As Earth science data increasingly migrate to cloud environments, traditional file formats and access patterns often struggle to deliver efficient, scalable performance.  This session explores cloud accessibility and cloud optimization for Earth science data, emphasizing approaches that improve performance, scalability, and accessibility in cloud and distributed environments.  We invite contributions on the development and adoption of cloud-native data formats, as well as strategies for enhancing legacy formats for high-performance access.  Topics also include best practices for organizing, chunking, and indexing data for efficient remote access, and virtual data store approaches that enable scalable, on-demand access without requiring full data duplication.  We further welcome work on interoperability, standards, and tools that support analysis workflows across distributed systems.  By highlighting emerging technologies and practical implementations, this session aims to advance how Earth science data are designed, managed, and accessed in cloud environments.