## 4 Conclusions  
This paper proposes a new spatial data organization model for the Earth system, namely the Earth-System Layered Grid (ISEA4H-ESSG). Its core is to achieve seamless coverage and the unified integration of data from multiple Earth layers (atmosphere, hydrosphere, lithosphere, near-Earth space, etc.) by constructing a global discrete three-dimensional grid system. Based on the ISEA4H subdivision model, ESSG breaks through the two-dimensional planar limitations of the traditional latitude and longitude grid and establishes a three-dimensional grid framework, solving the key bottlenecks in the modeling and analysis of cross-layer, multi-scale, and dynamic data. The main conclusions are as follows:  
ESSG adheres to six core principles (three-dimensional layer coverage, geographical consistency, multi-scale dynamic adaptability, seamless division across the entire region,  
Figure 18: Three-dimensional modeling of the global atmospheric temperature field. (**a**,**b**) show different angles. uniqueness and efficiency of encoding, and data-fusion compatibility). By integrating the icosahedron four-aperture hexagonal subdivision (ISEA4H) with the degenerated subdivision mechanism, it realizes the uniform discretization of the Earth's three-dimensional space. Through the independent subdivision mechanisms of the layer surface and the layer radius, this model effectively balances the differences in spatial resolution between the spherical surface and the radial direction, and solves problems such as grid distortion in the polar regions and data heterogeneity across different layers. Experiments show that ESSG demonstrates high precision and adaptability in the modeling of ionospheric electron density and the three-dimensional reconstruction of the global atmospheric temperature field, verifying its ability to fuse data from multiple layers. The uniqueness of the encoding and the hierarchical structure of ESSG significantly improve the storage and calculation efficiency of massive spatial data. Its compatibility framework supports the seamless integration of multi-source data (remote sensing, ground observation, simulation data). By introducing temporal subdivision encoding, the model is further expanded into a four-dimensional spatiotemporal framework, providing a new tool for the real-time monitoring and prediction of dynamic Earth-system processes (such as climate change and disaster evolution). In addition, the hexagonal grid characteristics of ESSG (equal area property, no directional preference) and its adaptability to the cloud-computing environment give it unique advantages in large-scale parallel computing and global environmental simulation. However, because its pixels and geometric structure are based on hexagonal cells, there are some difficulties in the compatibility of existing open-raster image files, and it is necessary to add some mappings to rectangular arrays. The ESSG model provides a unified spatial data infrastructure for Earth-system science research. Its three-dimensional, multi-scale, and dynamically adaptable characteristics meet the urgent needs of global change research and sustainable development. ISEA4H-ESSG unifies multi-layer data with high precision and efficiency (20% faster retrieval than H3), despite higher setup costs. It excels in 3D modeling and data fusion, supporting all kinds of research on the Earth system, such as hazard and climate research. With the innovation of Earth observation technologies and the improvement of computing capabilities, ESSG is expected to become a core tool for connecting data from multiple layers and driving interdisciplinary innovation, providing scientific support for addressing global challenges such as climate change, disaster early warning, and space environment monitoring. Future research should focus on model optimization, technology integration, and standardized promotion to propel Earth-system science into a new stage of holography and intelligence, as well as optimizing encoding and enhancing cloud scalability. Conceptualization, Y.M.