The GFDL Earth System Model Version 4.1 (GFDL‐ESM 4.1): Overall Coupled Model Description and Simulation Characteristics

Journal of Advances in Modeling Earth Systems, Journal Year: 2020, Volume and Issue: 12(11)

Published: Aug. 13, 2020

Abstract 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 developments at GFDL over 2013–2018 for carbon‐chemistry‐climate contributing to sixth phase Coupled Intercomparison Project. In contrast with CM4.0 development effort that focuses ocean resolution physical climate, ESM4.1 comprehensiveness system interactions. features doubled horizontal both atmosphere (2° 1°) (1° 0.5°) relative previous‐generation ESM2‐carbon CM3‐chemistry models. brings together key representational advances in dynamics physics along those aerosols their precursor emissions, land ecosystem vegetation canopy competition, multiday fire; ecological biogeochemical interactions, comprehensive land‐atmosphere‐ocean cycling CO 2 , dust iron, interactive ocean‐atmosphere nitrogen are described detail across this volume JAMES presented here terms overall coupling resulting fidelity. provides much improved fidelity chemistry ESM2 CM3, captures most CM4.0's simulations characteristics, notably improves (1) Southern Ocean mode intermediate water ventilation, (2) aerosols, (3) reduced spurious heat uptake. has transient equilibrium climate sensitivity compared CM4.0. Fidelity concerns include moderate degradation sea surface temperature biases, some regions, strong centennial scale modulation by convection.

Language: Английский

---

Overview of the Norwegian Earth System Model (NorESM2) and key climate response of CMIP6 DECK, historical, and scenario simulations

Geoscientific model development, Journal Year: 2020, Volume and Issue: 13(12), P. 6165 - 6200

Published: Dec. 4, 2020

The second version of the coupled Norwegian Earth System Model (NorESM2) is presented and evaluated. NorESM2 based on Community (CESM2) shares with CESM2 computer code infrastructure many system model components. However, employs entirely different ocean biogeochemistry models. atmosphere component (CAM-Nor) includes a module for aerosol physics chemistry, including interactions cloud radiation; additionally, CAM-Nor improvements in formulation local dry moist energy conservation, global angular momentum computations deep convection air–sea fluxes. surface components have minor changes albedo calculations to land sea-ice We present results from simulations that were carried out sixth phase Coupled Intercomparison Project (CMIP6). Two versions are used: one lower (∼ 2∘) atmosphere–land resolution medium 1∘) resolution. stability pre-industrial climate sensitivity abrupt gradual quadrupling CO2 assessed, along ability simulate historical under CMIP6 forcings. Compared observations reanalyses, represents an improvement over previous NorESM most aspects. appears less sensitive greenhouse gas forcing than its predecessors, estimated equilibrium 2.5 K both resolutions 150-year time frame; however, this estimate increases window at equilibration much higher. also consider response future scenarios as defined by selected Shared Socioeconomic Pathways (SSPs) Scenario CMIP6. Under four (SSP1-2.6, SSP2-4.5, SSP3-7.0, SSP5-8.5), warming period 2090–2099 compared 1850–1879 reaches 1.3, 2.2, 3.0, 3.9 NorESM2-LM, 2.1, 3.1, NorESM-MM, robustly similar resolutions. NorESM2-LM shows rather satisfactory evolution recent area. In ice-free Arctic Ocean only avoided SSP1-2.6 scenario.

Language: Английский

---

Integrating the evidence for a terrestrial carbon sink caused by increasing atmospheric CO₂

New Phytologist, Journal Year: 2020, Volume and Issue: 229(5), P. 2413 - 2445

Published: Aug. 13, 2020

Atmospheric carbon dioxide concentration ([CO2 ]) is increasing, which increases leaf-scale photosynthesis and intrinsic water-use efficiency. These direct responses have the potential to increase plant growth, vegetation biomass, soil organic matter; transferring from atmosphere into terrestrial ecosystems (a sink). A substantial global sink would slow rate of [CO2 ] thus climate change. However, ecosystem CO2 are complex or confounded by concurrent changes in multiple agents change evidence for a ]-driven can appear contradictory. Here we synthesize theory broad, multidisciplinary effects increasing (iCO2 ) on sink. Evidence suggests since pre-industrial times. Established theory, supported experiments, indicates that iCO2 likely responsible about half increase. Global budgeting, atmospheric data, forest inventories indicate historical sink, these apparent high comparison experiments predictions theory. Plant mortality highly uncertain. In conclusion, range supports positive response , albeit with uncertain magnitude strong suggestion role additional

Language: Английский

---

Climate model projections from the Scenario Model Intercomparison Project (ScenarioMIP) of CMIP6

Earth System Dynamics, Journal Year: 2021, Volume and Issue: 12(1), P. 253 - 293

Published: March 1, 2021

Abstract. The Scenario Model Intercomparison Project (ScenarioMIP) defines and coordinates the main set of future climate projections, based on concentration-driven simulations, within Coupled phase 6 (CMIP6). This paper presents a range its outcomes by synthesizing results from participating global coupled Earth system models. We limit our scope to analysis strictly geophysical outcomes: mainly averages spatial patterns change for surface air temperature precipitation. also compare CMIP6 projections CMIP5 results, especially those scenarios that were designed provide continuity across CMIP phases, at same time highlighting important differences in forcing composition, as well results. precipitation changes end century (2081–2100) encompassing Tier 1 experiments Shared Socioeconomic Pathway (SSP) (SSP1-2.6, SSP2-4.5, SSP3-7.0 SSP5-8.5) SSP1-1.9 spans larger compared CMIP5, due higher warming (by close 1.5 ∘C) reached upper 5 %–95 % envelope highest scenario (SSP5-8.5). is both wider radiative new cover sensitivities some models their predecessors. Spatial averaged over have familiar features, an variations confirms model structural be dominant source uncertainty. Models differ with respect size evolution internal variability measured individual models' initial condition ensemble spreads, according simulations available under SSP3-7.0. These suggest tendency decrease along course this scenario, result will benefit further Benefits mitigation, all else being equal terms societal drivers, appear clearly when comparing developed SSP but which different degrees mitigation been applied. It found mild overshoot few decades around mid-century, represented SSP5-3.4OS, does not affect outcome 2100, return levels gradually increasing SSP4-3.4 (not erasing possibility, however, other aspects may easily reversible). Central estimates means reach given level might biased inclusion shown faster historical period than observed. Those show reaching ∘C 1850–1900 baseline second half current decade, span between slow fast covering 20 27 years present. 2 early 2039 mean SSP5-8.5 late mid-2060s SSP1-2.6. considered (5 only until mid-2090s.

Language: Английский

---

Soil moisture–atmosphere feedback dominates land carbon uptake variability

Nature, Journal Year: 2021, Volume and Issue: 592(7852), P. 65 - 69

Published: March 31, 2021

Abstract Year-to-year changes in carbon uptake by terrestrial ecosystems have an essential role determining atmospheric dioxide concentrations 1 . It remains uncertain to what extent temperature and water availability can explain these variations at the global scale 2–5 Here we use factorial climate model simulations 6 show that variability soil moisture drives 90 per cent of inter-annual land uptake, mainly through its impact on photosynthesis. We find most this ecosystem response occurs indirectly as moisture–atmosphere feedback amplifies humidity anomalies enhances direct effects stress. The strength mechanism explains why coupled models indicate has a dominant 4 , which is not readily apparent from surface observational analyses 2,5 These findings highlight need account for between dryness when estimating cycle climatic change globally 5,7 well conducting field-scale investigations droughts 8,9 Our results modelled driven vapour pressure deficit are controlled moisture.

Language: Английский

---

Ubiquity of human-induced changes in climate variability

Earth System Dynamics, Journal Year: 2021, Volume and Issue: 12(4), P. 1393 - 1411

Published: Dec. 9, 2021

Abstract. While climate change mitigation targets necessarily concern maximum mean state changes, understanding impacts and developing adaptation strategies will be largely contingent on how variability responds to increasing anthropogenic perturbations. Thus far Earth system modeling efforts have primarily focused projected changes the sensitivity of specific modes variability, such as El Niño–Southern Oscillation. However, our knowledge forced in overall spectrum higher-order statistics is relatively limited. Here we present a new 100-member large ensemble projections conducted with Community System Model version 2 over 1850–2100 examine internal fluctuations greenhouse warming. Our unprecedented simulations reveal that considered broadly terms probability distribution, amplitude, frequency, phasing, patterns, are ubiquitous span wide range physical ecosystem variables across many spatial temporal scales. Greenhouse warming model alters variance spectra characterized by non-Gaussian distributions, rainfall, primary production, or fire occurrence. results important implications for efforts, resource management, seasonal predictions, assessing potential stressors terrestrial marine ecosystems.

Language: Английский

---

CMIP6 Simulations With the CMCC Earth System Model (CMCC‐ESM2)

Journal of Advances in Modeling Earth Systems, Journal Year: 2022, Volume and Issue: 14(3)

Published: Feb. 11, 2022

Abstract This article introduces the second generation CMCC Earth System Model (CMCC‐ESM2) that extends a number of marine and terrestrial biogeochemical processes with respect to its CMIP5 predecessor. In particular, land biogeochemistry was extended wider set carbon pools plant functional types, along prognostic representation nitrogen cycle. The ecosystem reshaped toward an intermediate complexity lower trophic level interactions, including interactive benthic compartment new formulation heterotrophic bacterial population. Details are provided on model setup implementation for different experiments performed as contribution sixth phase Coupled Intercomparison Project. CMCC‐ESM2 shows equilibrium climate sensitivity 3.57°C transient response 1.97°C which close CMIP6 multi‐model averages. evaluation coupled climate‐carbon in historical period against available observational datasets show consistent both physical quantities. However, sink is found be weaker than current global estimates simulated primary production slightly below satellite‐based average over recent decades. Future projections coherently prominent warming northern hemisphere intensified precipitations at high latitudes. expected ranges variability oceanic pH oxygen, well soil storage, compare favorably those assessed from other models.

Language: Английский

---

Framing, Context, and Methods

Cambridge University Press eBooks, Journal Year: 2023, Volume and Issue: unknown, P. 147 - 286

Published: June 29, 2023

A summary is not available for this content so a preview has been provided. As you have access to content, full PDF via the 'Save PDF' action button.

Language: Английский

---

National contributions to climate change due to historical emissions of carbon dioxide, methane, and nitrous oxide since 1850

Scientific Data, Journal Year: 2023, Volume and Issue: 10(1)

Published: March 29, 2023

Abstract Anthropogenic emissions of carbon dioxide (CO 2 ), methane (CH 4 ) and nitrous oxide (N O) have made significant contributions to global warming since the pre-industrial period are therefore targeted in international climate policy. There is substantial interest tracking apportioning national change informing equitable commitments decarbonisation. Here, we introduce a new dataset caused by historical dioxide, methane, during years 1851–2021, which consistent with latest findings IPCC. We calculate mean surface temperature response three gases, including recent refinements account for short atmospheric lifetime CH . report resulting from each gas, disaggregation fossil land use sectors. This will be updated annually as datasets updated.

Language: Английский

---

Is there warming in the pipeline? A multi-model analysis of the Zero Emissions Commitment from CO<sub>2</sub>

Biogeosciences, Journal Year: 2020, Volume and Issue: 17(11), P. 2987 - 3016

Published: June 15, 2020

Abstract. The Zero Emissions Commitment (ZEC) is the change in global mean temperature expected to occur following cessation of net CO2 emissions and as such a critical parameter for calculating remaining carbon budget. Model Intercomparison Project (ZECMIP) was established gain better understanding potential magnitude sign ZEC, addition processes that underlie this metric. A total 18 Earth system models both full intermediate complexity participated ZECMIP. All conducted an experiment where atmospheric concentration increases exponentially until 1000 PgC has been emitted. Thereafter are set zero configured allow free evolution concentration. Many additional second-priority simulations with different cumulative emission totals alternative idealized pathway gradual transition emissions. inter-model range ZEC 50 years after cease −0.36 0.29 ∘C, model ensemble −0.07 median −0.05 standard deviation 0.19 ∘C. Models exhibit wide variety behaviours cease, some continuing warm decades millennia others cooling substantially. Analysis shows uptake by ocean terrestrial biosphere important counteracting warming effect from reduction heat cease. This difficult constrain due high uncertainty efficacy uptake. Overall, most likely value on multi-decadal timescales close zero, consistent previous experiments simple theory.

Language: Английский

---