Reviews of Geophysics最新文献

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.

On behalf of the authors and readers of Reviews of Geophysics (RoG), the American Geophysical Union, and the broader scientific community, the editors wish to wholeheartedly thank those who reviewed manuscripts for RoG in 2024.

Climate change drives disturbance in hydrology and geomorphology in terrestrial polar landscapes underlain by permafrost, yet measurements of, and theories to understand, these changes are limited. Water flowing from permafrost hillslopes to channels is often modulated by water tracks, zones of enhanced soil moisture in unchannelized depressions that concentrate water flow downslope. Water tracks, which dominate hillslope hydrology in some permafrost landscapes, lack a consistent definition and identification method, and their global occurrence, morphology, climate relationships, and geomorphic roles remain understudied despite their role in the permafrost carbon cycle. Combining a literature review with a synthesis of prior work, we identify uniting and distinguishing characteristics between water tracks from disparate polar sites with a toolkit for future field and remotely sensed identification of water tracks. We place previous studies within a quantitative framework of “top-down” climate and “bottom-up” geology controls on track morphology and hydrogeomorphic function. We find the term “water track” is applied to a broad category of concentrated suprapermafrost flowpaths exhibiting varying morphology, degrees of self-organization, hydraulic characteristics, subsurface composition, vegetation, relationships to thaw tables, and stream order/hillslope position. We propose that the widespread occurrence of water tracks on both poles across varying geologic, ecologic, and climatic factors implies that water tracks are in dynamic equilibrium with the permafrost environment but that they may experience change as the climate continues to warm. Current knowledge gaps include these features' trajectories in the face of ongoing climate change and their role as an analog landform for an active Martian hydrosphere.

Assessing landslide risk is a fundamental requirement to plan suitable prevention actions. To date, most risk studies focus on individual slopes or catchments. Whereas regional, national or continental scale assessments are hardly available because of methodological and/or data limitations. In this contribution, we present an overview of all requirements and limitations in landslide risk studies across all spatial scales, by means of a hybrid form that combines elements of original research with the comprehensive characteristics of a review study. The review critically analyses each component in the landslide risk analysis providing a detailed explanation of their state-of-the-art, with dedicated sections on susceptibility, hazard, exposure, and vulnerability. To put the theoretical framework to test, we also dive into a case study, expressed at the continental scale. Specifically, we take the main European mountain ranges and provide the reader with a textbook example of risk assessment for such a large territory. In doing so, we take into account issues associated with cross-national differences in landslide mapping. As a result, we identify landslide-prone European landscape and explore the associated possible economic consequences (human settlements and agricultural areas). We also analyze the population at risk during daytime and nighttime. Moreover, a modern view of the problem is explored in the form of how risk outcomes should be delivered to master planners and geoscientific personnel alike. Specifically, we convert our output into an interactive Web Application (https://pan-european-landslide-risk.github.io/) to include notions of scientific communication both to a large public as well as to a technical audience.

Karst water resources are valuable freshwater sources for around 10% of the world's population. Nonetheless, anthropogenic impacts and global changes have seriously deteriorated karst water quality and dependent ecosystems. Multiscale karstic heterogeneity—referring to the spatial variations of the karst aquifer's physical and chemical characteristics at varying scales—is the main challenge in describing karst flow and contaminant transport dynamics. Solute transport models are powerful tools to represent and predict the spatiotemporal behaviors of contaminant migration in karst water resources. By enhancing our understanding of the transport processes, the solute transport models enable us to explore contamination risks and potential outcomes of the contamination-related issues in karst systems. Because of that, they are often used for monitoring, controlling, and managing karst water quality and dependent ecosystem functioning. This paper reviews the current state of knowledge on the modeling of karst transport processes with a focus on single-phase solute transport. By unveiling the fundamental challenges underlying a successful real-world application of karst transport models, we discuss to what extent and how we can handle these challenges. By further deriving the key challenges afront the successful modeling applications in karst systems, we, therefore, provide directions to ensure the reliable modeling of karst transport dynamics in the present context of global changes.

Rock glaciers are distinctive debris landforms found worldwide in cold mountainous regions. They express the long-term movement of perennially frozen ground. Rock Glacier Velocity (RGV), defined as the time series of the annualized surface velocity of a rock glacier unit or a part of it, has been accepted as an Essential Climate Variable Permafrost Quantity in 2022. This review aims to highlight the relationship between rock glacier velocity and climatic factors, emphasizing the scientific relevance of interannual rock glacier velocity in generating RGV products within the context of observed rock glacier kinematics. Under global warming, rock glacier velocity exhibits widespread (multi-)decennial acceleration. This acceleration varies regionally in onset timing (from the 1950s to the 2010s) and magnitude (up to a factor of 10), and has been observed in regions such as the European Alps, High Mountain Asia, and the Andes. Despite different local conditions, a synchronous interannual velocity pattern prevails in the European Alps since the 2000s, highlighting the primary influence of climate. A common pattern is the seasonal velocity rhythm, which peaks in late summer to autumn and declines in spring. RGV assesses permafrost evolution via (multi-)decennial and interannual changes in rock glacier velocity, influenced by air temperature shifts with varying time lags and snow cover effects. Although not integrated into the RGV products, seasonal variations should be examined. This rhythmic behavior is attributed to alterations in pore water pressure influenced by air temperature, snow cover, and ground water conditions.

The soil health assessment has evolved from focusing primarily on agricultural productivity to an integrated evaluation of soil biota and biotic processes that impact soil properties. Consequently, soil health assessment has shifted from a predominantly physicochemical approach to incorporating ecological, biological and molecular microbiology indicators. This shift enables a comprehensive exploration of soil microbial community properties and their responses to environmental changes arising from climate change and anthropogenic disturbances. Despite the increasing availability of soil health indicators (physical, chemical, and biological) and data, a holistic mechanistic linkage has not yet been fully established between indicators and soil functions across multiple spatiotemporal scales. This article reviews the state-of-the-art of soil health monitoring, focusing on understanding how soil-microbiome-plant processes contribute to feedback mechanisms and causes of changes in soil properties, as well as the impact these changes have on soil functions. Furthermore, we survey the opportunities afforded by the soil-plant digital twin approach, an integrative framework that amalgamates process-based models, Earth Observation data, data assimilation, and physics-informed machine learning, to achieve a nuanced comprehension of soil health. This review delineates the prospective trajectory for monitoring soil health by embracing a digital twin approach to systematically observe and model the soil-plant system. We further identify gaps and opportunities, and provide perspectives for future research for an enhanced understanding of the intricate interplay between soil properties, soil hydrological processes, soil-plant hydraulics, soil microbiome, and landscape genomics.

Topography affects the distribution and movement of water on Earth, yet new insights about topographic controls continue to surprise us and exciting puzzles remain. Here we combine literature review and data synthesis to explore the influence of topography on the global terrestrial water cycle, from the atmosphere down to the groundwater. Above the land surface, topography induces gradients and contrasts in water and energy availability. Long-term precipitation usually increases with elevation in the mid-latitudes, while it peaks at low- to mid-elevations in the tropics. Potential evaporation tends to decrease with elevation in all climate zones. At the land surface, topography is expressed in snow distribution, vegetation zonation, geomorphic landforms, the critical zone, and drainage networks. Evaporation and vegetation activity are often highest at low- to mid-elevations where neither temperature, nor energy availability, nor water availability—often modulated by lateral moisture redistribution—impose strong limitations. Below the land surface, topography drives the movement of groundwater from local to continental scales. In many steep upland regions, groundwater systems are well connected to streams and provide ample baseflow, and streams often start losing water in foothills where bedrock transitions into highly permeable sediment. We conclude by presenting organizing principles, discussing the implications of climate change and human activity, and identifying data needs and knowledge gaps. A defining feature resulting from topography is the presence of gradients and contrasts, whose interactions explain many of the patterns we observe in nature and how they might change in the future.