Investigation of Near-Surface Production of Iodocarbons - Rates and Exchange (INSPIRE)

碘是一种重要元素。例如，人类生长激素含有碘，因此它是我们饮食的重要组成部分，缺乏碘会严重影响我们的生长和大脑发育。此外，在大气中，碘参与了导致气候变化的化学过程，如臭氧消耗和云的形成。地球上生命的持久性取决于通过微生物活动维持的主要生物地球化学循环发生的基本元素的不断循环。我们必须知道碘是如何在海洋、空气和陆地之间循环的。海洋含有地球上总碘量的很大一部分，这种元素从海水到大气的转移是其全球循环的重要组成部分。在将碘转移到海面上起主要作用的一组化合物是挥发性碘碳，包括CH3I、CH2I2和CH2ClI。虽然我们可以测量海水中的碘碳，但我们并不完全了解是什么控制了它们在海水中的浓度，拼图的关键部分仍有待发现。INSPIRE将把碘碳浓度分布与表明生物、化学和光化学过程的测量值进行比较，并在实验室和两次研究航行中进行实验，以确定对这些化合物浓度的主要控制措施。例如，该项目将研究水样暴露在阳光下、浮游动物吃浮游植物、浮游生物死亡和腐烂以及细菌生长如何影响我们在海水中测量的碘碳浓度。一旦我们确定了这一点，我们将建立一个数学模型来模拟碘碳的产生，使我们能够预测有多少碘从海洋转移到大气中。这将有助于我们更好地了解碘的地球化学循环如何运作，以及它如何随着未来的气候变化而改变。

Iodine is a vital element. For example, human growth hormones contain iodine so it is an essential part of our diet and a deficiency in this will severely affect how we grow and our brains develop. Also, in the atmosphere iodine is involved in chemical processes that contribute to climate change such as ozone depletion and cloud formation. The persistence of life on earth depends upon the constant recycling of essential elements that occurs via the major biogeochemical cycles that are maintained by the activities of microorganisms. It is crucial that we know how iodine is cycled between the oceans, air and land. The oceans contain a large proportion of the total iodine on the planet and the transfer of this element from seawater to the atmosphere is known to be an important part of its global cycle. One group of compounds that play a major role in transferring iodine across the sea surface are the volatile iodocarbons, this includes CH3I, CH2I2 and CH2ClI. Although we can measure the iodocarbons in seawater we do not fully understand what controls their concentrations in seawater and crucial parts of the jigsaw are still to be discovered. INSPIRE will compare iodocarbon concentration distributions with measurements that indicate biological, chemical and photochemical processes, and carry out experiments in the laboratory and during two research cruises to work out what the main controls on the concentrations of these compounds are. For example, the project will examine how the exposure of water samples to sunlight, zooplankton grazing of phytoplankton, plankton death and decay and bacterial growth influences the concentrations of the iodocarbons we measure in seawater. Once we have identified this we will then produce a mathematical model to simulate iodocarbon production to allow us to predict how much iodine is transferred from the oceans to the atmosphere. This will help us to understand how the iodine biogeochemical cycle operates much better and how it might alter with future climatic change.