The influence of ocean circulation on local biogeochemistry and melting tidewater glaciers in northern Baffin Bay

海洋环流对巴芬湾北部当地生物地球化学和潮水冰川融化的影响

• 批准号: NE/X008304/1
• 负责人: Adrian Jenkins
• 金额: $ 1.59万
• 依托单位: Northumbria University
• 依托单位国家: 英国
• 项目类别: Research Grant
• 财政年份: 2022
• 资助国家: 英国
• 起止时间: 2022 至 无数据
• 项目状态: 已结题
• 来源: https://gtr.ukri.org/projects?ref=NE%2FX008304%2F1
• 关键词: influence; ocean; circulation; local; biogeochemistry

"NERC : Emma Louise White : NE/S007512/1"Climate change has disproportionately affected the Arctic, and the recent Sixth Assessment Report from the IPCC states that the Arctic is highly likely to continue warming at twice the average global rate. Outside of Greenland and Antarctica, the melting of glacial ice in the Canadian Arctic Archipelago has made the largest contribution to recent sea-level rise. This makes the Canadian Arctic Archipelago a critical region to understand, yet it remains understudied due to its remoteness. There are over 300 tidewater glaciers in the Canadian Arctic Archipelago which are in contact with the ocean. To understand the recent melting and ice mass loss from these glaciers, it is highly important to understand how the ocean influences them. This work will focus on an area of the Canadian Arctic Archipelago called northern Baffin Bay, which is an important area to understand due to the presence of the two fastest retreating tidewater glaciers in the region. The North Water Polynya is also present in northern Baffin Bay, which is a large area of open water which remains free of sea ice. There is very high primary productivity in this area, and it sustains a large diversity of marine life which has led to it being classified as an Ecologically and Biologically Significant Area by Fisheries and Oceans Canada. The aim of this work is to improve understanding of ocean circulation in northern Baffin Bay, and the influence that ocean circulation has on melting tidewater glaciers in the region as well as local nutrient distributions.This study will use data from an ocean circulation model, along with a software called ARIANE, to release modelled particles in the vicinity of tidewater glaciers in northern Baffin Bay. These modelled virtual particles will be traced backwards in time, providing information on the origin of the particles and pathways that water follows as it enters the region. Once we have identified these pathways, we will then consider the temperature of water travelling along these pathways, and where warmer water is able to access. In particular, we will assess if warmer, deeper water originating from the Atlantic Ocean is able to reach the tidewater glaciers in the region. This is important to understand, as warmer water is able to drive more melting of glaciers, so it is crucial to understand if warmer Atlantic Water is in contact with tidewater glaciers. We will also consider the nutrients that are supplied to the region by the ocean circulation pathways identified. Phytoplankton are photosynthetic organisms that form the base of many marine food chains, similar to plants. They are found in the surface ocean where there is light availability, and they also require nutrients to grow. Ocean circulation pathways can provide these nutrients to the surface ocean, and it is therefore an important control on primary productivity. Tidewater glaciers can influence the supply of nutrients to the surface ocean because where the glaciers are in contact with the ocean, the freshwater buoyancy input from them can lead to upwelling of deeper, nutrient rich waters towards the surface, where these nutrients can stimulate phytoplankton growth. In summary, the main aims of this work will be to 1) identify pathways of water transport to northern Baffin Bay to improve understanding of ocean circulation in the region; 2) assess the influence of ocean circulation and pathways of warmer water on melting tidewater glaciers; and 3) assess the impact that ocean circulation has on nutrient distributions, and therefore primary productivity.

“NERC：Emma Louise白色：NE/S 007512/1“气候变化对北极造成了不成比例的影响，IPCC最近的第六次评估报告指出，北极极有可能以全球平均速度的两倍继续变暖。在格陵兰岛和南极洲之外，加拿大北极群岛的冰川融化对最近海平面上升的贡献最大。这使得加拿大北极群岛成为了解的关键区域，但由于其偏远，它仍然没有得到充分的研究。加拿大北极群岛有300多个冰川与海洋接触。为了了解这些冰川最近的融化和冰量损失，了解海洋如何影响它们是非常重要的。这项工作将集中在加拿大北极群岛的一个地区，称为北方巴芬湾，这是一个重要的地区，以了解由于存在的两个最快的退缩冰川在该地区。北水Polynya也存在于北方巴芬湾，这是一个大面积的开放水域，仍然没有海冰。该地区的初级生产力非常高，维持着大量多样的海洋生物，因此被加拿大渔业和海洋局列为具有重要生物和生态意义的地区。这项工作的目的是提高对北方巴芬湾海洋环流的认识，以及海洋环流对该地区冰川融化和当地营养物分布的影响，这项研究将使用海洋环流模型的数据，沿着一个名为ARIANE的软件，在北方巴芬湾的冰川附近释放模拟粒子。这些模拟的虚拟粒子将被追溯到过去，提供粒子起源和水进入该地区时所遵循的路径的信息。一旦我们确定了这些路径，我们将考虑沿着这些路径沿着流动的水的温度，以及温暖的水能够到达的地方。特别是，我们将评估来自大西洋的更温暖，更深的水是否能够到达该地区的冰川。这一点很重要，因为温暖的海水能够推动更多的冰川融化，因此了解温暖的大西洋海水是否与冰川接触至关重要。我们还将考虑通过所确定的海洋环流途径向该区域提供的营养物质。浮游植物是光合生物，形成许多海洋食物链的基础，类似于植物。它们被发现在有光可用的海洋表面，它们也需要营养来生长。海洋环流路径可以为表层海洋提供这些营养物质，因此它是初级生产力的重要控制因素。潮水冰川可以影响营养物质向表层海洋的供应，因为在冰川与海洋接触的地方，冰川输入的淡水浮力可以导致更深的、营养丰富的沃茨向表层涌升，这些营养物质可以刺激浮游植物生长。总之，这项工作的主要目标是：1）确定水输送到北方巴芬湾的路径，以提高对该地区海洋环流的认识; 2）评估海洋环流和温暖的水对融化的冰川的影响; 3）评估海洋环流对营养分布的影响，从而对初级生产力产生影响。