MASS2ANT Snowfall Dataset (Downscaling @5.5km over Dronning Maud Land, Antarctica, 1850 - 2014): Daily fields (Part 2)

We provide in this dataset maps at 5.5 km resolution of the daily and yearly accumulated snowfall over emerged land (Ice Sheet) of Dronning Maud Land (Antarctica) from 1850 to 2014. We used a statistical method to derive fine resolution maps from GCM runs (CESM2, 10 runs). In the method, we searched for analogs in a database we constructed from the association between re-analyses large-scale meteorological fields (ERA5 and ERA-Interim) and RCM daily accumulated snowfall (RACMO2.3p5.5). RACMO2.3p5.5 data are available freely on request (https://www.projects.science.uu.nl/iceclimate/models/antarctica.php). CESM2 CMIP6 runs are also freely available (https://esgf-node.llnl.gov/search/cmip6/). The complete description of the algorithm and performance is described in: <strong><em>Ghilain </em><em>N.,</em><em> Vannitsem </em><em>S.,</em><em> Dalaiden </em><em>Q.,</em><em> Goosse </em><em>H.,</em><em> De Cruz </em><em>L.,</em><em> </em><em>Wei</em><em> </em><em>W., </em><em>Reconstruction</em><em> of d</em><em>aily snowfall accumulation at 5.</em><em>5</em><em>km resolution over Dronning Maud Land, Antarctica, from 1850 to 2014 </em><em>using an analog-based downscaling technique</em></strong>, submitted to Earth System Science Data (ESSD). The MASS2ANT Snowfall dataset is composed of the annual estimations of snowfall over Dronning Maud Land, the daily time series for the total period for all the emerged grid points of the domain, the principal components time series and Empirical Orthogonal Functions (EOF) offering the possibility to analyze the synoptic weather patterns associated to snowfall over the ice sheet and the Principal Component weights (PCs) time series from the re-analysis in case one wants to extend or improve the database. Realistic weather patterns can be recomposed in associating (product of matrices) the PCs with the EOFs. Here (Daily fields - Part 2), we provide the daily snowfall time series resulting from the downscaling of the 7 first members of CESM2, using ERA-Interim and RACMO2.3p5.5 for training.本数据集提供了1850年至2014年间，南极毛德皇后地（Dronning Maud Land）露岩区域（冰盖（Ice Sheet））上日累积与年累积降雪量的5.5千米分辨率地图。我们采用统计方法从全球气候模式（GCM）试验（CESM2，共10组试验）中推导得到高分辨率地图。该方法依托我们构建的数据库进行相似样本检索，该数据库由再分析大尺度气象场（ERA5与ERA-Interim）与区域气候模式（RCM）日累积降雪量（RACMO2.3p5.5）的关联关系构建而成。RACMO2.3p5.5数据可通过申请免费获取（https://www.projects.science.uu.nl/iceclimate/models/antarctica.php）。CESM2 CMIP6试验数据同样可免费获取（https://esgf-node.llnl.gov/search/cmip6/）。该算法的完整原理与性能细节详见已提交至《地球系统科学数据（Earth System Science Data，ESSD）》的论文：Ghilain N.、Vannitsem S.、Dalaiden Q.、Goosse H.、De Cruz L.、Wei W. 撰写的《1850年至2014年基于相似样本降尺度技术重建南极毛德皇后地5.5千米分辨率日降雪累积量》。MASS2ANT降雪数据集包含毛德皇后地的年降雪量估算值、研究区域内所有露岩网格点的全时段日降雪时间序列、主成分时间序列与经验正交函数（EOF）——这两类数据可用于分析冰盖降雪相关的天气系统模式；此外还包含来自再分析资料的主成分权重（PCs）时间序列，以供用户扩展或优化数据库使用。通过将主成分权重（PCs）与经验正交函数（EOF）进行矩阵相乘，可重构出贴合实际的天气系统模式。本部分（日数据场——第2部分）提供了以ERA-Interim与RACMO2.3p5.5作为训练集，对CESM2的前7个成员样本进行降尺度后得到的日降雪时间序列。