MASS2ANT Snowfall Dataset (Downscaling @5.5km over Dronning Maud Land, Antarctica, 1850 - 2014): Daily fields (Part 3)

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 3), we provide the daily snowfall time series resulting from the downscaling of the 3 last members of CESM2, using ERA-Interim (or ERA5) 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）裸露陆地（冰盖）区域的日累计与年累计降雪量5.5公里分辨率地图。我们采用统计方法，从通用气候模型（Global Climate Model, GCM）的模拟结果（CESM2，共10组试验）中推导得到高分辨率地图。该方法通过自建数据库搜索相似样本实现：该数据库由再分析资料的大尺度气象场（ERA5与ERA-Interim）与区域气候模型（Regional Climate Model, RCM）日累计降雪量数据（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模拟结果同样可免费获取（https://esgf-node.llnl.gov/search/cmip6/）。本算法的完整细节与性能表现已在以下文献中详述：<strong><em>Ghilain N., Vannitsem S., Dalaiden Q., Goosse H., De Cruz L., Wei W. 《基于相似样本降尺度技术重建1850-2014年南极毛德皇后地5.5公里分辨率日降雪量》</em></strong>，该文已提交至《地球系统科学数据》（Earth System Science Data, ESSD）。MASS2ANT降雪数据集包含以下内容：毛德皇后地的年降雪量估算值、研究区域内所有裸露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（Empirical Orthogonal Functions, EOF）——后者可用于分析与冰盖降雪相关的天气系统；此外还提供了再分析资料的主成分权重（Principal Component weights, PCs）时间序列，以供用户扩展或优化数据库。通过将主成分与经验正交函数进行矩阵相乘，可重构出符合实际的天气模式。本次发布的「日度数据-第三部分」提供了以ERA-Interim（或ERA5）与RACMO2.3p5.5作为训练集，对CESM2最后3组模拟结果进行降尺度后得到的日降雪时间序列。