Observations collected between 18th October 2018 and 29th March 2019 aboard Aurora Australis by AIRBOX and associated instruments

This gives the slant column density for each trace gas at each elevation angle (level one product). The differential slant column density (dSCD) is determined by taking the ratio of low elevation angle scans with zenith scans, producing tropospheric specific information. Typically some atmospheric corrections are required to be included in the analysis including a polynomial, which accounts for broadband absorption and scattering processes, and corrections for the filling in of solar Fraunhofer lines (the Ring effect).

By inverting measured dSCDs, and dSCDS modelled using a radiative transfer model, vertical profile information for trace gases can be calculated using MAX-DOAS observations. Finally, since knowing the elevation angle precisely is crucial to retrieval of vertical profile information from MAX-DOAS measurements, this dataset also includes Euler angles measured using a co-located accelerometer which may, if necessary, be used to correct MAX-DOAS elevation angles for the pitch and roll of the ship in the Southern Ocean.

MAX-DOAS instrument specifications: Two ultra-low straylight 75mm Avantes spectrometers: UV: 295 – 450nm, 100 μm m slit (from fibre), 0.6nm resolution, Hamamatsu backthinned detector optimized for UV, Schott BG3 filter. Visible: 430 – 565nm, 100 μ m slit (from fibre), 0.6nm resolution, Sony 2048L detector Typical instrumental stray light less than 0.05% , RMS of 1 · 10−4 (vis) and 2 · 10−4 (uv) for 1000 scans around noon.

Spectrometers temperature stabilized at a fixed temperature (20 C) with a deviation of less than 0.05 C Elevation angle accuracy less than 0.1 Telescope field of view (opening angle) less than 0.3 Other instruments/datasets detailed in the file: Gaseous oxidised mercury measurements Gaseous elemental mercury Radon measurements HiVolume sampler Ozone monitor Sea state cameras Lufft weather station Spectronus greenhouse gas analyser NAIS ToF-ACSM SMPS Nephelometer MAAP Black carbon analyser CPC TSI 3776 CPC TSI 3772 CCNC mini-MPL (micropulse lidar) Microtops Further information is available in the word document in the download file.