Met City meteorological and surface flux measurements (Level 2 Processed), Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC), central Arctic, October 2019 - September 2020.

Processed (Level 2) measurements and derive parameters from a collection of instruments at the Met City location within the Central Observatory of the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition drifting with the central Arctic sea ice from October 2019 through September 2020. Measurements are from a 10-meter meteorological and flux tower, a radiation suite (operated by the DOE Atmospheric Radiation Measurement Program), and at times also a meteorological mast located nearby. The collective MET CITY systems measured many parameters of the surface energy budget, air-ice momentum flux, near-surface meteorology, and local position. Measurements of meteorology and high-resolution 3-dimensional winds were observed at nominal heights of 2-, 6-, and 10-m, with some measurements at either 30- or 23-m when the mast was also operational. Measurements of upwelling broadband radiation were made at a nominal height of 3 m, while measurements of downwelling broadband radiation were made at a nominal height of 1.5 m above the ice surface. The measurements are included in three netCDF files per day. The “1min” mosmet files are comprised of 1-min averages of measured and derived variables, including near-surface meteorology, surface skin temperature, snow depth, radiative fluxes, and position. The “10min” mosseb files are 10-min averages of the same variables as in the 1-min files and also include calculations of turbulent sensible and latent heat fluxes, momentum flux, and associated diagnostics, surface stress, and Monin-Obukhov parameters using both eddy covariance and bulk methodologies, all valid for the 10-min intervals. Both of these file types also contain a “_qc” variable paired with each measurement variable, or family of variables, that is a temporally-matched quality control code: 0 = good data, 1 = caution (data may be suspect), 2 = bad data, 3 = engineering (data was collected for testing purposes and is unsuitable for scientific research), and -1 = missing (no data was collected). An independent set of flag variables, pertaining specifically to the collection of turbulence variables and the direction of winds, was devised to document times when the prevailing wind direction was influenced by non-natural structures on the sea ice and the data should be treated with caution. The “10hz” files include 3-dimensional winds and gas densities of water vapor and carbon dioxide that are quality-controlled, aggregated to a regular 10-Hz temporal grid, and (for winds) rotated into the earth coordinate frame. A detailed documentation of the measurement conditions, the processing steps taken to construct this data set, and other caveats and uncertainties are provided in an accompanying published data manuscript (Cox et al. 2023). For the scientific purposes of most users, we recommend use of the Level 3 data files, as these include only the best estimates of essential climate variables. Level 2 data is useful for those that want enhanced turbulence diagnostics parameters and/or to consider the use of some data that has been flagged as unsuitable for research. These data were obtained via a collaboration among the University of Colorado, NOAA Physical Sciences Laboratory, NOAA Global Ocean Monitoring and Observing (GOMO) program, Department of Energy Atmospheric Radiation Measurement Program, and University of Leeds, UK. Cox, C.J., M. Gallagher, M.D. Shupe, P.O.G. Persson, A. Solomon, C. W. Fairall, T. Ayers, B. Blomquist, I. Brooks, D. Costa, A. Grachev, D. Gottas, J. Hutchings, M. Kutchenreiter, J. Leach, S.M. Morris, V. Morris, J. Osborn, S. Pezoa, A. Preusser, L. Riihimaki, and T. Uttal (2023): Continuous observations of the surface energy budget and meteorology over Arctic sea ice during MOSAiC. To be submitted, Nature Scientific Data.