Atmospheric Surface Flux Station #40 measurements (Level 3 Final), Multidisciplinary Drifting Observatory for the Study of Arctic Climate (MOSAiC), central Arctic, October 2019 - September 2020.

Final, processed (Level 3) measurements and derive parameters from the Atmospheric Surface Flux Station #40 (ASFS40) deployed at various locations during 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. The ASFS measured all variables of the surface energy budget, air-ice momentum flux, near-surface meteorology, and local position. Measurements high-resolution 3-dimensional winds were observed at a nominal height of 4-m. Measurements of upwelling broadband radiation and meteorology observed from a nominal height of 2-m. The measurements are included in two 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 other turbulence 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). Data with associated qc flag = 2 or qc flag = 3 have been removed from the data set as they are not appropriate for scientific use. Data with associated qc flag = 1 are retained in the data set, but should be considered with caution and their removal from analysis is at the discretion of the user. 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, and the NOAA Global Ocean Monitoring and Observing (GOMO) program. 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. Nature Scientific Data.

本数据集为2019年10月至2020年9月期间，在随北极中央海冰漂流的多学科北极气候研究漂流观测站（Multidisciplinary drifting Observatory for the Study of Arctic Climate, MOSAiC）科考活动中，于多个点位部署的第40号大气地表通量站（Atmospheric Surface Flux Station #40, ASFS40）的最终处理后（Level 3级）观测数据与衍生参数。该通量站观测了地表能量收支、气-冰动量通量、近地表气象参数及本地位置的全部相关变量，其中高分辨率三维风场的标称观测高度为4米，上行宽带辐射与气象参数的标称观测高度为2米。
每日的观测数据以两份netCDF格式文件存储。名为「1min」的mosmet文件包含观测变量与衍生变量的1分钟平均值，涵盖近地表气象、地表皮肤温度、雪深、辐射通量与位置信息。名为「10min」的mosseb文件则包含与1min文件相同变量的10分钟平均值，同时还采用涡动相关法与整体通量法，针对10分钟时间区间计算了湍流感热通量、潜热通量、动量通量及其他湍流参数。
两类文件均为每个观测变量或变量组配备了「_qc」变量，即与时间匹配的质量控制码，其取值含义如下：0代表有效数据，1代表需谨慎使用（数据可能存疑），2代表无效数据，3代表工程测试数据（仅用于测试，不适用于科学研究），-1代表缺失数据（未采集到有效观测）。本数据集已剔除质量控制标记为2或3的数据，因其不适用于科学研究；质量控制标记为1的数据虽保留在数据集中，但需谨慎使用，是否将其从分析中移除由使用者自行决定。
关于观测条件、本数据集的构建处理步骤，以及其他注意事项与不确定性的详细文档，已随附于已发表的相关数据论文（Cox等人，2023）中。针对大多数用户的科学研究需求，我们推荐使用Level 3级数据文件，因其仅包含核心气候变量的最优估算结果；Level 2级数据则适用于需要更丰富湍流诊断参数，或希望考虑使用部分被标记为不适用于研究的数据的使用者。
本数据集由科罗拉多大学、美国国家海洋和大气管理局（National Oceanic and Atmospheric Administration, NOAA）物理科学实验室以及NOAA全球海洋监测与观测（Global Ocean Monitoring and Observing, GOMO）项目合作提供。
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与T. Uttal（2023）：MOSAiC科考期间北极海冰上方地表能量收支与气象连续观测数据，《自然·科学数据》（Nature Scientific Data）。