GMM-SWE v1.0: Hemispheric Snow Water Equivalent, Snow Depth, and Snow Density (35°–85°N), 2003–2022

This dataset contains monthly hemispheric estimates of Snow Water Equivalent (SWE), snow depth, and bulk snow density produced by the Gravity–Meteorology Coupled Model (GMM-SWE) for the Northern Hemisphere (35°–85°N) over the period January 2003 to December 2022. The dataset was generated by assimilating GRACE and GRACE-FO terrestrial water storage anomalies with meteorological data using a physics-constrained data assimilation framework based on an adaptive Kalman Filter and a Rauch–Tung–Striebel (RTS) smoother. Snow mass anomalies were isolated from total terrestrial water storage using auxiliary estimates of soil moisture, groundwater, and surface water storage from global land surface and hydrological models. Snow depth and density were subsequently derived through a dynamic snow density evolution scheme based on SNOW-17 compaction physics. All variables are provided at 1° × 1° spatial resolution and monthly temporal resolution in NetCDF format.The dataset is intended to support large-scale hydrological analysis, cryospheric monitoring, and climate trend assessment, particularly in regions where conventional snow products are limited by terrain complexity or sensor saturation. The final dataset includes three core variables: SWE: Snow Water Equivalent, in millimeters. Snow_Depth: Snow depth, in millimeters. Snow_Density: Bulk snow density, in kg m⁻³.