Antarctic Circumnavigation Expedition event log: recording data and sample collection in the Southern Ocean during the austral summer of 2016/17.

***** Dataset abstract *****

The Antarctic Circumnavigation Expedition (ACE) spent 90 days circumnavigating Antarctica on the R/V Akademik Tryoshnikov during the austral summer of 2016/17. This dataset provides a record of the instrument deployments as well as dataset and sample collection events that took place during the expedition. 

***** Original data collection ******

The time at which instrument deployments, and data and sample collection events were recorded into a MySQL database using a Django application during the expedition. These were recorded by the researchers and the data manager on board. Each deployment or event was assigned a unique number, known as an event number. 

The accuracy of the start and end times of events depends on the sampling method being used (methods are described in the sampling_method_descriptions.csv file). It may vary from seconds to minutes. All times were recorded in UTC because the ship regularly changed time zone. Where a computer time was used, the computers had been synced with a time server, however very often a personal watch was used to record the time. 

Some deployments took place at a station which was defined as a location where a set of measurements were taken. Whilst at sea, this is where the ship stopped for a period of time (normally several hours) and several instruments were deployed in the same location. On other occasions, a station was a sampling location on an island or glacier. In this case, sampling was generally concentrated around the station location. 

Full details of the events can be found in the cruise report (Walton and Thomas, 2018). 

Locations of the events can be found by matching the cruise report with the ship track (Landwehr, Thomas and Schmale, 2020).

***** Data processing *****

Dates and times of events have been checked against individual projects' records and the ship's track to ensure they are as accurate as possible. There is still the possibility that times have been misrecorded, so contacting the project that was involved in that particular sampling activity would be the best way to have the most accurate information. 

The database was installed on a Linux server. Once corrections had been made to the event details, the data were exported to a CSV file.

***** Dataset contents *****

- ace_events.csv, data file, comma-separated values
- sampling_method_descriptions.csv, metadata, comma-separated values
- README.txt, metadata, text
- data_file_header.txt, metadata, text

***** Dataset contact *****

Jen Thomas, Swiss Polar Institute. ORCID: 0000-0002-5986-7026. Email: jen.thomas@swisspolar.ch

***** Dataset license *****

This event log is made available under a Creative Commons Attribution 4.0 International License (CC BY 4.0) whose full text can be found at https://creativecommons.org/licenses/by/4.0/