado em 6 (seis) estações fixas, em duas etapas, uma entre 1996 e 1999 e outra nos meses de Janeiro e julho de 2009 (período seco e chuvoso respectivamente), demarcadas em função da topografia e distância do Porto. No laboratório, as amostras foram triadas e fixadas em formol a 4%, neutralizadas com bórax. A identificação taxonômica baseou-se na observação da morfologia externa e interna. Foi observada, ainda, a distribuição espacial das espécies nas faixas de maré e a associação com outras algas. Foram identificados 27 táxons pertencentes a 5 ordens (Ectocarpales, Scytosiphonales, Dictyotales e Fucales) e a 6 famílias (Chnoosporaceae, Ectocarpaceae, Scytosiphonaceae, Dictyotaceae e Sargassaceae). Através da análise de similaridade foi possível observar dois grupos distintos em função da proximidade do Porto, esses dados também foram corroborados pela Permanova. A biomassa das espécies de Phaeophyceae variou de 0.001 ± 0.01 (rainy season) to 77.410 ± 3.87 g. m-2 (dry season), sendo a maior contribuição para essa biomassa o peso das espécies de Sargassum. A diversidade de Phaeophyceae da região foi baixa, e diminuiu com a proximidade do porto e com o período chuvoso. A área pode ser considerada resiliente pois apesar dos impactos existentes, as espécies de Phaeophyceae estão bem representadas, o que indica uma grande capacidade de recuperação do ecossistema, tendo em vista mais de 30 anos de implantação do Porto. Palavras-chave: Macroalgas, Phaeophyceae, recifes, complexo portuário, Suape.

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