“What Now/What Next/What If” Or NASA Earth System Digital Twins

Although the concept of digital twins (DTs) has been introduced and utilized in various fields for more than 20 years, it is only recently that this concept has gained interest in the Earth science domain. In this article, we briefly review the DT concept in Earth science and other domains and describe how the National Aeronautics and Space Administration (NASA) Earth Science Technology Office’s Intelligent Systems Technologies (IST) Group defines “Earth system digital twins” (ESDTs). This article also reviews the required capabilities and technologies needed to build powerful ESDTs and introduces a proposed ESDT architecture framework, a few science use cases, as well as some information system technologies and prototypes providing the first steps toward future DTs of Earth.