Dynamics of the Earth System In REcovery ('DESIRE')

恢复中的地球系统动力学（“DESIRE”）

• 批准号: NE/I021322/1
• 负责人: Sandra Arndt
• 金额: $ 31.69万
• 依托单位: University of Bristol
• 依托单位国家: 英国
• 项目类别: Fellowship
• 财政年份: 2011
• 资助国家: 英国
• 起止时间: 2011 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FI021322%2F1
• 关键词: Dynamics; Earth; System; REcovery; DESIRE

As we are doing now, at times in the distant geological past, there were massive releases of greenhouse gases such as CO2 to the atmosphere. In the rock record we find evidence for a warming of climate and change in rainfall patterns. How does the Earth recover from being put into this 'greenhouse' state? The obvious way of cooling climate is to remove the CO2 that has been added and to bury it in a form that will not quickly leak back to the atmosphere. By some complicated geochemical and biological trickery, the Earth can turn rocks such as granite into chalks and limestones, which contains carbon atoms bound tightly to calcium, locking up carbon for millions and millions of years (the carbon in the white cliffs of Dover has been safely stored there for over 65 millions years!). Another way to bury carbon is as organic matter and the Earth system has a really fascinating mechanism for preserving this carbon involving the gas given off by rotten eggs - hydrogen sulphide. This can react with organic matter to form new molecules that are more resistant to being broken down by bacteria. The process is a bit like making car tires (which appear highly resistant to decay judging by how many seem to lie strewn across our cities and countryside). So what conditions in the ocean lead to the most preservation and hence burial of organic matter, and what impact on atmospheric CO2 and climate does preserving organic matter with rotten eggs really have? Computer models are great tools and can help answer this. How we understand and represent the Earth's climate system in computer models, while still far from perfect, is progressively improving. Mostly the climate system involves physics, and despite what most students may conclude from school: physics is easy. More difficult to understand is chemistry and biology, particularly when it occurs in smelly (sulphidic) mud sitting at the bottom of the ocean. Yet this is important to understand, because if bacteria were to use up all the oxygen at the ocean floor, they would suddenly find it much harder to break down all the dead 'bodies' of the microscopic plants (phytoplankton) that live and grow in the sunlight at the ocean surface and sink down to depth when they die. I will therefore develop a computer model of chemical reactions to represent how hydrogen sulphide can turn the organic matter from phytoplankton into a much more resistant form in the sediments. Using this model I can firstly better understand the conditions that might produce the perfect rocks for producing oil (and gas). Together with a global carbon cycle and climate model, I will also utilize the geological record to help understand what is possible and how important the different modes of recovery are, and will investigate and compare the burial of these dead bodies in sulphidic mud during two past global warming events: Paleocene-Eocene Thermal Maximum ('PETM') ~55 million years ago (Ma) and the Ocean Anoxic Events ('OAEs') of the early Jurassic (ca. 183 Ma - the Toarcian OAE). From all this, I expect to be able to understand better how increases in the amount of carbon being buried helps the Earth system recover from greenhouse climates and test whether the Earth system might have a special emergency mechanism - if climate gets too warm and oxygen starts to run out in the ocean - the production of hydrogen sulphide as oxygen starts to run out in the ocean and increased burial or organic matter.

正如我们现在所做的那样，在遥远的地质过去，有大量的温室气体，如二氧化碳排放到大气中。在岩石记录中，我们找到了气候变暖和降雨模式变化的证据。地球如何从这种“温室”状态中恢复过来？冷却气候的最明显的方法是去除增加的二氧化碳，并以不会很快泄漏回大气的形式将其掩埋。通过一些复杂的地球化学和生物学技巧，地球可以将花岗岩等岩石变成粉笔和石灰石，其中含有与钙紧密结合的碳原子，将碳锁定数百万年（多佛白色悬崖中的碳已经安全地储存了6500万年以上！）。另一种将碳埋藏的方法是将其作为有机物，地球系统有一种非常迷人的机制来保存这种碳，包括臭鸡蛋释放的气体-硫化氢。它可以与有机物反应形成新的分子，这些分子更能抵抗细菌的分解。这个过程有点像制造汽车轮胎（从我们的城市和农村散落着多少轮胎来判断，这些轮胎似乎具有很强的耐腐性）。那么，海洋中的什么条件导致有机物的保存和埋葬，以及用臭鸡蛋保存有机物对大气二氧化碳和气候的影响？计算机模型是很好的工具，可以帮助回答这个问题。我们如何在计算机模型中理解和代表地球的气候系统，虽然还远远不够完美，但正在逐步改进。大多数情况下，气候系统涉及物理学，尽管大多数学生可能从学校得出结论：物理学很容易。更难理解的是化学和生物学，特别是当它发生在海底发臭的（硫化物）泥中时。然而，理解这一点很重要，因为如果细菌耗尽了海底的所有氧气，它们会突然发现很难分解所有死的微生物（浮游植物）的“尸体”，这些微生物在海洋表面的阳光下生活和生长，当它们死亡时沉入海底。因此，我将开发一个化学反应的计算机模型，以说明硫化氢如何将浮游植物中的有机物质转化为沉积物中更具抵抗力的形式。使用这个模型，我首先可以更好地了解可能产生用于生产石油（和天然气）的完美岩石的条件。连同全球碳循环和气候模型，我还将利用地质记录来帮助了解不同的恢复模式是多么重要，并将调查和比较过去两次全球变暖事件中这些尸体在硫化物泥浆中的埋葬情况：古新世-始新世热最大期（PETM）~ 5500万年前（Ma）和早侏罗世（约1000万年）的海洋缺氧事件（OAE）。183 Ma -Toarcian OAE）。从所有这些，我希望能够更好地理解碳被掩埋量的增加如何帮助地球系统从温室气候中恢复，并测试地球系统是否可能有一个特殊的应急机制-如果气候变得过于温暖，氧气开始在海洋中耗尽-随着氧气开始在海洋中耗尽而产生硫化氢，并增加掩埋或有机物质。

项目成果

C-GEM (v 1.0): a new, cost-efficient biogeochemical model for estuaries and its application to a funnel-shaped system

C-GEM (v 1.0)：一种新的、经济高效的河口生物地球化学模型及其在漏斗形系统中的应用

• DOI: 10.5194/gmdd-6-5645-2013
• 发表时间: 2013
• 作者: Volta C

Dissolved inorganic carbon and alkalinity fluxes from coastal marine sediments: model estimates for different shelf environments and sensitivity to global change

• DOI: 10.5194/bg-10-371-2013
• 发表时间: 2013-01-01
• 期刊: BIOGEOSCIENCES
• 影响因子: 4.9
• 作者: Krumins, V.;Gehlen, M.;Regnier, P.
• 通讯作者: Regnier, P.

Controls on organic carbon and molybdenum accumulation in Cretaceous marine sediments from the Cenomanian-Turonian interval including Oceanic Anoxic Event 2

包括海洋缺氧事件2在内的塞诺曼期-土伦期白垩纪海洋沉积物中有机碳和钼积累的控制

• DOI: 10.1016/j.chemgeo.2011.10.004
• 发表时间: 2012
• 期刊: Chemical Geology
• 影响因子: 3.9
• 作者: Dale A

Mitigation of Extreme Ocean Anoxic Event Conditions by Organic Matter Sulfurization

• DOI: 10.1029/2018pa003470
• 发表时间: 2019-04-01
• 期刊: PALEOCEANOGRAPHY AND PALEOCLIMATOLOGY
• 影响因子: 3.5
• 作者: Hulse, D.;Arndt, S.;Ridgwell, A.
• 通讯作者: Ridgwell, A.

Modelling Estuarine Biogeochemical Dynamics: From the Local to the Global Scale

• DOI: 10.1007/s10498-013-9218-3
• 发表时间: 2013-11
• 期刊: Aquatic Geochemistry
• 影响因子: 1.6
• 作者: P. Régnier;S. Arndt;N. Goossens;C. Volta;G. Laruelle;R. Lauerwald;J. Hartmann