Reviews of Geophysics最新文献

As climate models become increasingly complex, there is a growing need to comprehensively and systematically assess model performance with respect to observations. Given the increasing number and diversity of climate model simulations in use, the community has moved beyond simple model intercomparison and toward developing methods capable of benchmarking a large number of simulations against a suite of climate metrics. Here, we present a detailed review of evaluation and benchmarking methods and approaches developed in the last decade, focusing primarily on scientific implications for Coupled Model Intercomparison Project (CMIP) simulations and CMIP6 results that contributed to the Intergovernmental Panel on Climate Change (IPCC) Sixth Assessment Report (AR6). Based on this review, we explain the resulting contemporary philosophy of model benchmarking, and provide clear distinctions and definitions of the terms model verification, process validation, evaluation, and benchmarking. While significant progress has been made in model development based on systematic evaluation and benchmarking efforts, some climate system biases still remain. The development of open-source community software packages has played a fundamental role in identifying areas of significant model improvement and bias reduction. We review the key features of several software packages that have been commonly used over the past decade to evaluate and benchmark global and regional climate models. Additionally, we discuss best practices for the selection of evaluation and benchmarking metrics and for interpreting the obtained results, the importance of selecting suitable sources of reference data and accurate uncertainty quantification.

The Meiyu-Baiu-Changma (MBC) is a critical rainy season in East Asia. The MBC rainfall is a vital water source but also causes devastating flooding, profoundly impacting agriculture, water resource management, and socio-economy across East Asia. The El Niño–Southern Oscillation (ENSO) plays a critical role in modulating the interannual variability of MBC. The response of MBC to ENSO is, however, complex, nonlinear, and stochastic, influenced by various ENSO characteristics including the phase, intensity, location, and decay pace. This review synthesizes recent advances in understanding the ENSO–MBC linkage, by incorporating existing literature and our new analyses, to elucidate the underlying mechanisms, model performance, and future projections regarding ENSO's impacts on the MBC under climate change. In this review, an increased correlation between ENSO and MBC over past decades is revealed. The two main paths of ENSO impacting the MBC via modulating the anomalous western North Pacific anticyclone, and the changes in the influence of these paths under climate change, are synthesized and analyzed. Seasonal prediction of ENSO-driven MBC anomalies remains challenging, despite the advances of climate models in simulating and predicting the ENSO-related large-scale ocean and atmospheric circulation anomalies. In the future, intensified global warming may lead to a further strengthened impact of ENSO on MBC and increased ENSO-driven MBC extremes. Exploring greenhouse gas forcing's influence, improving high-resolution coupled models, refining representation of key dynamic processes, and utilizing artificial intelligence techniques are essential to advance understanding, simulation, prediction, and climate adaptation strategies related to ENSO-MBC connection.

Rising global temperatures pose significant risks to marine ecosystems, biodiversity, and fisheries. Recent comprehensive assessments suggest that large-scale mitigation efforts to limit warming are falling short, and all feasible future climate projections, including those that represent optimistic emissions reductions, exceed the Paris Agreement's 1.5°C or 2° warming targets during this century. While avoiding further CO₂ emissions remains the most effective way to prevent environmental destabilization, interest is growing in climate interventions—deliberate, large-scale manipulations of the environment aimed at reducing global warming. These include carbon dioxide removal (CDR) to reduce atmospheric CO₂ concentrations over time, and solar radiation modification (SRM), which reflects sunlight to lower surface temperatures but does not address root CO₂ causes. The effects of these interventions on marine ecosystems, both direct and in combination with ongoing climate change, remain highly uncertain. Given the ocean's central role in regulating Earth's climate and supporting global food security, understanding these potential effects is crucial. This review provides an overview of proposed intervention methodologies for marine CDR and SRM and outlines the potential trade-offs and knowledge gaps associated with their impacts on marine ecosystems. Climate interventions have the potential to reduce warming-driven impacts, but could also alter marine food systems, biodiversity and ecosystem function. Effects will vary by pathway, scale, and regional context. Pathway-specific impact assessments are thus crucial to quantify trade-offs between plausible intervention scenarios as well as to identify their expected impacts on marine ecosystems in order to prioritize scaling efforts for low-risk pathways and avoid high-risk scenarios.

Mountain glaciers are among the natural systems most vulnerable to climate change. However, their interactions with the atmosphere are complex and not fully understood. These interactions can trigger rapid adjustments and climate feedbacks that either amplify or attenuate atmospheric signals, influencing both glacier response and large-scale atmospheric circulation. Observing this functional coupling in nature is challenging because the key processes occur over a wide range of spatial and temporal scales. However, recent advances in observational techniques and modeling have provided new insights into these interactions. In this review, we summarize the current state of knowledge on glacier-atmosphere interactions in high-mountain regions at different scales, and highlight recent advances in observational and numerical modeling. We also highlight important knowledge gaps and outline future research directions to improve the prediction of glacier change in a warming world.

Frozen soils, including seasonally frozen ground and permafrost, are rapidly changing under a warming climate, with cascading effects on water, energy, and carbon cycles. We synthesize recent advances in the physics, observation, and modeling of frozen-soil hydrology, emphasizing freeze–thaw dynamics, infiltration regimes and preferential flow, groundwater–permafrost interactions (including talik development and advective heat), and resulting shifts in streamflow seasonality. Progress in in situ sensing, geophysics, and remote sensing now resolves unfrozen water, freezing fronts, and active-layer dynamics across scales, while land-surface and tracer-aided hydrological models increasingly represent phase change, macropore bypass, and vapor transport. Thaw-induced activation of subsurface pathways alters recharge and baseflow, influences vegetation and biogeochemistry, and modulates greenhouse-gas emissions. Key uncertainties persist in scaling micro-scale processes, parameterizing ice-impeded hydraulics, and representing abrupt thaw and wetland dynamics. We outline a tiered modeling framework, priority observations, and integration of vegetation–hydrology–carbon processes to improve projections of cold-region water resources and climate feedbacks.

The increasing threat of soil degradation presents significant challenges to soil health, especially within agroecosystems that are vital for food security, climate regulation, and economic stability. This growing concern arises from intricate interactions between land use practices and climatic conditions, which, if not addressed, could jeopardize sustainable development and environmental resilience. This review offers a comprehensive examination of soil degradation, including its definitions, global prevalence, underlying mechanisms, and methods of measurement. It underscores the connections between soil degradation and land use, with a focus on socio-economic consequences. Current assessment methods frequently depend on insufficient data, concentrate on singular factors, and utilize arbitrary thresholds, potentially resulting in misclassification and misguided decisions. We analyze these shortcomings and investigate emerging methodologies that provide scalable and objective evaluations, offering a more accurate representation of soil vulnerability. Additionally, the review assesses both physical and biological indicators, as well as the potential of technologies such as remote sensing, artificial intelligence, and big data analytics for enhanced monitoring and forecasting. Key factors driving soil degradation, including unsustainable agricultural practices, deforestation, industrial activities, and extreme climate events, are thoroughly examined. The review emphasizes the importance of healthy soils in achieving the United Nations Sustainable Development Goals, particularly concerning food and water security, ecosystem health, poverty alleviation, and climate action. It suggests future research directions that prioritize standardized metrics, interdisciplinary collaboration, and predictive modeling to facilitate more integrated and effective management of soil degradation in the context of global environmental changes.

For decades it has been observed that rates of silicate mineral reactions appear slower in field settings than when measured in the laboratory. Since the 1980s, researchers have proposed explanations for the discrepancy. Over that time, researchers have also advanced the state of laboratory and field rate measurements as well as models of mineral-water reaction kinetics at different temporal and spatial scales. Developments in reactive transport modeling are constantly whittling away at the discrepancy as models are improved, coupled to hydrologic models, and driven by climate data. The lab-field discrepancy has great relevance today because of the proposal that weathering of silicates (especially basalts) could be accelerated to remove CO₂ from the atmosphere and sequester it either as aqueous alkalinity or as carbonate mineral precipitate. Such “enhanced rock weathering” relies on mining and grinding silicate rock for dispersal on farmland to enable weathering by carbonic acid. In general, field rates become increasingly slower than lab rates at larger spatial and temporal scales because of factors related to surface area, hydrology, heterogeneities, biota, and system-level effects. This implies surface area is not always an appropriate scaling factor. The measurements of enhanced rates of basalt weathering on croplands published so far are relatively consistent with previously published lab and field rates of basalt weathering because the durations of weathering are small. But the rates of CO₂ consumption from the atmosphere are very slow, and will decrease with time, necessitating huge acreages of basalt spreading to reach gigatons of CO₂ sequestration.