Assessment and Constraint of Mesozooplankton in CMIP6 Earth System Models

Global Biogeochemical Cycles, Journal Year: 2022, Volume and Issue: 36(11)

Published: Nov. 1, 2022

Abstract Although zooplankton play a substantial role in the biological carbon pump and serve as crucial link between primary producers higher trophic level consumers, skillful representation of is not often focus ocean biogeochemical models. Systematic evaluations models could improve their representation, but so far, skill assessment Earth system model (ESM) ensembles have included zooplankton. Here we use recently developed global, observationally based map mesozooplankton biomass to assess six CMIP6 ESMs. We also employ biome‐based ability these reproduce observed relationship surface chlorophyll. The combined analysis found that most were able reasonably simulate large regional variations at global scale. Additionally, three ESMs simulated mesozooplankton‐chlorophyll within observational bounds, which used an emergent constraint on future projections. highlight where differences structure parameters may give rise varied distributions under historic conditions, resultant wide ensemble spread projected changes biomass. Despite differences, strength relationships across all was related globally biomes. These results suggest improved observations chlorophyll will better constrain projections climate change impacts important animals.

Language: Английский

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Seasonal Variability of the Surface Ocean Carbon Cycle: A Synthesis

Global Biogeochemical Cycles, Journal Year: 2023, Volume and Issue: 37(9)

Published: Aug. 24, 2023

Abstract The seasonal cycle is the dominant mode of variability in air‐sea CO 2 flux most regions global ocean, yet discrepancies between different seasonality estimates are rather large. As part Regional Carbon Cycle Assessment and Processes Phase project (RECCAP2), we synthesize surface ocean p from models observation‐based estimates, focusing on both a present‐day climatology decadal changes 1980s 2010s. Four main findings emerge: First, biogeochemistry (GOBMs) ( products) disagree amplitude phase, primarily due to DIC. Second, has increased over last three decades products GOBMs. Third, increases amplitudes subtropical biomes for GOBMs driven by increasing DIC concentrations stemming uptake anthropogenic (C ant ). In subpolar Southern Ocean biomes, however, change dominated C invasion, whereas an indeterminate combination invasion climate modulates changes. Fourth, biome‐aggregated largely detectable against mapping uncertainty (reducible) natural (irreducible), but not at gridpoint scale much northern oceans Ocean, underscoring importance sustained high‐quality seasonally resolved measurements these regions.

Language: Английский

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The Southern Ocean Carbon Cycle 1985–2018: Mean, Seasonal Cycle, Trends, and Storage

Global Biogeochemical Cycles, Journal Year: 2023, Volume and Issue: 37(11)

Published: Nov. 1, 2023

Abstract We assess the Southern Ocean CO 2 uptake (1985–2018) using data sets gathered in REgional Carbon Cycle Assessment and Processes Project Phase 2. The acted as a sink for with close agreement between simulation results from global ocean biogeochemistry models (GOBMs, 0.75 ± 0.28 PgC yr −1 ) p ‐observation‐based products (0.73 0.07 ). This is only half that reported by RECCAP1 same region timeframe. present‐day net to first order response rising atmospheric , driving large amounts of anthropogenic (C ant into ocean, thereby overcompensating loss natural atmosphere. An apparent knowledge gap increase since 2000, ‐products suggesting growth more than twice strong uncertain GOBMs (0.26 0.06 0.11 0.03 Pg C decade respectively). despite nearly identical trends when both are compared at locations where was measured. Seasonal analyses revealed processes winter uncertainty magnitude outgassing, whereas discrepancies fundamental summer, exhibit difficulties simulating effects non‐thermal biology mixing/circulation. interior accumulation points an underestimate storage GOBMs. Future work needs link surface fluxes transport, build long overdue systematic observation networks push toward better process understanding drivers carbon cycle.

Language: Английский

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Annex II: Models

Published: June 29, 2023

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Language: Английский

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The representation of alkalinity and the carbonate pump from CMIP5 to CMIP6 Earth system models and implications for the carbon cycle

Biogeosciences, Journal Year: 2023, Volume and Issue: 20(7), P. 1195 - 1257

Published: April 3, 2023

Abstract. Ocean alkalinity is critical to the uptake of atmospheric carbon in surface waters and provides buffering capacity towards associated acidification. However, unlike dissolved inorganic (DIC), not directly impacted by anthropogenic emissions. Within context projections future ocean potential ecosystem impacts, especially through Coupled Model Intercomparison Projects (CMIPs), representation main driver its distribution interior, calcium carbonate cycle, have often been overlooked. Here we track changes from CMIP5 CMIP6 with respect Earth system model (ESM) pump which depletes biological production releases it at depth export dissolution. We report an improvement ESMs relative those CMIP5, simulating lower concentrations, increased meridional gradient enhanced global vertical gradient. This can be explained part increase (CaCO3) for some ESMs, redistributes strengthens water column. were able constrain a particulate (PIC) estimate 44–55 Tmol yr−1 100 m match observed alkalinity. Reviewing CaCO3 cycle across CMIP5/6, find substantial range parameterizations. While all biogeochemical models currently represent pelagic calcification, they do so implicitly, benthic calcification. In addition, most simulate marine calcite but aragonite. CMIP6, certain groups complexity simulated production, sinking, dissolution sedimentation. this insufficient explain overall representation, therefore likely result biogeochemistry tuning or ad hoc Although modellers aim balance budget order limit drift under pre-industrial conditions, varying assumptions related closure and/or initialization procedure influence uptake. For instance, many models, burial are independent seawater saturation state, when considered, sensitivities substantial. As such, impact acidification on pump, turn uptake, potentially underestimated current insufficiently constrained.

Language: Английский

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Assessment of Global Ocean Biogeochemistry Models for Ocean Carbon Sink Estimates in RECCAP2 and Recommendations for Future Studies

Journal of Advances in Modeling Earth Systems, Journal Year: 2024, Volume and Issue: 16(3)

Published: March 1, 2024

Abstract The ocean is a major carbon sink and takes up 25%–30% of the anthropogenically emitted CO 2 . A state‐of‐the‐art method to quantify this are global biogeochemistry models (GOBMs), but their simulated uptake differs between systematically lower than estimates based on statistical methods using surface p interior measurements. Here, we provide an in‐depth evaluation from 1980 2018 GOBM ensemble. As sources inter‐model differences ensemble‐mean biases our study identifies (a) model setup, such as length spin‐up, starting date simulation, fluxes rivers into sediments, (b) circulation, Atlantic Meridional Overturning Circulation Southern Ocean mode intermediate water formation, (c) oceanic buffer capacity. Our analysis suggests that late in circulation cause too low anthropogenic across Surface might also be low, current setup prevents robust assessment. For simulations sink, recommend short‐term start at common before industrialization associated atmospheric increase, conduct sufficiently long spin‐up GOBMs reach steady‐state, key metrics for biogeochemistry, land‐ocean interface. In long‐term, improving representation these GOBMs.

Language: Английский

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The Land Component LM4.1 of the GFDL Earth System Model ESM4.1: Model Description and Characteristics of Land Surface Climate and Carbon Cycling in the Historical Simulation

Journal of Advances in Modeling Earth Systems, Journal Year: 2024, Volume and Issue: 16(5)

Published: April 30, 2024

Abstract We describe the baseline model configuration and simulation characteristics of Geophysical Fluid Dynamics Laboratory (GFDL)'s Land Model version 4.1 (LM4.1), which builds on component coupled developments over 2013–2019 for carbon‐chemistry‐climate Earth System Version (ESM4.1) as part sixth phase Coupled Intercomparison Project. Analysis ESM4.1/LM4.1 is focused biophysical biogeochemical processes interactions with climate. Key features include advanced vegetation dynamics multi‐layer canopy energy moisture exchanges, daily fire, land use representation, dynamic atmospheric dust coupling. compare LM4.1 performance in GFDL (ESM) ESM4.1 to previous generation LM3.0 ESM2G configuration. provides significant improvement treatment ecological from GFDL's models. However, likely overestimates influence cover change characteristics, particularly pasturelands, it competitiveness grasses versus trees tropics, a result, underestimates present‐day biomass carbon uptake comparison observations.

Language: Английский

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An Assessment of CO₂ Storage and Sea‐Air Fluxes for the Atlantic Ocean and Mediterranean Sea Between 1985 and 2018

Global Biogeochemical Cycles, Journal Year: 2024, Volume and Issue: 38(4)

Published: April 1, 2024

Abstract As part of the second phase Regional Carbon Cycle Assessment and Processes project (RECCAP2), we present an assessment carbon cycle Atlantic Ocean, including Mediterranean Sea, between 1985 2018 using global ocean biogeochemical models (GOBMs) estimates based on surface dioxide (CO 2 ) partial pressure (pCO products) interior dissolved inorganic observations. Estimates basin‐wide long‐term mean net annual CO uptake GOBMs pCO products are in reasonable agreement (−0.47 ± 0.15 PgC yr −1 −0.36 0.06 , respectively), with higher GOBM‐based likely being a consequence deficit representation natural outgassing land derived carbon. In GOBMs, increases time at rates close to what one would expect from atmospheric increase, but estimate rate twice as fast. The largest disagreement flux is found north 50°N, coinciding seasonal interannual variability. accumulation anthropogenic (C ant over 1994–2007 Ocean 0.52 0.11 according 28% 20% lower than that Around 70% this C taken up atmosphere, while remainder imported Southern through lateral transport.

Language: Английский

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Detecting, attributing, and projecting global marine ecosystem and fisheries change: FishMIP 2.0

Authorea (Authorea), Journal Year: 2024, Volume and Issue: unknown

Published: Jan. 22, 2024

There is an urgent need for models that can robustly detect past and project future ecosystem changes risks to the services they provide people. The Fisheries Marine Ecosystem Model Intercomparison Project (FishMIP) was established develop model ensembles projecting long-term impacts of climate change on fisheries marine ecosystems while informing policy at spatio-temporal scales relevant Inter-Sectoral Impact (ISIMIP) framework. While contributing FishMIP have improved over time, large uncertainties in projections remain, particularly coastal shelf seas where most world’s occur. Furthermore, previous impact mostly ignored fishing activity due a lack standardized historical scenario-based human forcing uneven capabilities dynamically across community. This, addition underrepresentation processes, has limited ability evaluate ensemble’s adequately capture states - crucial step building confidence projections. To address these issues, we developed two parallel simulation experiments (FishMIP 2.0) on: 1) evaluation detection 2) scenarios Key advances include forcing, captures oceanographic features not previously resolved, systematically test effects models. 2.0 key towards attribution framework regional global scales, enhanced relevance through increased ensemble

Language: Английский

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Priorities, opportunities, and challenges for integrating microorganisms into Earth system models for climate change prediction

mBio, Journal Year: 2024, Volume and Issue: 15(5)

Published: March 25, 2024

ABSTRACT Climate change jeopardizes human health, global biodiversity, and sustainability of the biosphere. To make reliable predictions about climate change, scientists use Earth system models (ESMs) that integrate physical, chemical, biological processes occurring on land, oceans, atmosphere. Although critical for catalyzing coupled biogeochemical processes, microorganisms have traditionally been left out ESMs. Here, we generate a “top 10” list priorities, opportunities, challenges explicit integration into We discuss need coarse-graining microbial information functionally relevant categories, as well capacity to rapidly evolve in response climate-change drivers. Microbiologists are uniquely positioned collect novel valuable necessary next-generation ESMs, but this requires data harmonization transdisciplinary collaboration effectively guide adaptation strategies mitigation policy.

Language: Английский

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