We describe the baseline coupled model configuration and simulation characteristics of GFDL's Earth System Model Version 4.1 (ESM4.1), which builds on component and coupled model developments at GFDL ...over 2013–2018 for coupled carbon‐chemistry‐climate simulation contributing to the sixth phase of the Coupled Model Intercomparison Project. In contrast with GFDL's CM4.0 development effort that focuses on ocean resolution for physical climate, ESM4.1 focuses on comprehensiveness of Earth system interactions. ESM4.1 features doubled horizontal resolution of both atmosphere (2° to 1°) and ocean (1° to 0.5°) relative to GFDL's previous‐generation coupled ESM2‐carbon and CM3‐chemistry models. ESM4.1 brings together key representational advances in CM4.0 dynamics and physics along with those in aerosols and their precursor emissions, land ecosystem vegetation and canopy competition, and multiday fire; ocean ecological and biogeochemical interactions, comprehensive land‐atmosphere‐ocean cycling of CO2, dust and iron, and interactive ocean‐atmosphere nitrogen cycling are described in detail across this volume of JAMES and presented here in terms of the overall coupling and resulting fidelity. ESM4.1 provides much improved fidelity in CO2 and chemistry over ESM2 and CM3, captures most of CM4.0's baseline simulations characteristics, and notably improves on CM4.0 in (1) Southern Ocean mode and intermediate water ventilation, (2) Southern Ocean aerosols, and (3) reduced spurious ocean heat uptake. ESM4.1 has reduced transient and equilibrium climate sensitivity compared to CM4.0. Fidelity concerns include (1) moderate degradation in sea surface temperature biases, (2) degradation in aerosols in some regions, and (3) strong centennial scale climate modulation by Southern Ocean convection.
Plain Language Summary
GFDL has developed a coupled chemistry‐carbon‐climate Earth System Model (ESM4.1) as part of its fourth‐generation coupled model development activities with model results contributed publicly to the sixth phase of the Coupled Model Intercomparison Project. With similar computational expense as GFDL's first coupled model CM4.0, ESM4.1 focuses on chemistry and ecosystem comprehensiveness rather than the ocean resolution‐focus of CM4.0. With fidelity near to that of CM4.0, ESM4.1 features much improved representation of climate mean patterns and variability from previous GFDL ESMs as well as comprehensive couplings for chemistry, carbon, and dust.
Key Points
A new coupled chemistry‐carbon‐climate Earth system model has been developed at the Geophysical Fluid Dynamics Laboratory
This model unifies component advances in chemistry, carbon, and ecosystem comprehensiveness within a single coupled climate framework
This model features much improved climate mean patterns and variability from previous chemistry and carbon coupled models
We describe the Geophysical Fluid Dynamics Laboratory's CM4.0 physical climate model, with emphasis on those aspects that may be of particular importance to users of this model and its simulations. ...The model is built with the AM4.0/LM4.0 atmosphere/land model and OM4.0 ocean model. Topics include the rationale for key choices made in the model formulation, the stability as well as drift of the preindustrial control simulation, and comparison of key aspects of the historical simulations with observations from recent decades. Notable achievements include the relatively small biases in seasonal spatial patterns of top‐of‐atmosphere fluxes, surface temperature, and precipitation; reduced double Intertropical Convergence Zone bias; dramatically improved representation of ocean boundary currents; a high‐quality simulation of climatological Arctic sea ice extent and its recent decline; and excellent simulation of the El Niño‐Southern Oscillation spectrum and structure. Areas of concern include inadequate deep convection in the Nordic Seas; an inaccurate Antarctic sea ice simulation; precipitation and wind composites still affected by the equatorial cold tongue bias; muted variability in the Atlantic Meridional Overturning Circulation; strong 100 year quasiperiodicity in Southern Ocean ventilation; and a lack of historical warming before 1990 and too rapid warming thereafter due to high climate sensitivity and strong aerosol forcing, in contrast to the observational record. Overall, CM4.0 scores very well in its fidelity against observations compared to the Coupled Model Intercomparison Project Phase 5 generation in terms of both mean state and modes of variability and should prove a valuable new addition for analysis across a broad array of applications.
Plain Language Summary
The Geophysical Fluid Dynamics Laboratory (GFDL) of the National Oceanic and Atmospheric Administration participates along with a number of model centers around the world in constructing state‐of‐the‐art climate models for use in studies for climate change and prediction. GFDL's latest multipurpose atmosphere‐ocean coupled climate model, CM4.0, is described here. It consists of GFDL's latest atmosphere and land models at about 100 km horizontal resolution and ocean and sea ice models at roughly 25 km horizontal resolution. A handful of standard experiments have been conducted with CM4.0 for participation in the Coupled Model Intercomparison Project Phase 6, an archive of climate model results utilized by the Intergovernmental Panel on Climate Change and the climate research community more generally. The model results have been extensively evaluated against observations. This paper makes the case that CM4.0 ranks high among state‐of‐the‐art coupled climate models by many measures of bias in the simulated climatology and in its ability to capture modes of climate variability such as the El Niño‐Southern Oscillation and Madden‐Julian Oscillation. The paper also discusses some potential weaknesses, including unrealistically large internal variability in the Southern Ocean and insufficient warming before 1990 in the simulation of the twentieth century.
Key Points
A team at GFDL has developed a new model of the physical climate system referred to as CM4.0
Strengths of model include ENSO simulation and small biases in TOA fluxes, precipitation, Arctic sea ice extent, and sea surface temperature
Problematic aspects include large variability in Southern Ocean and historical simulation with little warming prior to 1990
In this two‐part paper, a description is provided of a version of the AM4.0/LM4.0 atmosphere/land model that will serve as a base for a new set of climate and Earth system models (CM4 and ESM4) under ...development at NOAA's Geophysical Fluid Dynamics Laboratory (GFDL). This version, with roughly 100 km horizontal resolution and 33 levels in the vertical, contains an aerosol model that generates aerosol fields from emissions and a “light” chemistry mechanism designed to support the aerosol model but with prescribed ozone. In Part 1, the quality of the simulation in AMIP (Atmospheric Model Intercomparison Project) mode—with prescribed sea surface temperatures (SSTs) and sea‐ice distribution—is described and compared with previous GFDL models and with the CMIP5 archive of AMIP simulations. The model's Cess sensitivity (response in the top‐of‐atmosphere radiative flux to uniform warming of SSTs) and effective radiative forcing are also presented. In Part 2, the model formulation is described more fully and key sensitivities to aspects of the model formulation are discussed, along with the approach to model tuning.
Key Points
A description is provided of the AM4.0/LM4.0 model that will serve as a base for a new set of GFDL/NOAA climate and Earth system models
The simulation quality in AMIP mode is described and compared with previous GFDL models and with the CMIP5 archive of AMIP simulations
The model's Cess sensitivity and effective radiative forcing are presented
In Part 2 of this two‐part paper, documentation is provided of key aspects of a version of the AM4.0/LM4.0 atmosphere/land model that will serve as a base for a new set of climate and Earth system ...models (CM4 and ESM4) under development at NOAA's Geophysical Fluid Dynamics Laboratory (GFDL). The quality of the simulation in AMIP (Atmospheric Model Intercomparison Project) mode has been provided in Part 1. Part 2 provides documentation of key components and some sensitivities to choices of model formulation and values of parameters, highlighting the convection parameterization and orographic gravity wave drag. The approach taken to tune the model's clouds to observations is a particular focal point. Care is taken to describe the extent to which aerosol effective forcing and Cess sensitivity have been tuned through the model development process, both of which are relevant to the ability of the model to simulate the evolution of temperatures over the last century when coupled to an ocean model.
Key Points
Part 2 of the AM4.0/LM4.0 paper provides documentation of key changes in individual components from previous GFDL models
Some sensitivities to choices of model formulation and parameter values are presented with emphasis on convection and tuning of clouds
We describe the extent to which the effect on aerosol forcing and Cess sensitivity has been taken into account during model development
A climate model represents a multitude of processes on a variety of timescales and space scales: a canonical example of multi-physics multi-scale modeling. The underlying climate system is physically ...characterized by sensitive dependence on initial conditions, and natural stochastic variability, so very long integrations are needed to extract signals of climate change. Algorithms generally possess weak scaling and can be I/O and/or memory-bound. Such weak-scaling, I/O, and memory-bound multi-physics codes present particular challenges to computational performance. Traditional metrics of computational efficiency such as performance counters and scaling curves do not tell us enough about real sustained performance from climate models on different machines. They also do not provide a satisfactory basis for comparative information across models. codes present particular challenges to computational performance. We introduce a set of metrics that can be used for the study of computational performance of climate (and Earth system) models. These measures do not require specialized software or specific hardware counters, and should be accessible to anyone. They are independent of platform and underlying parallel programming models. We show how these metrics can be used to measure actually attained performance of Earth system models on different machines, and identify the most fruitful areas of research and development for performance engineering. codes present particular challenges to computational performance. We present results for these measures for a diverse suite of models from several modeling centers, and propose to use these measures as a basis for a CPMIP, a computational performance model intercomparison project (MIP).
Alkaline hydrolysis was first legalized in 2003 in the United States by Minnesota.6 Alkaline hydrolysis is currently legal in 21 states in the United States.7 The USCCB Committee has specifically ...stated that cremation via alkaline hydrolysis is not permitted due to the lack of respect the process brings to the body, and that it does not carry hope in resurrection.8 Cremation is against Jewish tradition, although if a Jewish person is cremated, a Rabbi may still choose to officiate prior to the cremation.9 Similarly, Muslims are never cremated, and cremation is considered a violation of the dignity to the body.10 On the other hand, it is Hindu tradition to cremate the remains of the deceased, except for the remains of babies, children, and saints, as those bodies have not accumulated any karma and are considered pure.11 Many states require a mandatory waiting period before remains can be cremated. The adult son of a decedent brought an action against a funeral home, seeking damages for mental anguish due to the funeral home's cremation of his mother without his consent.12 When the decedent died unexpectedly, the decedent's sisters were contacted and travelled to where the decedent resided at her death. Upon learning of his mother's passing and the disposition of her remains without his approval, the decedent's son filed the negligence action against the funeral home seeking damages for mental anguish. According to the National Funeral Directors Association (NFDA), the national median cost of a funeral with viewing and burial for an adult in 2021 was $7,848.14 This is a 6.6% increase in median
The chapter presents a mechanism for exchange of quantities among components of a coupled earth system model, where each component is independently discretized. The exchange grid is formed by ...overlaying two grids such that each exchange grid cell has a unique parent cell on each of its antecedent grids. In earth system models, processes occurring near component surfaces require special surface-boundary-layer physical processes to be represented on the exchange grid. The exchange grid is thus more than just a stage in a sequence of regridding between component grids. The exchange grid is designed not as a sparse matrix among all possible pairs of parent grid cells but as a compact array pointing back to the parents. When parent grids have dynamic tiles, each tile appears as an independent cell on the exchange grid rather than an extra tile dimension. The chapter also presents the design and use of a two-dimensional exchange grid on a horizontal planetary surface in the Geophysical Fluid Dynamics Laboratory (GFDL) flexible modeling system (FMS), highlighting issues of parallelism and performance.
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