SIMbRICS: Sea Ice Microbiology and the Role In Cycling of Sulfur (DMS, DMSP, DMSO, MT)

SIMbRICS：海冰微生物学和硫循环中的作用（DMS、DMSP、DMSO、MT）

基本信息

批准号：
NE/S002596/1
负责人：
Hendrik Schaefer
金额：
$ 38.98万
依托单位：
University of Warwick
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2019
资助国家：
英国
起止时间：
2019 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FS002596%2F1
关键词：
SIMbRICS Sea Ice Microbiology Role

项目摘要

The Arctic Ocean is undergoing unprecedented changes as the Earth warms due to climate change. Increasing global temperatures are resulting in increased rates of glacial melting and retreat, thawing of the permafrost and a steady trend towards reduced sea ice extent in winter. Inputs of freshwater into the Arctic Ocean are also increasing as a result of the increased melting rates. As the sea ice retreats, the reflective surface of the ice is replaced by absorptive 'dark' ocean, and results in a greater absorption of incoming sunlight and heat energy, thus driving up the rate of global temperature increase. However, this picture is too simplistic, and there are many physical and biological processes taking place within the Arctic Ocean water and sea ice which we do not fully understand, but which could affect our projections of changes within the Arctic Ocean. In Autumn 2019, the German Icebreaker FS Polarstern is undertaking a unique expedition, to sail to the edge of the Arctic sea ice in the Russian Laptev Sea, and allow the sea ice to form around the ship. The ship will then drift with the ice pack, close to the North Pole, and exit the sea ice in Autumn 2020 near the east coast of Greenland. This opportunity will allow scientists access to newly formed 'first year' sea ice, as well as older 'multi-year' ice, and allow them to study all aspects of the Arctic environment across an entire year and all the seasonal changes: physical interactions between atmosphere, sea ice and water column, and the biological activities taking place in all three environments. It is essential we work towards gathering this information now, as it will allow us much better understanding of the processes taking place, and allow us to improve our model predictions of how the Arctic will change over the coming decades. This project has been designed as a key part of this expedition, and will study the formation of a gas called dimethylsulfide (DMS), a key ingredient in the cocktail of gases that makes up the 'smell of the sea'. It is produced worldwide by single celled algae and bacteria in both freshwater and saltwater environments, but our previous research has shown that sea-ice-dwelling algae produce concentrations of DMS tens to hundreds of times higher than in the water. While only a small proportion (up to 16%) of this DMS is released into the atmosphere, once there it forms cloud-seeding compounds which can influence our weather and climate. When it rains, sulfur compounds are deposited back into the soils of our continents. The remainder of the DMS formed in the oceans stays there, facing consumption by marine microbes and incorporation into the oceanic sulfur cycle. As we know that sea ice is an important source of DMS, the reduction in sea-ice extent with increasing climate change will have significant effects on the volume of DMS entering the atmosphere. Our project aims to investigate the changes in the microbial (bacterial and algal) community across the seasonal changes in the Arctic, and to look at how these changes affect the production rates of DMS and associated organic sulfur compounds. To this end, we will undertake 2 months stationed on FS Polarstern during the boreal spring, and form international collaborations to extend our sample availability to over 6 months through spring to summer. We will continue our research in the home laboratory by studying so-called 'model micro-organisms' which we will collect during our time at sea (or in the ice!). All our data collected in the Arctic will be compared to our previous studies in the Antarctic, to give a much clearer picture of the importance of the polar regions as a source of DMS, and how climate change will affect our global climate as these areas change.

随着由于气候变化而导致的地球变暖，北极海洋正在发生前所未有的变化。全球温度的升高导致冰川融化和撤退的速度增加，永久冻土融化以及冬季降低海冰范围的稳定趋势。由于熔融速率提高，北极海洋中淡水的投入也正在增加。随着海冰的撤退，冰的反射表面被吸收性的“黑暗”海洋取代，并导致进出的阳光和热能吸收更大，从而提高了全球温度的升高。但是，这张照片太简单了，北极海水和海冰内发生了许多物理和生物学过程，我们不完全理解，但可能会影响我们在北极海洋中变化的预测。 2019年秋天，德国破冰船FS Polarstern正在进行一次独特的探险，驶向俄罗斯Laptev海北极海冰的边缘，并让海冰在船上形成。然后，该船将与冰袋一起漂移，靠近北极，并于2020年秋天在格陵兰东海岸附近退出海冰。这个机会将使科学家进入新成立的“第一年”海冰以及较旧的“多年”冰，并允许他们整个一年中研究北极环境的各个方面，以及所有季节性的变化：身体互动在大气，海冰和水柱之间以及在所有三种环境中进行的生物活动。我们现在努力收集这些信息至关重要，因为这将使我们可以更好地了解发生的过程，并让我们改善对未来几十年北极如何变化的模型预测。该项目被设计为这次探险的关键部分，并将研究一种称为二甲基硫化物（DMS）的气体的形成，这是气体鸡尾酒中的关键成分，构成了“海味的气味”。它是在淡水和盐水环境中由单细胞藻类和细菌在全球范围内生产的，但是我们先前的研究表明，海冰藻类藻类的DMS浓度比水中的数十倍至数百倍。虽然只有一小部分（最高16％）的DMS被释放到大气中，一旦那里形成云种植化合物，可能会影响我们的天气和气候。下雨时，将硫化合物沉积在我们大洲的土壤中。海洋中形成的DMS的其余部分留在那里，面对海洋微生物的消费，并融入了海洋硫周期。我们知道，海冰是DM的重要来源，随着气候变化的增加，海冰范围的减少将对进入大气的DMS的体积产生重大影响。我们的项目旨在调查北极季节性变化的微生物（细菌和藻类）社区的变化，并研究这些变化如何影响DMS的生产率和相关的有机硫化合物的生产率。为此，我们将在北方春季驻扎在FS Polarstern上的2个月，并进行国际合作，以将我们的样本可用性扩展到春季至夏季的6个月以上。我们将通过研究所谓的“模型微生物”来继续我们在房屋实验室的研究，我们将在海上（或在冰上！）期间收集。我们在北极收集的所有数据将与我们先前在南极的研究进行比较，以更清楚地了解极地区域作为DM的来源的重要性，以及随着这些地区的变化，气候变化将如何影响我们的全球气候。