All-sky images taken from the Cloud-Cam instrument on the RSV Aurora Australis during the K-Axis campaign between 22-Jan-2016 and 16-Feb-2016 [days 22 to 47]. Images were acquired at 1-minute cadence, and are presented as timelapse movies analysed for cloud fraction, and keograms (obtained by horizontally accumulating a vertical slice through the zenith pixel of each image).

Krill, salps and pteropods were collected with an RMT8 net during the K-Axis cruise. Specimens were removed from the samples, measured and frozen at -20C until ready for analysis in Hobart. Individuals of known species were dried at -60C, ground to a fine powder, encapsulated into tin cups and analysed with an ICP-MS in the Central Science Laboratories, University of Tasmania. Samples were analysed for delta15N and delta13C. The salp was the common Southern Ocean species Salpa thompsoni and the krill were Euphausia superba, E. triacantha, E. frigida and Thysanoessa macrura. A small number (2) of the siphonphore Diphyes antarctica were also analysed. Pteropods analysed included both shelled (thecosomes) and naked (gymnosomes) pteropods. Columns E-O in the Pteropods worksheet in the spreadsheet are expressed as ratios.

Oceanographic measurements were collected aboard Aurora Australis cruise au1603, voyage 3 2015/2016, from 11th January to ~24th February 2016. The cruise commenced with the K-AXIS project, the major marine science component of the cruise. This was the Australian component (P.I.’s Andrew Constable, Steve Rintoul and others) of a combined biological and oceanographic study in the vicinity of the Kerguelen Axis. After conclusion of marine science work the ship went to Mawson for a resupply. During a storm on 24th February the ship broke free of its mooring lines and ran aground on the rocks at West Arm in Horseshoe Harbour, thus ending the cruise. Expeditioners were eventually taken to Casey on the Shirase, then flown home. Meanwhile the Aurora Australis was refloated and sailed to Fremantle, then on to Singapore for repairs. This report discusses the oceanographic data from CTD operations on the cruise. A total of 47 CTD vertical profile stations were taken on the cruise (Table 1). Over 850 Niskin bottle water samples were collected for the measurement of salinity, dissolved oxygen, nutrients (phosphate, nitrate+nitrite and silicate), dissolved inorganic carbon (i.e. TCO2), alkalinity, POC and PN, and biological parameters, using a 24 bottle rosette sampler. A UVP particle counter/camera system was attached to the CTD package (P.I. Emmanuel Laurenceau). A separate trace metal rosette system was deployed from the trawl deck (P.I. Andrew Bowie). Upper water column current profile data were collected by a ship mounted ADCP, and meteorological and water property data were collected by the array of ship's underway sensors. Eight drifting floats were deployed over the course of the cruise. Processing/calibration and data quality for the main CTD data are described in this report. Underway sea surface temperature and salinity data are compared to near surface CTD data. CTD station positions are shown in Figure 1, while CTD station information is summarised in Table 1. Float deployments (5 x Argo/Apex, 2 x SOCCOM and 1 x Provor) are summarised in Table 10. Further cruise itinerary/summary details can be found in the voyage leader report (Australian Antarctic Division unpublished report: Voyage 3 2015-2016, RSV Aurora Australis, Voyage Leader’s report - see the metadata record "Aurora Australis Voyage 3 2015/16 Track and Underway Data" for access to the Voyage Report).

Water samples were collected from the seawater line on the Aurora Australis during the K-Axis voyage. They were filtered so that two fractions of each sample were collected: a fraction that was between 1.2 and 210 um and a fraction that was between 210 and 1000 um. A 47 mm diameter 1000 um mesh was placed upstream of all samples, and this prevented larger particles (e.g. zooplankton) from entering the samples. The underway water was taken from the pCO2 rig at 1.4 to 1.5 atmospheres. All samples were collected on 25 mm diameter 1.2um Sterlitech silver membrane filters. The greater than 210 samples were collected on mesh and refiltered onto silver filters. The filters were stored frozen until they were processed in Hobart. Subsamples of the filters were analysed at the Central Science Laboratories, University of Tasmania to determine elemental N and C. The remainder of the filters were analysed by ANSTO (NSW) to determine delta15N and delta13C. Volumes are in litres, and the values for the nitrogen isotopes are presented as ratios.

During the K-Axis marine voyage from mid Jan-late Feb 2016, a diverse range of sampling techniques were employed to collect specimens and data. Each sampling event was recorded by scientists and technical support staff in a logbook that was kept in the operations room on board the Aurora Australis. This is a direct digital copy/transcription of the paper logbook. event_number: A unique event identifier in the log, in the order that the events were written down (usually but not always chronologically) event_type: The code defined and used by each research project to identify the types of equipment deployed or samples collected for an event. event_type_prefix: A non-mandatory prefix field used by some research projects to identify the type of an event event_type_number: A sequential number or alphanumeric-number combination defined and used by each research project to identify unique equipment deployment or sample collection events station_number: A universal (voyage-wide) station number used across all projects to identify a nominal lat/lon position defined during voyage planning leg: A nominally straight-line section of the voyage track defined during voyage planning. The voyage track was planned as a series of roughly N-S and E-W transects that intersected in some locations. Legs start at a station and continue through more stations to a vertex-station which is the start of the next leg. Legs are numbered consecutively. waypoint: A GPS waypoint used by Aurora Australis crew, AAD science technical support and researchers to identify target lat/lon positions in the voyage. Some waypoints correspond with station numbers. start_date_utc: The start date of the event in UTC start_time_utc: The start time of the event in UTC start_lat_deg: The latitude (whole degrees) of the vessel at the beginning of the event start_lat_min: The latitude (minutes) of the vessel at the beginning of the event start_lat_dec_deg: The latitude (decimal degrees) of the vessel at the beginning of the event start_lon_deg: The longitude (whole degrees) of the vessel at the beginning of the event start_lon_min: The longitude (minutes) of the vessel at the beginning of the event start_lon_dec_deg: The longitude (decimal degrees) of the vessel at the beginning of the event end_date_utc: The end date of the event in UTC end_time_utc: The end time of the event in UTC end_lat_deg: The latitude (whole degrees) of the vessel at the end of the event end_lat_min: The latitude (minutes) of the vessel at the end of the event end_lat_dec_deg: The latitude (decimal degrees) of the vessel at the end of the event end_lon_deg: The longitude (whole degrees) of the vessel at the end of the event end_lon_min: The longitude (minutes) of the vessel at the end of the event end_lon_dec_deg: The longitude (decimal degrees) of the vessel at the end of the event remarks: Comments/remarks written by researchers when completing the paper log transcribe_comments: Comments/remarks made by the transcriber when the log was digitised

During the K-Axis marine voyage from mid Jan-late Feb 2016, a diverse range of sampling techniques were employed to collect specimens and data. Each sampling event was recorded by scientists and technical support staff in a logbook that was kept in the operations room on board the Aurora Australis. This is a PDF of the scanned original document, compiled on paper during the voyage. event_number: A unique event identifier in the log, in the order that the events were written down (usually but not always chronologically) event_type: The code defined and used by each research project to identify the types of equipment deployed or samples collected for an event. event_type_prefix: A non-mandatory prefix field used by some research projects to identify the type of an event event_type_number: A sequential number or alphanumeric-number combination defined and used by each research project to identify unique equipment deployment or sample collection events station_number: A universal (voyage-wide) station number used across all projects to identify a nominal lat/lon position defined during voyage planning leg: A nominally straight-line section of the voyage track defined during voyage planning. The voyage track was planned as a series of roughly N-S and E-W transects that intersected in some locations. Legs start at a station and continue through more stations to a vertex-station which is the start of the next leg. Legs are numbered consecutively. waypoint: A GPS waypoint used by Aurora Australis crew, AAD science technical support and researchers to identify target lat/lon positions in the voyage. Some waypoints correspond with station numbers. start_date_utc: The start date of the event in UTC start_time_utc: The start time of the event in UTC start_lat_deg: The latitude (whole degrees) of the vessel at the beginning of the event start_lat_min: The latitude (minutes) of the vessel at the beginning of the event start_lat_dec_deg: The latitude (decimal degrees) of the vessel at the beginning of the event start_lon_deg: The longitude (whole degrees) of the vessel at the beginning of the event start_lon_min: The longitude (minutes) of the vessel at the beginning of the event start_lon_dec_deg: The longitude (decimal degrees) of the vessel at the beginning of the event end_date_utc: The end date of the event in UTC end_time_utc: The end time of the event in UTC end_lat_deg: The latitude (whole degrees) of the vessel at the end of the event end_lat_min: The latitude (minutes) of the vessel at the end of the event end_lat_dec_deg: The latitude (decimal degrees) of the vessel at the end of the event end_lon_deg: The longitude (whole degrees) of the vessel at the end of the event end_lon_min: The longitude (minutes) of the vessel at the end of the event end_lon_dec_deg: The longitude (decimal degrees) of the vessel at the end of the event remarks: Comments/remarks written by researchers when completing the paper log

During the K-Axis marine voyage from mid Jan-late Feb 2016, a diverse range of sampling techniques were employed to collect specimens and data. Each sampling event was recorded by scientists and technical support staff in a logbook that was kept in the operations room on board the Aurora Australis. This is a direct digital transcription of the paper logbook with interpolated lat/lon from underway data to supplement start times as recorded in the log. The method used to obtain the supplementary position is described in the associated eventlog_matchup.html file. event_number: A unique event identifier in the log, in the order that the events were written down (usually but not always chronologically) event_type: The code defined and used by each research project to identify the types of equipment deployed or samples collected for an event. event_type_prefix: A non-mandatory prefix field used by some research projects to identify the type of an event event_type_number: A sequential number or alphanumeric-number combination defined and used by each research project to identify unique equipment deployment or sample collection events station_number: A universal (voyage-wide) station number used across all projects to identify a nominal lat/lon position defined during voyage planning leg: A nominally straight-line section of the voyage track defined during voyage planning. The voyage track was planned as a series of roughly N-S and E-W transects that intersected in some locations. Legs start at a station and continue through more stations to a vertex-station which is the start of the next leg. Legs are numbered consecutively. waypoint: A GPS waypoint used by Aurora Australis crew, AAD science technical support and researchers to identify target lat/lon positions in the voyage. Some waypoints correspond with station numbers. start_date_utc: The start date of the event in UTC start_time_utc: The start time of the event in UTC start_lat_deg: The latitude (whole degrees) of the vessel at the beginning of the event start_lat_min: The latitude (minutes) of the vessel at the beginning of the event start_lat_dec_deg: The latitude (decimal degrees) of the vessel at the beginning of the event start_lon_deg: The longitude (whole degrees) of the vessel at the beginning of the event start_lon_min: The longitude (minutes) of the vessel at the beginning of the event start_lon_dec_deg: The longitude (decimal degrees) of the vessel at the beginning of the event end_date_utc: The end date of the event in UTC end_time_utc: The end time of the event in UTC end_lat_deg: The latitude (whole degrees) of the vessel at the end of the event end_lat_min: The latitude (minutes) of the vessel at the end of the event end_lat_dec_deg: The latitude (decimal degrees) of the vessel at the end of the event end_lon_deg: The longitude (whole degrees) of the vessel at the end of the event end_lon_min: The longitude (minutes) of the vessel at the end of the event end_lon_dec_deg: The longitude (decimal degrees) of the vessel at the end of the event remarks: Comments/remarks written by researchers when completing the paper log transcribe_comments: Comments/remarks made by the transcriber when the log was digitised utc: The start date and time of the event in UTC start_lon_dec_deg_interp: The latitude (decimal degrees) of the vessel at the beginning of the event interpolated from the vessel underway data start_lat_dec_deg_interp: The longitude (decimal degrees) of the vessel at the beginning of the event interpolated from the vessel underway data