DOI: 10.18739/a2gx44w6j
title: Merged Datasets for the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) Central Observatory in the Arctic Ocean (2019-2020)

description: The Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) produced a wealth of observational data along the drift of the R/V Polarstern in the Arctic Ocean from October 2019 to September 2020. These data can further process-level understanding and improvements in models. However, the observational records contain temporal gaps and are provided in different formats. One goal of the MOSAiC Single Column Model Working Group (MSCMWG: https://mosaic-expedition.org/science/cross-cutting_groups/) is to provide consistently-formatted, gap-filled, merged datasets representing the conditions at the MOSAiC Central Observatory (the intensively studied region within a few km of R/V Polarstern) that are suitable for driving models on this spatial domain (e.g., single column models, large eddy simulations, etc). The MSCMWG is an open group, please contact the dataset creators if you would like to contribute to future versions of these merged datasets (including new variables).
 This dataset contains version 1 of these merged datasets, and comprises the variables necessary to force a single column ice model (e.g., Icepack: https://zenodo.org/doi/10.5281/zenodo.1213462). The atmospheric variables are primarily derived from Met City (~66 percent (%) of record, https://doi.org/10.18739/A2PV6B83F), with temporal gaps filled by bias and advection corrected data from Atmospheric Surface Flux Stations ( https://doi.org/10.18739/A2XD0R00S, https://doi.org/10.18739/A25X25F0P, https://doi.org/10.18739/A2FF3M18K). Some residual gaps in shortwave radiation were filled with ARM ship-board radiometer data.
 Three different options for snowfall precipitation rate (prsn) are provided, based on in-situ observations that precipitation greatly exceeded accumulation on level ice, and accumulation rates varied on different ice types. MOSAiC_kazr_snow_MDF_20191005_20201001.nc uses 'snowfall_rate1' derived from the vertically-pointing, ka-band radar on the vessel (https://doi.org/10.5439/1853942). MOSAiC_Raphael_snow_fyi_MDF_20191005_20201001.nc and MOSAiC_Raphael_snow_syi_MDF_20191005_20201001.nc use snow accumulation measurements from manual mass balance sites (https://doi.org/10.18739/A2NK36626) to derived a pseudo-precipitation. MOSAiC_Raphael_snow_fyi_MDF_20191005_20201001.nc is based on the First Year Ice (fyi) sites. MOSAiC_Raphael_snow_syi_MDF_20191005_20201001.nc is based on the Second Year Ice (syi) sites. The other atmospheric variables for these files are identical.
 Oceanic variables are in MOSAiC_ocn_MDF_20191006_20200919.nc and are derived from https://doi.org/10.18739/A21J9790B.
 The data are netCDF files formatted according to the Merged Data File format (https://doi.org/10.5194/egusphere-2023-2413, https://gitlab.com/mdf-makers/mdf-toolkit). The code 'recipes' that were used to produce these data are available at: https://doi.org/10.5281/zenodo.10819497.
 If you use these datasets, please also cite the appropriate publications:
 Meteorological variables (excluding precipitation): Cox et al., 2023 (https://doi.org/10.1038/s41597-023-02415-5)
 Oceanographic variables: Schulz et al., 2023 (https://doi.org/10.31223/X5TT2W)
 KAZR-derived precipitation: Matrosov et al., 2022 (https://doi.org/10.1525/elementa.2021.00101)
 Accumulation-derived pseudo-precipitation: Raphael et al., in review.
 The following are known issues that will be addressed in future dataset releases:
 1. Residual gaps occupy approximately 20% of the data record (see addendum)
 2. Some transitions to shiprad downwelling shortwave are unreasonable abrupt
 3. MDF format does not currently include a field for point-by-point data source
 Addendum:
 For atmospheric variables, below indicates the percentage sourced from each dataset (and the amount missing a.k.a NaN)
 Air Temperature
 metcity 0.661943
 NaN 0.193333
 asfs30 0.134910
 asfs40 0.008607
 asfs50 0.001207
 Specific Humidity
 metcity 0.658890
 NaN 0.196298
 asfs40 0.008695
 Wind Velocity
 metcity 0.666334
 NaN 0.255003
 asfs30 0.068828
 asfs40 0.008630
 asfs50 0.001205
 Downwelling Longwave
 metcity 0.549417
 asfs30 0.241502
 NaN 0.209081
 Downwelling Shortwave
 metcity 0.674166
 NaN 0.158814
 asfs30 0.140794
 shipradS1 0.026226
 Note that the 21 day gap from the end of Central Observatory 2 to the start of Central Observatory 3 occupies 5.8% of the record.