Summing-up

1981 ◽  
Vol 302 (1472) ◽  
pp. 683-689 ◽  
Keyword(s):  
Biological Activity ◽  
Cold Water ◽  
Shelf Break ◽  
Shelf Edge ◽  
Physical Processes ◽  
European Shelf ◽  
Shelf Seas ◽  
The Subject ◽  
General Aspects ◽  
Northwest European Shelf

The various contributions to the Discussion Meeting are related to general aspects of the subject, and some topics requiring further investigation are identified. These include the evolution and stability of fronts, and the processes by which cross-frontal and cross-shelf mixing take place. The relation of physical processes to the growth of phytoplankton in the vicinity of fronts needs further study. Among points relating particularly to the northwest European shelf seas are the influence of the oceanic flow at the shelf edge and the nature of the band of cold water, with its zone of enhanced biological activity, that occurs over the Celtic Sea shelf break in summer.

scholarly journals High Resolution pH Measurements Using a Lab-on-Chip Sensor in Surface Waters of Northwest European Shelf Seas

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2622 ◽  
Author(s):  
Victoire Rérolle ◽  
Eric Achterberg ◽  
Mariana Ribas-Ribas ◽  
Vassilis Kitidis ◽  
Ian Brown ◽  
...  
Keyword(s):  
High Resolution ◽  
Surface Waters ◽  
Ph Sensor ◽  
Ph Measurements ◽  
Lab On Chip ◽  
European Shelf ◽  
Shelf Seas ◽  
On Chip ◽  
Chemistry Dynamics ◽  
Northwest European Shelf

Increasing atmospheric CO2 concentrations are resulting in a reduction in seawater pH, with potential detrimental consequences for marine organisms. Improved efforts are required to monitor the anthropogenically driven pH decrease in the context of natural pH variations. We present here a high resolution surface water pH data set obtained in summer 2011 in North West European Shelf Seas. The aim of our paper is to demonstrate the successful deployment of the pH sensor, and discuss the carbonate chemistry dynamics of surface waters of Northwest European Shelf Seas using pH and ancillary data. The pH measurements were undertaken using spectrophotometry with a Lab-on-Chip pH sensor connected to the underway seawater supply of the ship. The main processes controlling the pH distribution along the ship’s transect, and their relative importance, were determined using a statistical approach. The pH sensor allowed 10 measurements h−1 with a precision of 0.001 pH units and a good agreement with pH calculated from a pair of discretely sampled carbonate variables dissolved inorganic carbon (DIC), total alkalinity (TA) and partial pressure of CO2 (pCO2) (e.g., pHDICpCO2). For this summer cruise, the biological activity formed the main control on the pH distribution along the cruise transect. This study highlights the importance of high quality and high resolution pH measurements for the assessment of carbonate chemistry dynamics in marine waters.

scholarly journals Controls on pH in surface waters of northwestern European shelf seas

2014 ◽  
Vol 11 (1) ◽  
pp. 943-974 ◽  
Author(s):  
V. M. C. Rérolle ◽  
M. Ribas-Ribas ◽  
V. Kitidis ◽  
I. Brown ◽  
D. C. E. Bakker ◽  
...  
Keyword(s):  
Biological Activity ◽  
Surface Water ◽  
Irish Sea ◽  
Carbonate Chemistry ◽  
Ph Distribution ◽  
European Shelf ◽  
Shelf Seas ◽  
Water Ph ◽  
The Impact ◽  
Chemistry Dynamics

Abstract. We present here a high resolution surface water pH dataset obtained in the Northwest European shelf seas in summer 2011. This is the first time that pH has been measured at such a high spatial resolution (10 measurements h–1) in this region. The aim of our paper is to investigate the carbonate chemistry dynamics of the surface water using pH and ancillary data. The main processes controlling the pH distribution along the ship's transect, and their relative importance, were determined using a statistical approach. The study highlights the impact of biological activity, temperature and riverine inputs on the carbonate chemistry dynamics of the shelf seas surface water. For this summer cruise, the biological activity formed the main control of the pH distribution along the cruise transect. Variations in chlorophyll and nutrients explained 29% of the pH variance along the full transect and as much as 68% in the northern part of the transect. In contrast, the temperature distribution explained ca. 50% of the pH variation in the Skagerrak region. Riverine inputs were evidenced by high dissolved organic carbon (DOC) levels in the Strait of Moyle (northern Irish Sea) and the southern North Sea with consequent remineralisation processes and a reduction in pH. The DOC distribution described 15% of the pH variance along the full transect. This study highlights the high spatial variability of the surface water pH in shelf seawaters where a range of processes simultaneously impacts the carbonate chemistry.

scholarly journals Uncertainty in climate projections for the 21st century northwest European shelf seas

2016 ◽  
Vol 148 ◽  
pp. 56-73 ◽  
Author(s):  
Jonathan Tinker ◽  
Jason Lowe ◽  
Anne Pardaens ◽  
Jason Holt ◽  
Rosa Barciela
Keyword(s):  
21St Century ◽  
Climate Projections ◽  
European Shelf ◽  
Shelf Seas ◽  
Northwest European Shelf

Wave power variability over the northwest European shelf seas

2013 ◽  
Vol 106 ◽  
pp. 31-46 ◽  
Author(s):  
Simon P. Neill ◽  
M. Reza Hashemi
Keyword(s):  
Wave Power ◽  
European Shelf ◽  
Shelf Seas ◽  
Northwest European Shelf

scholarly journals The impact of melt water discharge from the Greenland ice sheet on the Atlantic nutrient supply to the Northwest European Shelf

2019 ◽  
Author(s):  
Moritz Mathis ◽  
Uwe Mikolajewicz
Keyword(s):  
Mixed Layer ◽  
Regime Shift ◽  
Greenland Ice Sheet ◽  
Nutrient Supply ◽  
Shelf Break ◽  
System Model ◽  
Ne Atlantic ◽  
European Shelf ◽  
The Impact ◽  
Northwest European Shelf

Abstract. Projected future shoaling of the wintertime mixed layer in the Northeast (NE) Atlantic has been shown to induce a regime shift in the main nutrient supply pathway from the Atlantic to the Northwest European Shelf (NWES) near the end of the 21st century. While reduced winter convection leads to a substantial decrease in the vertical nutrient supply and biological productivity in the open ocean, vertical mixing processes at the shelf break maintain a connection to the subpycnocline nutrient pool and thus productivity on the shelf. Here we investigate how meltwater discharge from the Greenland ice sheet (GIS) not yet taken into account impacts the mixed layer shoaling and the regime shift in terms of spatial distribution and temporal variability. To this end we have downscaled sensitivity experiments by a global earth system model for various GIS melting rates with a regionally coupled ocean-atmosphere climate system model. The model results indicate that increasing GIS meltwater discharge leads to a general intensification of the regime shift. Atlantic subpycnocline water masses mixed up at the shelf break become richer in nutrients and thus limit the projected nutrient decline on the shelf. Moreover, the stronger vertical nutrient gradient through the pycnocline results in an enhanced interannual variability of on-shelf nutrient fluxes which, however, do not significantly increase variations in nutrient concentrations and primary production on the shelf. Moreover, due to the impact of the GIS meltwater discharge on the NE Atlantic mixed layer depth, the regime shift becomes initiated earlier in the century by about 1–2 decades, depending on the discharge rate. The effect on the onset timing, though, is found to be strongly damped by the weakening of the Atlantic meridional overturning circulation. A GIS melting rate that is even 10 times higher than expected for emission scenario RCP8.5 would lead to an onset of the regime shift not until the 2070s.

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