This HISTOZ2_readme.txt file was generated on 20221019 by Stefan Brönnimann ------------------- GENERAL INFORMATION ------------------- 1. Title of dataset: 2. Contributor information: Name: Brönnimann, Stefan Role/Function: Data collector Institution: Institute of Geography, University of Bern Address: Hallerstr. 12, 3012 Bern Email: stefan.broennimann@giub.unibe.ch 3. Date of data collection: 20221019 4. Geographic location of data collection: global 5. Keywords describing the subject of your dataset: Total column ozone, reconstruction, data assimilation 6. Information about funding sources that supported the collection of the data: Funding agency name: European Research Council Grant number: 787574 ------------------- SHARING/ACCESS INFORMATION ------------------- 1. Licenses/restrictions placed on the data: CC-BY 2. Links to publications that cite or use the data: None 3. Links to other publicly accessible locations of the data: None 4. Links/relationships to additional data sets: None 5. Was data derived from another source? Yes Part of the data set is an update of Brönnimann, Stefan; Bhend, Jonas; Franke, Jörg; Flückiger, Simon; Fischer, Andreas M.; Bleisch, René; Bodeker, G.; Hassler, B.; Rozanov, E.; Schraner, M. (2013). A global historical ozone data set and prominent features of stratospheric variability prior to 1979. [Dataset]. https://boris.unibe.ch/71600/ 6. Recommended citation for this dataset: Brönnimann, Stefan (2022) HISTOZ2 [Dataset]. Bern. --------------------- DATA & FILE OVERVIEW --------------------- 1. File List: Filename: HISTOZ2_TOZ_1924_1978.nc File format: netCDF File encoding: netCDF Short description: Monthly zonal mean total column ozone as a function of latitude from 1924-1978 from a data assimilation approach (updated from approach described in https://10.5194/acp-13-9623-2013). Date of creation: 20221019 Filename: HISTOZ2_TOZ_1924_1978_adj2NIWA.nc File format: netCDF File encoding: netCDF Short description: Monthly zonal mean total column ozone as a function of latitude from 1924-1978 from a data assimilation approach (updated from approach described in https://10.5194/acp-13-9623-2013), adjusted to the NIWA total column ozone data set (Bodeker et al., 2021, https://doi.org/10.5194/essd-13-3885-2021) based on the 1979-1999 period. Date of creation: 20221019 Filename: HISTOZ2_2D_ozone_number_density_1901_1978.nc File format: netCDF File encoding: netCDF Short description: Monthly 2D fields (latitude, pressure level) of ozone number density from 1901-1978 from a data assimilation approach (updated from approach described in https://10.5194/acp-13-9623-2013). Date of creation: 20221019 2. Relationship between files: 3. Are there multiple versions of the dataset? yes File HISTOZ2_2D_ozone_number_density_1901_1978.nc is an update of Brönnimann, Stefan; Bhend, Jonas; Franke, Jörg; Flückiger, Simon; Fischer, Andreas M.; Bleisch, René; Bodeker, G.; Hassler, B.; Rozanov, E.; Schraner, M. (2013). A global historical ozone data set and prominent features of stratospheric variability prior to 1979. [Dataset], https://boris.unibe.ch/71600/ In the new version, more observations were integrated, and the data assimilation scheme was upated. -------------------------- METHODOLOGICAL INFORMATION -------------------------- 1. Description of methods used for collection/generation of data: HISTOZ2 is an assimlated ozone data set that originates from assimilationg monthly total column observations since 1924 into an ensemble of chemistry climate model simulations. The approach is an update of the approach described Brönnimann et al., (2013), https://10.5194/acp-13-9623-2013. Changes include the integration of additional historical observations as well as changes in the assimilation scheme. These changes are described in Brönnimann, S. (2022) Evolution of total column ozone prior to the era of ozone depletion, Frontiers in Erath Science (submitted). 2. Methods for processing the data: see above 3. Instrument- or software-specific information needed to interpret the data: NetCDF libraries 4. Standards and calibration information: Not applicable 5. Environmental/experimental conditions: Not applicable 6. Describe any quality-assurance procedures performed on the data: The data set was evaluated against satellite data in an overlapping period (1979-1999). Results of the evaluation are described in Brönnimann, S. (2022) Evolution of total column ozone prior to the era of ozone depletion, Frontiers in Erath Science (submitted). 7. People involved with sample collection, processing, analysis and/or submission: Brönnimann, Stefan ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: HISTOZ2_TOZ_1924_1978.nc ----------------------------------------- 1. Number of variables: 1 variable, 3 dimensions 2. Number of cases/rows: 48 latitudes, 660 time steps (months), 11 members (9 individual ensemble members, member 10 is mean if members 1 to 9, member 11 is the prior) 3. Variable List TCO3, total column ozone in Dobson Units 4. Missing data codes: 1e-30 5. Specialized formats of other abbreviations used None ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: HISTOZ2_TOZ_1924_1978_adj2NIWA.nc ----------------------------------------- 1. Number of variables: 1 variable, 3 dimensions 2. Number of cases/rows: 48 latitudes, 660 time steps (months), 11 members (9 individual ensemble members, member 10 is mean if members 1 to 9, member 11 is the prior) 3. Variable List TCO3, total column ozone in Dobson Units 4. Missing data codes: 1e-30 5. Specialized formats of other abbreviations used None ----------------------------------------- DATA-SPECIFIC INFORMATION FOR: HISTOZ2_2D_ozone_number_density_1901_1978.nc ----------------------------------------- 1. Number of variables: 1 variable, 4 dimensions 2. Number of cases/rows: 36 latitudes, 30 pressure levels, 936 time steps (months), 10 members (9 individual ensemble members, member 10 is mean if members 1 to 9) 3. Variable List O3, ozone number density in 10^12 molec./cm3 4. Missing data codes: 1e-30 5. Specialized formats of other abbreviations used None