BIGCOW · BIoGeochemistry in a high CO2 World (BIGCOW): lessons from the Ocean Anoxic Events
7РП — „Хора“ (Действия „Мария Кюри“)
- Период
- 2009-11-01 → 2011-10-31
- Финансиране от ЕС
- 174 703 €
- Участници
- 1
- Схема
- MC-IEF
Линиите свързват координатора с партньорите.
Накратко на български
Древните събития с липса на кислород в океаните се анализират чрез модели, за да се разбере дали са причинени от затоплянето или от повишената морска продуктивност. Резултатите помагат да се разбере как Земята реагира на въглеродния диоксид и как се образуват петролните залежи.
Кратко обяснение, генерирано от езиков модел по текста на CORDIS. Оригиналът е по-долу.
Резултати накратко
Biogeochemistry in a high CO2 world: Lessons from the ocean anoxic events
Ancient oceanic anoxic events (OAEs) represent profound perturbations of the global carbon cycle and oxygenation of the global oceans and are the times when much of the world's oil and gas reserves were formed during deposition of unusually organic carbon rich 'black shale' layers in marine sediments. This project assessed the relative importance of changes in oxygen supply (combining oxygen solubility and ocean circulation) and marine productivity in creating these extreme environmental conditions. An Earth system model was set up to account for the main ocean dynamics and biogeochemistry of the cretaceous climate. The impact of higher temperatures and marine productivity were then evaluated in the model against a new compilation of observations for seafloor anoxia. The model shows that temperature is not able alone to reproduce observations but rather the observed patterns of ocean anoxia are reproduced mainly via enhanced marine productivity due to higher nutrient content. The results have implications for our understanding of how the Earth system responds to long-term carbon dioxide (CO2) release and warming and how and when conditions for oil source rock formation are created. The finding that warming alone exerts only a minor influence in promoting seafloor anoxia reduces the concerns that any such similar occurrence could be a possibility in the near future.
Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз
Цел на проекта
Model predictions are regularly made about the state of marine ecosystems and carbon cycle in a future high CO2 world. But while increased ocean stratification means lower future biological export production in some models, in others, higher temperatures inducing faster rates of biological activity drive completely the opposite response. Rates of nitrogen fixation may increase in a warmer ocean and support higher production, but at the same time, loss rates of nitrate will increase as oxygen minimum zones expand and intensify. The cycling of iron also plays a critical role in controlling marine productivity and may limit nitrogen fixation. Yet, while iron bio-availability will be affected by changes in temperature, acidity, and oxygenation, no current model accounts for how iron solubility will respond to future ocean geochemical environmental changes. How can we increase confidence in predicting the intertwined response of nutrient and carbon cycles in a high CO2 world? The geological record contains case studies into the range of possible Earth system behaviours, states, and strengths of feedbacks. Of particularly interest here are the Ocean Anoxic Events of the Mesozoic, which were associated with profound global-scale perturbations of climate and marine biogeochemical cycles, high plankton turnover rates and biological extinction, and the burial of economically important quantities of organic carbon in black shales. They have relevance to future marine biological consequences of warming and acidification, and the spread oxygen minimum zones. Here we propose the first model of marine iron cycle applicable to a high CO2 world, the first analysis of the dynamical interaction of all three nutrient cycles (P, N, Fe), CO2, and climate associated with the onset of Ocean Anoxic Event like conditions, and the first explicit test of the role of iron in triggering an Ocean Anoxic Event.
Оригинален текст от CORDIS (на английски).
Участници
- UNIVERSITY OF BRISTOL · BRISTOLКоординаторОбединеното кралство
Връзки
Данни: CORDIS, © Европейски съюз