Raw spectra measurements of scattered sunlight collected using a MAX-DOAS (Multi-Axis Differential Optical Absorption Spectroscopy) instrument in the austral summer of 2016/17 during the Antarctic Circumnavigation Expedition (ACE).

Dataset abstract

To achieve the objectives of the project, we installed a MAX-DOAS (Multi-AXis Differential Optical Absorption Spectroscopy) instrument on the vessel “Akademik Tryoshnikov”. This instrument is based on the DOAS technique, which is used to measure trace gas concentrations in the atmosphere. The method consists of the analysis of the spectral absorption lines that each trace gas produces in the solar spectra. The DOAS technique uses the narrowband features that every trace gas has in their spectral absorption coefficients. This differential cross section is unique and acts like a fingerprint for the trace gases, allowing to differentiate between them and to estimate their concentrations (for further details see Platt and Stutz, 2008).

In the past decades, atmospheric chemists have come to realize that halogen species (like Cl, Br or I and their oxides ClO, BrO and IO) exert a powerful influence on the chemical composition of the troposphere and through that influence affect the evolution of pollutants, hence having a significant impact on climate. These reactive halogen species are potent oxidizers for organic and inorganic compounds throughout the troposphere. In particular, halogen cycles can act on several compounds (such as methane, ozone, particles…), all of which are climate forcing agents through direct and indirect radiative effects. Dynamic exchange of halogens between the ocean, sea ice, snowpack and atmosphere is the main driver for the frequent occurrence of Ozone Depletion Events (ODEs) and Atmospheric Mercury Depletion Events (AMDEs) (Saiz-Lopez and von Glasow, 2012).

In this dataset we present the raw spectra measurements of scattered sunlight recorded by the MAX-DOAS onboard a research vessel in the Southern Ocean and Atlantic Ocean. Included are position and vessel inclination data. Data coverage is from December 2016 to April 2017.

Dataset contents

• ace_maxdoas_gps.zip
• GPS_JDDD.txt, data file, ASCII text
• ace_maxdoas_inclination.zip
• Inclination_JDDD.txt, data file, ASCII text
• ace_maxdoas_spectra-YYYY-MM.zip
• - MAXDOAS
  - - WWW
  - - - JDDD
  - - - - LiveInfo_DDDhhmmss.WWW, data file, ASCII text
  - - - - Atmos
  - - - - - DDDhhmmss_90.WWW, data file, ASCII text
  - ZENITH
  - - WWW
  - - - JDDD
  - - - - LiveInfo_DDDhhmmss.WWW, data file, ASCII text
  - - - - Atmos
  - - - - - DDDhhmmss_90.WWW, data file, ASCII text
• README.txt, metadata, text
• data_file_header_gps.txt, metadata, text
• data_file_header_inclination.txt, metadata, text
• data_file_header_spectra_atmos.txt, metadata, text
• data_file_header_spectra_liveinfo.txt, metadata, text

where YYYY is the year and MM is the month. JDDD is the day of the year (Julian day) YYYY in which the file was recorded. hhmmss is the time. WWW is the central wavelength of the measured spectrum in the UV or VIS region.

Dataset license

This dataset of raw spectra of scattered sunlight measurements from ACE is made available under the 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/