Projected 21st-century changes in marine heterotrophic bacteria under climate change

Frontiers in Microbiology, Journal Year: 2023, Volume and Issue: 14

Published: Feb. 16, 2023

Marine heterotrophic Bacteria (or referred to as bacteria) play an important role in the ocean carbon cycle by utilizing, respiring, and remineralizing organic matter exported from surface deep ocean. Here, we investigate responses of bacteria climate change using a three-dimensional coupled biogeochemical model with explicit bacterial dynamics part Coupled Model Intercomparison Project Phase 6. First, assess credibility century-scale projections (2015–2099) stock rates upper 100 m layer skill scores compilations measurements for contemporary period (1988–2011). Second, demonstrate that across different scenarios, simulated biomass trends (2076–2099) are sensitive regional temperature stocks. Bacterial declines 5–10% globally, while it increases 3–5% Southern Ocean where semi-labile dissolved (DOC) stocks relatively low particle-attached dominate. While full analysis drivers underpinning changes all is not possible due data constraints, mechanisms DOC uptake free-living first-order Taylor decomposition. The results increase drives Ocean, northern high latitudes. Our study provides systematic at global scale critical step toward better understanding how affect functioning biological pump partitioning pools between layers.

Language: Английский

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Enhanced causal effect of ecosystem photosynthesis on respiration during heatwaves

Science Advances, Journal Year: 2023, Volume and Issue: 9(43)

Published: Oct. 25, 2023

Because of global warming, Earth's ecosystems have been experiencing more frequent and severe heatwaves. Heatwaves are expected to tip terrestrial carbon sequestration by elevating ecosystem respiration suppressing gross primary productivity (GPP). Here, using the convergent cross-mapping technique, this study detected positive bidirectional causal effects between GPP in two unprecedented European enhanced effect strength on rather than across 40 site-years observations. Further analyses simulations revealed spatial heterogeneity heatwave response link respiration, which was jointly driven local climate vegetation properties. However, showed considerable uncertainties CMIP6 models. This reveals an during heatwaves, shedding light improving projections for sink dynamics under future extremes.

Language: Английский

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Probabilistic evaluation of three generations of climate models for simulating precipitation over the Western Himalayas

Journal of Earth System Science, Journal Year: 2024, Volume and Issue: 133(1)

Published: Jan. 8, 2024

Language: Английский

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Future projections of hurricane intensity in the southeastern U.S.: sensitivity to different Pseudo-Global Warming methods

Frontiers in Climate, Journal Year: 2024, Volume and Issue: 6

Published: Feb. 13, 2024

Tropical cyclones are prone to cause fatalities and damages reaching far into billions of US Dollars. There is evidence that these events could intensify under ongoing global warming, accordingly disaster prevention adaptation strategies necessary. We apply Pseudo-Global Warming (PGW) as a computational cost-efficient alternative conventional long-term modeling, enabling the assessment historical future storylines. Not many studies specifically assess sensitivity PGW in context short-term extreme United States. In an attempt close this gap, study explores hurricane intensity different configurations, including purely thermodynamic, dynamic, more comprehensive modulation initial boundary conditions using Weather Research Forecasting Model (WRF). The climate perturbations calculated two individual CMIP6 models with relatively low high temperature change ensemble mean, all SSP5-8.5. WRF was set up two-way nesting framework domains 25 5 km spatial resolution. Results show uncertainties exist between thermodynamic dynamic approaches, whereas deviations approach variable low. Hurricanes modeled tend toward higher intensities, perturbation wind may impose unwanted effects on cyclogenesis, for example due increased vertical shear. highest sensitivity, however, stems from selected model. conclude should thoroughly imposed by scheme, similar those model parameterizations. All simulation results suggest increase maximum speeds precipitation impact mean. An unfolding inspected warmer world therefore exacerbate impacts nature society.

Language: Английский

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Representation of the Terrestrial Carbon Cycle in CMIP6

Published: March 4, 2024

Abstract. Improvements in the representation of land carbon cycle Earth system models participating Coupled Model Intercomparison Project Phase 6 (CMIP6) include interactive treatment both and nitrogen cycles, improved photosynthesis, soil hydrology. To assess impact these model developments on aspects global cycle, System Evaluation Tool (ESMValTool) is expanded to compare CO2 concentration emission driven historical simulations from CMIP5 CMIP6 observational data sets. A particular focus differences with without an terrestrial cycle. Overestimations photosynthesis (gross primary productivity (GPP)) were largely resolved for but remaining one. This points importance including nutrient limitation. Simulating leaf area index (LAI) remains challenging a large spread CMIP6. In ESMs, mean uptake (net biome (NBP)) well reproduced multi-model means. However, this result underestimation NBP northern hemisphere, which compensated by overestimation southern hemisphere tropics. Carbon stocks remain uncertainty models. While vegetation content slightly better represented CMIP6, inter-model range same between Overall, slight improvement simulation parameters found compared CMIP5, many biases remaining, further improvements LAI required. Models modeling groups CMIP phases generally perform similarly or their not as significant means due more new especially those using older versions Community Land (CLM). Emission just despite added process-realism. Due we recommend ESMs future standard so that climate-carbon feedbacks are fully active. The inclusion limitation led process, suggesting need view necessary part all Possible benefits when limiting nutrients such phosphorus should also be considered.

Language: Английский

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