Circulation Patterns Research Articles

Chumnungwa Glass Beads: New Insights into the Geochemistry, Circulation, and Consumption Patterns of Pre-European Glass Beads in Iron Age Southern Africa, CE 980–1650

Chumnungwa Glass Beads: New Insights into the Geochemistry, Circulation, and Consumption Patterns of Pre-European Glass Beads in Iron Age Southern Africa, CE 980–1650

Microfacies and species richness analysis of upper Bartonian and Priabonian carbonate shelf deposits from the Thrace Basin (Tethyan Ocean, Greece): Paleoenvironmental evolution and species-richness hotspot revealed

Sediment, thin section, microfacies and foraminiferal analyses were conducted on middle-upper Eocene carbonate deposits to shed new light on the paleoenvironmental evolution and species richness of the Thrace Basin (Tethyan Ocean, Greece). Material from a total of 7 new sites, covering localities on the mainland and the north-eastern Aegean islands of Samothraki and Lemnos, was examined in order to analyze the general conditions and environmental evolution of the basin over as large a geographical area as possible. Analysis of the sedimentological and paleontological data allowed the identification of 5 microfacies types. These can be assigned to a sequence of interior to outer shelf environments and speak in favor of a model of a rimmed carbonate shelf with isolated platforms. Both open and restricted water circulation patterns have prevailed on and between the platforms. Triggered and driven by dynamic syn-rifting, topographic highs have developed in this area on which productive and species-rich reef structures could thrive. In the late Eocene carbonate deposits we found the highest documented species richness of larger symbiont-bearing foraminifers (LBF) to date, characterizing the Thrace Basin not only as a particularly species-rich and diverse area, but also as a LBF hotspot of diversity.

Multivariate post‐processing of probabilistic sub‐seasonal weather regime forecasts

AbstractReliable forecasts of quasi‐stationary, recurrent, and persistent large‐scale atmospheric circulation patterns—so‐called weather regimes—are crucial for various socio‐economic sectors, including energy, health, and agriculture. Despite steady progress, probabilistic weather regime predictions still exhibit biases in the exact timing and amplitude of weather regimes. This study thus aims at advancing probabilistic weather regime predictions in the North Atlantic–European region through ensemble post‐processing. Here, we focus on the representation of seven year‐round weather regimes in sub‐seasonal to seasonal reforecasts of the European Centre for Medium‐Range Weather Forecasts (ECMWF). The manifestation of each of the seven regimes can be expressed by a continuous weather regime index, representing the projection of the instantaneous 500‐hPa geopotential height anomalies (A) onto the respective mean regime pattern. We apply a two‐step ensemble post‐processing involving first univariate ensemble model output statistics and second ensemble copula coupling, which restores the multivariate dependence structure. Compared with current forecast calibration practices, which rely on correcting the field by the lead‐time‐dependent mean bias, our approach extends the forecast skill horizon for daily/instantaneous regime forecasts moderately by 1 day (from 13.5 to 14.5 days). Additionally, to our knowledge our study is the first to evaluate the multivariate aspects of forecast quality systematically for weather regime forecasts. Our method outperforms current practices in the multivariate aspect, as measured by the energy and variogram score. Still, our study shows that, even with advanced post‐processing, weather regime prediction becomes difficult beyond 14 days, which likely points towards intrinsic limits of predictability for daily/instantaneous regime forecasts. The proposed method can easily be applied to operational weather regime forecasts, offering a neat alternative for cost‐ and time‐efficient post‐processing of real‐time weather regime forecasts.

Spatiotemporal variation of modern lake, stream, and soil water isotopes in Iceland

Abstract. As global warming progresses, changes in high-latitude precipitation are expected to impart long-lasting impacts on Earth systems, including glacier mass balance and ecosystem structures. Reconstructing past changes in high-latitude precipitation and hydroclimate from networks of continuous lake records offers one way to improve forecasts of precipitation and precipitation–evaporation balances, but these reconstructions are currently hindered by the incomplete understanding of controls on lake and soil water isotopes. Here, we study the distribution of modern water isotopes in Icelandic lakes, streams, and surface soils collected in 2002, 2003, 2004, 2014, 2019, and 2020 to understand the geographic, geomorphic, and environmental controls on their regional and interannual variability. We find that lake water isotopes in open-basin (through-flowing) lakes reflect local precipitation, with biases toward the cold season, particularly in lakes with sub-annual residence times. Closed-basin lakes have water isotope and deuterium excess values consistent with evaporative enrichment. Interannual and seasonal variabilities of lake water isotopes at repeatedly sampled sites are consistent with instrumental records of winter snowfall; summer relative humidity; and atmospheric circulation patterns, such as the North Atlantic Oscillation. Summer surface soil water isotopes span the entire range of seasonal precipitation values in Iceland and appear to be consistently overprinted by evaporative enrichment, which can occur throughout the year, although the sampling depths were shallower than rooting depths for many plant types. This dataset provides new insight into the functionality of water isotopes in Icelandic environments and offers renewed possibilities for optimized site selection and proxy interpretation in future paleohydrological studies on this North Atlantic outpost.

Remote Forcing for a Circulation Pattern Favorable to Surface Melt over the Ross Ice Shelf

Abstract The Ross Ice Shelf (RIS) experiences surface melt events in summer, which could accelerate ice loss and destabilize the ice sheet in a warming world. This study links the interannual variability of RIS surface melt to the northerly wind anomaly over the Ross Sea sector, which is established in association with the quasigeostrophic barotropic Rossby wave trains from the tropical Pacific and subtropical Australia toward West Antarctica. Atmospheric general circulation model experiments suggest that these Rossby wave trains are regulated by El Niño–related sea surface temperature (SST) anomalies in the tropical central–eastern Pacific and atmospheric heating anomalies over western Australia. El Niño provides an important forcing of the atmospheric circulation anomalies over the Ross Sea via inducing a Rossby wave train, and most surface melt events over the RIS happen during El Niño years. In addition, the anomalous atmospheric heating over western Australia, which is independent of El Niño, is another important forcing that triggers a Rossby wave train extending from subtropical Australia to the Ross Sea. The northerly flow toward the Ross Sea induces strong poleward moisture and heat transport, which further contributes to surface melt over the RIS. Significance Statement During austral summer, surface melt occurs over the Ross Ice Shelf, accelerates ice loss, and poses ice-sheet destabilization risks in a warming world. The northerly wind anomaly over the Ross sector provides strong poleward heat and moisture transport and is favorable for the surface melt. This wind anomaly is influenced by two remote forcings, El Niño and heating anomaly over western Australia, through generating Rossby wave trains from the tropics and subtropical Australia. This study reveals a previously unexplored relationship that atmospheric heating over western Australia influences large-scale circulation, contributing to surface melt.

Skillful Long-Lead Seasonal Predictions in the Summertime Northern Hemisphere Midlatitudes

Abstract In contrast to boreal winter when extratropical seasonal predictions benefit greatly from ENSO-related teleconnections, our understanding of forecast skill and sources of predictability in summer is limited. Based on 40 years of hindcasts of the Canadian Seasonal to Interannual Prediction System, version 3 (CanSIPSv3), this study shows that predictions for the Northern Hemisphere summer surface air temperature are skillful more than 6 months in advance in several midlatitude regions, including eastern Europe–Middle East, central Siberia–Mongolia–North China, and the western United States. These midlatitude regions of statistically significant predictive skill appear to be connected to each other through an upper-tropospheric circumglobal wave train. Although a large part of the forecast skill for the surface air temperature and 500-hPa geopotential height is attributable to the linear trend associated with global warming, there is significant long-lead seasonal forecast skill related to interannual variability. Two additional idealized hindcast experiments are performed to help shed light on sources of the long-lead forecast skill using one of the CanSIPSv3 models and its uncoupled version. It is found that tropical ENSO-related sea surface temperature (SST) anomalies contribute to the forecast skill in the western United States, while land surface conditions in winter, including snow cover and soil moisture, in the Siberian and western U.S. regions have a delayed or long-lasting impact on the atmosphere, which leads to summer forecast skill in these regions. This implies that improving land surface initial conditions and model representation of land surface processes is crucial for the further development of a seasonal forecasting system. Significance Statement Useful seasonal predictions in the boreal summer midlatitude regions are of great value. In this study, we show that predictions for the boreal summer season are skillful more than 6 months in advance in several midlatitude regions, including eastern Europe–Middle East, central Siberia–Mongolia–North China, and the western United States. The forecast skill in these regions is associated with a circumglobal teleconnection atmospheric circulation pattern. Sources of the long-lead forecast skill include the global warming–related trend and anomalies in the ocean and land surface initial conditions. It is found that the wintertime snow cover and soil moisture in the Siberian and western U.S. regions have a delayed or long-lasting impact on the atmosphere, which leads to summer forecast skill.

The impact of the destruction of the Kakhovka reservoir dam on the oceanographic conditions in the north-western part of the Black Sea according to the results of modeling

Based on the results of numerical modelling, characteristic features of distribution of transformed and polluted waters of the Dnieper River in the water area of the north-western part of the Black Sea (NWBS) are determined and analyzed. This pollution of the marine environment resulted from the extremely large man-made flood caused by the destruction of the Kakhovka Reservoir dam by the Russian occupation forces in June 2023. Various types of pollutants, which contained in the Kakhovka Reservoir, in the lower Dnieper River and in the bottom sediments, were carried out into the sea by the flood discharge. A significant amount of pollutants was washed into the sea from the flooded areas of the lower Dnieper basin. Special attention is given to changes in oceanographic conditions in the Dnieper-Bug estuary region (DBR) of the Black Sea, which determine the extent of marine pollution. Sea water salinity was used as an indicator of the degree of infiltration of polluted seawater from the estuary into the sea. It was identified that the least transformed river waters with low salinity correspond to high pollution levels. Delft3D-Flow Flexible Mesh hydrodynamic model, developed by Deltares, was used in this study. The simulation was performed for the time period 01 to 30 June 2023. During the first days after the dam break the desalinated and polluted transitional waters, flowing from the Dnieper-Bug estuary, spread over the entire water column down to 15-20 m depth in the DBR area. In this case, the spreading of transitional waters was atypical, as it usually occurs only within the thin near-surface layer of the sea. By mid-June the flow of transitional water with a salinity of 4-6 ‰ covered the entire water column from surface to bottom near the northern coast of the NWBS and over the Odessa Bank. This was facilitated by the supermassive volumes of transformed Dnieper river waters flowing out over a short period of time due to dam break, as well as by the resulting intense gradient currents and mixing caused by spatial gradients in the velocity of the generated currents. The width of the desalinated water plume and its area in the bottom layer were smaller than in the surface layer. The largest vertical salinity gradients were formed to the south of the Odessa Bank, where salinity was 4-6 ‰ in the surface layer and 14-17 ‰ in the bottom. Dilution of the desalinated water plume in the bottom water layer was much more intensive than in the surface water. The character of water circulation pattern in the northern part of the NWBS in the first days after the inflow of transient waters from the Dnieper-Bug estuary was determined by the runoff gradient currents, which later were replaced by wind-driven currents in the Odessa area and over the Odessa Bank, and by the meandering flow of gradient density currents further south. The findings of this study contribute to a better understanding of the impact of the inflow of transformed river waters from the Dnieper-Bug estuary on the variability of oceanographic characteristics and the ecological state of marine waters in the Dnieper-Bug region of the northwestern Black Sea.

KAJIAN EFEKTIFITAS POLA SIRKULASI KAWASAN WISATA DESA TRADISONAL PENGLIPURAN

Bali, as one of the main tourist destinations in Indonesia, has a variety of attractions, including the Penglipuran Traditional Tourism Village in Bangli Regency. The popularity of this tourist village has led to a significant increase in vehicle flow, especially on weekends and holidays, resulting in congestion around tourist areas. Vehicles parked carelessly on the side of the road interfere with mobility for both locals and other tourists. This study aims to evaluate the effectiveness of current circulation patterns and identify potential solutions. Using a qualitative method with a naturalistic approach, this study will observe and analyze vehicle movement patterns, parking behavior, and their impact on traffic and visitor comfort. The results of this study are expected to provide recommendations for more effective circulation pattern arrangement, including parking management, alternative routes, and road infrastructure improvements. With the implementation of the right solutions, it is hoped that the comfort and experience of tourists in the Penglipuran Traditional Tourism Village can be significantly improved, while maintaining smooth traffic for local residents.

Variation of surface solar radiation components from 2016 to 2020 in China: Perspective from geostationary satellite observation with a high spatiotemporal resolution

At present, traditional satellite datasets still grapple with inadequacies in terms of capturing solar radiation with fine spatiotemporal granularity. This study utilizes the high spatiotemporal resolution of CARE data, which is developed based on geostationary satellite observations, and employs multivariate analysis techniques to conduct an in-depth investigation into the multidimensional spatiotemporal variations of different types of solar radiation across various regions in China from 2016 to 2020. In addition, the potential of solar energy resources was also assessed using cluster analysis method. The results revealed an upward trend in different components of solar radiation across most of China, with shortwave radiation exhibiting a significantly negative correlation with PM2.5 concentrations (R = −0.91, p < 0.05). This finding suggests that the increase in SWR may be attributed to the effective implementation of China's Air Pollution Prevention and Control Action Plan. It suggests that China's endeavors to mitigate air pollution have not only resulted in improvements in national air quality but have also had an indirect positive effect on enhancing the potential for photovoltaic power generation. The assessment of solar energy resources potential indicated, with 99 % statistical confidence, that western China constitutes the core region for solar energy resources development, whereas northeastern and southeastern regions face certain constraints in solar energy resources utilization. Furthermore, we examined the specific influence of atmospheric circulation patterns on solar energy resources, uncovering that the El Niño phenomenon, by altering cloud distribution and variability, indirectly affects solar radiation intensity in specific regions. This study aids in understanding China's solar radiation variations, crucial for shaping effective energy policies towards carbon neutrality.

Investigating the role of path architecture complexity in users’ movement patterns in hospital circulation systems: case studies in Golestan, Iran

PurposeThis study aims to explore how users’ movement is influenced by different hospital ward layouts, by using space syntax theory. This study also compared four circulation patterns to find the best one for the study goal.Design/methodology/approachThe authors used both qualitative and quantitative methods to study how users’ wayfinding in hospitals depends on various indicators and factors. The study used Depth Map software to do case studies and then analyzed the indicators from theoretical foundations and used the Pearson Test to check the correlation between indicators. This study also looked at Iran’s Ministry of Health standards for ward layouts. Finally, the results obtained from the research data were compared to achieve a suitable model based on the research objectives.FindingsThe linear-patterned plan was the best for easy wayfinding and accessibility among four patterns. The optimal hospital circulation patterns can improve wayfinding and reduce wayfinding problems and user movement.Originality/valueBy pioneering space syntax in hospital research, this study unveils the novel interaction between path architecture and user movement. It gives new insights into current trends, helping architects, administrators and policymakers improve health-care design, efficiency and patient experience.

Evaluating heat stress and occupational risks in the Southern Himalayas under current and future climates

The southern Himalayas, characterized by its dense population and hot, humid summers, are confronted with some of the world’s most severe heat stress risks. This study uses the hourly ERA5 dataset (1979–2022) and CMIP6 projections (2005–2100) to evaluate past and future heat stress based on the Wet Bulb Globe Temperature (WBGT). This has significant implications for the management of occupational workloads in the southern Himalayas. Heat stress levels are classified into 6 categories (0 to 5) using WBGT threshold intervals of 23 °C, 25 °C, 28 °C, 30 °C, and 33 °C. With heat stress surpassing level 3 for almost half of the time, people are constrained to engage in less than moderate workloads to ensure their health remains uncompromised. Flow-analogous algorithm is employed to contextualize the unprecedented heat stress case in the summer of 2020 and the associated atmospheric circulation patterns from historical and future perspectives. The results show that over 80% of the time in 2020, heat stress levels were at 3 and 4. The identified circulation pattern explains 27.6% of the extreme intensity, and such an extreme would have been nearly impossible in pre-21st-century climate conditions under the identified pattern. Future projections under SSP2-4.5 and SSP5-8.5 scenarios indicate that heat stress similar to what was experienced in 2020 will likely become a common occurrence across the southern Himalayas. Under a similar circulation pattern, the heat stress levels by the end of the 21st century would be elevated by at least one category compared to the climatic baseline in over 70% of the region, leading to an additional 120.5 (420.1) million daily population exposed to the highest heat stress level under the SSP2-4.5 (SSP5-8.5) scenario.

Differentiated influences of anomalous subtropical high on extreme persistent precipitation and heatwave events in the Yangtze River Valley

AbstractIn the summers of 2020 and 2022, the Western Pacific Subtropical High (WPSH) intensified extremely and extended westward. However, in summer 2020, the Yangtze River Valley (YRV) witnessed record‐breaking floods, while in 2022, an unprecedented and prolonged heatwave occurred. Distinctly, these two extreme events were caused by different effects of the WPSH: one is enhancement of the transportation of water vapor and the other is adiabatic heating caused by the descending airflow. In June–July 2020, the stable extension of the WPSH ridge line to South China directed a southwesterly airflow along its northwest flank, leading to sustained precipitation in the YRV. Additionally, the midlatitude circulation pattern featured two troughs and two ridges. Such a circulation configuration, combined with the strong and westward WPSH, enabled the continuous southward intrusion of cold air and northward transport of warm moist air, converging over the YRV, and thus influenced extreme persistent precipitation. In contrast, the WPSH covered the YRV almost entirely during summer 2022. Under this influence, the clear‐sky condition and descending airflow through adiabatic warming directly resulted in the heatwave. In addition, local land–atmosphere feedback was crucial in its development and persistence. The soil moisture deficit induced by high temperatures increased the sensible heat flux between the soil and atmosphere upward, further enhanced the surface air temperature and strengthened the heat dry condition.

Spatial and Temporal Variations’ Characteristics of Extreme Precipitation and Temperature in Jialing River Basin—Implications of Atmospheric Large-Scale Circulation Patterns

In recent years, extreme climate events have shown to be occurring more frequently. As a highly populated area in central China, the Jialing River Basin (JRB) should be more deeply explored for its patterns and associations with climatic factors. In this study, based on the daily precipitation and atmospheric temperature datasets from 29 meteorological stations in JRB and its vicinity from 1960 to 2020, 10 extreme indices (6 extreme precipitation indices and 4 extreme temperature indices) were calculated. The spatial and temporal variations of extreme precipitation and atmospheric temperature were analyzed using Mann–Kendall analysis, to explore the correlation between the atmospheric circulation patterns and extreme indices from linear and nonlinear perspectives via Pearson correlation analysis and wavelet coherence analysis (WTC), respectively. Results revealed that among the six selected extreme precipitation indices, the Continuous Dry Days (CDD) and Continuous Wetness Days (CWD) showed a decreasing trend, and the extreme precipitation tended to be shorter in calendar time, while the other four extreme precipitation indices showed an increasing trend, and the intensity of precipitation and rainfall in the JRB were frequent. As for the four extreme temperature indices, except for TN10p, which showed a significant decreasing trend, the other three indices showed a significant increasing trend, and the number of low-temperature days in JRB decreased significantly, the duration of high temperature increased, and the basin was warming continuously. Spatially, the spatial variation of extreme precipitation indices is more obvious, with decreasing stations mostly located in the western and northern regions, and increasing stations mostly located in the southern and northeastern regions, which makes the precipitation more regionalized. Linearly, most of the stations in the extreme atmospheric temperature index, except TN10p, show an increasing trend and the significance is more obvious. Except for the Southern Oscillation Index (SOI), other atmospheric circulation patterns have linear correlations with the extreme indices, and the Arctic Oscillation (AO) has the strongest significance with the CDD. Nonlinearly, NINO3.4, Pacific Decadal Oscillation (PDO), and SOI are not the main circulation patterns dominating the changes of TN90p, and average daily precipitation intensity (SDII), maximum daily precipitation amount (RX1day), and maximum precipitation in 5 days (Rx5day) were most clearly associated with atmospheric circulation patterns. This also confirms that atmospheric circulation patterns and climate tend not to have a single linear relationship, but are governed by more complex response mechanisms. This study aims to help the relevant decision-making authorities to cope with the more frequent extreme climate events in JRB, and also provides a reference for predicting flood, drought and waterlogging risks.

Drying and wetting trend in Xinjiang and related circulations background over the past 60 years

The study of climate variability and trend provides important evidence for water resource management strategies in Xinjiang. The scientific community has systematically studied the ‘warming and wetting’ process in the Xinjiang region. However, significant controversy persists regarding whether this trend has stagnated, and there remains a gap in understanding the decadal climate variability across different seasons within the subregions of Xinjiang. Here, we analyzed the spatiotemporal characteristics of seasonal-to-annual climate variations in Southern and Northern Xinjiang over the past 60 years by the Standardized Precipitation Evapotranspiration Index (SPEI-3) and identified the change points of mean and trend changes in the SPEI series and further explored the atmospheric circulation patterns before and after the transition from dry/wet conditions. Specifically, although the mean change point test indicated a wetter climate after 1986 at both the annual and seasonal scales, the trend analysis showed a shift from wet to dry from 1996, which has persisted until the present. There were significant interdecadal features in the spatial distribution of SPEI. Xinjiang exhibited a predominantly dry pattern from 1961 to 1980, which changed to a wetter pattern from 1981 to 2000, Xinjiang experienced its wettest decade from 1991 to 2000, and the whole region returned to a drier pattern from 2001 to 2020. From the annual and seasonal variation, the rate of change is greater in the south, with stronger change amplitude in summer and autumn and a higher frequency of anomalous SPEI. The results of the atmospheric circulation analysis demonstrated that the net water vapor flux in the Xinjiang region increased by about 8.30 g·kg−1·m·s−1 in the period 1987–2020 compared to 1961–1986 due to the combined interaction of high-, mid-, and low-latitude systems with the Central Asian low-pressure system. The results indicated a sharp increase in aridification in Xinjiang, providing valuable insights for disaster prevention, mitigation, and risk management related to regional drought hazards.

East–West Difference in the Ionospheric Response During the Recovery Phase of May 2024 Super Geomagnetic Storm Over the East Asian

AbstractIn this study, we offer an extensive examination of the F‐region ionospheric disturbances during the May 2024 superstorm, focusing primarily on the middle‐low latitude regions of East Asia. Our analysis is grounded in a wealth of data sources including Total Electron Content (TEC), ionospheric parameters NmF2 and hmF2, Electron Density Profile (EDP) retrieved from Radio Occultation (RO) data, and ∑[O]/[N2] from the Global Ultraviolet Imager (GUVI), among others, complemented by model simulations. The observed negative ionospheric storm effect, characterized by a significant and long‐lasting reduction in electron density across the entire China, commenced immediately following the sudden storm commencement (SSC) on 10 May and continued through the main and early recovery phase of the storm on 11 May. On 11–12 May, positive ionospheric storm impacts were initially observed in a restricted geographical area from the post‐midnight to sunrise, first manifesting over the eastern regions of China and then shifting to the central regions. Subsequently, a pronounced negative storm effect persisted throughout the later stages of recovery phase. In contrast, the western regions of China experienced a positive storm effect on 12 May followed by a comparatively mild negative storm phase. This persistent extensive zonal gradient in electron density across the East Asian region resembles the scenarios depicted in prior superstorms attributed to the thermospheric circulation patterns. The disparity in the ionospheric response from east to west in this area is probably a common feature during superstorms, potentially resulting from an arch‐shaped structure of elevated ∑[O]/[N2].

Infection Rates and Symptomatic Proportion of SARS-CoV-2 and Influenza in Pediatric Population, China, 2023.

We conducted a longitudinal cohort study of SARS-CoV-2 and influenza rates in childcare centers and schools in Wuxi, China, collecting 1,760 environmental samples and 9,214 throat swabs from 593 students (regardless of symptoms) in weekly collections during February-June 2023. We estimated a cumulative infection rate of 124.8 (74 episodes)/1,000 persons for SARS-CoV-2 and 128.2 (76 episodes)/1,000 persons for influenza. The highest SARS-CoV-2 infection rate was in persons 18 years of age, and for influenza, in children 4 years of age. The asymptomatic proportion of SARS-CoV-2 was 59.6% and 66.7% for influenza; SARS-CoV-2 symptomatic proportion was lower in 16-18-year-olds than in 4-6-year-olds. Only samples from frequently touched surface tested positive for SARS-CoV-2 (4/1,052) and influenza (1/1,052). We found asynchronous circulation patterns of SARS-CoV-2 and influenza, similar to trends in national sentinel surveillance. The results support vaccination among pediatric populations and other interventions, such as environmental disinfection in educational settings.

Long-Term Climate Impacts of Large Stratospheric Water Vapor Perturbations

Abstract The amount of water vapor injected into the stratosphere after the eruption of Hunga Tonga–Hunga Ha’apai (HTHH) was unprecedented, and it is therefore unclear what it might mean for surface climate. We use chemistry–climate model simulations to assess the long-term surface impacts of stratospheric water vapor (SWV) anomalies similar to those caused by HTHH but neglect the relatively minor aerosol loading from the eruption. The simulations show that the SWV anomalies lead to strong and persistent warming of Northern Hemisphere landmasses in boreal winter, and austral winter cooling over Australia, years after eruption, demonstrating that large SWV forcing can have surface impacts on a decadal time scale. We also emphasize that the surface response to SWV anomalies is more complex than simple warming due to greenhouse forcing and is influenced by factors such as regional circulation patterns and cloud feedbacks. Further research is needed to fully understand the multiyear effects of SWV anomalies and their relationship with climate phenomena like El Niño–Southern Oscillation. Significance Statement Volcanic eruptions typically cool Earth’s surface by releasing sulfur dioxide, which then converts into aerosols, which reflect sunlight. However, a recent eruption released a significant amount of water vapor—a strong greenhouse gas—into the stratosphere with unknown consequences. This study neglects the aerosol effect and examines the consequences of large stratospheric water vapor anomalies and reveals that surface temperatures across large regions of the world increase by over 1.5°C for several years, although some areas experience cooling close to 1°C. Additionally, the research suggests a potential connection between the eruption and sea surface temperatures in the tropical Pacific, which warrants further investigation.

Seasonal, Interannual and Long‐Term Variability of Sea Surface Temperature in the NW Iberian Upwelling, 1982–2020

AbstractHere the seasonal, inter‐annual and long‐term variability of satellite‐derived sea surface temperature (SST) was analyzed in the NW Iberian margin from 1982 to 2020 to explore spatial differences at high (5‐km) resolution. In‐situ temperature measurements from five coastal buoys were used to validate the satellite‐derived SST data, discarding pixels from areas close to the shoreline. Regional SST increased significantly from 0.07 to 0.25°C per decade, with the lowest rates in shelf waters directly affected by seasonal coastal upwelling. Upwelling filaments also contributed to dampen the temperature increase in the adjacent slope and ocean waters. The spatial variability observed in the amplitude and timing of the seasonal cycle of SST is directly related to hydrography and circulation patterns of the region such as upwelling events during summer and the development of the river's buoyant plume and the warm Iberian Poleward Current during winter.

Long‐Term Surface Current Variability Across the Continental Shelf and Slope

AbstractContinental shelves are amongst the most dynamic and vulnerable regions in the oceans, and understanding their dynamics has implications for the transport of organisms and materials in both coastal and offshore zones. Determining the circulation patterns in systems experiencing high variability is crucial, but challenging as continuous and high‐resolution long‐term data sets are still scarce. In this paper, we use 9‐years (2010–2018) of High‐Frequency Radar surface current observations and satellite‐derived Sea Surface Temperature to investigate the spatiotemporal variability of surface currents on the offshore, shelf break and inner continental regions along the Wadjemup (Rottnest) Continental Shelf (WCS), South‐West Australia. We use the indigenous Noongar calendar that defines six‐seasons: Birak (DJ), Bunuru (FM), Djeran (AM), Makuru (JJ), Djilba (AS), and Kambarang (ON); to better represent the seasonal changes in local winds and surface circulation. The surface currents revealed the poleward‐flowing Leeuwin Current (LC), the equatorward‐flowing Capes Current (CC), their interactions, and eddy features (radii &gt;10 km). The LC was the strongest (weakest) over Djeran/Makuru (Birak/Bunuru), whilst CC and offshore eddies were persistent from Kambarang‐Bunuru. Along WCS, CC and offshore eddies locally modulated LC strength and position, whereas the El Niño Southern Oscillation influenced its interannual variability. During El Niño (La Niña) years, LC was weakened (strengthened), whilst CC and offshore eddy activity were strengthened (weakened). Particularly during La Niña years, LC increased its cross‐shore migration and had an unseasonal peak in 2011. Our findings contribute to the understanding of the variability of boundary and coastal currents, and their local impacts on coastal circulation.

Synoptic controls on warm-season O3 pollution in eastern China: A focus on O3-NOx-VOC chemistry

The design of emission abatement measures to effectively reduce ozone (O3) pollution is highly complex due to non-linear chemistry, multi-source precursor emissions, and regional-scale transport. All these processes also depend on the synoptic circulation conditions. This study classified large-scale circulations to explore the synoptic controls on surface O3 pollution over eastern China (EC) during the warm seasons (May to September) from 2013 to 2022. Four prevailing circulation patterns (CPs) were identified, distinguishable by distinct differences in surface O3 anomaly distribution over the EC region. Regional meteorological variables, satellite-based precursors (NO2 and CH2O), and CH2O/NO2 ratio-based O3 formation sensitivity (OFS) were projected onto each CP to explore the underlying physiochemical mechanism of synoptic midualtion to surface O3 pollution. The results indicated that circulation-driven regional transport governed the spatial variability of surface O3 anomaly distribution on a synoptic timescale. Additionally, circulation-driven temperature changes caused unsynchronized changes in NO2 and CH2O across different CPs, leading to circulation-dependent OFS distribution. Geographical O3 anomaly changes generally followed the O3-VOC-NOx chemical principle in most synoptic circulation situations, thereby providing a framework for formulating spatiotemporal sensitivity-oriented mitigation strategies for forthcoming O3 pollution episodes with the assistance of synoptic circulation forecasts.