ALBERT

Description: The hemispherical-directional reflectance factor (HDRF) of snow surfaces was measured in Antarctica during austral summer in 2013/14. The HDRF was retrieved from airborne measurements using a digital 180° fish-eye camera onboard the research aircraft Polar 6 operated by the Alfred Wegener Institute, Helmholtz Centre for Polar and Marine Research (AWI), Bremerhaven, Germany. -- The dataset contains the weighting functions for isotropic (f_iso), volumetric (f_vol), and geometric (f_geo) scattering obtained by inverting the kernel-driven, semi-empirical Ross-Thick-Li-Sparse-Reciprocal model for the bidirectional reflectance distribution function (BRDF). Along with the weighting functions f_iso, f_vol, and f_geo, the weights of determination (WoD) and root-mean-square errors (RMSE) are given as a criterion for the quality of the inversion for all 3 camera channels (Red: 602 nm central wavelength, Green: 538 nm, Blue: 470 nm). In addition, the footprint size of the camera observations is stated. -- The snow HDRF was measured over a variety of different solar zenith angles, optical-equivalent snow grain sizes, and surface roughness, which are given as parameters within the dataset. The optical-equivalent snow grain size was retrieved from spectral surface albedo measurements with the Spectral Modular Airborne Radiation measurement sysTem (SMART) mounted on Polar 6 using observations at 1280 and 1100 nm wavelength. The surface roughness was measured using the airborne laser scanner RIEGL VQ580 on Polar 6. -- Averaging was performed over time intervals of 30 s. The number of camera pictures, SSA measurements and laser scanner observations used for averaging over each 30s-interval are given. -- The dataset further includes basic flight parameters such as the second of day, longitude, latitude, flight altitude, surface elevation, aircraft velocity, and an attitude flag (0 = okay, 1 = do not use) corresponding to the times of measurement. -- Use of these data requires prior OK from the PIs.

Description: From January 2016 until August 2018, an automated Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) instrument was operated at the German research station Neumayer III (NMIII) in coastal Antarctica to measure trace gas mixing ratios in the boundary layer close to the ground (average altitude above the snow surface: 4m). Two different atmospheric light paths with total lengths of 3100 m and 5900m were available and used depending on the spectral window and visibility. Detectable species were bromine monoxide (BrO), bromine dioxide (OBrO), molecular bromine (Br2), chlorine monoxide (ClO), chlorine dioxide (OClO), iodine monoxide (IO), iodine dioxide (OIO), molecular iodine (I2), sulphur dioxide (SO2), nitrogen dioxide (NO2), nitrous acid (HONO), nitrate (NO3), and ozone (O3). The evaluated data was filtered based on RMS (root mean square) thresholds of optical density residuals of the DOAS fits (see individual data sets for respective values). Detection limits based on a 3-sigma criterion were used and are provided in the data sets for all detectable species. For BrO, ClO, OClO, IO, SO2, and NO2, observations above the respective detection limit were made. For all absorbers the retrieved mixing ratios/concentrations with respective total errors (corresponding to 1-sigma) are provided. The data sets include the observations below the respective detection limit scattered around 0, which due to the spectral analysis with the DOAS approach can include negative values. Significant data points can be selected using the separately provided detection limits (3-sigma criterion - recommended). Alternatively, the total errors can be used. Since total errors and hence detection limits are determined from spectral information, for absorbers not observed at significant levels (OBrO, Br2, OIO, I2, HONO, and NO3), the respective detection limits can serve as an upper limit for an atmospheric presence. The mixing ratios provided here were calculated using meteorological data from Neumayer III station already published on PANGAEA. A list of data sets is included in the "Related to" section. The spectral raw data of the measurements is stored on the measurement data server of the Institute of Environmental Physics, University of Heidelberg. -- Technical details and performance of employed LP-DOAS instrument: Nasse et al. (2019, doi:10.5194/amt-2019-69) Detailed description of measurements and evaluation: Nasse, Jan-Marcus (2019): Halogens in the coastal boundary layer of Antarctica (PhD Thesis). University of Heidelberg

Description: From January 2016 until August 2018, an automated Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) instrument was operated at the German research station Neumayer III (NMIII) in coastal Antarctica to measure trace gas mixing ratios in the boundary layer close to the ground (average altitude above the snow surface: 4m). Two different atmospheric light paths with total lengths of 3100 m and 5900m were used depending on visibility. The DOAS evaluation of I2 was performed between 532.5 and 549 nm. Fits with residual optical density RMS (root mean square) values larger than 4.0e-4 were discarded. The resulting mean residual RMS is 2.3e-4. The mean detection limit is 78 pmol/mol. The data sets include the observations below the respective detection limit scattered around 0, which due to the spectral analysis with the DOAS approach can include negative values. I2 was not detected above a 3-sigma detection limit. Since total errors and hence detection limits are determined from spectral information, the detection limit of I2 can serve as an upper limit for an atmospheric presence. The mixing ratios provided here were calculated using meteorological data from Neumayer III station already published on PANGAEA. A list of data sets is included in the "Related to" section of the bibliography this data set is part of. The spectral raw data of the measurements is stored on the measurement data server of the Institute of Environmental Physics, University of Heidelberg.

Description: From January 2016 until August 2018, an automated Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) instrument was operated at the German research station Neumayer III (NMIII) in coastal Antarctica to measure trace gas mixing ratios in the boundary layer close to the ground (average altitude above the snow surface: 4m). Two different atmospheric light paths with total lengths of 3100 m and 5900m were used depending on visibility. The DOAS evaluation of Br2 was performed between 532.5 and 549 nm. Fits with residual optical density RMS (root mean square) values larger than 4.0e-4 were discarded. The resulting mean residual RMS is 2.3e-4. The mean detection limit is 3.9 nmol/mol. The data sets include the observations below the respective detection limit scattered around 0, which due to the spectral analysis with the DOAS approach can include negative values. Br2 was not detected above a 3-sigma detection limit. Since total errors and hence detection limits are determined from spectral information, the detection limit of Br2 can serve as an upper limit for an atmospheric presence. The mixing ratios provided here were calculated using meteorological data from Neumayer III station already published on PANGAEA. A list of data sets is included in the "Related to" section of the bibliography this data set is part of. The spectral raw data of the measurements is stored on the measurement data server of the Institute of Environmental Physics, University of Heidelberg.

Description: From January 2016 until August 2018, an automated Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) instrument was operated at the German research station Neumayer III (NMIII) in coastal Antarctica to measure trace gas mixing ratios in the boundary layer close to the ground (average altitude above the snow surface: 4m). Two different atmospheric light paths with total lengths of 3100 m and 5900m were used depending on visibility. The DOAS evaluation of OBrO was performed between 532.5 and 549 nm. Fits with residual optical density RMS (root mean square) values larger than 4.0e-4 were discarded. The resulting mean residual RMS is 2.3e-4. The mean detection limit is 11 pmol/mol. The data sets include the observations below the respective detection limit scattered around 0, which due to the spectral analysis with the DOAS approach can include negative values. OBrO was not detected above a 3-sigma detection limit. Since total errors and hence detection limits are determined from spectral information, the detection limit of OBrO can serve as an upper limit for an atmospheric presence. The mixing ratios provided here were calculated using meteorological data from Neumayer III station already published on PANGAEA. A list of data sets is included in the "Related to" section of the bibliography this data set is part of. The spectral raw data of the measurements is stored on the measurement data server of the Institute of Environmental Physics, University of Heidelberg.

Description: From January 2016 until August 2018, an automated Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) instrument was operated at the German research station Neumayer III (NMIII) in coastal Antarctica to measure trace gas mixing ratios in the boundary layer close to the ground (average altitude above the snow surface: 4m). Two different atmospheric light paths with total lengths of 3100 m and 5900m were used depending on visibility. The DOAS evaluation of HONO was performed between 352.5 and 386.5 nm. Fits with residual optical density RMS (root mean square) values larger than 3e-4 were discarded. The resulting mean residual RMS is 1.5e-4. The mean detection limit is 174 pmol/mol. The data sets include the observations below the respective detection limit scattered around 0, which due to the spectral analysis with the DOAS approach can include negative values. HONO was not detected above a 3-sigma detection limit. Since total errors and hence detection limits are determined from spectral information, the detection limit of HONO can serve as an upper limit for an atmospheric presence. The mixing ratios provided here were calculated using meteorological data from Neumayer III station already published on PANGAEA. A list of data sets is included in the "Related to" section of the bibliography this data set is part of. The spectral raw data of the measurements is stored on the measurement data server of the Institute of Environmental Physics, University of Heidelberg.

Description: From January 2016 until August 2018, an automated Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) instrument was operated at the German research station Neumayer III (NMIII) in coastal Antarctica to measure trace gas mixing ratios in the boundary layer close to the ground (average altitude above the snow surface: 4m). Two different atmospheric light paths with total lengths of 3100 m and 5900m were used depending on visibility. The DOAS evaluation of BrO was performed between 301.7 and 346.4 nm as well as between 332.5 and 370.5 nm (for subsequent measurements in two different instrumental setups). Fits with residual optical density RMS (root mean square) values larger than 4.0e-4 and 3.5e-4 respectively were discarded. The resulting mean residual RMS are 2.4e-4 and 2.2e-4 respectively. The mean detection limits of the two evaluations are 2.2 and 3.8 pmol/mol. The data sets include the observations below the respective detection limit scattered around 0, which due to the spectral analysis with the DOAS approach can include negative values. Significant data points can be selected using the separately provided detection limits (3-sigma criterion - recommended). Alternatively, the total errors can be used. The mixing ratios provided here were calculated using meteorological data from Neumayer III station already published on PANGAEA. A list of data sets is included in the "Related to" section of the bibliography this data set is part of. The spectral raw data of the measurements is stored on the measurement data server of the Institute of Environmental Physics, University of Heidelberg.

Description: From January 2016 until August 2018, an automated Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) instrument was operated at the German research station Neumayer III (NMIII) in coastal Antarctica to measure trace gas mixing ratios in the boundary layer close to the ground (average altitude above the snow surface: 4m). Two different atmospheric light paths with total lengths of 3100 m and 5900m were used depending on visibility. The DOAS evaluation of NO3 was performed between in a split window between 616.5 and 648.0 nm plus 660.5 to 673.2 nm. Fits with residual optical density RMS (root mean square) values larger than 1.2e-3 were discarded. The resulting mean residual RMS is 0.8e-3. The mean detection limit is 8 pmol/mol. The data sets include the observations below the respective detection limit scattered around 0, which due to the spectral analysis with the DOAS approach can include negative values. NO3 was not detected above a 3-sigma detection limit. Since total errors and hence detection limits are determined from spectral information the detection limit of NO3 can serve as an upper limit for an atmospheric presence. The mixing ratios provided here were calculated using meteorological data from Neumayer III station already published on PANGAEA. A list of data sets is included in the "Related to" section of the bibliography this data set is part of. The spectral raw data of the measurements is stored on the measurement data server of the Institute of Environmental Physics, University of Heidelberg.

Description: From January 2016 until August 2018, an automated Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) instrument was operated at the German research station Neumayer III (NMIII) in coastal Antarctica to measure trace gas mixing ratios in the boundary layer close to the ground (average altitude above the snow surface: 4m). An atmospheric light path with a total length of 3100 m was used. The DOAS evaluation of ClO was performed between 287.0 and 306.0 nm. Fits with residual optical density RMS (root mean square) values larger than 5e-4 were discarded. The resulting mean residual RMS is 2.2e-4. The mean detection limit is 11 pmol/mol. The data sets include the observations below the respective detection limit scattered around 0, which due to the spectral analysis with the DOAS approach can include negative values. Significant data points can be selected using the separately provided detection limits (3-sigma criterion - recommended). Alternatively, the total errors can be used. The mixing ratios provided here were calculated using meteorological data from Neumayer III station already published on PANGAEA. A list of data sets is included in the "Related to" section of the bibliography this data set is part of. The spectral raw data of the measurements is stored on the measurement data server of the Institute of Environmental Physics, University of Heidelberg.

Description: From January 2016 until August 2018, an automated Long-Path Differential Optical Absorption Spectroscopy (LP-DOAS) instrument was operated at the German research station Neumayer III (NMIII) in coastal Antarctica to measure trace gas mixing ratios in the boundary layer close to the ground (average altitude above the snow surface: 4m). Two different atmospheric light paths with total lengths of 3100 m and 5900m were used depending on visibility. The DOAS evaluation of OClO was performed between 301.7 and 346.4 nm as well as between 332.5 and 370.5 nm (for subsequent measurements in two different instrumental setups). Fits with residual optical density RMS (root mean square) values larger than 3.5e-4 and 2.5e-4 respectively were discarded. The resulting mean residual RMS are 1.7e-4 and 1.4e-4 respectively. The mean detection limits of the two evaluations are 3.8 and 3.9 pmol/mol. The data sets include the observations below the respective detection limit scattered around 0, which due to the spectral analysis with the DOAS approach can include negative values. Significant data points can be selected using the separately provided detection limits (3-sigma criterion - recommended). Alternatively, the total errors can be used. The mixing ratios provided here were calculated using meteorological data from Neumayer III station already published on PANGAEA. A list of data sets is included in the "Related to" section of the bibliography this data set is part of. The spectral raw data of the measurements is stored on the measurement data server of the Institute of Environmental Physics, University of Heidelberg.