Possible shift in controls of the tropical Pacific surface warming pattern

Nature, Год журнала: 2024, Номер 630(8016), С. 315 - 324

Опубликована: Июнь 12, 2024

Язык: Английский

---

Reduced Southern Ocean warming enhances global skill and signal-to-noise in an eddy-resolving decadal prediction system

npj Climate and Atmospheric Science, Год журнала: 2023, Номер 6(1)

Опубликована: Июль 31, 2023

Abstract The impact of increased model horizontal resolution on climate prediction performance is examined by comparing results from low-resolution (LR) and high-resolution (HR) decadal simulations conducted with the Community Earth System Model (CESM). There general improvement in global skill signal-to-noise characteristics, particularly noteworthy improvements eastern tropical Pacific, when order 1° all components to 0.1°/0.25° ocean/atmosphere. A key advance ocean eddy-resolving HR system reduction unrealistic warming Southern Ocean (SO) which we hypothesize has ramifications through its impacts Pacific multidecadal variability. suggest that accurate representation SO processes critical for improving predictions globally addressing longstanding issues coupled recent change.

Язык: Английский

---

Regional climate change: consensus, discrepancies, and ways forward

Frontiers in Climate, Год журнала: 2024, Номер 6

Опубликована: Май 3, 2024

Climate change has emerged across many regions. Some observed regional climate changes, such as amplified Arctic warming and land-sea contrasts have been predicted by models. However, other changes in tropical sea surface temperature monsoon rainfall are not well simulated model ensembles even when taking into account natural internal variability structural uncertainties the response of models to anthropogenic radiative forcing. This suggests predictions may fully reflect what our future will look like. The discrepancies between observations understood due several real apparent puzzles limitations “signal-to-noise paradox” real-world record-shattering extremes falling outside possible range Addressing these discrepancies, is essential, because understanding reliably predicting necessary order communicate effectively about underlying drivers change, provide reliable information stakeholders, enable societies adapt, increase resilience reduce vulnerability. challenges achieving this greater Global South, especially lack observational data over long time periods a scientific focus on South change. To address models, it important prioritize resources for analyzing where why disagree via testing hypotheses biases using Gaps can be discovered filled exploiting new tools, artificial intelligence/machine learning, high-resolution modeling experiments hierarchy, better quantification forcing, observations. Conscious efforts needed toward creating opportunities that allow experts, particularly those from take lead research. includes co-learning technical aspects simulations physics dynamics Finally, improved methods communication needed, which uncertainties, actionable stakeholders media.

Язык: Английский

---

Opinion: Why all emergent constraints are wrong but some are useful – a machine learning perspective

Atmospheric chemistry and physics, Год журнала: 2025, Номер 25(4), С. 2365 - 2384

Опубликована: Фев. 21, 2025

Abstract. Global climate change projections are subject to substantial modelling uncertainties. A variety of emergent constraints, as well several other statistical model evaluation approaches, have been suggested address these However, they remain heavily debated in the science community. Still, central idea relate future already observable quantities has no real substitute. Here, we highlight validation perspective predictive skill machine learning community a promising alternative viewpoint. Specifically, argue for quantitative approaches which each constraining relationship can be evaluated comprehensively based on out-of-sample test data – top qualitative physical plausibility arguments that commonplace justification new constraints. Building this perspective, review ideas types controlling-factor analyses (CFAs). The principal behind CFAs is use find climate-invariant relationships historical hold approximately under strong scenarios. On basis existing archives, validated perfect-climate-model frameworks. From such three reasons: (a) objectively both past and data, (b) provide more direct and, by design, physically plausible links between observations potential climates, (c) take high-dimensional complex into account functions learned constrain response. We demonstrate advantages two recently published CFA examples form constraints feedback mechanisms (clouds, stratospheric water vapour) discuss further challenges opportunities using example rapid adjustment mechanism (aerosol–cloud interactions). avenues work, including strategies non-linearity, tackle blind spots ensembles, integrate helpful priors Bayesian methods, leverage physics-informed learning, enhance robustness through causal discovery inference.

Язык: Английский

---

The greater role of Southern Ocean warming compared to Arctic Ocean warming in shifting future tropical rainfall patterns

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Апрель 1, 2025

The recent rapid decline in Antarctic sea ice highlights the need to understand whether rising Southern Ocean temperatures have an influence on global climate. While Arctic warming has been extensively studied, importance of is emerging only now. Here, using multi-model simulations, we show that over 1.5 °C surface can offset projected northward shift tropical zonal-mean precipitation by mid-21st century, driven stronger northern high-latitude under greenhouse gas concentrations. SST nudging experiments suggest a 1.0 could impact as significantly Arctic. Regionally, increases rainfall northeastern Brazil while heightening drought risks Sahel. These effects are comparable to, or slightly more pronounced than, those caused weakening Atlantic Meridional Overturning Circulation and associated development North hole. Thus, may play crucial role than shaping climate patterns coming decades.

Язык: Английский

---

Crucial role of sea surface temperature warming patterns in near-term high-impact weather and climate projection

npj Climate and Atmospheric Science, Год журнала: 2024, Номер 7(1)

Опубликована: Июнь 13, 2024

Abstract Recent studies indicate that virtually all global climate models (GCMs) have had difficulty simulating sea surface temperature (SST) trend patterns over the past four decades. GCMs produce enhanced warming in eastern Equatorial Pacific (EPAC) and Southern Ocean (SO) warming, while observations show intensified Indo-Pacific Warm Pool (IPWP) slight cooling EPAC SO. Using Geophysical Fluid Dynamics Laboratory’s latest higher resolution atmospheric model coupled prediction system, we biases SST pattern profound implications for near-term projections of high-impact storm statistics, including frequency rivers (AR), tropical storms (TS) mesoscale convection systems (MCS), as well hydrological sensitivity. If future continues to resemble observed from few decades rather than GCM simulated/predicted patterns, our results suggest (1) a drastically different projection their associated hydroclimate changes, especially Western Hemisphere, (2) stronger sensitivity, (3) substantially less due negative feedback lower The roles EPAC, IPWP, SO, North Atlantic cyclone Main Development Region (AMDR) are isolated, quantified, used understand simulated differences. Specifically, AMDR crucial modeled differences AR MCS frequency, those IPWP essential TS Atlantic.

Язык: Английский

---

Tropical eastern Pacific cooling trend reinforced by human activity

npj Climate and Atmospheric Science, Год журнала: 2024, Номер 7(1)

Опубликована: Июль 24, 2024

Abstract It remains unresolved whether the La Niña-like sea surface temperature (SST) trend pattern during satellite era, featuring a distinct warming in northwest/southwest Pacific but cooling tropical eastern Pacific, is driven by either external forcing or internal variability. Here, conducting comprehensive analysis of observations and series climate model simulations for historical period, we show that combination variability human activity may have shaped observed SST pattern. As observations, SSTs each ensemble member multi-decadal swing between El Niño-like patterns due to The ensemble-mean trends some models are, however, found exhibit an enhanced zonal gradient along equatorial over periods such as 1979–2010, suggesting role forcing. In line with this hypothesis, single-forcing large human-induced stratospheric ozone depletion and/or aerosol changes acted enhance via strengthening trade winds, although effect dependent. Our finding suggests unlikely persist under sustained global because both impacts will eventually weaken.

Язык: Английский

---

Confronting Earth System Model trends with observations

Science Advances, Год журнала: 2025, Номер 11(11)

Опубликована: Март 12, 2025

Anthropogenically forced climate change signals are emerging from the noise of internal variability in observations, and impacts on society growing. For decades, Climate or Earth System Models have been predicting how these will unfold. While challenges remain, given growing trends lengthening observational record, science community is now a position to confront signals, as represented by historical trends, models with observations. This review covers state ability represent system. It also outlines robust procedures that should be used when comparing modeled observed move beyond quantification into understanding. Finally, this discusses cutting-edge methods for identifying sources discrepancies importance future confrontations.

Язык: Английский

---

Tropical and Antarctic sea ice impacts of observed Southern Ocean warming and cooling trends since 1949

npj Climate and Atmospheric Science, Год журнала: 2024, Номер 7(1)

Опубликована: Сен. 2, 2024

Язык: Английский

---

Recent Multi‐Decadal Southern Ocean Surface Cooling Unlikely Caused by Southern Annular Mode Trends

Geophysical Research Letters, Год журнала: 2023, Номер 50(23)

Опубликована: Дек. 7, 2023

Abstract Over recent decades, the Southern Ocean (SO) has experienced multi‐decadal surface cooling despite global warming. Earlier studies have proposed that SO been caused by strengthening of westerlies associated with a positive trend Annular Mode (SAM) forced ozone depletion. Here we revisit this hypothesis examining relationships between SAM, zonal winds and sea‐surface temperature (SST). Applying low‐frequency component analysis to observations, show while SAM anomalies can induce SST as previously found, seasonal‐to‐interannual modulation makes only small contribution observed long‐term cooling. Global climate models well capture interannual SAM‐SST relationship, yet generally fail simulate The in decades is thus unlikely main cause cooling, pointing limited role Antarctic hole.

Язык: Английский

---