Microbiology-Ocean-Cloud Coupling in the High Arctic (MOCCHA): Met Office Unified Model data and associated Cloudnet outputs (UM_RA2T_Cloudnet)

Met Office Unified Model single-site (Oden) output during MOCCHA. These model and observation data are used in McCusker et al.: Evaluating Arctic clouds modelled with the Unified Model and Integrated Forecasting System, Atmospheric Chemistry and Physics, 2023. Model data from the Met Office Unified Model are in directory 'um_model_data/'. Data are hourly data taken from grid box closest to ship location. Where the ship covers more than one grid box within an hour period, data are averaged from all grid boxes crossed. All data files are in a netCDF format, with one file per day. Rose suite ID: u-cc568. Model options include: Cloud microphysics: Both the global model and LAM use the PC2 (Wilson et al., 2008) cloud scheme (i_cld_vn = 2); specifically, the LAM uses the RA2T_CON configuration. Also set l_subgrid_qcl_mp to .true. to allow for turbulent production of mixed-phase cloud. Extended boundary layer diagnostic list. U and V wind components interpolated on to common vertical grid. Model data from directory um_model_data/ are subsequently passed through the Cloudnet algorithm to produce calibrated model data that may be used for direct comparisons with observations. Cloudnet combines cloud radar, ceilometer, microwave radiometer, and radiosonde profiles averaged to a common grid at the cloud radar resolution to derive a set of retrieved cloud properties. The Cloudnet products are designed to be used for evaluation of weather forecast models as well as fundamental process studies of cloud. From a modelling perspective, Cloudnet converts liquid and ice mass mixing ratios to the respective cloud water contents for direct comparison with observations, as well as filtering ice water contents for values that would be unobservable by radar. Note that the latitude/longitude relevant for each date in question can be found in these Cloudnet files. In directories: iwc-Z-T-metum-grid/ - data include ice water content and total ice water path for observations and model. lwc-scaled-metum-grid/ - data include cloud liquid water content and liquid water path for observations and model. cloud-fraction-metum-grid/ - data include cloud fractions by volume for observations and model.

本数据集为MOCCHA计划期间英国气象局统一模式（Met Office Unified Model）单点（奥登号，Oden）输出结果。此类模式与观测数据已被用于McCusker等人于2023年发表在《大气化学与物理学》（Atmospheric Chemistry and Physics）的《基于统一模式与集成预报系统的北极云模拟评估》一文。英国气象局统一模式的模式数据存放于目录"um_model_data/"中，该数据为取自距船舶位置最近网格格点的逐小时数据；若某一小时内船舶跨越多个网格格点，则对所有跨越格点的数据取平均。所有数据文件均采用netCDF格式，每日对应一个数据文件。Rose套件标识为u-cc568。

模式的云微物理方案配置如下：全球模式与区域模式（Limited Area Model, LAM）均采用PC2（Wilson等，2008）云方案（i_cld_vn = 2），其中区域模式具体采用RA2T_CON配置；同时将l_subgrid_qcl_mp设为.true.，以实现混合相云的湍流生成。此外还扩展了边界层诊断项列表，并将U、V风场分量插值至统一垂直网格。

存放于"um_model_data/"目录的模式数据后续将通过Cloudnet算法（Cloudnet）处理，以生成可直接与观测数据对比的校准后模式数据。Cloudnet算法结合云雷达、云高仪、微波辐射计及无线电探空仪廓线，将其插值至云雷达分辨率的统一网格后，反演得到一系列云属性参数。Cloudnet产品可用于天气预报模式评估及云物理过程基础研究。从模式研究视角来看，Cloudnet将液态和固态冰质量混合比转换为对应的云水含量，以匹配观测数据的对比需求，同时过滤掉雷达无法观测到的冰水含量数值。需注意，各对应日期的经纬度信息可在这些Cloudnet文件中获取。

相关数据目录说明如下：
- "iwc-Z-T-metum-grid/"：该目录下的数据包含观测与模式的冰水含量及总冰云水路径
- "lwc-scaled-metum-grid/"：该目录下的数据包含观测与模式的云液态水含量及液态云水路径
- "cloud-fraction-metum-grid/"：该目录下的数据包含观测与模式的体积云分数