Geology topics

Research about United States

Source-linked reports with geographic coverage including United States.

At least 1,747 records · Page 97Linked to original sources

USGS2025

Pluvial and potential compound flooding in a coupled coastal modeling framework: New York City during post-tropical Cyclone Ida (2021)

Many coastal urban areas are prone to extreme pluvial flooding due to limitations in stormwater system capacity, with the additional potential for flooding compounded by storm surge, tides, and waves. Understanding and simulating these processes can improve prediction and flood risk management. Here, we adapt the Coupled Ocean–Atmosphere–Wave–Sediment Transport modeling framework (COAWST) to simulate pluvial flooding from post-tropical Cyclone Ida (2021) in the Jamaica Bay watershed of New York City (NYC). We modify the model to capture the volumetric effects of rainfall and parameterize soil infiltration and a stormwater conveyance system as the drainage rate. We generate a spatially continuous flood map of Ida with a root-mean-square error (RMSE) of 20 cm when compared to high-water marks, useful for understanding Ida's impacts and subsequent mitigation planning. Results show that over 23 km 2 and 4621 buildings were flooded deeper than 0.3 m during Ida. Sensitivity analyses are used to study the broader risk from events like Ida (pluvial flooding) as well as potential compound (pluvial–coastal) flooding. Spatial shifting of the storm track within a typical 12 h forecast uncertainty reveals a worst-case scenario that increases this flooded area to 62 km 2 (5907 buildings). Shifting Ida's rainfall to coincide with high tide increases this flooded area by 1 km 2 , a relatively small change due to the lack of significant storm surge. The application of COAWST to this storm event addresses a broader goal of developing the capability to model compound pluvial–coastal flooding by simultaneously representing coastal storm processes such as rain, tide, waves, erosion, and atmosphere–wave–ocean interactions. The sensitivity analysis results underscore the need for detailed flood risk assessments, showing that Ida, already NYC's worst rain event, could have been even more devastating with slight shifts in the storm track.

New York↗

USGS2025

Discovery of late Holocene-aged Acropora palmata reefs in Dry Tortugas National Park, Florida, USA: The past as a key to the future?

Emblematic of global coral-reef ecosystem decline, the coral ecosystem-engineer Acropora palmata is now rare throughout much of the western Atlantic. Understanding when and where this foundation species occurred during the past can provide information about the environmental limits defining its distribution through space and time. In this paper, the present, historical and newly dated geological records of A. palmata are compared to reveal novel insights into the environmental constraints on its occurrence in Dry Tortugas National Park, a subtropical reef system at the south-western terminus of the Florida reef tract. Although past geological investigation found little evidence of the species in the park, a single, moderately sized A. palmata reef existed throughout historical times (1881 Common Era [CE] to present day; ‘historical population’, termed herein). Over the last 140 years, repeated population declines occurred with little to no recovery, culminating in the extirpation of A. palmata from the area during the 2023–2024 CE global coral bleaching event. Reported here for the first time is a significant record of Late Holocene A. palmata populations that existed from ca 4500 to 375 years before present (‘Late Holocene population,’ termed herein) in three broadly distributed areas of the shallow Dry Tortugas platform. This discovery challenges previous assumptions regarding the species' limited contribution to reef development in the area by providing data that extend the known spatial and stratigraphic extent of Holocene populations in this location. It is posited that, although the Late Holocene climate largely suppressed regional reef development, the new records provide evidence for centennial-scale periods of more favourable and stable climate that allowed for short-term expansions of A. palmata populations in the Dry Tortugas. In conclusion, the species' prospects for future success in this and other subtropical location

Florida↗

USGS2025

Regional patterns in U.S. wildfire activity: The critical role of ignition sources

As extreme wildfires increase globally, understanding their causes is critical for effective management. While climate and housing growth are commonly linked to rising fire activity, the role of specific ignition sources—particularly human-caused—remains understudied. Analyzing a 79-year dataset (1940–2019) from U.S. Forest Service regions across the continental United States, we found that different ignition sources in different regions have been a major driver of wildfire trends, accounting for 60%–80% of the interannual variation in fire frequency and approximately 20% in area burned across most U.S. regions. Lightning and campfires were the dominant sources in western regions, while arson drove fire activity east of the Mississippi River. Trends also varied significantly by region and over time, with housing growth explaining more in terms of fire frequency and climate primarily influencing area burned. Importantly, frequent fires often originated from different sources than those causing the largest areas burned. Prevention of human-caused ignitions, such as campfires and arson, could offer efficient and effective strategies to mitigate wildfire impacts on human and natural systems under changing climate and land-use conditions.

contiguous United States↗

USGS2025

Growth patterns of invasive Silver Carp in the Mississippi River basin

Silver Carp ( Hypophthalmichthys molitrix ) are an invasive fish in the Mississippi River Basin. Their rapid expansion over recent decades coupled with extraordinary growth rates have arguably caught many by surprise. Understanding the atypical growth rates that could be the driving force behind the Silver Carp's explosive expansion may be crucial for development of management strategies. Towards this goal, I synthetized existing data on the growth and maturity patterns of Silver Carp. I compiled 62 estimates of growth representing populations of native Silver Carp in East Asia and invasive Silver Carp in the Mississippi River Basin. A remarkably rapid increase in length at earlier ages, undocumented in their ancestral range, was a defining feature of Silver Carp in the Mississippi River Basin. Some of the fastest growth rates of Silver Carp were recorded in hypereutrophic floodplain lakes and at lower latitudes. Invasive Silver Carp frequently deviated from the growth patterns established by native species as evidenced by abnormally high growth coefficients ( K ) in relation to asymptotic length ( L ∞ ). There is evidence of genetic differentiation between native Silver Carp and those expanding in the Mississippi River Basin possibly resulting from genetic background of introductions, genetic drift, and ecological selection. There is also limited evidence of enemy release, allowing for reallocation of energy from defenses to the rapid growth; though speculative, this is a plausible hypothesis that merits further research. This overview of the growth patterns of invasive Silver Carp underscores the need for novel strategies to mitigate the rapid generation time induced by the atypical growth patterns.

Mississippi River basin↗

USGS2025

Causal effects verses causal mechanisms: Two traditions with different requirements and contributions towards causal understanding

The scientific aspiration of building causal knowledge has received little explicit discussion in ecology despite its fundamental importance. When methods are described as ‘causal’, emphasis is increasingly placed on statistical techniques for isolating associations so as to quantify causal effects. In contrast, natural scientists have historically approached the pursuit of causal knowledge through the investigation of mechanisms that interconnect the components of systems. In this paper, we first summarise a recently published multievidence paradigm for causal studies meant to reconcile conflicting viewpoints. We then describe some of the basic principles of causal statistics and the challenge of estimating pure causal effects. We follow that by describing basic principles related to causal mechanistic investigations, which focus on characterising the structures and processes conveying causal effects. While causal statistics focuses on estimating effect sizes, mechanistic investigations focus on characterising the attributes of the underlying structures and processes linking causative agents to responses. There are important differences between how one approaches each endeavour, as well as differences in what is obtained from each type of investigation. Finally, the case is made that an explicit assessment of existing mechanistic knowledge should be an initial step in causal investigations.

Florida, Louisiana, Texas↗

USGS2025

Hydrogeologic framework and considerations for drilling and grouting of closed-loop geothermal bores in the Erie-Ontario Lowlands and Allegheny Plateau of New York State

The hydrogeologic framework at closed-loop geothermal sites in the Erie-Ontario Lowlands and Allegheny Plateau of central and western New York is the result of the complex interaction of bedrock geology, glacial geology, and groundwater hydrology, and the occurrence of petroleum and gas. Considerations for closed-loop geothermal bore installation include the thickness and character of glacial deposits, bedrock solubility and depth to competent rock, karst development, the distribution of highly permeable zones and their hydraulic heads, and the presence of saline water, gas, and oil. The hydrogeology of the Erie-Ontario Lowlands and Allegheny Plateau poses challenges to closed-loop geothermal bore drilling and casing; managing drill cuttings, discharge water, and gas; and grouting. The potential to encounter severe challenges typically increases with bore depth. This report highlights hydrogeologic considerations for closed-loop geothermal bore installation in New York’s Erie-Ontario Lowlands and Allegheny Plateau to help guide the efficient and safe development of geothermal resources in the regions.

New York↗

USGS2025

Invasive African clawed frogs ( Xenopus laevis ) in Washington State: Status, response efforts, and lessons learned

The African clawed frog (ACF, Xenopus laevis ), which is indigenous to sub-Saharan Africa, is an aquatic invasive species known to have severe ecological impacts on native fauna when introduced into non-endemic regions. In 2015, ACFs were detected in Washington State, U.S. for the first time, and the species is now documented at three cities across western Washington: Lacey, Bothell, and Issaquah. We cataloged the known ACF occurrences, early management efforts, biological data about the frogs, and status of these invasive populations at the three sites from 2015–2023. The ACFs appear to be established in at least three watersheds in the Puget Sound region despite substantial effort at eradicating them at one site. Presence of ACFs in watersheds that lack surface connectivity implies independent introduction events, and the capture of frogs in multiple subbasins in the same watershed may reflect the potential for further spread. Because the ACF is nocturnal and otherwise behaviorally and visually highly cryptic, other established populations may go undetected. Where the ACFs are largely confined to stormwater ponds — as many of our current observations suggest — eradication may still be possible, though a substantial, focused effort would be required. In addition, significant refinement of eradication approaches will be needed to ensure effectiveness in topographically and vegetatively complex Pacific Northwest aquatic environments.

Washington↗

USGS2025

The scientific benefits of a statewide, standardized, coastal wetland monitoring program in Hawaiʻi

In this viewpoint, we provide a scientific justification for a statewide, standardized, coastal wetland monitoring program for Hawaiʻi, USA. Hawaiian coastal wetlands provide important habitat for endangered waterbirds, invertebrates, plants, and the Hawaiian hoary bat (ʻōpeʻapeʻa; Lasiurus semotus ) as well as support Indigenous food systems. Currently, numerous agencies and groups in Hawaiʻi collect data on coastal wetlands, but information is not typically shared and methods are not standardized. A statewide, standardized, coastal wetland monitoring program with a centralized database would allow managers to keep better track of progress toward restoration goals, population changes of conservation-reliant species, outbreaks and impacts of avian botulism, rates of coastal salinization, and many other critical issues across space and time. Monitoring combined with targeted research could fill critical knowledge gaps about the types, functions, values, and biodiversity of Hawaiian coastal wetlands. Ultimately, the improved knowledge gained from long-term coastal wetland monitoring could inform landscape-scale restoration actions and adaptive management of coastal wetlands under sea-level rise and climate change.

Hawaii↗

USGS2025

Do mule deer surf peaks in forage quality while on summer range?

Many animals track ephemeral peaks in food abundance and quality that propagate across landscapes. Migrating ungulates, in particular, track waves of newly emerging plants from low-elevation winter ranges to high-elevation summer ranges—known as “green-wave surfing.” Because plants lose crude protein and gain insoluble fiber with maturation, ruminants are expected to exploit peaks in forage quality among individual plants (i.e., Forage Maturation Hypothesis). Although ample evidence supports the long-standing hypothesis that migratory ungulates surf peaks in forage quality during migration, the hypothesis that ungulates track peaks in forage quality at a small scale (i.e., microsurf while on summer range) remains less known. We studied a partially migratory population of mule deer ( Odocoileus hemionus ) in Wyoming, USA, to understand whether temperate ungulates optimize the use of high-quality forage as plants grow and senesce on disparate summer ranges. Specifically, we evaluated how crude protein, digestible energy, and relative abundance changed throughout the growing season and whether deer altered their diet to reflect species-specific changes in plant phenology. In support of the Forage Maturation Hypothesis, forage quality declined as large-scale patterns of phenology progressed away from a remotely sensed metric of peak green-up for most plant species on the summer ranges of deer that migrated short (<50 km), medium (50–130 km), and long distances (>130 km). Declining rates in forage quality among plant species were heterogeneous, providing deer with the phenological diversity required to microsurf. Deer changed their diet throughout the growing season and prioritized the consumption of some plants, including Rosa woodsii and Purshia tridentata , as the rank of forage quality increased ( p < 0.01). In light of the complexities common to studies on foraging behavior, our findings suggest that deer may have some potential to microsurf on summer range when heterogeneity in resource phenology is prevalent. Moreover, our findings validate the accuracy of remote sensing in quantifying peak forage quality for plants within sagebrush shrublands and montane habitats.

Wyoming↗

USGS2025

Ecologically informed solar enables a sustainable energy transition in U.S. croplands

United States (U.S.) croplands are ideal recipient environments for solar photovoltaic (PV) energy because they are flat and have a high solar resource. Perceived threats of solar to agriculture have led some stakeholders to suggest that croplands be exclusively used to produce food. However, 12 million hectares of U.S. croplands, an area about the size of New York State, are already dedicated to corn grown for ethanol (i.e., biofuel), an energy product that requires significantly more land than solar PV per unit energy. Ecosystem service benefits of an ecologically-informed approach to solar development (i.e., ecovoltaics), coupled with significant land-use advantages over corn ethanol, make solar an attractive solution for a sustainable energy transition in croplands. Here, we evaluated how the conversion of a small fraction of corn-ethanol croplands into ecovoltaic solar facilities might improve land-use efficiency of energy generation, enhance ecosystem services, and provide landscape diversification. Through spatial analyses, we determined that converting just 3.2% of land currently used for corn ethanol would increase the share of utility-scale solar energy in the U.S. from 3.9% to 13%. We also identified target locations where strategic conversion of corn ethanol to solar PV co-located with perennial vegetation could filter excess nutrients transported from adjacent farm runoff, diversify and connect agricultural landscapes, and provide local wildlife habitat. In contrast to the common perception of land-use competition and land scarcity in the energy transition, our findings highlight benefits of co-located energy landscapes that integrate fundamental principles of energy development and sustainable agroecosystems.

contiguous United States↗

USGS2025

Using DNA barcoding to evaluate freshwater mussel and fish-host relationships in the Flint River (Georgia, USA)

Freshwater mussels have a unique life history in which larval mussels (glochidia) act as obligate parasites to fish hosts. Host selectivity may be species specific, and identification of host fish is a critical step in conservation planning for individual mussel species. The Flint River harbors ~23% of the freshwater mussel (order Unionida) diversity in the state of Georgia, USA. Nine species in the basin are state or federally listed, and local diversity is threatened by shifting hydrologic conditions, increasing habitat loss, and sedimentation. However, knowledge on host species is lacking for nearly 40% of mussel species in the Flint River, limiting the efforts of conservation managers. In this study, we assessed the use of host fish by mussels by identifying the species of naturally encysted mussel larvae and transformed juveniles found on wild-caught fishes. Infested fishes were collected in the summers of 2021 and 2022 and held in laboratory conditions. Glochidia and juvenile mussels were collected as they excised from live hosts and were identified by DNA barcoding with the cytochrome oxidase c subunit I locus. Twenty-eight unique mussel–host relationships were identified, 27 of which were considered novel when cross-referenced to the existing mussel–host databases and peer-reviewed literature. Our data build upon knowledge of host use in unionids and further demonstrate the importance of understanding patterns in wild host use.

Georgia↗

USGS2025

Interspecific effects of invasive wild pigs (Sus scrofa) on native nine-banded armadillos (Dasypus novemcinctus)

Biological invasions pose significant risks to ecosystems and native species. Wild pigs ( Sus scrofa ) are a highly detrimental invasive species in North America, directly and indirectly affecting native species. Co-occurrence of wild pigs and native species may lead to interspecific interactions that alter ecological communities. Accordingly, we investigated spatial and temporal factors influencing detection and occupancy of Eurasian Wild Pig and Nine-banded Armadillo ( Dasypus novemcinctus ) before examining interspecific effects. We analyzed camera-trap data collected from August to September 2021 using a hierarchical modeling framework to estimate detection and occupancy of both species individually (single-species analyses) and concurrently (conditional co-occurrence analyses). We observed higher Wild Pig detection rates and space use in late summer and in areas with greater riparian cover, respectively. Armadillo detection increased linearly throughout our sampling season and in response to precipitation. Moreover, armadillo detection was 3.5 to 5.1× higher at sites used by wild pigs, regardless of whether wild pigs were detected during a survey period. Occupancy of armadillo was best explained by a quadratic trend in site elevation but did not depend on the presence of wild pigs. Our results indicate that wild pigs may influence armadillo detection (or site-use intensity), but not occupancy, therefore revealing nuanced interspecific interactions. Between species, we observed high overlap in diel activity but significantly different activity peaks, with armadillos being strictly nocturnal and wild pigs being crepuscular but with more cathemeral activity, suggesting that fine-scale temporal partitioning may have occurred. Our results provide insights into the influence of a large-bodied and destructive invasive species (Wild Pig) on a smaller, ecologically important native species (Nine-banded Armadillo).

Oklahoma↗

USGS2025

Groundwater budget for the surficial aquifer surrounding Lake Nokomis, Minneapolis, Minnesota

During prolonged periods of above-average precipitation, rising groundwater levels have the potential to cause damage to and interfere with underground infrastructure and building foundations. To understand the relations between precipitation and groundwater in the vicinity of Lake Nokomis, the U.S. Geological Survey, in collaboration with the University of Minnesota, quantified five components of the groundwater budget: groundwater recharge, change in surficial aquifer storage, surficial aquifer groundwater discharge to Lake Nokomis, groundwater evapotranspiration, and groundwater discharge to underlying bedrock aquifers. Field data, geologic records, and empirical calculation methods were used to quantify groundwater budget components for April 2023 through April 2024. Lake water budget data indicate that Lake Nokomis is a flowthrough system during periods with no outflow through the weir, with groundwater inputs equal to outputs. Roughly 40 percent of precipitation that fell in the study area was added to the surficial aquifer as recharge. Uncertainty in the vertical hydraulic conductivity resulted in wide-ranging estimates (spanning three orders of magnitude) of water discharging from the surficial aquifer to the underlying bedrock aquifer. Drought conditions persisted for the duration of this study and were not representative of the conditions that motivated this study. This study is a start towards understanding relations between precipitation, Lake Nokomis levels, and groundwater levels that could affect local underground infrastructure.

Minnesota↗

USGS2025

Simulated effects of future water availability and protected species habitat in a perennial wetland, Santa Barbara County, California

This study evaluates the potential water availability in Barka Slough and the effects of changing hydrological conditions on the aquatic habitat of five protected species. Barka Slough is a historically perennial wetland at the downstream western end of the San Antonio Creek Valley watershed (SACVW). A previously published hydrologic model of the SACVW for 1948–2018 was extended to include 2019–2021 and then modified to simulate the future years of 2022–2051. Two models simulating the future years of 2022–2051 were constructed, each with different climate inputs: (1) a repeated historical climate and (2) a 2070-centered Drier Extreme Warming climate (2070 DEW). The model with the 2070 DEW climate had warmer temperatures and an increase in average annual precipitation driven by larger, albeit more infrequent, precipitation events than the model with the historical climate. Simulated groundwater pumpage resulted in cumulative groundwater storage depletion and groundwater-level decline in Barka Slough in both future models. The simulations indicate that Barka Slough may transition from a perennial to an ephemeral wetland. Streamflow, stream disconnection, and depth to groundwater are key habitat metrics for federally listed species in Barka Slough. Future seasonal conditions for each metric are more likely to affect federally listed species’ habitats under 2070 DEW climatic conditions. Future seasonal streamflow volume may negatively impact unarmored threespine stickleback ( Gasterosteus aculeatus williamsoni ) and tidewater goby ( Eucyclogobis newberryi) habitats. Future seasonal stream disconnection may negatively impact the unarmored threespine stickleback habitat. Future groundwater-level decline may negatively impact Gambel’s watercress ( Nasturtium gambelii ) and La Graciosa thistle ( Cirsium scariosum var. loncholepis ) habitats and could influence the ability to use Barka Slough as a restoration or reintroduction site for these species. Results from this study can be used to inform water management decisions to sustain future groundwater availability in the SACVW.

California↗

USGS2025

Object detection-assisted workflow facilitates cryptic snake monitoring

Camera traps are an important tool used to study rare and cryptic animals, including snakes. Time-lapse photography can be particularly useful for studying snakes that often fail to trigger a camera's infrared motion sensor due to their ectothermic nature. However, the large datasets produced by time-lapse photography require labor-intensive classification, limiting their use in large-scale studies. While many artificial intelligence-based object detection models are effective at identifying mammals in images, their ability to detect snakes is unproven. Here, we used camera data to evaluate the efficacy of an object detection model to rapidly and accurately detect snakes. We classified images manually to the species level and compared this with a hybrid review workflow where the model removed blank images followed by a manual review. Using a ≥0.05 model confidence threshold, our hybrid review workflow correctly identified 94.5% of blank images, completed image classification 6× faster, and detected large (>66 cm) snakes as well as manual review. Conversely, the hybrid review method often failed to detect all instances of a snake in a string of images and detected fewer small (<66 cm) snakes than manual review. However, most relevant ecological information requires only a single detection in a sequence of images, and study design changes could likely improve the detection of smaller snakes. Our findings suggest that an object detection-assisted hybrid workflow can greatly reduce time spent manually classifying data-heavy time-lapse snake studies and facilitate ecological monitoring for large snakes.

Florida↗

USGS2025

Latitudinal gradients of snow contamination in the Rocky Mountains associated with anthropogenic sources

Seasonal snow is an important source of drinking water and recreation, and for agriculture in the Rocky Mountain region. Monitoring snow-water quality can inform on the effects to the albedo and energy balance of the snowpack, and the sources of natural and anthropogenic aerosol and gases. This study analyzed metals in the seasonal snowpack from water year (WY) 2018 for 49 sites. Calcium, lanthanum, and cerium concentrations support the importance of mineral dust to the southern Rocky Mountains. Mercury (Hg), zinc (Zn), and cadmium (Cd) concentrations showed a similar spatial pattern to mineral dust, whereas antimony (Sb) concentrations were highest in the northern Rocky Mountains. To assess the relative contributions from dust versus anthropogenic contaminant sources, enrichment factors (EF) were calculated, with values above 10 indicating anthropogenic contamination. For Cd, Hg, Sb, and Zn, EF values exceeded 10 at northern sites. These observations were compared to spatial trends of EF values of Hg from WY2009 to WY2018, regional monitoring networks, and back trajectory analyses. The agreement between these datasets revealed temporally consistent contaminant sources and/or transport processes to the northern Rocky Mountains snowpack. Sources include current and historical mining and smelting in the region. Strategies to limit the emissions of these metals to the Northern Rockies could benefit from focusing on remediation of contaminated sites, and continued monitoring and mitigation of active mining and smelting.

Colorado , Idaho, Montana, New Mexico, Utah, Wyomi↗

USGS2025

Habitat and predator influences on the spatial ecology of nine-banded armadillos

Mesopredator suppression has implications for community structure, biodiversity, and ecosystem function, but mesopredators with physical defenses may not avoid apex predators. We investigated nine-banded armadillos ( Dasypus novemcinctus ) in southwestern Oklahoma (USA) to evaluate if a species with physical defenses was influenced by a dominant predator, the coyote ( Canis latrans ). We sampled nine-banded armadillos and coyotes with motion-activated cameras. We used single-species and conditional two-species occupancy models to assess the influences of environmental factors and coyotes on nine-banded armadillo occurrence and site-use intensity (i.e., detection). We used camera-based detections to characterize the diel activity of each species and their overlap. Nine-banded armadillo occupancy was greater at sites closer to cover, with lower slopes, and further from water, whereas coyote space use was greater at higher elevations; both species were positively associated with recent burns. Nine-banded armadillo occurrence was not influenced by coyotes, but site-use intensity was suppressed by the presence of coyotes. Nine-banded armadillos (strictly nocturnal) and coyotes (predominantly nocturnal) had a high overlap in summer diel activity. Nine-banded armadillos are ecosystem engineers but are often considered a threat to species of concern and/or a nuisance. Thus, understanding the role of interspecific interactions on nine-banded armadillos has important implications for conservation and management.

Oklahoma↗

USGS2025

Observations reveal changing coastal storm extremes around the United States

Understanding extreme storm surge events that threaten low-lying coastal communities is key to effective flood mitigation/adaptation measures. However, observational estimates are sparse and highly uncertain along most coastal regions with a lack of observational evidence about long-term underlying trends and their contribution to overall extreme sea-level changes. Here, using a spatiotemporal Bayesian hierarchical framework, we analyse US tide gauge record for 1950–2020 and find that observational estimates have underestimated likelihoods of storm surge extremes at 85% of tide gauge sites nationwide. Additionally, and contrary to prevailing beliefs, storm surge extremes show spatially coherent trends along many widespread coastal areas, providing evidence of changing coastal storm intensity in the historical monitoring period. Several hotspots exist with regionally significant storm surge trends that are comparable to trends in mean sea-level rise and its key components. Our findings challenge traditional coastal design/planning practices that rely on estimates from discrete observations and assume stationarity in surge extremes.

Nature Climate Change↗