Dimethyl sulfide and other biogenic volatile organic compound emissions from branching coral and reef seawater: Potential sources of secondary aerosol over the Great Barrier Reef

Volatile organic compounds (VOCs) in the headspace of bubble chambers containing branches of live coral in filtered reef seawater were analysed using gas chromatography with mass spectrometry (GC-MS). When the coral released mucus it was a source of dimethyl sulfide (DMS) and isoprene; however, these VOCs were not emitted to the chamber headspace from mucus-free coral. This finding, which suggests that coral is an intermittent source of DMS and isoprene, was supported by the observation of occasional large pulses of atmospheric DMS (DMSa) over Heron Island reef on the southern Great Barrier Reef (GBR), Australia, in the austral winter. The highest DMSa pulse (320 ppt) was three orders of magnitude less than the DMS mixing ratio (460 ppb) measured in the headspace of a dynamically purged bubble chamber containing a mucus-coated branch of Acropora aspera indicating that coral reefs can be strong point sources of DMSa. Static headspace GC-MS analysis of coral fragments identified mainly DMS and seven other minor reduced sulfur compounds including dimethyl disulfide, methyl mercaptan, and carbon disulfide, while coral reef seawater was an indicated source of methylene chloride, acetone, and methyl ethyl ketone. The VOCs emitted by coral and reef seawater are capable of producing new atmospheric particles < 15 nm diameter as observed at Heron Island reef. DMS and isoprene are known to play a role in low-level cloud formation, so aerosol precursors such as these could influence regional climate through a sea surface temperature regulation mechanism hypothesized to operate over the GBR.

Through the Colour Lens

Colour is used to adorn and decorate and many have tried to find an organisational system that could concretely states how colour is to be used correctly. In this book Marisha McAuliffe examines the concept of colour and its uses for those who design professionally or those who simply want to appreciate the complexities of colour. It examines light and contrast, and explains the pitfalls that are to be avoided in colour design. The book explores different concepts relating to, and including, colour history, systems and theories, requirements for a colour-based design project, research, and generation of colour schemes so as to create optimal experiences for colour in architecture, interior architecture and design. To fully understand colour, the book ventures into its scientific and ‘non-scientific’ elements compiling key points about its many characteristics. Taken together, this book is a compressive guide for those who seek to work with colour and to tap its enormous potentials for design effect.