Air—sea C0 2 transfer and the carbon budget of the North Atlantic

1995 ◽  
Vol 348 (1324) ◽  
pp. 211-219 ◽  

A model simulation of the global carbon cycle demonstrates that the biological and solubility pumps are of comparable importance in determining the spatial distribution of annual mean air-sea fluxes in the Atlantic. The model also confirms that the impact of the (steady state) biological pump on the magnitude and spatial distribution of anthropogenic CO 2 uptake is minimal. An Atlantic Ocean carbon budget developed from analysis of the model combined with observations suggests that the air-sea flux of carbon is inadequate to supply the postulated large dissolved inorganic carbon export from the Atlantic. Other sources of carbon are required, such as an input from the Pacific via the Bering Strait and Arctic, river inflow, or an import of dissolved organic carbon.

2016 ◽  
Vol 13 (3) ◽  
pp. 841-863 ◽  
Author(s):  
H. Brenner ◽  
U. Braeckman ◽  
M. Le Guitton ◽  
F. J. R. Meysman

Abstract. It has been previously proposed that alkalinity release from sediments can play an important role in the carbonate dynamics on continental shelves, lowering the pCO2 of seawater and hence increasing the CO2 uptake from the atmosphere. To test this hypothesis, sedimentary alkalinity generation was quantified within cohesive and permeable sediments across the North Sea during two cruises in September 2011 (basin-wide) and June 2012 (Dutch coastal zone). Benthic fluxes of oxygen (O2), alkalinity (AT) and dissolved inorganic carbon (DIC) were determined using shipboard closed sediment incubations. Our results show that sediments can form an important source of alkalinity for the overlying water, particularly in the shallow southern North Sea, where high AT and DIC fluxes were recorded in near-shore sediments of the Belgian, Dutch and German coastal zone. In contrast, fluxes of AT and DIC are substantially lower in the deeper, seasonally stratified, northern part of the North Sea. Based on the data collected, we performed a model analysis to constrain the main pathways of alkalinity generation in the sediment, and to quantify how sedimentary alkalinity drives atmospheric CO2 uptake in the southern North Sea. Overall, our results show that sedimentary alkalinity generation should be regarded as a key component in the CO2 dynamics of shallow coastal systems.


2014 ◽  
Vol 11 ◽  
pp. 72-81
Author(s):  
Peter Wood

In April, 1845, the Rev. Richard Taylor passed through the area of the North Island now marked by the town of Levin. At this time, he described Lake Horowhenua as being of singular appearance for the small storehouses built over the water on poles. As was his predilection, Taylor made a drawing of the lake huts, a version of which was belatedly included in the second edition of his most important literary contribution, Te Ika-a-Māui (1870). This image would have remained as little more than a questionable curiosity was it not for Messrs Black Bros who, in the course of exploring the lake bed for Māori artefacts in 1932, legitimised Taylor's observation with their discovery of the submerged architectural remains of an aquatic hut. Nonetheless, almost a century after Taylor's original diary entry, GL Adkin, writing for The Journal of the Polynesian Society, lamented the neglect shown toward these remarkable structures, and which he cited as just one example of the "tantalising gaps" in the recorded history of Māori custom and culture. Sadly, it is well beyond the scope of this research to properly redress the historical neglect shown toward lake pātaka. What I do wish to do is to link these structures to an event on the shores of the Lake of Zurich, Switzerland, when Dr Ferdinand Keller noticed some half-submerged piles in 1854. Upon these remains Keller made a great, if erroneous, case for primitive "pile-work habitations" in the Swiss lakes. The impact of this argument cannot be understated. It became the privileged model for architectural origins in the German and French parts of Switzerland, and by the 1890s it was a part of standard teaching texts in Swiss schools, where it was firmly inculcated into the curriculum at the time that Charles Edouard Jeanneret was a child. This in turn has led Vogt to suggest that, in Keller's "dwellings on the water," Le Corbusier found a Primitive Hut typology that underpinned all his architectural thinking, and which is made most explicit in his principled use of piloti. What makes this all the more involved is that Keller, in searching for examples to visualise the construction of the Swiss lake dwellings, turned to the Pacific (which he categorised as at a developmental stage of architectural evolution akin to early Europe). In this paper I identify the exact etching by Louis Auguste de Sainson that Keller took for direct influence. The problem, however, is that de Sainson depicted a conventional whare built on land, and Keller transposed it to the water. So we have on the one side of this paper an authentic lake whare that is all but forgotten, and a famed European lake-hut that is all but Māori, and between the two is the figure of Le Corbusier who may or may not have unknowingly based one on his major innovations on influences found in the pātaka of Lake Horowhenua.


2008 ◽  
Vol 86 (1) ◽  
pp. 76-79 ◽  
Author(s):  
Jeff W. Higdon

The comments by A. Romero and S. Kannada (2006. Can. J. Zool. 84: 1059–1065) provide a brief summary of North Atlantic whaling history as a critique of T. Rastogi et al. (2004. Can. J. Zool. 82: 1647–1654) . However, they fall far short of providing an accurate review of whaling history in this region. The authors present a number of factual errors, misuse several key sources, and make significant omissions, ultimately defeating the purpose of providing information to biologists, managers, and historians. In this comment I highlight the mistakes in their representation of the history of North Atlantic whaling for bowhead whales ( Balaena mysticetus L., 1758). There are unacceptable errors for most nations covered, and for American whaling in particular. The authors assert that over 30 000 bowhead whales were landed by Yankee whalers in the North Atlantic when the vast majority were in fact taken on the Pacific grounds. Although a summary of whaling history is an admirable goal and of potential value, it is unfortunate that the authors missed such an opportunity by failing to adequately research this topic, failing to include important citations, and by including sources that do not provide the information indicated. Providing a whaling summary with such errors and omissions only adds further confusion to an already confusing theme.


2010 ◽  
Vol 40 (12) ◽  
pp. 2661-2678 ◽  
Author(s):  
Elaine L. McDonagh ◽  
Paula McLeod ◽  
Brian A. King ◽  
Harry L. Bryden ◽  
Sinhué Torres Valdés

Abstract In May and June 2005, a transatlantic hydrographic section along 36°N was occupied. A velocity field is calculated using inverse methods. The derived 36°N circulation has an overturning transport (maximum in the overturning streamfunction) of 16.6 Sv (1 Sv ≡ 106 m3 s−1) at 1070 m. The heat transport across the section, 1.14 ± 0.12 PW, is partitioned into overturning and horizontal heat transports of 0.75 and 0.39 PW, respectively. The horizontal heat flux is set by variability at the gyre rather than by mesoscale. The freshwater flux across the section is 1.55 ± 0.18 Sv southward based on a 0.8-Sv flow from the Pacific through the Bering Strait at a salinity of 32.5 psu. The oceanic divergence of freshwater implies a net input of freshwater to the ocean of 0.75 Sv over the North Atlantic and Arctic between 36°N and the Bering Strait. Most (85%) of the recently ventilated upper North Atlantic Deep Water (water originating in the Labrador Sea) transport across the section occurs in the deep western boundary current rather than being associated with an interior pathway to the west of the mid-Atlantic ridge.


Paleobiology ◽  
2012 ◽  
Vol 38 (3) ◽  
pp. 374-390 ◽  
Author(s):  
Heather S. Birch ◽  
Helen K. Coxall ◽  
Paul N. Pearson

The carbon stable isotope (δ13C) composition of the calcitic tests of planktonic foraminifera has an important role as a geochemical tracer of ocean carbon system changes associated with the Cretaceous/Paleogene (K/Pg) mass extinction event and its aftermath. Questions remain, however, about the extent of δ13C isotopic disequilibrium effects and the impact of depth habitat evolution on test calcite δ13C among rapidly evolving Paleocene species, and the influence this has on reconstructed surface-to-deep ocean dissolved inorganic carbon (DIC) gradients. A synthesis of new and existing multispecies data, on the relationship between δ13C and δ18O and test size, sheds light on these issues. Results suggest that early Paleocene species quickly radiated into a range of depths habitats in a thermally stratified water column. Negative δ18O gradients with increasing test size in some species ofPraemuricasuggest either ontogenetic or ecotypic dependence on calcification temperature that may reflect depth/light controlled variability in symbiont photosynthetic activity. The pattern of positive δ13C test-size correlations allows us to (1) identify metabolic disequilibrium δ13C effects in small foraminifera tests, as occur in the immediate aftermath of the K/Pg event, (2) constrain the timing of evolution of foraminiferal photosymbiosis to 63.5 Ma, ∼0.9 Myr earlier than previously suggested, and (3) identify the apparent loss of symbiosis in a late-ranging morphotype ofPraemurica. These findings have implications for interpreting δ13C DIC gradients at a resolution appropriate for incoming highly resolved K/Pg core records.


Author(s):  
Javad Koohpayma ◽  
Amir Tahooni ◽  
Mohammad reza Jelokhni ◽  
Jamal Jokar Arsanjani

Car parking is a challenging part of urban transportation and the traffic violations around it cause many problems for citizens. In recent years, due to the fast growth and development of urbanization, temporary and unauthorized stopping of cars along the streets, especially in large cities, has led to an increased traffic, urban disorders, dangers for citizens, and violation of rules. Studies have shown that there is a direct relationship between vehicle parking violations and urban places. GIScience capabilities and tools play an important role in analysing the spatial distribution of these violations. In this study, we investigated the spatial distribution of vehicle violations in a region of Tehran, Iran that is suffering from a heavy traffic load and heavily polluted air. Although two dissimilar urban segregations exist in the north and south of the study area, our analysis indicates a similar pattern of car parking violations. In both of the areas, about 70% of all curb parks are legal, while the remaining are illegal. Also, spatial analysis reveals a direct relationship between some POIs and the occurrence of car park violations so that the density of legal curb parks is high near some POIs, and less near some others and vice versa. For example, the number of vehicle park violation around the hospitals is more than the average of the study area. However, the number of park violations around the universities is less than the average. Our findings reveal that co-location of certain POIs, for instance a hotel and a supermarket will lead to an increase in the number of park violations. In other words, there is a strong correlation between the type of POIs and curb-parks violations. Our results also show that POIs have an impact radius that leads to violations occurring in that area. For example, the area of the impact of a hospital on the creation of car park violations was estimated at 125 meters. Our presented approach along with the discussed findings along with conclusions can be useful to a large range of stakeholders including urban planner, traffic police departments, local municipalities, law enforcement agencies, and environmentalists to have a better perspective of infrastructure planning.


2021 ◽  
Vol 8 ◽  
Author(s):  
Jean-Philippe Gac ◽  
Pierre Marrec ◽  
Thierry Cariou ◽  
Emilie Grosstefan ◽  
Éric Macé ◽  
...  

Weekly and bi-monthly carbonate system parameters and ancillary data were collected from 2008 to 2020 in three coastal ecosystems of the southern Western English Channel (sWEC) (SOMLIT-pier and SOMLIT-offshore) and Bay of Brest (SOMLIT-Brest) located in the North East Atlantic Ocean. The main drivers of seasonal and interannual partial pressure of CO2 (pCO2) and dissolved inorganic carbon (DIC) variabilities were the net ecosystem production (NEP) and thermodynamics. Differences were observed between stations, with a higher biological influence on pCO2 and DIC in the near-shore ecosystems, driven by both benthic and pelagic communities. The impact of riverine inputs on DIC dynamics was more pronounced at SOMLIT-Brest (7%) than at SOMLIT-pier (3%) and SOMLIT-offshore (<1%). These three ecosystems acted as a weak source of CO2 to the atmosphere of 0.18 ± 0.10, 0.11 ± 0.12, and 0.39 ± 0.08 mol m–2 year–1, respectively. Interannually, air-sea CO2 fluxes (FCO2) variability was low at SOMLIT-offshore and SOMLIT-pier, whereas SOMLIT-Brest occasionally switched to weak annual sinks of atmospheric CO2, driven by enhanced spring NEP compared to annual means. Over the 2008–2018 period, monthly total alkalinity (TA) and DIC anomalies were characterized by significant positive trends (p-values < 0.001), from 0.49 ± 0.20 to 2.21 ± 0.39 μmol kg−1 year−1 for TA, and from 1.93 ± 0.28 to 2.98 ± 0.39 μmol kg–1 year–1 for DIC. These trends were associated with significant increases of calculated seawater pCO2, ranging from +2.95 ± 1.04 to 3.52 ± 0.47 μatm year–1, and strong reductions of calculated pHin situ, with a mean pHin situ decrease of 0.0028 year–1. This ocean acidification (OA) was driven by atmospheric CO2 forcing (57–66%), Sea surface temperature (SST) increase (31–37%), and changes in salinity (2–5%). Additional pHin situ data extended these observed trends to the 2008–2020 period and indicated an acceleration of OA, reflected by a mean pHin situ decrease of 0.0046 year–1 in the sWEC for that period. Further observations over the 1998–2020 period revealed that the climatic indices North Atlantic Oscillation (NAO) and Atlantic Multidecadal Variability (AMV) were linked to trends of SST, with cooling during 1998–2010 and warming during 2010–2020, which might have impacted OA trends at our coastal stations. These results suggested large temporal variability of OA in coastal ecosystems of the sWEC and underlined the necessity to maintain high-resolution and long-term observations of carbonate parameters in coastal ecosystems.


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