AARI 10-Day Arctic Ocean EASE-Grid Sea Ice Observations, Version 1

NOTE: This data set has been replaced by the Sea Ice Charts of the Russian Arctic in Gridded Format, 1933-2006 data set. These gridded ice charts represent a reformatting of information contained in another data set, the Russian Arctic and Antarctic Research Institute's (AARI) 10 Day Digital Arctic Sea Ice Charts. AARI digitized Arctic sea iceconcentration and stage of development charts as part of an international data exchange program. The AARI source charts, similar to operational charts distributed by the National Ice Center describing ice type and constitution, were developed from aircraft and satellite observations for shipping purposes, and provide extremely detailed information.Such data are particularly valued in process studies tracking the growth and recession of polynyas, or for looking at the preponderance of ice at certain stages of development in a particular area. NSIDC does not maintain the operational charts, but archives the AARI digitized version. However, the Arctic and Antarctic Research Institute (AARI) 10 Day Digital Arctic Sea Ice Charts were encoded in SIGRID (Sea Ice Grid) format, which assigns numerical values to ice parameters and records them at specific lat/lon grid points. But due to the difficulties of visualizing, extracting and working with data in SIGRID, NSIDC is now providing AARI data in NSIDC's Equal Area SSM/I Earth Grid. The EASE-Grid format makes it especially easy to compare observed ice concentrations or ice types with the same parameters derived from satellite data (such as ice concentrations from passive microwave sensors). AARI sea ice data in the EASE-Grid projection are gridded at a 12.5 km resolution, for both Western (24W to 110E) and Eastern (105E to 130W) sectors . Data extend from 1953 through 1990. Postscript (.ps) files depicting coverage per year are also provided with the data.注意：本数据集已由《1933-2006年网格化格式俄罗斯北极海冰图》数据集替代。 此类网格化海冰图是对另一数据集所含信息的重新格式化产物，该数据集即俄罗斯北极与南极研究所（Arctic and Antarctic Research Institute，简称AARI）的《10日数字化北极海冰图》。作为国际数据交换计划的组成部分，AARI完成了北极海冰密集度与冰况发展阶段图的数字化工作。AARI的源海冰图与国家冰情中心发布的用于描述冰型与冰体组成的业务海冰图类似，其基于航空观测与卫星观测数据编制，服务于航运作业需求，包含极为详尽的海冰信息。此类数据在追踪冰间湖消长的过程性研究，或是分析特定区域内特定冰况发展阶段的冰体占比等场景中具有极高研究价值。美国国家冰雪数据中心（National Snow and Ice Data Center，简称NSIDC）并未留存原始业务海冰图，但存档了AARI的数字化版本。 不过，AARI的《10日数字化北极海冰图》采用SIGRID（海冰网格，Sea Ice Grid）格式进行编码，该格式为各类海冰参数赋予数值，并在指定的经纬度网格点上记录这些数据。但由于SIGRID格式的数据在可视化、提取与处理方面存在诸多困难，NSIDC现已将AARI的数据转换为NSIDC自主制定的等面积SSM/I地球网格格式。 EASE网格格式可极大简化观测得到的海冰密集度或冰型数据，与卫星反演得到的同类参数（如被动微波传感器反演的海冰密集度）之间的对比工作。 采用EASE网格投影的AARI海冰数据，空间分辨率为12.5千米，覆盖两个北极扇区：西经24°至东经110°、东经105°至西经130°，时间跨度为1953年至1990年。数据包中还附带了可逐年描绘海冰覆盖范围的PostScript（.ps）文件。