Rusty Benson

This work describes the implementation strategy and technical challenges involved in integrating the Geophysical Fluid Dynamics Laboratory (GFDL)’s Land Model (LM4) with dynamic subgrid tiling capabilities within the atmospheric model, System for High-resolution modeling for Earth-to-Local Domains (SHiELD), capable of kilometer-scale global simulations. A key challenge addressed in this effort is coupling LM4, which was designed for implicit surface flux coupling, with SHiELD’s explicit physics solver. We achieve this through a refactoring of the atmospheric physics suite and code drivers, enabling implicit land-atmosphere coupling of heat and moisture within the well-established FMS coupler infrastructure. The resulting flexible architecture supports multiple model configurations from a single executable without recompilation. This extends SHiELD from an uncoupled atmospheric model, in which land processes are treated as a part of the atmospheric physics package, to a fully coupled high-resolution atmosphere-ocean-land-ice model. We demonstrate the new system through a high-resolution global simulation of Hurricane Helene's landfall where the land component realistically captures the rapid soil saturation, localized runoff generation and multi-day river flooding in Western North Carolina. These results demonstrate the technical coupling strategy, unlock new forecast capabilities, and highlight the importance of interactive land-atmosphere coupling for simulating extreme weather and hydrological events.

This work describes the implementation strategy and technical challenges involved in integrating the Geophysical Fluid Dynamics Laboratory (GFDL)'s Land Model (LM4) with dynamic subgrid tiling capabilities within the atmospheric model, System for High-resolution modeling for Earth-to-Local Domains (SHiELD), capable of kilometer-scale global simulations. A key challenge addressed in this effort is coupling LM4, which was designed for implicit surface flux coupling, with SHiELD's explicit physics solver. We achieve this through a refactoring of the atmospheric physics suite and code drivers, enabling implicit land-atmosphere coupling of heat and moisture within the well established FMS coupler infrastructure. The resulting flexible architecture supports multiple model configurations from a single executable without recompilation. This extends SHiELD from an uncoupled atmospheric model, in which land processes are treated as a part of the atmospheric physics package, to a fully coupled high resolution atmosphere-ocean-land-ice model. We demonstrate the new system through a high-resolution global simulation of Hurricane Helene's landfall where the land component realistically captures the rapid soil saturation, localized runoff generation and multi-day river flooding concentration in Western North Carolina. These results validate the technical coupling strategy, unlock new forecast capabilities, and highlight the importance of interactive land-atmosphere coupling for simulating extreme weather and hydrological events.

This work describes the implementation strategy and technical challenges involved in integrating the Geophysical Fluid Dynamics Laboratory (GFDL)'s Land Model (LM4) with dynamic subgrid tiling capabilities within the atmospheric model, System for High-resolution modeling for Earth-to-Local Domains (SHiELD), capable of kilometer-scale global simulations. A key challenge addressed in this effort is coupling LM4, which was designed for implicit surface flux coupling, with SHiELD's explicit physics solver. We achieve this through a refactoring of the atmospheric physics suite and code drivers, enabling implicit land-atmosphere coupling of heat and moisture within the well established FMS coupler infrastructure. The resulting flexible architecture supports multiple model configurations from a single executable without recompilation. This extends SHiELD from an uncoupled atmospheric model, in which land processes are treated as a part of the atmospheric physics package, to a fully coupled high resolution atmosphere-ocean-land-ice model. We demonstrate the new system through a high-resolution global simulation of Hurricane Helene's landfall where the land component realistically captures the rapid soil saturation, localized runoff generation and multi-day river flooding concentration in Western North Carolina. These results validate the technical coupling strategy, unlock new forecast capabilities, and highlight the importance of interactive land-atmosphere coupling for simulating extreme weather and hydrological events.

This work describes the implementation strategy and technical challenges involved in integrating the Geophysical Fluid Dynamics Laboratory (GFDL)'s Land Model (LM4) with dynamic subgrid tiling capabilities within the atmospheric model, System for High-resolution modeling for Earth-to-Local Domains (SHiELD), capable of kilometer-scale global simulations. A key challenge addressed in this effort is coupling LM4, which was designed for implicit surface flux coupling, with SHiELD's explicit physics solver. We achieve this through a refactoring of the atmospheric physics suite and code drivers, enabling implicit land-atmosphere coupling of heat and moisture within the well established FMS coupler infrastructure. The resulting flexible architecture supports multiple model configurations from a single executable without recompilation. This extends SHiELD from an uncoupled atmospheric model, in which land processes are treated as a part of the atmospheric physics package, to a fully coupled high resolution atmosphere-ocean-land-ice model. We demonstrate the new system through a high-resolution global simulation of Hurricane Helene's landfall where the land component realistically captures the rapid soil saturation, localized runoff generation and multi-day river flooding concentration in Western North Carolina. These results validate the technical coupling strategy, unlock new forecast capabilities, and highlight the importance of interactive land-atmosphere coupling for simulating extreme weather and hydrological events.

As part of the development of GFDL’s new high resolution, seamless weather to S2S to climate timescale coupled model, we present the integration of GFDL’s atmospheric model SHiELD and land model LM4, enabling a suite of Earth system interactions, including extreme hydroclimate events, ecological droughts, and fires. This work details the implementation strategy and technical challenges of integrating GFDL’s LM4 with dynamic subgrid tiling capabilities within SHiELD capable of kilometer-scale global and global-nested simulation. In addition, this effort demonstrates how GFDL terrestrial components designed for implicit flux coupling could be integrated with SHiELD physics designed for an explicit atmospheric solver. The primary objective is to extend SHiELD from an uncoupled atmospheric model, in which land processes are treated as a part of the atmospheric physics package, to a fully coupled high resolution atmosphere-ocean-land-ice-wave model leveraging GFDL’s FMS full coupler infrastructure. This enhanced coupling enables more accurate simulations of land-surface feedbacks, cryosphere and hydrological processes, and extreme weather events such as flooding and abrupt changes in aerosols emissions from fires. We demonstrate the model’s capability through validation test cases. The results underscore the importance of robust land-atmosphere coupling for high-resolution prediction and provide a framework for future development of fully coupled Earth system models of high resolution for forecast and earth system prediction applications.

We present a new high-resolution coupled atmosphere–ocean model, SHiELD-MOM6, which integrates the Geophysical Fluid Dynamics Laboratory (GFDL) advanced atmospheric model, the System for High-resolution modeling for Earth-to-Local Domains (SHiELD), the Modular Ocean Model version 6 (MOM6), and the Sea Ice Simulator (SIS2). The model leverages the Flexible Modeling System (FMS) coupler and its innovative exchange grid to enable a robust and scalable two-way interaction between the atmosphere and ocean. The atmospheric component is built on the non-hydrostatic Finite-Volume Cubed-Sphere Dynamical Core (FV3) with the latest version of the SHiELD physics parameterization suite, while the ocean component is the latest version of MOM, supporting kilometer-scale, high-resolution and regional applications. Validation of this new coupled model is demonstrated through a suite of experiments, including idealized hurricane simulations and a realistic North Atlantic case study featuring Hurricane Helene of 2024. By analyzing the storm intensity, its structure, and its effects on the ocean phenomena such as the upwelling and sea-level changes, the results reveal that air–sea interactions are effectively captured. Scalability tests further confirm the model's computational efficiency. This work established a unified modular cornerstone for advancing high-resolution coupled modeling with significant implications for weather forecasting and climate research.

We present a new high-resolution coupled atmosphere-ocean model, SHiELD-MOM6, which integrates GFDL's advanced atmospheric model, System for High-resolution modeling for Earth-to-Local Domain (SHiELD), the Modular Ocean Model version 6 (MOM6), and the Sea Ice Simulator (SIS2). The model leverages the Flexible Modeling System (FMS) coupler and its innovative exchange grid to enable a robust and scalable two-way interaction between the atmosphere and ocean. The atmospheric component is built on the non-hydrostatic Finite-Volume Cubed-Sphere Dynamical Core (FV3) with the latest version of SHiELD physics parametrization suite, while the ocean component is the latest version of MOM supporting kilometer-scale high-resolution and regional applications. Validation of this new coupled model is demonstrated through a suite of experiments, including idealized hurricane simulations and a realistic North Atlantic case study featuring Hurricane Helene 2024. The results reveal that air-sea interactions are effectively captured, by analyzing the storm intensity, structure and its effects on the ocean phenomena such as the upwelling and sea level changes. Scalability tests further confirms the model's computational efficiency. This work established a unified modular cornerstone for advancing high-resolution coupled modeling with significant implication for weather forecasting and climate research.

We present a new high-resolution coupled atmosphere-ocean model, SHiELD-MOM6, which integrates GFDL's advanced atmospheric model, System for High-resolution modeling for Earth-to-Local Domain (SHiELD), the Modular Ocean Model version 6 (MOM6), and the Sea Ice Simulator (SIS2). The model leverages the Flexible Modeling System (FMS) coupler and its innovative exchange grid to enable a robust and scalable two-way interaction between the atmosphere and ocean. The atmospheric component is built on the non-hydrostatic Finite-Volume Cubed-Sphere Dynamical Core (FV3) with the latest version of SHiELD physics parametrization suite, while the ocean component is the latest version of MOM supporting kilometer-scale high-resolution and regional applications. Validation of this new coupled model is demonstrated through a suite of experiments, including idealized hurricane simulations and a realistic North Atlantic case study featuring Hurricane Helene 2024. The results reveal that air-sea interactions are effectively captured, by analyzing the storm intensity, structure and its effects on the ocean phenomena such as the upwelling and sea level changes. Scalability tests further confirms the model's computational efficiency. This work established a unified modular cornerstone for advancing high-resolution coupled modeling with significant implication for weather forecasting and climate research.

We present a new high-resolution coupled atmosphere-ocean model, SHiELD-MOM6, which integrates GFDL's advanced atmospheric model, System for High-resolution modeling for Earth-to-Local Domain (SHiELD), the Modular Ocean Model version 6 (MOM6), and the Sea Ice Simulator (SIS2). The model leverages the Flexible Modeling System (FMS) coupler and its innovative exchange grid to enable a robust and scalable two-way interaction between the atmosphere and ocean. The atmospheric component is built on the non-hydrostatic Finite-Volume Cubed-Sphere Dynamical Core (FV3) with the latest version of SHiELD physics parametrization suite, while the ocean component is the latest version of MOM supporting kilometer-scale high-resolution and regional applications. Validation of this new coupled model is demonstrated through a suite of experiments, including idealized hurricane simulations and a realistic North Atlantic case study featuring Hurricane Helene 2024. The results reveal that air-sea interactions are effectively captured, by analyzing the storm intensity, structure and its effects on the ocean phenomena such as the upwelling and sea level changes. Scalability tests further confirms the model's computational efficiency. This work established a unified modular cornerstone for advancing high-resolution coupled modeling with significant implication for weather forecasting and climate research.

We present a new high-resolution coupled atmosphere-ocean model, SHiELD-MOM6, which integrates GFDL's advanced atmospheric model, System for High-resolution modeling for Earth-to-Local Domain (SHiELD), the Modular Ocean Model version 6 (MOM6), and the Sea Ice Simulator (SIS2). The model leverages the Flexible Modeling System (FMS) coupler and its innovative exchange grid to enable a robust and scalable two-way interaction between the atmosphere and ocean. The atmospheric component is built on the non-hydrostatic Finite-Volume Cubed-Sphere Dynamical Core (FV3) with the latest version of SHiELD physics parametrization suite, while the ocean component is the latest version of MOM supporting kilometer-scale high-resolution and regional applications. Validation of this new coupled model is demonstrated through a suite of experiments, including idealized hurricane simulations and a realistic North Atlantic case study featuring Hurricane Helene 2024. The results reveal that air-sea interactions are effectively captured, by analyzing the storm intensity, structure and its effects on the ocean phenomena such as the upwelling and sea level changes. Scalability tests further confirms the model's computational efficiency. This work established a unified modular cornerstone for advancing high-resolution coupled modeling with significant implication for weather forecasting and climate research.