Historic and future surface mass balance contributions to Antarctic and Greenland freshwater fluxes from regional climate models

This dataset provides harmonized output from multiple Regional Climate Models (RCMs) for the Antarctic and Greenland ice sheets. It includes historical simulations forced with ERA5 reanalysis, as well as historical and future simulations extending to 2100 driven by a selection of Earth System Models (ESMs) under different SSP scenarios. The RCMs included are MAR, RACMO, and HIRHAM5, forced by ERA5 and by various ESMs, including MPI-ESM, CESM2, UKESM, IPSL-CM6A, CNRM-CM6, EC-Earth3, NorESM, and CNRM-ESM. The dataset covers SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5, with availability depending on the specific model combination. All variables are provided as monthly accumulated fluxes with units of kg m⁻². The dataset includes the following variables: prsn – snowfall prra – rainfall, calculated as total precipitation minus snowfall melt – melt of snow or ice mrro – runoff of rainfall or meltwater subl – surface sublimation and evaporation (>0 = sublimation, <0 = deposition) smb – surface mass balance sndivgl – blowing snow transport divergence (>0 = erosion, <0 = deposition). Available only in RACMO2.4p1 and RACMO2.3p2, where it was used to compute the surface mass balance. Note: The blowing snow scheme performs significantly better in RACMO2.4p1 compared to RACMO2.3p2; therefore, we recommend using RACMO2.4p1 outputs when considering blowing snow as a freshwater flux. sndivsn – blowing snow transport divergence on non-glaciated tiles (<0=deposition). Available only in RACMO2.4p1. All gridded data are stored in NetCDF4 format, with one file per simulation. Files follow a standardized naming convention: {domain}_{RCM}{version}_{resolution}_{forcing}_{ssp/historical}_{year_start}_{year_end}.nc For example 'ANT_MARv311_35km_MPI-ESM_historical_1980_2014.nc' contains the monthly output from MAR version 3.11 for the Antarctica domain, forced with historical MPI-ESM for the period 1980 - 2014In addition to the model output, the dataset includes mask files for each model domain that provide grid-cell information required for regional and ice-sheet–integrated analyses. Mask files follow the naming convention: {domain}_{RCM}{version}_{resolution}_mask.nc For example: GR_RACMO24p1_5.5km_mask.nc Each mask file includes at least the following variables: ice_mask – fraction of ice-covered area per grid cell (0–1) cell_area – grid cell area in m² ocean_sectors – classification of grid cells into ocean sectors ice_mask_greenland or ice_mask_antarctica – masks defining the glaciated regions used for computing ice-sheet–integrated mass balance (0-1) For RACMO2.4p1 and MAR, the ice masks are fractional, whereas RACMO2.3p2 and HIRHAM5 use binary masks. Two python scripts are given which can be used to compute yearly ice sheet or ocean sector integrated SMB terms in Gt/yr.本数据集提供了针对南极与格陵兰冰盖的多套区域气候模型（Regional Climate Models, RCMs）经过统一协调处理的输出结果。数据集包含以ERA5再分析数据为强迫场的历史模拟试验，以及由多套地球系统模型（Earth System Models, ESMs）在不同共享社会经济路径（Shared Socioeconomic Pathways, SSP）下驱动的、时长延伸至2100年的历史与未来模拟试验。 所纳入的区域气候模型包括MAR、RACMO与HIRHAM5，其强迫场涵盖ERA5数据以及多套地球系统模型，具体包括MPI-ESM、CESM2、UKESM、IPSL-CM6A、CNRM-CM6、EC-Earth3、NorESM与CNRM-ESM。数据集覆盖SSP1-2.6、SSP2-4.5、SSP3-7.0以及SSP5-8.5四种情景，具体可用情景取决于模型组合情况。 所有变量均以月累计通量形式提供，单位为kg m⁻²。数据集包含以下变量： - prsn – 降雪量（snowfall） - prra – 降雨量，由总降水量减去降雪量计算得到 - melt – 积雪或冰体融水量 - mrro – 降雨或融水径流量 - subl – 地表升华与蒸发（数值>0为升华，<0为凝华沉积） - smb – 地表质量平衡 - sndivgl – 吹雪输送散度（数值>0为侵蚀，<0为沉积）。该变量仅在RACMO2.4p1与RACMO2.3p2版本中可用，曾用于地表质量平衡的计算。注：相较于RACMO2.3p2，RACMO2.4p1的吹雪方案表现更优，因此若将吹雪作为淡水通量考量时，推荐使用RACMO2.4p1的输出结果。 - sndivsn – 非冰盖格点的吹雪输送散度（数值<0为沉积），该变量仅在RACMO2.4p1版本中可用。 所有格点数据均以NetCDF4格式存储，每场模拟对应一个文件。文件遵循标准化命名规范： {domain}_{RCM}{version}_{resolution}_{forcing}_{ssp/historical}_{year_start}_{year_end}.nc 示例：'ANT_MARv311_35km_MPI-ESM_historical_1980_2014.nc' 包含了1980-2014年期间，以MPI-ESM为强迫场的南极区域MAR v3.11版本模型的月尺度输出结果。 除模型输出外，数据集还包含各模型区域的掩膜文件，用于提供区域与冰盖综合分析所需的格点信息。掩膜文件的命名规范为： {domain}_{RCM}{version}_{resolution}_mask.nc 示例：'GR_RACMO24p1_5.5km_mask.nc' 每份掩膜文件至少包含以下变量： - ice_mask – 每个格点的冰覆盖面积占比（取值范围0~1） - cell_area – 格点面积，单位为m² - ocean_sectors – 格点的大洋扇区分类 - ice_mask_greenland 或 ice_mask_antarctica – 用于计算冰盖综合质量平衡的冰盖区域掩膜（取值范围0~1）。 其中，RACMO2.4p1与MAR版本的冰掩膜为分数型掩膜，而RACMO2.3p2与HIRHAM5版本则采用二进制掩膜。 数据集还提供了两段Python脚本，可用于计算以Gt/yr为单位的年尺度冰盖或大洋扇区综合地表质量平衡项。