Understanding hydrodynamics and sediment dynamics is crucial for developing the ability of assessing the environmental changes and protecting the aquatic ecosystems in estuaries and coastal seas, as the transport and delivery of waterborne materials are mainly governed by physical processes. In this session we invite abstracts that can help refine the description and understand the dynamics of coastal flows, turbulence, and sediment transport. Topics of particular interest include but are not limited to: 1) estuarine and coastal circulations, 2) coastal submesoscale processes, 3) coastal turbulence, 4) sediment transport, 5) coastal morphodynamics, and 6) extreme coastal events. The objectives of this session are: 1) promote exchange of information on recent developments in physics of estuaries and coastal seas, 2) stimulate interaction between coastal oceanographers and coastal engineers, and 3) provide a forum for junior scientists and engineers where they feel comfortable presenting and testing their ideas. The emphasis is on the results of field and laboratory measurements, and theoretical and numerical analysis, with the aim of better understanding the underlying physical processes.

Turbulence or turbulence-like phenomena are ubiquitous in nature. In general, it can be defined as a system with a large number of freedoms where all possible statuses are excited due to the interaction among those freedoms, resulting in a hierarchical cascade, with energy injection and dissipation under various conditions. The milestone work by Kolmogorov (1941) states that in three-dimensional locally isotropic and homogeneous turbulence, kinetic energy is injected into the system via large-scale structures and transferred to small-scale structures until fluid viscosity converts the kinetic energy into heat, which leads to an energy conservation with a power-law scaling of energy in Fourier space, i.e., E(k)~k-5/3. Such scaling behavior also emerges under very different situations, e.g., two-dimensional turbulence theory by Kraichnan in 1967, geostrophic turbulence theory by Charney in 1971. This session invites studies focusing on a better understanding of turbulence and related scaling processes in the ocean. Observations, models, and theories of wave-turbulence interaction, small-scale turbulence, and geostrophic turbulence, are welcomed.

Most sediment in the ocean is supplied from river-sea dispersal systems, large and small, and serves as an important archive for understanding the Earth’s history. Two major factors affecting the basin wide sediment signals of these systems are human influence and global climate change, which determine the sediment load at land-sea interfaces. Long-term sediment dispersal is manifested in the type of depositional systems on the continental shelf, such as subaqueous deltas, mud belts, or clinoforms, and in changes in coastal landforms, such as the evolution between deltaic and estuarine systems. Understanding modern-day processes of sediment dynamics and morphodynamics of these systems will help us better understand the impact of human activity and global climate change on these systems. Such understanding serves as a key to unveiling the past, while these depositional systems also form archives for paleoenvironmental changes, postglacial evolution, and anthropogenic impact. In this session we encourage cross-disciplinary exchange of theoretical, observational, and experimental findings in sediment dispersal systems in the coastal ocean through space and time from a source-to-sink perspective.

The low-latitude western equatorial Pacific and Indian Ocean are affected by numerous globally significant ocean-atmosphere phenomena. Those comprise the Walker and Hadley circulations, the El Niño-Southern Oscillation, the Indian Ocean Dipole Mode, and the monsoon systems. In addition, the Indonesian Throughflow (ITF), which exchanges water masses between the tropical Pacific and the Indian Ocean, is influenced by and modulates climate in the Indo-Pacific region. It also conveys heat and salt to the Indian Ocean Gateway, which, via the Agulhas Leakage, influences overturning circulation strength in the North Atlantic and hence global climate. Modern observations and the examination of climate and oceanographic variability in this region and comparison with other regional records will help to comprehend the role of Indo-Pacific-driven low-latitude processes on global environmental change on a range of timescales throughout the Cenozoic. It is the intention of this session to bring together studies on modern and past oceanographic and climatic dynamics of the tropical western Pacific and Indian Ocean as deduced from modern observations, speleothem and coral archives covering the last centuries and millennia, and marine sedimentary archives spanning the Cenozoic.

http://www.atmosp.physics.utoronto.ca/people/moore/moore.htmlThe Arctic Ocean is undergoing dramatic change. Sea ice extent and thickness have been declining steadily, air temperatures have been rapidly warming, and the hydrological cycle has been accelerating. As a result of the enhanced ice loss, the Arctic Ocean is now more susceptible to dynamic and thermodynamic forcings. For example, the central Arctic has become more energetic due to the increased momentum transfer from the atmosphere to the ocean. At the same time, solar absorption has increased through areas of open water, while more heat is being fluxed from sub-polar latitudes into the Arctic via the ocean and atmosphere. Extreme conditions are becoming more frequent, including increased freshwater content in the Arctic, more common wind-driven upwelling and polynya formation, and larger levels of primary productivity and occurrences of under-ice phytoplankton blooms. The spatial and temporal variability of the Arctic Ocean strongly influences global climate via atmosphere-ocean interaction and Arctic-Subarctic freshwater and heat fluxes. The loss of sea ice has had both local and remote effects on atmospheric circulation, including intensified storms and more frequent extreme weather conditions. Enhanced freshwater export from the Arctic into the Nordic Seas and Labrador Sea, in conjunction with the retreating ice edge, is thought to impact the meridional overturning circulation. In addition to effects on climate, new organisms may start to flourish in the warmer and fresher Arctic. For example, harmful algal blooms are now threatening regional ecosystems in the Pacific sector of the Arctic Ocean. This session aims to understand the: (1) variations and dynamics of the physical processes in the Arctic Ocean and their interaction with the subarctic regions in both the Pacific and Atlantic sectors; (2) climate responses to the declining sea ice, including atmospheric feedbacks and impacts on the North Atlantic meridional overturning circulation; (3) role of physical processes in regulating the Arctic ecosystem.

Microbes in the world’s oceans are extremely diverse, and so is dissolved organic matter (DOM). With the advancements of molecular technologies and analytical tools, we are now able to explore microbial diversity and chemodiversity of DOM in the aquatic environment in unprecedented detail. It is now possible to explore the relationship between certain microbes and the utilization and transformation of specific DOM signatures. This session explores the current knowledge of the dynamic microbe-DOM relationship and how it relates to the taxonomic and functional diversity of microbial communities, genomics and metagenomics, and the detailed chemical analyses of DOM species.

Nitrogen is a key element for all life on Earth. The status of biologically available nitrogen in the ocean limits primary productivity in many oceanic regions and exerts a strong control on the concentrations of greenhouse gases in the atmosphere. A better understanding of the nitrogen cycle in the modern ocean is thus critical for predicting future changes in the ocean ecosystem and climate, especially given the fact that human activities have dramatically altered the global nitrogen cycle through fertilizer use and fossil fuel combustion. Furthermore, studies of the past can provide an effective way for improving our understanding of the marine nitrogen cycle as well as its connections to other elemental cycles and climate. Recent studies have significantly advanced our understanding of the marine nitrogen cycle across multiple spatial and temporal scales— from genes to ecosystems and from the geological past to the future. This session aims to highlight these advances and welcomes submissions describing new observations, experimental results, modeling studies as well as analytical methods focused on the marine N cycle.

Our knowledge of ocean processes is constrained by observational limitations. As policy-makers and the general public become increasingly aware of the importance of marine observations for system-modeling and societal management, efficient and comprehensive monitoring of the dynamic marine environment becomes more and more essential. Traditional shipboard sampling cannot provide data at the scales requisite to accurate modeling of the ocean's complex physical and biogeochemical characteristics. Capabilities to make highly-resolved autonomous measurements on broad spatial and temporal scales in both open-ocean and coastal regions requires the use of autonomous measurements (e.g. shipboard and in situ analyzers/sensors) and platforms (e.g. Argo profiling floats, gliders, and cable-based observing systems). This session will focus on both the technical developments and their applications in ocean observations at regional and global scales.

Because of increasing anthropogenic activities, environmental pollutants enter the marine environments mainly through riverine inputs, atmospheric deposition, and direct discharge, subsequently affecting the molecular, physiological, developmental, reproductive and survival of marine organisms, and jeopardizing the bio-diversity, composition, function, and services of existing marine ecosystems. This session aims to facilitate interdisciplinary discussion among environmental scientists, chemists, biologists, and oceanographers in order to integrate current knowledge on the fate and transport of pollutants in marine environments, bioaccumulation and bioavailability, underlying toxic mechanisms, and their ecological effects. All studies in the areas of marine pollution and ecotoxicology are welcome to this session.

In order to provide technical support for marine monitoring, the research team of marine environmental monitoring instruments focuses on the development of various analytical methods and instruments. The target analytes include trace nutrients, metals and total alkalinity in seawater.
In trace nutrients and metals analyses, various advanced methodologies, including flow analysis, loop analysis, solid phase extraction, catalytic spectrophotometry, fluorescence spectrophotometry, long optical pathlength flow cell methodology, are used to improve analytical sensitivity and selectivity. The detection limits of phosphates, nitrate, nitrite, ammonium, iron (II)/(III), manganese and aluminum are as low as nmol/L. In the determination of total alkalinity, based on automatic single titration and spectrophotometric pH measurement technique, system precision can reach 2 µmol/kg with high spatial and temporal resolution.
The methods and instruments have the advantages of high sensitivity, precision, stability, reliability, fast analysis speed, and have been applied in field, both shipboard and underway, to obtain environmental data for marine research.

This poster session will bring together scientists to present and discuss new research in the projects PACECS (National Key R&D Program of China “Climate Change Program”, PI: Yao Zhang) and MEMCS (NSFC Major Research Program “Hydrosphere Microorganism Program”, PI: Nianzhi Jiao).
The ocean is the largest carbon pool on earth, serving as a buffer of global climate change, absorbing about 1/3 of CO₂ produced by human activities. Carbon captured by the marine ecosystem is called the "Blue Carbon Sink", which is one of the most important mechanisms for the sea to store carbon. The initial form of blue carbon is visible plant carbon sequestration in the coastal zone. As a matter of fact, the invisible microorganisms (phytoplankton, bacteria, archaea, and protozoa), which have always been ignored, account for 90% of the marine biomass and constitutes the main component of blue carbon. The marginal sea covers one third of the total territory of China, and the immense potential of these carbon sinks must be explored. The project PACECS looks at the key processes and mechanisms of carbon sequestration in coastal ecosystems and ways to increase the ocean carbon sink.
The "microbial carbon pump" (MCP) is the major mechanism of the marine carbon sink. The increasing eutrophication of coastal waters in China is often accompanied by environmental problems such as algal blooms, hypoxia, and acidification, which may affect the carbon storage efficiency of the MCP. The project MEMCS looks at the processes and mechanisms of the MCP under hypoxic and acidic situations by combining field investigations, laboratory research, and mesocosm experiments.
We welcome scientists who are interested in microbial ecology, microbially driven carbon, nitrogen, and sulphur biogeochemical cycles to exchange new findings and ideas.

The open ocean, coastal ocean and terrestrial ecosystem are three major components modulating atmospheric CO₂ and thereby the earth climate system. The complexity of carbon cycling in the coastal ocean under the impact of both land inputs and dynamic exchanges with the open ocean make it a huge challenge to be included in any realistic prognostic climate simulations. CHOICE-C II is a five-year (January 2015 to August 2019) interdisciplinary research project involving 19 PIs/CoIs from 4 institutes in Mainland China and Hong Kong, renewed by the Ministry of Science and Technology of China based on the CHOICE-C (Carbon Cycling in China Seas: Budget, Controls and Ocean Acidification) project. Through comparative studies of carbon cycling in River-dominated Ocean Margins (RiOMar, the northern South China Sea shelf being a case) and Ocean-dominated Margins (OceMar, the South China Sea basin being a case), CHOICE-C II focuses on the carbon cycle in the South China Sea in terms of its budget, controls and global implications. The key question we sought to answer is: “Why are some marginal seas a source of atmospheric CO₂, while others are a sink?” So far, we have conducted extensive interdisciplinary mapping measurements and process studies and have developed a novel coupled physical-biogeochemical modelling system to diagnose factors controlling the CO₂ source and sink in the South China Sea. This poster session presents our current achievements from four interlinked tasks in CHOICE-C II to determine (1) CO₂ source and sink patterns and its major biogeochemical controls; (2) Carbon fixation of phytoplankton and its controls in the carbon cycle; (3) Recycling and export of organic carbon and coupling between C, N and Si; and (4) Physical controls, synthesis and future trends.