Bio-optical measurements (radiometry, spectral backscatter, attenuation, absorption) for particle and phytoplankton characterisation acquired during Australian Marine National Facility RV Investigator voyage IN2016_V01. The biooptical package consisted of SeaBird 19plus CTD, Satlantic HyperOCR upwelling radiance and downwelling irradiance sensors, WetLabs ac-9, HobiLabs Hydroscat-6. At selected stations the bio-optical package was lowered to the depth of 240 m (or 20 m above the sea bottom if the depth was lower than 260 m) at 20 m/minute. The radiometric measurements were taken only during the day. Parameters measured: SeaBird CTD (4 Hz frequency): - Temperature - Salinity - Pressure - PAR - Fluorescence - Oxygen Satlantic HyperOCR: - Upwelling radiance (Lu) - spectral - Downwelling irradiance (Ed) – spectral - Pressure HobiLabs Hydroscat: - Backscattering coefficient at 6 wavelengths (442, 488, 550, 589, 676, 850 nm) - Fluorescence (550, 676 nm) - Pressure WetLabs ac-9 (2 Hz frequency) - Light absorption coefficient at 9 wavelengths (412, 440, 488, 510, 532, 555, 650, 676, 715 nm) - Light attenuation coefficient at 9 wavelengths (412, 440, 488, 510, 532, 555, 650, 676, 715 nm) At some stations transmissometer data at 650 nm using the Wetlabs c-Star were collected. Data type product(s) created: raw and calibrated data files were created on board, processed and quality controlled files (.dat and/or .csv) will be available by the end of 2016. Owner of instrument: CSIRO Units: CTD data: units given in the header Hydroscat data: bbp_HEOBI_all: all bbp in m^-1, slope unitless Calibrated: depth in m, all bb in m^-1,all betabb sr^-1 m^-1 Radiometers: all Ed uW/cm^2/nm All Lu uW/cm^2/nm/sr Depth is always given in meters. See the metadata file in the download for more information.

---- Public Summary from Project ---- Understanding the strength of possible biological feedbacks is crucial to the science of climate change. This project aims to improve our understanding of one such feedback, the biogenic production of dimethylsulphide (DMS) and its impact on atmospheric aerosols. The Antarctic ocean is potentially a major source of DMS-derived aerosols. The project will investigate the coupling between satellite-derived aerosol optical depth, phytoplankton biomass and DMS production in the Antarctic Southern Ocean. From the abstract of the attached paper: We analysed the correlation between zonal mean satellite data on surface chlorophyll (CHL) and aerosol optical depth (AOD), in the Southern Ocean (in 5-degree bands between 50-70 degrees south) for the period 1997-2004), and in sectors of the Eastern Antarctic, Ross and Weddell Seas. Seasonality is moderate to strong in both CHL and AOD signatures throughout the study region. Coherence in the CHL and AOD time series is strong between 50-60 degrees south, however this synchrony is absent south of 60 degrees south. Marked interannual variability in CHL occurs south of 60 degrees south. We find a clear latitudinal difference in the cross-correlation between CHL and AOD, with the AOD peak preceding the CHL bloom by up to six weeks in the sea ice zone (SIZ). This is consistent with the ventilation of dimethysulphide (DMS) from sea-ice during melting, and supports field data that records high levels of sulfur species in sea-ice and surface seawater during ice-melt. The fields in this dataset are: Timeseries Worksheet: Date Mean Chlorophyll (mg CHL/cubic metre) Mean Aerosol Optical Depth (no units) 5 Day mean chlorophyll averages 5 day mean aerosol optical depth averages Correlation Worksheet: n - number lag r - correlation coefficient t - student t statistic Global Worksheet Column A = SeaWiFS filename Counter+1 is a counter to indicate the image number in series Date Mean Chlorophyll (mg CHL/cubic metre) Mean Aerosol Optical Depth (no units) Chlorophyll Standard Deviation Mean Aerosol Optical Depth Standard Deviation Chlorophyll Standard Error Mean Aerosol Optical Depth Standard Error Chlorophyll Count (the number of data 'pixels' in the image - the basic pixel size is 9x9km2) Mean Aerosol Optical Depth (the number of data 'pixels' in the image - the basic pixel size is 9x9km2)