Crocus-ERA5 daily snow product over the Northern Hemisphere at 0.25 degree resolution

The Crocus-ERA5 daily snow product is derived from the complex snow scheme Crocus coupled to the ISBA (Interactions between Soil–Biosphere–Atmosphere) land surface model (Brun et al., 2013) and embedded into the SURFEX numerical platform (https://www.umr-cnrm.fr/surfex/). The model is driven by a meteorological forcing (temperature, precipitation, humidity, winds, etc) derived from the ERA5 global atmospheric reanalysis (https://www.ecmwf.int/en/forecasts/dataset/ecmwf-reanalysis-v5). This product only concerns open field snowpack, i.e. only low vegetation is modeled (no forest). It covers the entire Northern Hemisphere at 0.25° resolution over the 1950-07-01 to 2023-06-30 period. All snow characteristics (see later) are available at a dailly frequency. This product is the successor of the Crocus-ERA-Interim daily snow product (Decharme, 2024). It is used by the NOAA Artic Report Card from 2021 to present for the annual survey of the Terrestrial Snow Cover anomalies over the Northern Hemisphere. An evaluation of the snow water equivalent product can be found in Mudryk et al. (2024) where it is compared to observations and to about twenty alternative datasets.

Crocus-ERA5 逐日积雪数据集源自耦合了ISBA（土壤-生物圈-大气相互作用，Interactions between Soil–Biosphere–Atmosphere）陆面模式的复杂积雪方案Crocus（Brun等，2013），并集成于SURFEX数值模拟平台（https://www.umr-cnrm.fr/surfex/）。该模式由ERA5全球大气再分析资料（ECMWF Reanalysis v5，https://www.ecmwf.int/en/forecasts/dataset/ecmwf-reanalysis-v5）衍生的气象强迫场（气温、降水、湿度、风速等）驱动。本数据集仅针对开阔区域积雪，即仅模拟低矮植被覆盖场景（不含森林）。其覆盖1950年7月1日至2023年6月30日的整个北半球，空间分辨率为0.25°，所有积雪特征参数（详见后文）均以逐日频率产出。本数据集是Crocus-ERA-Interim逐日积雪数据集的升级版本（Decharme，2024）。自2021年起至今，该数据集被应用于美国国家海洋和大气管理局（NOAA）北极报告卡中，用于北半球陆地积雪覆盖异常的年度监测。关于雪水当量产品的评估可参见Mudryk等（2024）的研究，该研究将本数据集与观测数据及约20套替代数据集进行了对比验证。