Unstructured global to coastal wave modeling for the Energy Exascale Earth System Model using WAVEWATCH III version 6.07

Abstract. Wind-wave processes have generally been excluded from coupled Earth system models due to the high computational expense of spectral wave models, which resolve a frequency and direction spectrum waves across space time. Existing uniform-resolution modeling approaches used in cannot appropriately represent climates global coastal ocean scales, largely because tradeoffs between resolution costs. To this challenge, we introduce unstructured mesh capability for WAVEWATCH III (WW3) model that is suitable coupling within US Department Energy's Energy Exascale System Model (E3SM). The new WW3 approach can provide accuracy higher resolutions areas at relative cost lower uniform resolutions. This enables simulation physically relevant scales as needed applications.