scholarly journals ARIOS: An acidification ocean database for the Iberian Upwelling Ecosystem (1976–2018)

2020 ◽  
Author(s):  
Xosé Antonio Padin ◽  
Antón Velo ◽  
Fiz F. Pérez
Keyword(s):  
Organic Matter ◽  
Surface Waters ◽  
Salinity Gradient ◽  
Longitudinal Section ◽  
Surface Salinity ◽  
The North ◽  
Lower Oxygen ◽  
Ría De Vigo ◽  
Biogeochemical Parameters

Abstract. A data product of 17,653 discrete samples from 3,357 oceanographic stations combining measurements of pH, alkalinity and other biogeochemical parameters off the North-western Iberian Peninsula from June 1976 to September 2018 is presented in this study. The oceanography cruises funded by 24 projects were primarily carried out in the Ría de Vigo coastal inlet, but also in an area ranging from the Bay of Biscay to the Portuguese coast. The robust seasonal cycles and long-term trends were only calculated along a longitudinal section, gathering data from the coastal and oceanic zone of the Iberian Upwelling System. The pH in the surface waters of these separated regions, which were highly variable due to intense photosynthesis and the remineralization of organic matter, showed an interannual acidification ranging from −0.0016 yr−1 to −0.0032 yr−1 that grew towards the coastline. This result is obtained despite the buffering capacity increasing in the coastal waters further inland as shown by the increase in alkalinity by 1.1±0.7 μmol kg−1 yr−1 and 2.6±1.0 μmol kg−1 yr−1 in the inner and outer Ría de Vigo respectively, driven by interannual changes in the surface salinity of 0.0193±0.0056 psu yr−1 and 0.0426±0.016 psu yr−1 respectively. The loss of the vertical salinity gradient in the long-term trend in the inner ria was consistent with other significant biogeochemical changes such as a lower oxygen concentration and fertilization of the surface waters. These findings seem to be related to a growing footprint of sediment remineralization of organic matter in the surface layer of a more homogeneous water column. Data are available at: https://doi.org/10.20350/digitalCSIC/12498 (Pérez et al., 2020).

scholarly journals ARIOS: a database for ocean acidification assessment in the Iberian upwelling system (1976–2018)

2020 ◽  
Vol 12 (4) ◽  
pp. 2647-2663
Author(s):  
Xosé Antonio Padin ◽  
Antón Velo ◽  
Fiz F. Pérez
Keyword(s):  
Organic Matter ◽  
Surface Waters ◽  
Salinity Gradient ◽  
Longitudinal Section ◽  
Surface Salinity ◽  
Upwelling System ◽  
Lower Oxygen ◽  
Ría De Vigo ◽  
Biogeochemical Parameters

Abstract. A data product of 17 653 discrete samples from 3343 oceanographic stations combining measurements of pH, alkalinity and other biogeochemical parameters off the northwestern Iberian Peninsula from June 1976 to September 2018 is presented in this study. The oceanography cruises funded by 24 projects were primarily carried out in the Ría de Vigo coastal inlet but also in an area ranging from the Bay of Biscay to the Portuguese coast. The robust seasonal cycles and long-term trends were only calculated along a longitudinal section, gathering data from the coastal and oceanic zone of the Iberian upwelling system. The pH in the surface waters of these separated regions, which were highly variable due to intense photosynthesis and the remineralization of organic matter, showed an interannual acidification ranging from −0.0012 to −0.0039 yr−1 that grew towards the coastline. This result is obtained despite the buffering capacity increasing in the coastal waters further inland as shown by the increase in alkalinity by 1.1±0.7 and 2.6±1.0 µmol kg−1 yr−1 in the inner and outer Ría de Vigo respectively, driven by interannual changes in the surface salinity of 0.0193±0.0056 and 0.0426±0.016 psu yr−1 respectively. The loss of the vertical salinity gradient in the long-term trend in the inner ria was consistent with other significant biogeochemical changes such as a lower oxygen concentration and fertilization of the surface waters. These findings seem to be related to a growing footprint of sediment remineralization of organic matter in the surface layer of a more homogeneous water column. Data are available at https://doi.org/10.20350/digitalCSIC/12498 (Pérez et al., 2020).

Impact of mesoscale eddies on salinity and CO2 ocean parameters in the western tropical Atlantic in February 2020

2021 ◽  
Author(s):  
Léa Olivier ◽  
Jacqueline Boutin ◽  
Nathalie Lefèvre ◽  
Gilles Reverdin ◽  
Peter Landschützer ◽  
...  
Keyword(s):  
Dissolved Inorganic Carbon ◽  
Salinity Gradient ◽  
Sea Surface Salinity ◽  
Amazon River ◽  
Tropical Atlantic ◽  
Surface Salinity ◽  
The North ◽  
Brazil Current ◽  
North Brazil

<p>Large oceanic eddies are formed by the retroflection of the North Brazil Current (NBC) near 8°N in the western tropical Atlantic. The EUREC<sup>4</sup>A-OA/Atomic cruise took place in January - February 2020, and extensively documented two NBC rings. The NBC flows northward across the Equator and pass the mouth of the Amazon River, entraining fresh and nutrient-rich water along its nearshore edge. From December to March, the Amazon river discharge is low but a freshwater filament stirred by a NBC ring was nevertheless observed. The strong salinity gradient can be used to delineate the NBC ring during its initial phase and its westward propagation. Using satellite sea surface salinity and ocean color associated to in-situ measurements of salinity, temperature, dissolved inorganic carbon, alkalinity and fugacity of CO<sub>2</sub> we characterize the salinity and biogeochemical signature of NBC rings.</p>

Long-term performance of biological ion exchange for the removal of natural organic matter and ammonia from surface waters

2018 ◽  
Vol 146 ◽  
pp. 1-9 ◽  
Author(s):  
Nargess Amini ◽  
Isabelle Papineau ◽  
Veronika Storck ◽  
Pierre R. Bérubé ◽  
Madjid Mohseni ◽  
...  
Keyword(s):  
Organic Matter ◽  
Ion Exchange ◽  
Natural Organic Matter ◽  
Surface Waters ◽  
Long Term Performance ◽  
Term Performance

scholarly journals Do separated taxa react differently to a long-term salinity increase? The meiobenthos changes in Bay Sivash, largest hypersaline lagoon worldwide

2019 ◽  
pp. 36 ◽  
Author(s):  
Nickolai Shadrin ◽  
Elena Kolesnikova ◽  
Tatiana Revkova ◽  
Alexander Latushkin ◽  
Anna Chepyzhenko ◽  
...  
Keyword(s):  
Salinity Gradient ◽  
Drainage Water ◽  
Irrigated Agriculture ◽  
The North ◽  
Filamentous Green Algae ◽  
Ecosystem Shift ◽  
Salinity Increase ◽  
Previous State ◽  
Hypersaline Lagoon

In the world's largest hypersaline lagoon Bay Sivash, its ecosystem twice transformed from a previous state to a new one due to human intervention. Before the North Crimean Canal construction, it was hypersaline (average salinity of 140 g l−1). The canal was built between 1963 and 1975, which resulted in intensive development of irrigated agriculture discharging drainage water into the bay. Between 1988 and 2013, salinity gradually dropped to average of 18–23 g l−1; a new ecosystem with a different biotic composition formed. In April 2014, the supply of Dnieper water into the North Crimean Canal ceased. This resulted in a gradual salinity increase in the bay to an average of 52 g l−1 in 2015. The start of second ecosystem shift was observed in 2015. In 2018, TSS, DOM and meiobenthos were studied in a salinity gradient from 30 to 88 g l−1. There was an increase in TSS and DOM with increasing salinity. The meiobenthos structure was significantly different in the bottom community and floating mats of filamentous green algae. No correlation was recorded between the number of meiobenthic macrotaxa in the sample and salinity. From 2013 to 2018, changes were seen in the taxocene structure of Nematoda and Harpacticoida. Changes in Nematoda were more dramatic and prolonged than in Harpacticoida. The structure of the Harpacticoida and Ostracoda taxocenes are less variable and more stable than that of the Nematoda taxocene. One of the reasons may be more mobility of Harpacticoida/Ostracoda than Nematoda and/or better osmoadaptation mechanisms.

Surface waters in the north of the Coral Sea

1975 ◽  
Vol 26 (2) ◽  
pp. 293 ◽  
Author(s):  
JR Donguy ◽  
C Henin
Keyword(s):  
Surface Waters ◽  
New Guinea ◽  
Wind Component ◽  
Local Formation ◽  
Surface Salinity ◽  
West Wind ◽  
Low Salinity ◽  
The North ◽  
Coral Sea

North of New Guinea, the eastward flow is not fast enough to bring the diluted water from the westernmost Pacific to the Coral Sea where, in the north, from February to June, the surface salinity is less than 34.5‰. This low salinity is always associated with a west wind component bringing rainfall. The surface salinity chart in January-February 1971 shows a salinity minimum isolated from its once supposed western origin by saltier water in the north of New Guinea. These features suggest local formation of this low salinity.

scholarly journals Landscape Influence on the Browning of a Lake Watershed in the Adirondack Region of New York, USA

Soil Systems ◽  
2020 ◽  
Vol 4 (3) ◽  
pp. 50 ◽  
Author(s):  
Nicholas A. LoRusso ◽  
Marykate McHale ◽  
Patrick McHale ◽  
Mario Montesdeoca ◽  
Teng Zeng ◽  
...  
Keyword(s):  
New York ◽  
Organic Matter ◽  
Surface Waters ◽  
Subsequent Increase ◽  
Carbon Quality ◽  
Lake Outlet ◽  
Parallel Factor ◽  
And Shifts ◽  
Insight Into

Watershed recovery from long-term acidification in the northeastern U.S. has been characterized by an increase in the influx of dissolved organic matter (DOM) into surface waters. Increases in carbon quantity and shifts to more aromatic and “colored” OM has impacted downstream lakes by altering thermal stratification, nutrient cycling and food web dynamics. Here, we used fluorescence spectroscopy coupled with parallel factor analysis (PARAFAC) to model predominant carbon quality fractions and their seasonal changes within surface waters along landscape positions of Arbutus Lake watershed in the Adirondack region of NY, USA. All DOM components were terrestrial in origin, however their relative fractions varied throughout the watershed. DOM in headwater streams contained high fractions of recalcitrant (~43%) and microbial reprocessed humic-like OM (~33%), sourced from upland forest soils. Wetlands above the lake inlet contributed higher fractions of high molecular weight, plant-like organic matter (~30%), increasing dissolved organic carbon (DOC) concentrations observed at the lake inlet (492.5 mg L−1). At the lake outlet, these terrestrial fractions decreased significantly during summer months leading to a subsequent increase in reprocessed OM likely through increased microbial metabolism and photolysis. Comparisons of specific ultraviolet absorbance between this study and previous studies at Arbutus Lake show that OM draining upland streams (3.1 L·mg C−1 m−1) and wetland (4.1 L·mg C−1 m−1) is now more aromatic and thus more highly colored than conditions a decade ago. These findings provide insight into the emerging role that watersheds recovering from acidification play on downstream water quality.

Sulphur constraints on peatland carbon cycle

2021 ◽  
Author(s):  
Fred Worrall ◽  
Ian Boothroyd ◽  
Catherine Moody ◽  
Gareth Clay ◽  
Geoff Abbott
Keyword(s):  
Organic Matter ◽  
Atmospheric Deposition ◽  
Peat Soil ◽  
Terminal Electron Acceptor ◽  
The North ◽  
Blanket Bog ◽  
Greenhouse Gas Budget ◽  
Groundwater Source ◽  
Reduction Capacity

<p>The reduction of sulphate  (SO ) represents an alternative terminal electron acceptor for the oxidation of organic matter in peat soils. The greenhouse gas budget in peatlands will be constrained by how much a peatland can utilise SO<sub>4</sub> reduction and provide an alternative to methanogenesis. This study used records of atmospheric deposition and stream chemistry coupled with elemental analysis of peat soil, vegetation and dissolved organic matter (DOM) from streams and soil porewater, to estimate a 23-year long sulphur (S) budget for a blanket bog-covered catchment in the North Pennines, England. The study showed that:</p><ul><li>1) Atmospheric deposition of total S significantly declined over the study period from 2.4 to 0.5 t S/km<sup>2</sup>/yr.</li> <li>2) Long term accumulation of S into deep peat at 1 m depth averaged 127 kg S/km<sup>2</sup>/yr.</li> <li>3) Based upon shallow soil water concentrations the total S fluvial flux peaked as 4.5 t S/km<sup>2</sup>/yr with an average of 0.7 t S/km<sup>2</sup>/yr. The flux of total S increased over the catchment suggesting a groundwater source of oxidised S.</li> <li>4) Over the 23 years of monitoring, 0.25 t S/km<sup>2</sup>/yr were reduced to either mineral sulphides or hydrogen sulphide; however, in 8 out of the 23 years the catchment was a net producer of S to the streams of the catchment.</li> </ul><p>At maximum observed S reduction capacity the peatland was capable of a net removal of 71% of atmospheric S deposition. Allowing for the efficiency of energy transfer in the redox process and the oxidation state of peat organic matter means that for every mole of SO<sub>4</sub> reduced, 1.69 moles of CO<sub>2</sub> were produced and not the 2 moles normally assumed. In this catchment an average of 0.47 t C/km<sup>2</sup>/yr are diverted from methanogenesis.</p>

scholarly journals Changes of Subtropical North Pacific Radiocarbon and Correlation with Climate Variability

Radiocarbon ◽  
2001 ◽  
Vol 43 (1) ◽  
pp. 15-25 ◽  
Author(s):  
Ellen R M Druffel ◽  
S Griffin ◽  
T P Guilderson ◽  
M Kashgarian ◽  
J Southon ◽  
...  
Keyword(s):  
Surface Waters ◽  
North Pacific ◽  
Physical Mechanism ◽  
Vertical Mixing ◽  
Past Century ◽  
The Past ◽  
The North ◽  
North Pacific Gyre ◽  
The North Pacific

We show that high-precision radiocarbon (Δ14C) measurements from annual bands of a Hawaiian surface coral decreased by 7‰ from AD 1893 to 1952. This decrease is coincident with the Suess Effect, which is mostly due to the dilution of natural levels of 14C by 14C-free fossil fuel CO2. This decrease is equal to that expected in surface waters of the subtropical gyres, and indicates that the surface waters of the North Pacific were in steady state with respect to long term mixing of CO2 during the past century. Correlation between Δ14C and North Pacific gyre sea surface temperatures indicates that vertical mixing local to Hawaii and the North Pacific gyre as a whole is the likely physical mechanism to result in variable Δ14C. Prior to 1920, this correlation starts to break down; this may be related to the non-correlation between biennial Δ14C values in corals from the southwest Pacific and El Niño events observed during this period as well.

scholarly journals Long-Term Variability of Temperature and 14C in the Gulf Stream: Oceanographic Implications

Radiocarbon ◽  
1983 ◽  
Vol 25 (2) ◽  
pp. 449-458 ◽  
Author(s):  
Ellen M Druffel
Keyword(s):  
Ocean Circulation ◽  
North Atlantic ◽  
Surface Waters ◽  
Gulf Stream ◽  
18Th Century ◽  
Maunder Minimum ◽  
Ice Age ◽  
The Past ◽  
The North

Variability in temperature and 14C levels are recorded in coralline aragonite that grew in the Gulf Stream during the past four centuries. In particular, 18O/16O ratios reflect a decrease of ca 1°C in surface water temperature during the latter part of the Little Ice age. 14C levels also rose in the surface waters of the Gulf Stream and in atmospheric CO2 during the Maunder minimum. These observations indicate that ocean circulation may have been significantly different in the North Atlantic around the beginning of the 18th century.

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