Projects per year
Abstract
Key messages:
1.1 The process of ocean acidification is now relatively well-documented at the global scale as a long-term trend in the open ocean. However, short-term and spatial variability can be high.
1.2 New datasets made available since Charting Progress 2 make it possible to greatly improve the characterisation of CO2 and ocean acidification in UK waters.
3.1 Recent UK cruise data contribute to large gaps in national and global datasets.
3.2 The new UK measurements confirm that pH is highly variable, therefore it is important to measure consistently to determine any long term trends.
3.3 Over the past 30 years, North Sea pH has decreased at 0.0035±0.0014 pH units per year.
3.4 Upper ocean pH values are highest in spring, lowest in autumn. These changes reflect the seasonal cycles in photosynthesis, respiration (decomposition) and water mixing.
3.5 Carbonate saturation states are minimal in the winter, and lower in 7 more northerly, colder waters. This temperature-dependence could have implications for future warming of the seas.
3.6 Over the annual cycle, North-west European seas are net sinks of CO2. However, during late summer to autumn months, some coastal waters may be significant sources.
3.7 In seasonally-stratified waters, sea-floor organisms naturally experience
lower pH and saturation states; they may therefore be more vulnerable to threshold changes.
3.8 Large pH changes (0.5 - 1.0 units) can occur in the top 1 cm of sediment;
however, such effects are not well-documented.
3.9 A coupled forecast model estimates the decrease in pH trend within the North Sea to be -0.0036±0.00034 pH units per year, under a high greenhouse gas emissions scenario (RCP 8.5).
3.10 Seasonal estimates from the forecast model demonstrate areas of the North Sea that are particularly vulnerable to aragonite undersaturation.
1.1 The process of ocean acidification is now relatively well-documented at the global scale as a long-term trend in the open ocean. However, short-term and spatial variability can be high.
1.2 New datasets made available since Charting Progress 2 make it possible to greatly improve the characterisation of CO2 and ocean acidification in UK waters.
3.1 Recent UK cruise data contribute to large gaps in national and global datasets.
3.2 The new UK measurements confirm that pH is highly variable, therefore it is important to measure consistently to determine any long term trends.
3.3 Over the past 30 years, North Sea pH has decreased at 0.0035±0.0014 pH units per year.
3.4 Upper ocean pH values are highest in spring, lowest in autumn. These changes reflect the seasonal cycles in photosynthesis, respiration (decomposition) and water mixing.
3.5 Carbonate saturation states are minimal in the winter, and lower in 7 more northerly, colder waters. This temperature-dependence could have implications for future warming of the seas.
3.6 Over the annual cycle, North-west European seas are net sinks of CO2. However, during late summer to autumn months, some coastal waters may be significant sources.
3.7 In seasonally-stratified waters, sea-floor organisms naturally experience
lower pH and saturation states; they may therefore be more vulnerable to threshold changes.
3.8 Large pH changes (0.5 - 1.0 units) can occur in the top 1 cm of sediment;
however, such effects are not well-documented.
3.9 A coupled forecast model estimates the decrease in pH trend within the North Sea to be -0.0036±0.00034 pH units per year, under a high greenhouse gas emissions scenario (RCP 8.5).
3.10 Seasonal estimates from the forecast model demonstrate areas of the North Sea that are particularly vulnerable to aragonite undersaturation.
Original language | English |
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Publisher | University of East Anglia |
Number of pages | 44 |
DOIs | |
Publication status | Published - 23 Jun 2016 |
Profiles
-
Dorothee Bakker
- School of Environmental Sciences - Professor in Marine Biogeochemistry
- Centre for Ocean and Atmospheric Sciences - Member
- ClimateUEA - Member
Person: Research Group Member, Academic, Teaching & Research
-
Tim Jickells
- School of Environmental Sciences - Emeritus Professor
- Centre for Ocean and Atmospheric Sciences - Member
- ClimateUEA - Member
Person: Honorary, Research Group Member
-
Carol Robinson
- School of Environmental Sciences - Professor of Marine Sciences
- Centre for Ecology, Evolution and Conservation - Member
- Centre for Ocean and Atmospheric Sciences - Member
- Collaborative Centre for Sustainable Use of the Seas - Member
- Environmental Biology - Member
- ClimateUEA - Member
Person: Research Group Member, Research Centre Member, Academic, Teaching & Research
Projects
- 1 Finished
-
UK Ocean Acidification Science Coordination Programme. (Dr P Williamson)
Natural Environment Research Council
1/04/07 → 31/03/16
Project: Research