The rates at which gases exchange between the oceans and the atmosphere are extremely important to global biogeochemical cycles and to predicting and modelling future climate change, but quantifying them accurately currently remains elusive. Some important issues requiring accurate estimates include the rate at which anthropogenic carbon dioxide can be taken up by the oceans and quantifying the marine sources of other important climate active gases such as dimethyl sulphide that scientists believe control cloud formation over the oceans. We plan to measure concentrations of DMS in the water so that we can use this data, together with a new technique for measuring the air-sea flux of DMS to be made by our project partners from the University of Hawaii, in order to better understand the processes that control the transfer of gases between the atmosphere and the ocean. We think that as well as the wind, the amounts of bubbles made by breaking waves will have an important impact on air--sea gas exchange. Much of the data on the amount of DMS that is present in seawater is collected from water pumped into research ships from the bottom of the ship. This is usually at a depth of about 5-8m. However, in order to calculate the amount of DMS that is transferring from the sea to the air we really need to know the concentration of this gas at the sea surface. Everybody assumes that the concentrations measurements from the ship's hull (ie 5-8m) are the same as those made at the sea surface. However, we know that DMS is produced and consumed by biological processes in the water and that it is rapidly destroyed by sunlight. We therefore want to check whether there is a difference between dimethyl sulphide concentrations at the sea surface compared to the depths of ship hulls. This would be have important consequences for calcuating the actual amount of dimethyl sulphide that the ocean supplies to the atmosphere. It is also important to know if there are any gradients when we want to compare the direct estimates of the DMS flux with the indirect estimates as this would impact on how important we think the bubbles might be in air-sea gas transfer. We plan to participate in a research cruisein the North Atlantic Ocean in the suimmer of 2007 when there will be many other groups making a variety of key measurements and observations (measure seastate, whitecapping and wave breaking and evaluating the role of bubbles and surfactants air-sea gas exchange.

The oceans have a major influence on the composition of our atmosphere and therefore on the climate that we live in. This is because significant quantities of important climate-active gases exchange between the oceans and the atmosphere. Understanding the rates at which these gases transfer across this interface is important for society in general because it enables us to improve the accuracy of mathematical models that predict global climate change. Dimethyl sulphide (DMS), produced by microbes in the surface oceans is the major source of sulphur to the vast, remote marine atmosphere. In the atmosphere it contributes to the formation of aerosols and clouds, reducing the amount of radiation reaching Earth. So it actually cools the planet, as opposed to carbon dioxide (CO2) and other greenhouse gases. We will join forces with a research group from the University of Hawaii to quantify the sea-to-air exchange rate of DMS on an expedition to the Southern Ocean. This high-profile expedition is funded and organised by the US National Oceanographic and Atmospheric Administration (NOAA) and will involve a suite of measurements focusing on gas exchange between ocean and atmosphere. Ours is a critical piece of research because: 1. DMS has its greatest influence on climate in remote regions such as the Southern Ocean; 2. The high winds and waves that exist in the Southern Ocean will allow us to untangle some of the key issues concerning air/sea gas exchange, particularly the impact of bubbles and breaking waves; and 3. the Southern Ocean is a major sink for anthropogenic CO2 and the information we will learn from studying DMS exchange rates will tell us a great deal about the controls on how fast CO2 enters the oceans from the atmosphere. The results of this work will be published in high-quality scientific journals. This information will be valuable to climate scientists and will ultimately improve the accuracy of assessments of Global Change for policy makers and the public.

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OVERVIEW One of community ecology's few paradigms is that complex habitats tend to contain more species and at higher abundances than simple habitats. Currently, human and natural disturbances are changing the complexity of habitats faster than at any previous time in history. Understanding and predicting the effects of these changes on biodiversity is now of paramount importance. Yet, we have only a crude, correlative understanding of how complexity changes affect biodiversity, predicting that if habitat becomes flatter, species' diversity and abundances decline. Generating accurate predictions requires integration of the geometric and ecological principles that underpin complexity-biodiversity relationships. This project will build the tools to allow us to make process-based predictions about biodiversity change as a function of habitat complexity. It will do so by using mathematical theory, experimental manipulations, and ecological observations to build the mechanistic framework needed to make these predictions. We use a highly complex species rich system, coral reefs, as a case-study to implement and test predictions. This research will produce a general framework for testing complexity-biodiversity relationships globally and across ecosystems. INTELLECTUAL MERIT The major innovation of this research is integrating three disparate research areas-biophysics, 3D surface modelling technology, and ecological theory. This integration will for the first time allow us to quantify the interactions between biodiversity and 3D habitat structure. While the underlying components of this project are very effective on their own, they have until now developed independently of each other and the benefit of combining them to model complexity-biodiversity relationships has only recently been recognized. Despite intense interest in modelling the effects of environmental change, few present-day efforts to do so have a mechanistic basis, and almost all build in some way on the correlative responses of organisms to the environment, thus limiting their generality and predictive power. In contrast, our approach will develop basic theory that scales individual-level habitat associations to ecosystem-level common currencies using geometric principles, novel imaging technologies, ecological theory, rich historical data sets and experimental manipulation. Success in this endeavor will represent a major breakthrough in ecological research and understanding, and provide a much-needed framework for predicting ecosystem responses to changing dimensionality of habitat structure. BROADER IMPACTS This project will train 2 post-docs, 1-2 PhD student and up to 10 undergraduate and other interns on the use of cutting-edge technology to quantify ecological change. Our research will provide a tool for assessing and projecting the impact of ecosystem flattening on biodiversity and ecosystem function, as well as for forecasting the impact of change on our ecosystems and economy. We will maximize the impact of this tool by publishing code on GitHub and producing vignettes which make the theory developed accessible to a broader audience of scientists and practitioners. We will promote these tools online through websites and social media, and will run summer workshops to promote the uptake of this approach to explore scenarios of change and predict ecological consequences of different environmental management actions. The 3D maps generated in this project are particularly effective at communicating ecosystem change to a broad audience. We will create a web interface to visualize these changes and will promote them to schools and through HIMB's outreach program. Finally, we will engage more broadly in the dissemination of the results of our project through a science-art collaborative exhibition, which will explore changing shapes in the natural world.

United States