Abstract Atmospheric rivers (ARs) often cause damaging winds, rainfall, and floods. However, the physical mechanisms governing their evolution remain poorly understood. To close this gap, we perform a global Vapor Kinetic Energy (VKE) budget analysis. Using two formulations of VKE, we show that ARs are governed by similar mechanisms regardless of ocean basins. ARs intensify primarily through the conversion of potential energy to kinetic energy (PE‐to‐KE), with horizontal convergence of vapor kinetic energy providing a secondary contribution in some regions. ARs decay mainly through condensation and turbulent dissipation, while their propagation is governed by the downstream convergence and upstream divergence of vapor kinetic energy. We also find PE‐to‐KE conversion varies spatially and strengthens in regions of greater baroclinic instability or enhanced topographic lifting, for example, along North America's west coast. Collectively, these findings demonstrate that the VKE framework provides a powerful diagnostic for how physical processes shape AR evolution and regional variability.

High pathogenicity avian influenza virus impacts poultry and wild birds worldwide. Since the introduction of clade 2.3.4.4b H5N1 isolates in Japan in late 2021, new cases have been reported in domestic birds and poultry each winter. To understand the role of wild birds in introducing these viruses in Japan, a phylodynamic analysis based on geography and host species was conducted using H5N1 isolates in Japan from 2021 to 2025. A total of 892 hemagglutinin gene sequences of H5N1 viruses, collected from birds between June 2021 and May 2025, along with additional sequences that were highly similar to those of Japanese isolates, were obtained from a public database. The role of wild birds in the transmission dynamics of H5N1 isolates in Japan across four winter seasons (2021–25) was assessed using a Bayesian phylodynamic approach with a Multi-Type Birth-Death model. Phylodynamic analysis revealed that the clade 2.3.4.4b comprised three distinct subgroups, G2b, G2c, and G2d, which were prevalent during the winter seasons. Isolates from G2b and G2c were linked to common ancestral strains from North Asia and Northeast Asia, respectively. Meanwhile, G2d, the dominant strain in Japan from 2021 to 2025, shared an ancestral strain from the Northwest America. During winters 2023–25, the ancestral strain was traced back to Northeast Asia, indicating a shift in the viral origin. This transition suggests an increase in virus migration events and expansion of host diversity, implying that Japan may function as a hub for intercontinental virus introductions, receiving multiple independent viral entries from North Asia, Northeast Asia, and Northwest America. Additionally, waterfowl and raptors played a role in introducing viruses into Japan, while poultry and crows generally serving as dead-end hosts. However, the continuous introduction of H5N1 isolates into Japan each winter can alter the disease transmission pattern observed in crows, resulting in more virus spillover from crows to other hosts, such as poultry and charadriiformes. These findings emphasize the importance of continuous monitoring and prompt information sharing to understand the global dynamics of viruses better.

Abstract. Gravity waves (GWs) are a major yet poorly constrained driver of middle-atmosphere dynamics. Using the high-top UA-ICON global circulation model, we conducted a set of six-member ensemble simulations in which orographic GW drag was selectively intensified over three Northern Hemisphere hotspots identified from observational and modeling studies – e.g., Himalayas (HI), Northwest America (NA), and East Asia (EA) – to assess their long-term dynamical impacts on the stratosphere. The imposed forcing generated distinctive vertical–horizontal drag structures in each region, yet produced a coherent hemispheric response. Resolved waves compensated the local drag through compensation mechanisms. In all three cases, added westward momentum suppressed upward and equatorward propagation of planetary waves, particularly of wavenumber 1, strengthening westerlies in the upper stratosphere–mesosphere. The frequency of sudden stratospheric warmings remained unchanged in the HI and NA experiments, but increased notably in EA, while the ratio of split to displacement events was unaffected. These results highlight the sensitivity of stratospheric variability to non-zonal GW forcing and underscore the importance of improving our understanding of GW–climate interactions. The simulation dataset presented here offers a valuable resource for future studies on gravity wave–induced variability in the climate system.

Integrated actions of Corvus and North West America Mackenzie Valley Wolf inspired optimization (ICNAW) algorithm and Hybrid Quasi Opposition Based White Headed Buffalo Weaver - Indian Leopard Cat Swarm Algorithm (QWBLO) are applied for solving the power loss diminution problem. Naturally there is an integrated action between Corvus and North American wolf for obtaining the food. North American wolf will act as foodstuff suppliers for Corvus. Conversely, Corvus will support the North American wolf to discover unidentified flesh. Corvus is societal bird and upon discovery of a deceased animal, Corvus has a habit of making lot of sound. This noise signals North American wolf that a foodstuff spring is situated in neighbouring or nearby level. Fundamentally White- headed buffalo Weavers act as architects and the itinerant. To determine the sustenance sources, the White- headed buffalo Weavers recurrently smear the scheme of architect and the itinerant. In QWBLO, the architects with higher aptness values possess the importance to attain sustenance in the exploration evolution. Computation of the rapidness of Indian Leopard Cat during the movement segment is included for the population diversity in the procedure. Validity of Integrated actions of Corvus and North West America Mackenzie Valley Wolf inspired optimization (ICNAW) algorithm and Hybrid Quasi Opposition Based White Headed Buffalo Weaver - Indian Leopard Cat Swarm Algorithm (QWBLO) is verified in 7 Benchmark functions, IEEE 30, 354, 300, 220KV systems.

Glaciers play a crucial role in shaping global hydrology and biogeochemical cycles, yet their climate-forced dynamic impact on chemical denudation and solute yields remain poorly understood. This study compiled data on 40 well-documented cationic denudation rates (CDR) from glaciers across Northwest America, the Svalbard/Arctic Canada, Iceland, Greenland, Europe, China-Tibet, Antarctica, and the Himalayas, revealing substantial spatial variability. CDRs ranged from 46 to 4160 meq m−2 yr−1. Northwest American and Himalayan glaciers exhibited the highest CDRs, with the Himalayan denudation rate exceeding the global average by more than fourfold. The exceptionally high mean chemical weathering intensity (CWI) of 801 meq m−3 from the Himalayan glaciers indicate a wide range of geochemical and climatic conditions within the region, while Northwest American and Greenland glaciers show comparatively lower mean intensities (273 and 247 meq m−3, respectively) suggesting a consistent geochemical regime. Northwest American glaciers had the highest specific discharge rates, while Svalbard/Arctic Canada glaciers had the lowest, reflecting regional disparities influenced by climatic and geological factors. A Bonferroni post hoc test highlighted significant differences in specific discharge between Northwest American glaciers and two other basins, emphasizing their distinct hydrological behavior. Predictive modeling revealed a statistically significant but weak relationship between CDR and specific discharge (R2 = 57%), suggesting that much of the variability in CDR cannot be explained by specific discharge alone. A regression coefficient of 382 meq m−2 yr−1 indicates that CDR increases with glacier discharge, although basin-specific analyses showed minimal variation in this relationship across regions. Svalbard/Arctic Canada, Antarctic, Greenlandic, Icelandic, and European Alpine glaciers displayed lower CDRs, which varied depending on underlying lithology, with higher rates observed in carbonate and basaltic terrains compared to other lithologies. We hypothesize that glacier retreat enhances the downward progression of the weathering reaction front, increasing CDR, particularly in rapidly retreating glaciers.

The determination of freight rates in liner shipping is influenced by the market dynamics and the strategic decisions of shipping alliances. This study investigates the effect of non-alliance tonnage on freight rates along the Asia–North America West Coast route, employing a quantile regression method. A dataset covering July 2021 to June 2023 was used, with bunker prices and the Dow Jones Index serving as control variables. The results reveal that the non-alliance share has a significant and negative impact on lower quantiles, suggesting that enhanced competition reduces freight rates when the prices are low. In contrast, this effect disappears at higher freight levels. Bunker prices and the stock market index also exhibit varying effects, depending on the quantile, with demand-side variables being more influential during low-freight conditions. These findings suggest that market concentration affects price-setting power, and quantile-based approaches offer deeper insights into these complex relationships than linear models. These insights contribute to the sustainable development of maritime transport by promoting fair competition, improving pricing transparency, and supporting efficient policy interventions in global liner shipping.

ABSTRACTOutcrops of sedimentary strata that infill the Georgia Basin, Canada and USA have been studied extensively as they record information on the tectonic evolution of western North America. However, these outcrops are situated in only a limited extent of the basin (mainly Vancouver Island) and preserve mainly Upper Cretaceous strata, and so the information that can be derived from outcrops is incomplete and spans less than half of the Georgia Basin's temporal history. The majority of the Georgia Basin, and the complete stratigraphy, occurs in the subsurface in the Whatcom Sub‐Basin, which extends below much of the Strait of Georgia, the Lower Mainland of British Columbia (LMBC), Canada and northwest Washington, USA. In this study, we reconstruct the stratigraphic architecture, evolution and palaeogeography of Upper Cretaceous and Cenozoic strata in the Whatcom Sub‐Basin, and we use these data to develop a more complete record of the depositional history of the Georgia Basin and its evolution relative to major tectonic events along North America's west coast. We focus on the Canadian extent of the Whatcom Sub‐Basin, the LMBC, because of the availability of two‐dimensional seismic reflection datasets and cored intervals, which enable facies characterisation and provide detrital zircon datasets. The stratigraphy of the Whatcom Sub‐Basin is divided into four stratal packages, including: lower Nanaimo Group, upper Nanaimo Group, Huntingdon Formation and Boundary Bay Formation. The few outcrops and a single cored interval suggest that the lower Nanaimo Group is dominated by fluvial strata in the Whatcom Sub‐Basin. The upper Nanaimo Group is dominated by fluvial strata in the central part of the Whatcom Sub‐Basin and turbidites and deep‐marine strata in the west, and this facies relationship indicates that sediment transport was to the west. The Eocene and younger Huntingdon and Boundary Bay formations record re‐organisation of the basin, with a shift in sediment transport to the south and southwest. Both the Huntingdon and Boundary Bay formations are dominated by terrestrial strata with evidence of marine influence increasing towards the southwest but decreasing stratigraphically upwards. Changing sediment transport pathways and recycling of Nanaimo Group strata in Eocene time reflect the bifurcation of the Georgia Basin with uplift of the forearc high (i.e., Vancouver Island). Boundary Bay Formation deposits extend further east than do all other stratigraphic units, and detrital zircon‐based maximum depositional age estimates indicate that parts of the Lower Mainland probably have experienced active subsidence for at least the past 15 million years. A comparison of our data to tectonic events along North America's western margin indicates that (a) the fill and geometry of the basin evolved due to syn‐ and post‐depositional tectonism, and (b) basin topography and syntectonic activity drove major changes in depositional environments both areally and temporally. For example, uplift of the forearc high and the associated re‐organisation of drainages in the Whatcom Sub‐Basin correlate temporally to docking of Siletzia in the early Eocene.

The fluctuations in the stock market serve as an indicator of societal and economic progress. To enhance the forecasting of financial time series data, this paper introduces a novel hybrid model that integrates successive variational mode decomposition (SVMD) with a long short‐term memory (LSTM) network. SVMD is used as a data‐decomposition technique to facilitate the division of complex original series into its decomposed intrinsic mode functions in order to reduce nonstationarity. This approach has been analyzed for both synthetic signals and financial time series data. LSTM is utilized to analyze each signal and take into consideration the influence of historical data in order to enhance prediction accuracy. The final predicted results are derived by reconstructing each predicted time series. To evaluate the model, financial time‐series data from global stock market have been selected for analysis, i.e., the Hong Kong Hang Seng Index (HSI), Stock Exchange Sensitive Index (SENSEX), Standard and Poor’s 500 (S&P500), and North America West Texas Intermediate (WTI). The proposed model has shown improved prediction results based on the performance metrics when compared with single models and other existing hybrid models.

ABSTRACT The time-averaged shear-wave velocity in the top 30 m, VS30, is used to represent the site condition in many ground-motion models (GMMs). Regionalized GMMs account for regional differences in the ln(VS30) scaling by including region-specific coefficients for the site term. For example, recent GMMs developed for subduction zone earthquakes as part of the Next Generation Attenuation-Subduction (NGA-Sub) project include region-specific VS30 scaling for seven regions: South America, Central America, Japan, New Zealand, Taiwan, Cascadia (Pacific Northwest America), and Alaska. Of these seven regions, South America has the largest within-event standard deviation. One cause for the larger within-event standard deviation is a weaker relation between VS30 and the site term in South America compared to other regions. A cause for this weak correlation is that most of the VS30 values for the South American region in the NGA-Sub data set are based on proxies. The relation between VS30 and the site term improves significantly for periods less than 1 s if only stations with measured VS30 are considered, but the correlation is weak for periods greater than 1 s even for stations with measured VS30, indicating that, for the South America region, VS30 is not well correlated with the deeper shear-wave velocity profile that controls the long-period amplification. To improve the site terms for South America, we develop a model based on the horizontal-to-vertical spectral ratio (HVSR) from microtremors, similar to the approach used by Pinilla-Ramos et al. (2022) for California. The data set includes 660 recordings from 51 earthquakes recorded at 274 sites. The site-term model includes the period-dependent HVSR amplitude and the geometric mean of the average HVSR amplitude over the frequency band of 0.25 to 15 Hz. Including these two parameters reduces the standard deviation of site-specific site terms over the period range 0.3–3 s, with the largest reduction in the period range 1–2 s. This site-term model can be incorporated into subduction GMMs and implemented in probabilistic seismic hazard analyses for South America.

Özellikle Kuzeybatı Amerika’daki toplumlarda görülen ve alanın uzmanları tarafından; “değiş tokuş edilen armağanlar sistemi” veya “yeniden bölüşümün aracı” olarak tanımlanan Potlaç geleneğinde, vermek veya yok etmek gücün sembolü olarak görülmektedir. Bu sistemde mevki sahibi olmak veya iktidarını kuvvetlendirmek verilen hediyenin değeri ve niteliği ile doğru orantılıdır. Bu çalışma ise eski toplumlarda Potlaç olarak adlandırılıp genel olarak; harcama, yok etme ve tüketme aracılığıyla bir güç gösterisi veya hakimiyet vasıtasına dönüşen geleneğin bozkır Türk kültüründeki izlerini aramaya yöneliktir. Potlaç geleneğine sahip toplumlarda olduğu gibi eski Türklerde de akrabalık bağları ve toplumsal dayanışma oldukça kuvvetlidir. Bu durum Türklerin çeşitli sebeplerle sık sık bir araya gelerek törenler tertip etmesine sebep olmuştur. Bu törenlerdeki uygulamaların ve anlayışın Potlaç geleneğindekilere benzerliği makalenin tartışma konusu olacaktır.

An annotated list of 42 species in 26 genera and four families of Orthoptera recorded from Beringia (Northeast Yakutia, Chukotka, Magadan region, and Kamchatka in Russia, Alaska in USA, Yukon and the Northwestern Territories in Canada) is given. The distribution of species is clarified. The exchange of orthopteran faunas between Asia and America by the Bering Land Bridge in Pleistocene was strongly limited. The only three species, Tetrix subulata (Linnaeus, 1761), Melanoplus frigidus (Boheman, 1846), and Stethophyma grossum (Linnaeus, 1758), are recorded from both Asian and American parts. The orthopteran fauna of Beringia is not original. Majority of Beringian species are widespread throughout either Asia or North America. There are only four endemic grasshoppers, namely two Asian subspesies, Melanoplus frigidus kamtchatkae (Sjosted, 1935) and Aeropedellus variegatus gelidus Mistshenko, 1951, and two American species, A. arcticus Hebard, 1935 and Bruneria yukonensis Vickery, 1969. Composition of the regional faunas is briefly discussed. The monotypic genus Bohemanella Ramme, 1951 is again considered as a synonym of Melanoplus Stål, 1873, where a type species of the former genus, Melanoplus frigidus (Boheman, 1846) comb. resurr., forming its own species group.

Exposure to persistent organic pollutants (POPs) can significantly impact marine mammal health, reproduction, and fitness. This study addresses a significant 20-year gap in gray whale contaminant monitoring through analysis of POPs in 120 blubber biopsies. The scope of this substantial sample set is noteworthy in its range and diversity with collection between 2003 and 2017 along North America's west coast and across diverse sex, age, and reproductive parameters, including paired mothers and calves. Mean blubber concentrations of polychlorinated biphenyls (∑PCBs), dichlorodiphenyltrichloroethanes (∑DDTs), and chlordanes (∑CHLs) generally decreased since previous reports (1968-1999). This is the first report of polybrominated diphenyl ethers (PBDEs) and select hexachlorocyclohexanes (HCHs) in this species. Statistical modeling of the 19 most frequently detected compounds in this dataset revealed sex-, age-, and reproductive status-related patterns, predominantly attributed to maternal offloading. Mean POP concentrations differed significantly by sex in adults (17 compounds, up to 3-fold higher in males) but not in immatures (all 19 compounds). Mean POP concentrations were significantly greater in adults versus immatures in both males (17 compounds, up to 12-fold) and females (13 compounds, up to 3-fold). POP concentrations were detected with compound-specific patterns in nursing calves, confirming maternal offloading for the first time in this species.

Container fleet renewal considering multiple sulfur reduction technologies and uncertain markets amidst COVID-19

Dinoflagellate cyst-based paleoenvironmental reconstructions and phytoplankton paleoecology across the Cretaceous–Paleogene (K/Pg) boundary interval, Vancouver Island, British Columbia, Canada

The CORDEX-CORE initiative was developed with the aim of producing homogeneous regional climate model (RCM) projections over domains world wide. In its first phase, two RCMs were run at 0.22° resolution downscaling 3 global climate models (GCMs) from the CMIP5 program for 9 CORDEX domains and two climate scenarios, the RCP2.6 and RCP8.5. The CORDEX-CORE simulations along with the CMIP5 GCM ensemble and the most recently produced CMIP6 GCM ensemble are analyzed, with focus on several temperature, heat, wet and dry hazard indicators for present day and mid-century and far future time slices. The CORDEX-CORE ensemble shows a better performance than the driving GCMs for several hazard indices due to its higher spatial resolution. For the far future time slice the 3 ensembles project an increase in all temperature and heat indices analyzed under the RCP8.5 scenario. The largest increases are always shown by the CMIP6 ensemble, except for Tx > 35 °C, for which the CORDEX-CORE projects higher warming. Extreme wet and flood prone maxima are projected to increase by the RCM ensemble over the la Plata basin in South America, the Congo basin in Africa, east North America, north east Europe, India and Indochina, regions where a better performance is obtained, whereas the GCM ensembles show small or negligible signals. Compound hazard hotspots based on heat, drought and wet indicators are detected in each continent worldwide in region like Central America, the Amazon, the Mediterranean, South Africa and Australia, where a linear relation is shown between the heatwave and drought change signal, and region like Arabian peninsula, the central and south east Africa region (SEAF), the north west America (NWN), south east Asia, India, China and central and northern European regions (WCE, NEU) where the same linear relation is found for extreme precipitation and HW increases. Although still limited, the CORDEX-CORE initiative was able to produce high resolution climate projections with almost global coverage and can provide an important resource for impact assessment and climate service activities.

Dall’s sheep (Ovis dalli dalli) are endemic to alpine areas of sub-Arctic and Arctic northwest America and are an ungulate species of high economic and cultural importance. Populations have historically experienced large fluctuations in size, and studies have linked population declines to decreased productivity as a consequence of late-spring snow cover. However, it is not known how the seasonality of snow accumulation and characteristics such as depth and density may affect Dall’s sheep productivity. We examined relationships between snow and climate conditions and summer lamb production in Wrangell-St Elias National Park and Preserve, Alaska over a 37-year study period. To produce covariates pertaining to the quality of the snowpack, a spatially-explicit snow evolution model was forced with meteorological data from a gridded climate re-analysis from 1980 to 2017 and calibrated with ground-based snow surveys and validated by snow depth data from remote cameras. The best calibrated model produced an RMSE of 0.08 m (bias 0.06 m) for snow depth compared to the remote camera data. Observed lamb-to-ewe ratios from 19 summers of survey data were regressed against seasonally aggregated modelled snow and climate properties from the preceding snow season. We found that a multiple regression model of fall snow depth and fall air temperature explained 41% of the variance in lamb-to-ewe ratios (R2 = .41, F(2,38) = 14.89, p<0.001), with decreased lamb production following deep snow conditions and colder fall temperatures. Our results suggest the early establishment and persistence of challenging snow conditions is more important than snow conditions immediately prior to and during lambing. These findings may help wildlife managers to better anticipate Dall’s sheep recruitment dynamics.

Dall's sheep (Ovis dalli dalli) are endemic to alpine areas of sub-Arctic and Arctic northwest America and are an ungulate species of high economic and cultural importance. Populations have historically experienced large fluctuations in size, and studies have linked population declines to decreased productivity as a consequence of late-spring snow cover. However, it is not known how the seasonality of snow accumulation and characteristics such as depth and density may affect Dall's sheep productivity. We examined relationships between snow and climate conditions and summer lamb production in Wrangell-St Elias National Park and Preserve, Alaska over a 37-year study period. To produce covariates pertaining to the quality of the snowpack, a spatially-explicit snow evolution model was forced with meteorological data from a gridded climate re-analysis from 1980 to 2017 and calibrated with ground-based snow surveys and validated by snow depth data from remote cameras. The best calibrated model produced an RMSE of 0.08 m (bias 0.06 m) for snow depth compared to the remote camera data. Observed lamb-to-ewe ratios from 19 summers of survey data were regressed against seasonally aggregated modelled snow and climate properties from the preceding snow season. We found that a multiple regression model of fall snow depth and fall air temperature explained 41% of the variance in lamb-to-ewe ratios (R2 = .41, F(2,38) = 14.89, p<0.001), with decreased lamb production following deep snow conditions and colder fall temperatures. Our results suggest the early establishment and persistence of challenging snow conditions is more important than snow conditions immediately prior to and during lambing. These findings may help wildlife managers to better anticipate Dall's sheep recruitment dynamics.

On the Kenai in Extreme Northwest America

Assessment of Aerosol optical depth under background and polluted conditions using AERONET and VIIRS datasets

Abstract Aims Invasive species, which recently expanded, may help understand how climatic niche can shift at the time scale of the current global change. Here, we address the climatic niche shift of an invasive shrub (common gorse, Ulex europaeus) at the world and regional scales to assess how it could contribute to increasing invasibility. Methods Based on a 28 187 occurrences database, we used a combination of 9 species distribution models (SDM) to assess regional climatic niche from both the native range (Western Europe) and the introduced range in different parts of the world (North-West America, South America, North Europe, Australia and New Zealand). Important Findings Despite being restricted to annual mean temperature between 4°C and 22°C, as well as annual precipitation higher than 300 mm/year, the range of bioclimatic conditions suitable for gorse was very large. Based on a native versus introduced SDM comparison, we highlighted a niche expansion in North-West America, South America and to a lesser degree in Australia, while a niche displacement was assessed in North Europe. These niche changes induced an increase in potential occupied areas by gorse by 49, 111, 202 and 283% in Australia, North Europe, North-West America and South America, respectively. On the contrary, we found no evidence of niche change in New Zealand, which presents similar climatic condition to the native environment (Western Europe). This study highlights how niche expansion and displacement of gorse might increase invasibility at regional scale. The change in gorse niche toward new climatic conditions may result from adaptive plasticity or genetic evolution and may explain why it has such a high level of invasibility. Taking into account the possibility of a niche shift is crucial to improve invasive plants management and control.