Iron Biogeochemistry in the High Latitude North Atlantic

北大西洋高纬度地区的铁生物地球化学

基本信息

批准号：
NE/E005489/1
负责人：
Eric Achterberg
金额：
$ 4.35万
依托单位：
University of Essex
依托单位国家：
英国
项目类别：
Research Grant
财政年份：
2007
资助国家：
英国
起止时间：
2007 至无数据
项目状态：
已结题

来源：
https://gtr.ukri.org/projects?ref=NE%2FE005489%2F1
关键词：
Iron Biogeochemistry Latitude North Atlantic

项目摘要

The concentration of carbon dioxide has increased significantly since the start of the industrial revolution as a result of burning of fossil fuels and deforestation. Carbon dioxide influences the climate on earth and its concentration is now so high that the earth's atmosphere is warming and the weather is becoming more extreme. Small floating plants in the ocean, called phytoplankton, take up carbon dioxide from the atmosphere and that way help to reduce the atmospheric concentrations. The phytoplankton cells also need nutrients like nitrogen, phosphorus and silicon to grow. Recently, it has been discovered that the phytoplankton in many regions of the world's oceans are lacking Fe. For example, in the Southern Ocean the growth of the phytoplankton cells is limited by very low Fe concentrations. Therefore, the phytoplankton in this ocean do not remove as much carbon dioxide from the atmosphere as they could do under ideal conditions. Many people think that the North Atlantic Ocean receives enough Fe through dust transport from the Sahara. However, recent experiments have shown that even in the North Atlantic phytoplankton cells may be lacking Fe. In this project, we want to study whether Fe is limiting phytoplankton growth in the North Atlantic at higher latitudes (>60 N). In order to achieve this, we will take part in 3 research cruises and take samples of water, sedimenting material, and atmospheric dust and rain. We will analyse Fe and nutrients in the samples and calculate the supply ratios of Fe to N, P, C to the surface oceans, and their ratios in sedimenting material. We will use models to aid us with the calculations for the oceanic transfers of these elements. If the phytoplankton are Fe limited in the high latitude N Atlantic then it will be because the amount of Fe they get in relation to other nutrients is too low. We will also directly investigate whether Fe is limiting the growth of phytoplankton in water samples from the high latitude N Atlantic. To find this out, we will grow phytoplankton cells taken from the surface ocean in transparent bottles on the deck of the ship. We will add Fe to some bottles, whereas other bottles will receive no added Fe at all. The growth and physiological state of the phytoplankton will be determined using a number of measurements, such as pigment (chlorophyll a) concentrations. These measurements will show us whether the bottles with added Fe show a higher number of phytoplankton cells and a higher growth, compared with the bottles to which we added no Fe. The results of the proposed project will provide us with a better understanding of the role that nutrients like Fe play in the growth of phytoplankton cells in the ocean. The gathered data will help the computer modellers to design improved climate models that will allow us to better predict the extend of climate change over the next 100s of years.

自工业革命开始以来，由于化石燃料的燃烧和森林砍伐，二氧化碳的浓度显着增加。二氧化碳影响地球气候，其浓度现在如此之高，导致地球大气变暖，天气变得更加极端。海洋中的小型漂浮植物（称为浮游植物）从大气中吸收二氧化碳，从而有助于降低大气浓度。浮游植物细胞的生长也需要氮、磷和硅等营养物质。近年来，人们发现世界海洋许多地区的浮游植物都缺乏铁。例如，在南大洋，浮游植物细胞的生长受到极低铁浓度的限制。因此，该海洋中的浮游植物无法像理想条件下那样从大气中清除尽可能多的二氧化碳。许多人认为北大西洋通过撒哈拉沙漠的沙尘输送获得了足够的铁。然而，最近的实验表明，即使在北大西洋的浮游植物细胞中也可能缺乏铁。在这个项目中，我们想要研究铁是否限制北大西洋高纬度地区（>60 N）浮游植物的生长。为了实现这一目标，我们将参加 3 次研究巡航，采集水、沉积物以及大气灰尘和雨水的样本。我们将分析样品中的Fe和营养盐，并计算Fe与N、P、C对表层海洋的供应比率以及它们在沉积物中的比率。我们将使用模型来帮助我们计算这些元素的海洋转移。如果北大西洋高纬度浮游植物的铁含量有限，那是因为它们获得的铁含量相对于其他营养物质来说太低。我们还将直接调查铁是否限制了北大西洋高纬度水样中浮游植物的生长。为了找到答案，我们将在船甲板上的透明瓶子中培养从表层海洋采集的浮游植物细胞。我们会在一些瓶子中添加铁，而其他瓶子则根本不添加铁。浮游植物的生长和生理状态将通过多种测量来确定，例如色素（叶绿素 a）浓度。这些测量结果将向我们展示，与未添加铁的瓶子相比，添加铁的瓶子是否显示出更多的浮游植物细胞数量和更高的生长速度。该项目的结果将使我们更好地了解铁等营养物质在海洋浮游植物细胞生长中所起的作用。收集到的数据将帮助计算机建模者设计改进的气候模型，使我们能够更好地预测未来数百年气候变化的范围。