Reviews of Geophysics最新文献

Coastal wetlands are critical components of the global carbon cycle, yet many have been degraded by drainage and land-use changes, releasing stored carbon and exacerbating climate change. Interest in wetland restoration is increasing globally due to their carbon storage capacity, ecosystem values, and biodiversity co-benefits. This is further supported by the United Nations' declaration that 2021–2030 is the “Decade on Ecosystem Restoration.” Various techniques have been applied to achieve ecological wetland restoration. However, additional opportunities should be explored to extend the co-benefits of restoration beyond ecological aspects. For these restoration co-benefits to be fully optimized, the science of wetland functions and processes must be understood and quantified. Groundwater plays a crucial role in wetland carbon transport, storage, and transformation. However, its processes are often overlooked or poorly quantified. This paper (a) provides the current state of knowledge on subsurface hydrology and biogeochemical processes in wetlands, (b) describes how the hydrologic restoration of wetlands may affect the physical and chemical processes within wetlands, and (c) discusses how restoration can alter wetland function, with a specific focus on carbon and greenhouse gas dynamics. The paper highlights the necessity for a holistic, interdisciplinary approach to wetland restoration research, considering the interplay of hydrological, biogeochemical, and climatic factors to optimize carbon sequestration and ensure the long-term success of restoration projects.

In the past 1000 years, the continuous need for fertile and strategically located land has led to the reclamation of intertidal areas. The direct and short-term impact of land reclamation is a reduction in intertidal storage space and the loss of ecological value. Its long-term impact on the tidal landscape is variable but surprisingly poorly known. In this contribution, we review the impacts of land reclamation in a wide range of physical environments. Land reclamation along exposed, muddy coastlines leads to erosion or accretion, depending on local transport conditions and sediment availability. Confined muddy coasts (typically estuaries) respond by progressive infilling of tidal channels, especially when their upper reaches have been reclaimed. More gradual reclamation along the length of an estuary can lead to tidal amplification, while reclamation at the estuary mouth may additionally lead to channel erosion. The response timescales may be very long (up to centuries) especially when controlled by positive feedback mechanisms between tidal dynamics and landscape evolution. Therefore, some of the present day land reclamations will influence or possibly control the evolution of the coastal landscape in the coming decades to even centuries. In sediment-poor coastal bays, the reduction in tidal prism mainly leads to lower exchange rates and, therefore, to a reduction in water quality. The framework introduced here facilitates the assessment of the past and future impacts of land reclamations in tide-dominated environments. This understanding is crucial to predict the response of land reclamation-impacted coastal systems to accelerated sea level rise.

The water in Earth's rivers propagates as waves through space and time across hydrographic networks. A detailed understanding of river dynamics globally is essential for achieving accurate knowledge of surface water storage and fluxes to support water resources management and water-related disaster forecasting and mitigation. Global in situ information on river flows are crucial to support such an investigation but remain difficult to obtain at adequate spatiotemporal scales, if they even exist. Many expectations are placed on remote sensing techniques as key contributors. Despite a rapid expansion of satellite capabilities, however, it remains unclear what temporal revisit, spatial coverage, footprint size, spatial resolution, observation accuracy, latency time, and variables of interest from satellites are best suited to capture the space-time propagation of water in rivers. Additionally, the ability of numerical models to compensate for data sparsity through model-data fusion remains elusive. We review recent efforts to identify the type of remote sensing observations that could enhance understanding and representation of river dynamics. Key priorities include: (a) resolving narrow water bodies (finer than 50–100 m), (b) further analysis of signal accuracy versus hydrologic variability and relevant technologies (optical/SAR imagery, altimetry, microwave radiometry), (c) achieving 1–3 days observation intervals, (d) leveraging data assimilation and multi-satellite approaches using existing constellations, and (e) new variable measurement for accurate water flux and discharge estimates. We recommend a hydrology-focused, multi-mission observing system comprising: (a) a cutting-edge single or dual-satellite mission for advanced surface water measurements, and (b) a constellation of cost-effective satellites targeting dynamic processes.

A glacial forebulge is a bending-related upheaval of the lithosphere outside a glaciated area that co-occurs to the depression of the lithosphere below an ice sheet. The forebulge of the last glaciation attracted attention over more than one century, but quantitative descriptions on the geometry of the forebulge are rare. While many studies mention forebulge dynamics as a possible cause for a certain observation, very few studies provide a detailed and systematic exploration of the forebulge's precise dynamics. That way the forebulge became occasionally a rather mysterious structure with many unknowns. We aim to shed light into the forebulge discussion. After reviewing the history of forebulge research, we outline the theory behind the spatio-temporal forebulge development including controlling factors, and present forebulge observations in geological and geodetic records of North America and the northern parts of Central Europe. We use a state-of-the art finite-element model that can fit multiple observations of the last glaciation simultaneously, to illustrate forebulge development in North America and northern Central Europe and address the issue of whether the zero-uplift hinge line is a good indication of the location of the forebulge front. Finally, we discuss effects of the forebulge on the sea-level change pattern and the evolution of lithospheric stresses, which can induce intraplate earthquakes. We also show that the existence of a glacial forebulge outside the ice margin is not consistent with the assumption of isostatic equilibrium at the Last Glacial Maximum, and there is no strain rate-stress paradox.

Fault displacement hazard poses significant risks to critical infrastructure such as buildings, roads, and pipelines. While some structures can tolerate a certain degree of surface displacement, others, such as buildings, are far more vulnerable. Probabilistic Fault Displacement Hazard Assessment (PFDHA) quantifies the probability of exceeding a certain level of displacement at a site due to surface-rupturing earthquakes. A PFDHA model consists primarily of two components: the surface rupture probability and the fault displacement models (FDMs). FDMs distinguish between principal fault rupture and distributed rupture. Principal fault rupture occurs along the primary fault plane, where seismic energy is primarily released during an earthquake. In contrast, distributed rupture refers to all other tectonic surface ruptures occurring away from the principal fault. This differentiation was first introduced during the pioneering PFDHA study conducted for the Yucca Mountain nuclear waste repository (Nevada, USA) in the early 2000s. Since then, the methodology has been applied to various fault types, including strike-slip and reverse faults. In recent years, the number of new models and the awareness of PFDHA has grown thanks to several international initiatives such as the worldwide and unified database of surface ruptures, the fault displacement hazard initiative, and the benchmark project led by the International Atomic Energy Agency. With growing interest and rapid advancements in this field, this article aims to provide a complete overview of all published models, discuss their applicability and limitations, standardize the terminology, and outline the necessary developments to guide future research.

Stemflow hydrodynamics is the study of water movement along the exterior surface area of plants. Its primary goal is to describe water velocity and water depth along the stem surface area. Its significance in enriching the rhizosphere with water and nutrients is not in dispute. Yet, the hydrodynamics of stemflow have been entirely overlooked. This review seeks to fill this knowledge gap by drawing from thin film theories to seek outcomes at the tree scale. The depth-averaged conservation equations of water and solute mass are derived at a point. These equations are then supplemented with the conservation of momentum that is required to describe water velocities or relations between water velocities and water depth. Relevant forces pertinent to momentum conservation are covered and include body forces (gravitational effects), surface forces (wall friction), line forces (surface tension), and inertial effects. The inclusion of surface tension opens new vistas into the richness and complexity of stemflow hydrodynamics. Flow instabilities such as fingering, pinching of water columns into droplets, accumulation of water within fissures due to surface tension and their sudden release are prime examples that link observed spatial patterns of stemflow fronts and morphological characteristics of the bark. Aggregating these effects at the tree- and storm- scales are featured using published experiments. The review discusses outstanding challenges pertaining to stemflow hydrodynamics, the use of dynamic similarity and 3D printing to enable the interplay between field studies and controlled laboratory experiments.

Major infectious diseases threatening human health are transmitted to people from animals or by arthropod vectors such as insects. In recent decades, disease outbreaks have become more common, especially in tropical regions, including new and emerging infections that were previously undetected or unknown. Even though there is growing awareness that altering natural habitats can lead to disease outbreaks, the link between land use change and emerging diseases is still often overlooked and poorly understood. Land use change typically destroys natural habitat and alters landscape composition and configuration, thus altering wildlife population dynamics, including those of pathogen hosts, domesticated (often intermediary) hosts, infectious agents, and their vectors. Moreover, land use changes provide opportunities for human exposure to direct contact with wildlife, livestock, and disease-carrying vectors, thereby increasing pathogen spillover from animals to humans. Here we explore the nexus between human health and land use change, highlighting multiple pathways linking emerging disease outbreaks and deforestation, forest fragmentation, urbanization, agricultural expansion, intensified farming systems, and concentrated livestock production. We connect direct and underlying drivers of land use change to human health outcomes related to infectious disease emergence. Despite growing evidence of land-use induced spillover, strategies to reduce the risks of emerging diseases are often absent from discussions on sustainable food systems and land management. A “One Health” perspective—integrating human, animal, and environmental health—provides a critical yet often-overlooked dimension for understanding the health impacts of land use change.

Subduction zones are host to some of the largest and most devastating geohazards on Earth. The magnitude of these hazards is often measured by the amount of energy they release over short periods of time, which itself depends on how much stored energy is available for the geologic processes that drive these hazards. By considering the energy transfer among processes within subduction zones, we can identify the energy inputs and outputs to the system and estimate the stored energy. Due to the multiscale nature of subduction zone processes, developing an energy budget of subduction zone hazards requires integrating a wide range of geologic and geophysical field, laboratory, and modeling studies. We present a framework for developing mechanical energy budgets of upper crustal deformation that considers processes within the magmatic system, at the subduction zone interface, distributed and localized deformation between the arc and trench, and surface processes that erode, transport, and store sediments. The subduction energy budget framework provides a way to integrate data and model results to explore interactions between diverse processes. Because fault mechanics, sediment transport and magmatic processes within subduction zones do not act in isolation, we gain insights by considering the common energetic elements of the subduction zone system. Building energy budgets reveals gaps in our understanding of subduction zone processes, and thus highlights opportunities for new interdisciplinary research on subduction zone processes that can inform hazard potential.

The Mediterranean Basin, renowned for its cultural, ecological, and climatic significance, frequently endures high-impact weather events driven by Mediterranean cyclones (Medcyclones), atmospheric low-pressure systems characterized by counterclockwise wind circulation. These meteorological phenomena, sometimes comparable to hurricanes in their intensity and impact, shape the region's weather and are responsible for diverse natural hazards, including torrential rainfall, flash floods, windstorms, and sea surges. Such events have profound and far-reaching socio-economic and ecological consequences, particularly for coastal and densely populated areas. Despite their critical role, the systematic assessment of Medcyclones' contribution to socio-economic losses and the effective communication of associated risks remains limited. This review synthesizes the existing body of knowledge on the socio-economic impacts of Medcyclones, with a focus on vulnerable sectors such as human health, energy, transportation, agriculture, and cultural heritage. It highlights pressing knowledge gaps, including the need for interdisciplinary research and improved engagement with stakeholders and the public. Advancing the field, this work provides an integrated perspective on Medcyclones' impacts and outlines strategies for resilience, including enhancing predictive models, fostering cross-sectoral impact studies, and improving disaster preparedness. By bridging the knowledge gaps, this review aims to inform policy-making and support the development of adaptive measures to mitigate the escalating threats posed by Medcyclones in the context of a changing climate.

The recharge oscillator (RO) is a simple mathematical model of the El Niño Southern Oscillation (ENSO). In its original form, it is based on two ordinary differential equations that describe the evolution of equatorial Pacific sea surface temperature and oceanic heat content. These equations make use of physical principles that operate in nature: (a) the air-sea interaction loop known as the Bjerknes feedback, (b) a delayed oceanic feedback arising from the slow oceanic response to winds within the equatorial band, (c) state-dependent stochastic forcing from fast wind variations known as westerly wind bursts (WWBs), and (d) nonlinearities such as those related to deep atmospheric convection and oceanic advection. These elements can be combined at different levels of RO complexity. The RO reproduces ENSO key properties in observations and climate models: its amplitude, dominant timescale, seasonality, and warm/cold phases amplitude asymmetry. We discuss the RO in the context of timely research questions. First, the RO can be extended to account for ENSO pattern diversity (with events that either peak in the central or eastern Pacific). Second, the core RO hypothesis that ENSO is governed by tropical Pacific dynamics is discussed from the perspective of influences from other basins. Finally, we discuss the RO relevance for studying ENSO response to climate change, and underline that accounting for ENSO diversity, nonlinearities, and better links of RO parameters to the long term mean state are important research avenues. We end by proposing important RO-based research problems.