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The regional climate of New Zealand's South Island is shaped by the interaction of the Southern Hemisphere westerlies with the complex orography of the Southern Alps. Due to its isolated geographical setting in the south‐west Pacific, the influence of the surrounding oceans on the atmospheric circulation is strong. Therefore, variations in sea surface temperature (SST) impact various spatial and temporal scales and are statistically detectable down to temperature anomalies and glacier mass changes in the high mountains of the Southern Alps. To enable future studies on the processes that govern the link between large‐scale SST and local‐scale high‐mountain climate, we utilized dynamical downscaling with the Weather Research and Forecasting (WRF) model to produce a regional atmospheric modelling dataset for the South Island of New Zealand over a 16‐year period between 2005 and 2020. The 2 km horizontal resolution ensures realistic representation of high‐mountain topography and glaciers, as well as explicit simulation of convection. The dataset is extensively evaluated against observations, including weather station and satellite data, on both regional (in the inner domain) and local (on Brewster Glacier in the Southern Alps) scales. Variability in both atmospheric water content and near‐surface meteorological conditions is well captured, with minor seasonal and spatial biases. The local high‐mountain climate at Brewster Glacier, where land use and topographic model settings have been optimized, yields remarkable accuracy on both monthly and daily time scales. The data provide a valuable resource to researchers from various disciplines studying the local and regional impacts of climate variability on society, economies and ecosystems in New Zealand. The model output from the highest resolution model domain is available for download in daily temporal resolution from a public repository at the German Climate Computation Center (DKRZ) in Hamburg, Germany (Kropač et al., 2023; 16‐year WRF simulation for the Southern Alps of New Zealand, World Data Center for Climate (WDCC) at DKRZ [data set]. https://doi.org/10.26050/WDCC/NZ‐PROXY_16yrWRF). [ABSTRACT FROM AUTHOR]

To reduce influenza-associated morbidity and mortality, countries in South America recommend annual influenza vaccination for persons at high risk for severe influenza illness, including young children, persons with preexisting health conditions, and older adults. Interim estimates of influenza vaccine effectiveness (VE) from Southern Hemisphere countries can provide early information about the protective effects of vaccination and help guide Northern Hemisphere countries in advance of their season. Using data from a multicountry network, investigators estimated interim VE against influenzaassociated severe acute respiratory illness (SARI) hospitalization using a test-negative case-control design. During March 13– July 19, 2024, Argentina, Brazil, Chile, Paraguay, and Uruguay identified 11,751 influenza-associated SARI cases; on average, 21.3% of patients were vaccinated against influenza, and the adjusted VE against hospitalization was 34.5%. The adjusted VE against the predominating subtype A(H3N2) was 36.5% and against A(H1N1)pdm09 was 37.1%. These interim VE estimates suggest that although the proportion of hospitalized patients who were vaccinated was modest, vaccination with the Southern Hemisphere influenza vaccine significantly lowered the risk for hospitalization. Northern Hemisphere countries should, therefore, anticipate the need for robust influenza vaccination campaigns and early antiviral treatment to achieve optimal protection against influenza-associated complications. [ABSTRACT FROM AUTHOR]

Abstract The regional climate of New Zealand's South Island is shaped by the interaction of the Southern Hemisphere westerlies with the complex orography of the Southern Alps. Due to its isolated geographical setting in the south‐west Pacific, the influence of the surrounding oceans on the atmospheric circulation is strong. Therefore, variations in sea surface temperature (SST) impact various spatial and temporal scales and are statistically detectable down to temperature anomalies and glacier mass changes in the high mountains of the Southern Alps. To enable future studies on the processes that govern the link between large‐scale SST and local‐scale high‐mountain climate, we utilized dynamical downscaling with the Weather Research and Forecasting (WRF) model to produce a regional atmospheric modelling dataset for the South Island of New Zealand over a 16‐year period between 2005 and 2020. The 2 km horizontal resolution ensures realistic representation of high‐mountain topography and glaciers, as well as explicit simulation of convection. The dataset is extensively evaluated against observations, including weather station and satellite data, on both regional (in the inner domain) and local (on Brewster Glacier in the Southern Alps) scales. Variability in both atmospheric water content and near‐surface meteorological conditions is well captured, with minor seasonal and spatial biases. The local high‐mountain climate at Brewster Glacier, where land use and topographic model settings have been optimized, yields remarkable accuracy on both monthly and daily time scales. The data provide a valuable resource to researchers from various disciplines studying the local and regional impacts of climate variability on society, economies and ecosystems in New Zealand. The model output from the highest resolution model domain is available for download in daily temporal resolution from a public repository at the German Climate Computation Center (DKRZ) in Hamburg, Germany (Kropač et al., 2023; 16‐year WRF simulation for the Southern Alps of New Zealand, World Data Center for Climate (WDCC) at DKRZ [data set]. https://doi.org/10.26050/WDCC/NZ‐PROXY_16yrWRF).

Abstract Subantarctic Nothofagus forests are the southernmost forests in the world, with negligible atmospheric nitrogen (N) deposition. Most paradigms about the role of ectomycorrhizal (ECM) fungi in N cycling and plant N uptake at high latitudes have been tested in boreal coniferous forests, while in the southern hemisphere, ECM hosts are primarily angiosperms. Using ITS1 meta‐barcoding, we characterized ECM and saprotrophic fungal communities in evergreen and deciduous Nothofagus forests forming monodominant and mixed stands in the archipelago of Tierra del Fuego (Chile and Argentina). We assessed the N economy of Nothofagus by correlating host species with fungal relative abundances, edaphic variables, net N mineralization, microbial biomass N and the activity of eight extracellular soil enzymes activities. The N economy of deciduous N. pumilio forests was strikingly similar to boreal coniferous forests, with the lowest inorganic N availability and net N mineralization, in correlation to higher relative abundances of ECM fungi with enzymatic capacity for organic N mobilization (genus Cortinarius). In contrast, the N economy of evergreen N. betuloides forests was predominantly inorganic and correlated with ECM lineages from the family Clavulinaceae, in acidic soils with poor drainage. Grassy understory vegetation in deciduous N. antarctica forests likely promoted saprotrophic fungi (i.e., genus Mortierella) in correlation with higher activities of carbon‐degrading enzymes. Differences between Nothofagus hosts did not persist in mixed forests, illustrating the range of soil fertility of these ECM angiosperms and the underlying effects of soil and climate on Nothofagus distribution and N cycling in southern Patagonia.

Abstract During the middle Permian through the Triassic, Tasmania moved from paleo-latitudes of 78° to 69°S, wedged between Antarctica and Australia, within the paleo-South polar circle. During this time, significant global carbon cycle disturbances triggered major environmental and climatic changes and mass extinction events globally. The Bicheno-5 core from Eastern Tasmania, Australia, provides the opportunity to examine middle Permian and Upper Triassic sediments from the paleo-Antarctic, using high-resolution organic carbon isotope (δ13CTOC) chemostratigraphy, pXRF, and sedimentology, combined with new palynological data integrated with the existing radiometric age model. While there is a significant unconformity in the Upper Permian to the middle Triassic associated with eustatic sea-level fall as a result of regional uplift in eastern Australia, three distinct carbon isotope excursions (CIEs), characterized by negative shifts of up to − 6 ‰ were identified; the middle Permian Guadalupian Carbon Isotope Excursions (G-CIE), the Carnian Pluvial Episode (CPE), and the mid-Norian Event (MNE). These three events highlight a significant climate shift through glacial and interglacial cycles to warmer non-glacial intervals in the Late Triassic, with evidence of the polar record of the Carnian Pluvial Episode and the mid-Norian Event, which are poorly studied in the Southern Hemisphere, specifically within the Paleo-Antarctic circle.

During the middle Permian through the Triassic, Tasmania moved from paleo-latitudes of 78° to 69°S, wedged between Antarctica and Australia, within the paleo-South polar circle. During this time, significant global carbon cycle disturbances triggered major environmental and climatic changes and mass extinction events globally. The Bicheno-5 core from Eastern Tasmania, Australia, provides the opportunity to examine middle Permian and Upper Triassic sediments from the paleo-Antarctic, using high-resolution organic carbon isotope (δ13CTOC) chemostratigraphy, pXRF, and sedimentology, combined with new palynological data integrated with the existing radiometric age model. While there is a significant unconformity in the Upper Permian to the middle Triassic associated with eustatic sea-level fall as a result of regional uplift in eastern Australia, three distinct carbon isotope excursions (CIEs), characterized by negative shifts of up to − 6 ‰ were identified; the middle Permian Guadalupian Carbon Isotope Excursions (G-CIE), the Carnian Pluvial Episode (CPE), and the mid-Norian Event (MNE). These three events highlight a significant climate shift through glacial and interglacial cycles to warmer non-glacial intervals in the Late Triassic, with evidence of the polar record of the Carnian Pluvial Episode and the mid-Norian Event, which are poorly studied in the Southern Hemisphere, specifically within the Paleo-Antarctic circle. [ABSTRACT FROM AUTHOR]

In recent decades, there have been significant problems worldwide related to global warming and the intensification of extreme temperature and rainfall events. This research evaluated daily temperature and rainfall indices trends to identify whether warming signals have occurred in South Australia over the past fifty years. Extreme cold, hot, and rainfall events were calculated using climatic data from 37 weather stations. A Mann–Kendall test was used for trend analysis with Sen's estimator. As a result, we determined that for the 1970–2021 period, the maximum and minimum temperatures increased by 1.1 and 0.7 °C, respectively, while precipitation had a negative trend (−52.2 mm per period). Since statistical significance was found in analysing extreme cold and hot events, we find that warming signals have several impacts on South Australia. In the case of rainfall events, we identified a heterogeneous pattern characterised by a reduction in the annual amount and an increase in extreme rainfall events. The findings enable us to conclude that the area shows signs of global warming that could affect the intensity and magnitude of droughts. This information is essential for continuing with current management strategies to adapt and mitigate the effects of global warming in South Australia. [ABSTRACT FROM AUTHOR]

This paper examines sightings of dwarf minke whales during the SOWER cruises. A total of 12 sightings were made between 1994/95 and 2003/04, across a relatively wide latitude (37°S–62°S) but limited longitude, between IWC Management Area III (0–70°E) and V (130°E–170°W), with no sightings in Area I (0–60°W) or II (60°W–120°W). Despite this low number of sightings, most were close to the Antarctic Convergence at 58°S–65°S. There may be some seasonality in their southbound migration. [ABSTRACT FROM AUTHOR]

Subseasonal‐to‐seasonal (S2S) prediction has gained momentum in the recent past as a need for predictions between the weather forecasting timescale and seasonal timescale exists. The availability of S2S databases makes prediction and predictability studies possible over all the regions of the globe. Most S2S studies are, however, relevant to the northern hemisphere. In this review, the S2S literature relevant to the southern hemisphere (SH) are presented. Predictive skill, sources of predictability, and the application of S2S predictions are discussed. Indications from the subseasonal predictability studies for the SH regions suggest that predictive skill is limited to 2 weeks in general, particularly for temperature and rainfall, which are the variables most frequently investigated. However, temperature has enhanced skill compared to rainfall. More S2S prediction studies that include the quantification of the sources of predictability and the identification of windows of opportunity need to be conducted for the SH, particularly for the southern African region. The African continent is vulnerable to weather‐ and climate‐related disasters, and S2S forecasts can assist in alleviating the risk of such disasters. [ABSTRACT FROM AUTHOR]

The inter-dataset agreement of trends in subweekly near-surface (850 hPa) temperature variability over Southern Hemisphere midlatitude land masses is assessed among 12 global atmospheric reanalysis datasets. A comparison of the climatological temperature variance and dominant sources and sinks of the variance reveals that, except for NCEP-NCAR (R1) and NCEP-DOE (R2), there is a relatively good agreement for their magnitudes and spatial distributions during the satellite era (1980–2022), which indicates that the key features of subweekly variability are sufficiently well represented. A good agreement is noted for the positive trends found in subweekly variability over the satellite era affecting South Africa in September–October–November (SON) and South America in December–January–February (DJF). Although there is agreement in most of the reanalyses concerning the positive trend affecting Australia in SON, this has not yet emerged from the noise associated with interannual variability when considering only the satellite era. It is significant, however, when the period is extended (1954–2022) or limited to the most recent decades (1990–2022). The trends are explained primarily by a more efficient generation of subweekly temperature variance by horizontal temperature advection. This generation is also identified as a source of biases among the datasets. The trends are found to be reproduced even in those reanalyses that do not assimilate satellite data (JRA-55C) or that assimilate surface observations only (ERA-20C, 20CRv2c, and 20CRv3). [ABSTRACT FROM AUTHOR]

There is a close correlation between sunspot number and sunspot area. Through the distribution of sunspot number and area size, we could note significantly disagreements for the two hemispheres. The paper concentrates on the relationship for the northern, the southern hemispheres and the global, and we propose a new method from segmentation regression for description the relationship between the sunspot number and sunspot area of different hemispheres and the global. By the sunspot number, we divide up the data into three parts, the low, the medium, and the high. The results indicate that the segmentation regression method could better describe the relation between sunspot area and number, in particular at the lower solar activity part and the higher part. We could obtain a better regression result for these parts, data more or less static, and data more discrete. Moreover, sunspot area and number behave very differently relationship for the north, the south and the global. In addition, the sunspot number being equal, the sunspot area of the south is usually greater than the north. [ABSTRACT FROM AUTHOR]

Abstract Subseasonal‐to‐seasonal (S2S) prediction has gained momentum in the recent past as a need for predictions between the weather forecasting timescale and seasonal timescale exists. The availability of S2S databases makes prediction and predictability studies possible over all the regions of the globe. Most S2S studies are, however, relevant to the northern hemisphere. In this review, the S2S literature relevant to the southern hemisphere (SH) are presented. Predictive skill, sources of predictability, and the application of S2S predictions are discussed. Indications from the subseasonal predictability studies for the SH regions suggest that predictive skill is limited to 2 weeks in general, particularly for temperature and rainfall, which are the variables most frequently investigated. However, temperature has enhanced skill compared to rainfall. More S2S prediction studies that include the quantification of the sources of predictability and the identification of windows of opportunity need to be conducted for the SH, particularly for the southern African region. The African continent is vulnerable to weather‐ and climate‐related disasters, and S2S forecasts can assist in alleviating the risk of such disasters.

We investigated reproductive behavior and sexual patterns in two odacid fish—Rainbow cale Heteroscarus acroptilus and Herring cale Olisthops cyanomelas—inhabiting temperate reefs in Australia on the basis of underwater observations and histological studies. The males of both species established a territory and continuously courted females they encountered in the territory. The males and females went up in the water column to release gametes in pairs. We found ovarian cavities in the gonadal tissue of H. acroptilus males, suggesting that protogynous sex change occurred in this species. Dichromatism is reported in O. cyanomelas, with males having a dark blue body color while females have a brown body color; however, we found small mature males also included among brown individuals. Furthermore, we diagnosed O. cyanomelas with gonochorism, which is rare in closely related labrids. We compared the similarities and differences in reproductive behavior and sexual patterns between the two species and with labrids. [ABSTRACT FROM AUTHOR]

The recently developed average latitudinal displacement (ALD) methodology is applied to assess the waviness of the austral-winter subtropical and polar jets using three different reanalysis data sets. As in the wintertime Northern Hemisphere, both jets in the Southern Hemisphere have become systematically wavier over the time series and the waviness of each jet evolves quite independently of the other during most cold seasons. Also, like its Northern Hemisphere equivalent, the Southern Hemisphere polar jet exhibits no trend in speed (though it is notably slower), while its poleward shift is statistically significant. In contrast to its Northern Hemisphere counterpart, the austral subtropical jet has undergone both a systematic increase in speed and a statistically significant poleward migration. Composite differences between the waviest and least wavy seasons for each species suggest that the Southern Hemisphere's lower-stratospheric polar vortex is negatively impacted by unusually wavy tropopause-level jets of either species. These results are considered in the context of trends in the Southern Annular Mode as well as the findings of other related studies. [ABSTRACT FROM AUTHOR]

Evaluations of vaccine effectiveness during the March– September Southern Hemisphere influenza season can provide valuable information for countries currently experiencing the influenza season and preceding the October–May Northern Hemisphere influenza season. Since 2013, multiple countries have participated in the Network for the Evaluation of Vaccine Effectiveness in Latin America and the Caribbean–influenza (la Red para la Evaluación de Vacunas en Latino América y el Caribe—influenza [REVELAC–i]) to estimate and monitor vaccine effectiveness (VE) in preventing severe acute respiratory infection (SARI)–associated hospitalization. Based on data contributed by Argentina, Brazil, Chile, Paraguay, and Uruguay on 2,780 SARI patients hospitalized during March 27–July 9, 2023, the adjusted VE against SARI hospitalization associated with any influenza virus during the 2023 Southern Hemisphere season was 51.9% (95% Confidence Interval [CI] 39.2%– 62.0%), including 55.2% (95% CI: 41.8%–65.5%) against the predominating A(H1N1)pdm09. These early, interim estimates, provided before the expected end of seasonal influenza virus circulation, suggest that vaccination substantially reduced the risk for severe influenza illnesses, underscoring the benefits of influenza vaccination. In anticipation of Northern Hemisphere influenza virus circulation, the World Health Organization and CDC recommend that health authorities encourage health care providers to administer annual influenza vaccination to all eligible persons, particularly emphasizing the importance of vaccination for persons at increased risk for severe outcomes (e.g., very young children, persons with preexisting health conditions [including pregnant women], and older adults). [ABSTRACT FROM AUTHOR]

An objective detection and tracking algorithm based on relative vorticity at 850 hPa using National Centers for Environmental Prediction--National Center for Atmospheric Research (NCEP--NCAR) Reanalysis-1 data was applied to track cyclones in the Southern Hemisphere during austral winters from 1948 to 2017. The climatological characteristics of extratropical cyclones, including track density, frequency, intensity, lifetime, and their related variabilities, are discussed. The frequency and average lifetime of cyclones have substantially decreased. The average maximum intensity of cyclones has shown an increasing trend over the 70-yr study period. The cyclone track density shows a decreasing trend in lower latitudes, consistent with the region where the upper-troposphere zonal wind weakens. Baroclinicity can explain the increase in cyclone intensity: when a cyclone moves to higher latitudes and enters the region with greater baroclinicity, it strengthens. As there is no discernible increase in cyclogenesis in the medium latitudes (45°-70°S), but significantly less cyclogenesis in lower and higher latitudes, it is hypothesized that there is no clear poleward cyclogenesis shift over the Southern Hemisphere. [ABSTRACT FROM AUTHOR]

This study identifies a new triggering mechanism of the Indian Ocean Dipole (IOD) from the Southern Hemisphere. This mechanism is independent from the El Niño-Southern Oscillation (ENSO) and tends to induce the IOD before its canonical peak season. The joint effects of this mechanism and ENSO may explain different lifetimes and strengths of the IOD. During its positive phase, development of sea surface temperature cold anomalies commences in the southern Indian Ocean, accompanied by an anomalous subtropical high system and anomalous southeasterly winds. The eastward movement of these anomalies enhances the monsoon off Sumatra-Java during May–August, leading to an early positive IOD onset. The pressure variability in the subtropical area is related with the Southern Annular Mode, suggesting a teleconnection between high-latitude and midlatitude climate that can further affect the tropics. To include the subtropical signals may help model prediction of the IOD event.

The performance of 61 global climate models participating in CMIP5 and 6 is evaluated for the Southern Hemisphere extratropics in terms of typical regional‐scale atmospheric circulation patterns. These patterns are known to be linked with a number of key variables in atmospheric physics and chemistry and provide an overarching concept for model evaluation. First, hemispheric‐wide error and ranking maps are provided for each model and regional details are described. Then, the results are compared with those obtained in a companion study for the Northern Hemisphere. For most models, the average error magnitude and ranking position is similar on both hemispheres, ruling out systematic tuning toward either of the two. CMIP6 models perform better on average than CMIP5 models and the interactive simulation of more climate system components does not deteriorate the results for most model families. Better performance is associated with higher resolution in the atmosphere, following a non‐linear relationship. Plain Language Summary: This letter provides a survey on the capability of global climate models to reproduce the regional atmospheric circulation in the Southern Hemisphere in present climate conditions. Climate models from the latest model generation are found to perform better on average than those of the previous generation and the obtained model ranking is similar to that found for the Northern Hemisphere in a companion study. While model performance is found to be generally unrelated to model complexity in terms of covered climate system components, better results are associated with higher model resolution in the atmosphere. Key Points: CMIP6 models perform better than CMIP5 models on averageSouthern Hemisphere model ranking similar to Northern Hemisphere rankingMore complex model versions perform similar to less complex ones [ABSTRACT FROM AUTHOR]

Environmental mercury (Hg) contamination is a global concern requiring action at national scales. Scientific understanding and regulatory policies are underpinned by global extrapolation of Northern Hemisphere Hg data, despite historical, political, and socioeconomic differences between the hemispheres that impact Hg sources and sinks. In this paper, we explore the primary anthropogenic perturbations to Hg emission and mobilization processes that differ between hemispheres and synthesize current understanding of the implications for Hg cycling. In the Southern Hemisphere (SH), lower historical production of Hg and other metals implies lower present-day legacy emissions, but the extent of the difference remains uncertain. More use of fire and higher deforestation rates drive re-mobilization of terrestrial Hg, while also removing vegetation that would otherwise provide a sink for atmospheric Hg. Prevalent Hg use in artisanal and small-scale gold mining is a dominant source of Hg inputs to the environment in tropical regions. Meanwhile, coal-fired power stations continue to be a significant Hg emission source and industrial production of non-ferrous metals is a large and growing contributor. Major uncertainties remain, hindering scientific understanding and effective policy formulation, and we argue for an urgent need to prioritize research activities in under-sampled regions of the SH. [ABSTRACT FROM AUTHOR]

Background: The dataset comprises geolocalised records of dive and surface interval durations, light level and temperature of the seawater during the post-resting and post-moulting tracks of 13 immature southern elephant seals, Mirounga leonina. It describes an unpublished open access version of the original data with records of light level and temperature of the water column using the Darwin Core standard (DwC) through ArOBIS, guaranteeing compliance with the FAIR principles, encompassing a wide time scale (2005, 2006 and 2007) and geographic range in the South Atlantic and Pacific Oceans (South West [-58.75, -81.29], North East [-37.60, -28.65]). Seals were simultaneously equipped with affordable light-temperature loggers (LTLs) and satellite tags. The LTLs recorded light level and temperature of the water column at 30-s intervals during dives and light-time records were applied to estimate dive parameters of diurnal records from 06:00 to 17:00 h, since movements up and down the water column are reflected by changes in light level. For that, the minimum light level reached at the surface of a dive was determined experimentally with diurnal dive simulations at sea using the LTLs devices before deployment. The dataset also includes variation of light and temperature of records between 17:00 to 06:00 h. Data can be used to identify temperature changes associated with seawater masses as drivers of the distribution of other taxa of interest and variation of light level in the seawater (light attenuation) could be linked to concentrations of phytoplankton assemblages as an index of primary productivity. New information: This dataset provides unpublished data of the duration of dives and surface intervals and associated records of light level and temperature variations along the movements throughout the seawater of 13 immature southern elephant seals in the Southern Hemisphere. The location data were generated by satellite tags and the light and temperature data were recorded with light-temperature loggers (LTLs), both devices deployed on individuals simultaneously and uploaded following the Darwin Core standard and compliance with the FAIR principles. [ABSTRACT FROM AUTHOR]

In this study, the author examined the tropical cyclone (TC) activity over the southern hemisphere (SH) and its relationship with tropical climate modes, such as the El Niño–Southern Oscillation (ENSO), during the austral summer (December–January–February; DJF) and fall (March–April–May; MAM). The correlation analysis between the TC activity and the global sea surface temperature (SST) suggested that an increased TC activity over the southwestern and southeastern Indian Ocean (SWIO and SEIO) was associated with a La Niña-like SST pattern, while an increased TC activity over the southwestern Pacific (SWP) was associated with an El Niño-like SST pattern. The atmospheric conditions accompanying the TC increase over the SWIO/SEIO indicated that a La Niña induces tropospheric cooling over the tropics with cyclonic circulation anomalies over the TC genesis region. Both the SST anomalies and the cyclonic circulation anomalies were significantly correlated with TC genesis parameters, suggesting that they contributed to TC genesis. To investigate the SST precursors, a lead-lag correlation analysis was performed. For the TC variations over the SEIO, an SST pattern that resembled the Pacific Meridional Mode (PMM) was statistically significant at a two-season lead. However, such a TC-ENSO relationship is seasonally dependent, with different patterns during DJF and MAM. These results suggest that the Matsuno-Gill response to ENSO is an important factor in TC activity but that this influence is seasonally modulated over the SH. [ABSTRACT FROM AUTHOR]

Little is known about how climate intervention through stratospheric aerosol injection (SAI) may affect the climatology of the Southern Hemisphere extratropical cyclones under warming scenarios. To address this knowledge gap, we tracked extratropical cyclones from 2015 to 2099 in a set of projections of three international projects: the Assessing Responses and Impacts of Solar Climate Intervention on the Earth System with Stratospheric Aerosol Injection (ARISE), the Stratospheric Aerosol Geoengineering Large Ensemble (GLENS), and the Geoengineering Model Intercomparison Project (GeoMIP/G6sulfur). Comparisons were performed between no-SAI and SAI scenarios as well as between different timeslices and their reference period (2015–2024). Among the findings, both no-SAI and SAI project a decrease in cyclone frequency towards the end of the century although weaker under SAI scenarios. On the other hand, cyclones tend to be stronger under no-SAI scenarios while keeping their intensity more similar to the reference period under SAI scenarios. This means that under SAI scenarios the climatology of cyclones is less affected by global warming than under no-SAI. Other features of these systems, such as travelling distance, lifetime, and mean velocity show small differences between no-SAI and SAI scenarios and between reference and future periods.

In recent decades, there have been significant problems worldwide related to global warming and the intensification of extreme temperature and rainfall events. This research evaluated daily temperature and rainfall indices trends to identify whether warming signals have occurred in South Australia over the past fifty years. Extreme cold, hot, and rainfall events were calculated using climatic data from 37 weather stations. A Mann–Kendall test was used for trend analysis with Sen’s estimator. As a result, we determined that for the 1970–2021 period, the maximum and minimum temperatures increased by 1.1 and 0.7 °C, respectively, while precipitation had a negative trend (−52.2 mm per period). Since statistical significance was found in analysing extreme cold and hot events, we find that warming signals have several impacts on South Australia. In the case of rainfall events, we identified a heterogeneous pattern characterised by a reduction in the annual amount and an increase in extreme rainfall events. The findings enable us to conclude that the area shows signs of global warming that could affect the intensity and magnitude of droughts. This information is essential for continuing with current management strategies to adapt and mitigate the effects of global warming in South Australia.

We compared 2019 influenza seasonality and vaccine effectiveness (VE) in four southern hemisphere countries: Australia, Chile, New Zealand and South Africa. Influenza seasons differed in timing, duration, intensity and predominant circulating viruses. VE estimates were also heterogeneous, with all-ages point estimates ranging from 7-70% (I2: 33%) for A(H1N1)pdm09, 4-57% (I2: 49%) for A(H3N2) and 29-66% (I2: 0%) for B. Caution should be applied when attempting to use southern hemisphere data to predict the northern hemisphere influenza season.

Abstract The performance of 61 global climate models participating in CMIP5 and 6 is evaluated for the Southern Hemisphere extratropics in terms of typical regional‐scale atmospheric circulation patterns. These patterns are known to be linked with a number of key variables in atmospheric physics and chemistry and provide an overarching concept for model evaluation. First, hemispheric‐wide error and ranking maps are provided for each model and regional details are described. Then, the results are compared with those obtained in a companion study for the Northern Hemisphere. For most models, the average error magnitude and ranking position is similar on both hemispheres, ruling out systematic tuning toward either of the two. CMIP6 models perform better on average than CMIP5 models and the interactive simulation of more climate system components does not deteriorate the results for most model families. Better performance is associated with higher resolution in the atmosphere, following a non‐linear relationship.

Mercury (Hg) fate and transport research requires more effort to obtain a deep knowledge of its biogeochemical cycle, particularly in the Southern Hemisphere and Tropics that are still missing of distributed monitoring sites.Continuous monitoring of atmospheric Hg concentrations and trend worldwide is relevant for the effectiveness evaluation of the Minamata Convention on Mercury (MCM) actions. In this context, Gaseous Elemental Mercury (GEM) and total mercury (THg) in precipitations were monitored from 2013 to 2019 at the Amsterdam Island Observatory (AMS - 37°48′S, 77°34′E) to provide insights into the Hg pathway in the remote southern Indian Ocean, also considering ancillary dataset of Rn-222, CO2, CO, and CH4. GEM average concentration was 1.06 ± 0.07 ng m−3, with a slight increase during the austral winter due to both higher wind speed over the surface ocean and contributions from southern Africa. In wet depositions, THg average concentration was 2.39 ± 1.17 ng L−1, whereas the annual flux averaged 2.04 ± 0.80 μg m−2 year−1. In general, both GEM and Volume-Weighted Mean Concentration (VWMC) of THg did not show an increasing/decreasing trend over the seven-year period, suggesting a substantial lack of evolution about emission of Hg reaching AMS.Air masses Cluster Analysis and Potential Source Contribution Function showed that oceanic evasion was the main Hg contributor at AMS, while further contributions were attributable to long-range transport events from southern Africa, particularly when the occurrence of El Niño increased the frequency of wildfires.

Shifts in flowering phenology have been studied in detail in the northern hemisphere and are a key plant response to climate change. However, there are relatively fewer data on species' phenological shifts in the southern hemisphere.We combined historic field data, data from herbarium specimens dating back to 1842 and modern field data for 37 Australian species to determine whether species were flowering earlier in the year than they had in the past. We also combined our results with data compiled in the southern and northern hemispheres, respectively, to determine whether southern hemisphere species are showing fewer advances in flowering phenology through time.Across our study species, we found that 12 species had undergone significant shifts in flowering time, with four species advancing their flowering and eight species delaying their flowering. The remaining 25 species showed no significant shifts in their flowering phenology. These findings are important because delays or lack of shifts in flowering phenology can lead to mismatches in trophic interactions between plants and pollinators or seed dispersers, which can have substantial impacts on ecosystem functioning and primary productivity. Combining our field results with data compiled from the literature showed that only 58.5% of southern hemisphere species were advancing their flowering time, compared with 81.6% of species that were advancing their flowering time in the northern hemisphere. Our study provides further evidence that it is not adequate for ecologists to assume that southern hemisphere ecosystems will respond to future climate change in the same way as ecosystems north of the Equator.Synthesis. Field data and data from the literature indicate that southern hemisphere species are showing fewer advances in their flowering phenology through time, especially in comparison to northern hemisphere species. [ABSTRACT FROM AUTHOR]

Francis Henry Dumville Smythe (1873-1966), a humble clergyman from England, spent a lifetime amassing his private collection of British watercolours. During the 1950s, he decided to gift the bulk of them to two art institutions in New Zealand - Dunedin Public Art Gallery and the National Art Gallery in Wellington. They were welcomed with open arms and celebrated as "the finest collection of water colour pictures in the Southern Hemisphere." However, they soon fell out of favour as shifting aesthetic tastes and calls for a new national identity dominated the art scene in New Zealand during the latter half of the twentieth century. This paper will examine Smythe's collecting habits and tastes in art, as well as the formation, gifting and reception of the collection in Wellington and Dunedin. It is based on two chapters from the author's PhD thesis "A Matter of Taste: The Fate of the Archdeacon Smythe Collection of British Watercolours in New Zealand" (2021). [ABSTRACT FROM AUTHOR]

Most climate models show a poleward shift of the southern hemispheric zonal-mean jet in response to climate change, but the inter-model spread is large. In an attempt to constrain future jet responses, past studies have identified an emergent constraint between the climatological jet latitude and the future jet shift in austral winter. However, we show that the emergent constraint only arises in the zonal mean and not in separate halves of the hemisphere, which questions the physicality of the emergent constraint. We further find that the zonal-mean jet latitude does not represent the latitude of a zonally coherent structure, due to the presence of a double-jet structure in the Pacific region during this season. The zonal asymmetry causes the previously noted large spread in the zonal-mean climatology but not in the response, which underlies the emergent constraint. We therefore argue that the emergent constraint on the zonal-mean jet cannot narrow down the spread in future wind responses, and we propose that emergent constraints on the jet response in austral winter should be based on regional rather than zonal-mean circulation features. [ABSTRACT FROM AUTHOR]

Much of Antarctica's highly endemic terrestrial biodiversity is found in small ice‐free patches. Substantial genetic differentiation has been detected among populations across spatial scales. Sampling is, however, often restricted to commonly‐accessed sites and we therefore lack a comprehensive understanding of broad‐scale biogeographic patterns, which could impede forecasts of the nature and impacts of future change. Here, we present a synthesis of published genetic studies across terrestrial Antarctica and the broader Antarctic region, aiming to identify current biogeographic patterns, environmental drivers of diversity and future research priorities. A database of all published genetic research from terrestrial fauna and flora (excl. microbes) across the Antarctic region was constructed. This database was then filtered to focus on the most well‐represented taxa and markers (mitochondrial COI for fauna, and nuclear ITS for flora). The final dataset comprised 7222 records, spanning 153 studies of 335 different species. There was strong taxonomic bias towards flowering plants (52% of all floral data sets) and springtails (54% of all faunal data sets), and geographic bias towards the Antarctic Peninsula and Victoria Land. Recent connectivity between the Antarctic continent and neighbouring landmasses, such as South America and the Southern Ocean Islands (SOIs), was inferred for some groups, but patterns observed for most taxa were strongly influenced by sampling biases. Above‐ground wind speed and habitat heterogeneity were positively correlated with genetic diversity indices overall though environment was a generally poor predictor of genetic diversity. The low resolution and variable coverage of data may also have reduced the power of our comparative inferences. In the future, higher‐resolution data, such as genomic SNPs and environmental modelling, alongside targeting sampling of remote sites and under sampled taxa, will address current knowledge gaps and greatly advance our understanding of evolutionary processes across the Antarctic region. [ABSTRACT FROM AUTHOR]

Background: Two antigenically and genetically distinct lineages of influenza B viruses (B/Victoria and B/Yamagata) have been co-circulating worldwide since 2002. Virological surveillance is essential to differentiate between both lineages with a view to the annual updating of the B component for the trivalent or quadrivalent influenza vaccine composition. Methods: The samples analyzed in the present study were collected by influenza sentinel units located in the Southeast, Midwest, North, and Northeast regions of Brazil, part of the National Influenza Virus Surveillance Network, coordinated by the Ministry of Health of Brazil. A total of 870 influenza B positive samples by reverse transcription real – time polymerase chain reaction (RT-qPCR), collected during 2014, 2015, and 2016 influenza seasons, were submitted to the influenza B lineage genotyping panel for characterization as B/Yamagata or Victoria lineages using RT-qPCR. Results: Of the 197 samples analyzed in 2014, a total of 160 (81 %) corresponded to the B/Yamagata lineage, 19 (10 %) to the B/Victoria lineage, and 18 (9 %) to indeterminate lineages. Of the 190 samples analyzed in 2015, a total of 124 (65 %) corresponded to the B/Yamagata lineage; 55 (29 %) to the B/Victoria lineage, whereas 11 (6 %) were of indeterminate lineages. Of the 483 samples analyzed in 2016, a total of 297 (62 %) corresponded to the B /Victoria lineage; 174 (36 %) to the B/Yamagata lineage and 12 (2 %) to indeterminate lineages. This cross-sectional study revealed influenza B virus (IBV) infection in all age groups, and among them, the highest prevalence was observed in individuals between 11 and 49 years of age Our findings demonstrate the match between influenza B virus lineages recommended by the World Health Organization (WHO) for the trivalent vaccine composition to be used in the Southern Hemisphere (SH) and the predominant circulating viruses during the 2014, 2015, and 2016 seasons.

High‐time resolution (1h) aerosol composition measurements were performed in the Southern Hemisphere during February 2018–April 2018. Na+ was the most abundant water‐soluble ion (WSI) species, accounting for 67% of the total WSIs. The highest Na+ levels were observed in low‐middle latitudes (20–40°S) with an average concentration of 2.69 ± 2.16 μg m−3. This was 2–3 times greater than in other regions. Low temperature (T) and strong short‐term variations of wind speed (WS) were associated with relatively low Na+ concentrations in high‐middle latitudes (40–60°S), where there was a strong mean WS (9.1 m s−1). When WS < 7 m s−1, Na+ concentrations were low in all T ranges. Temperature and Na+ concentrations were moderately positively correlated when 10 ≤ WS < 13 m s−1 and WS ≥ 13 m s−1 (R2 = 0.48 and 0.34, respectively). Na+ concentrations were very low when relative humidity (RH) < 60% and significantly increased when RH was between 70% and 90%. However, Na+ concentrations under high RH (90%–100%) were not higher than those with RH between 70% and 90%, implying that a number of fine particles will increase their mass and convert to coarse particles and lead to a greater gravity sedimentation in high RH. Close to the Antarctic, Na+ concentrations decreased significantly under high WS levels, suggesting that sea ice cover reduces the production of sea salt aerosols (SSAs). What's more, air mass trajectory and the source of air mass also had an effect on the concentrations of SSAs. The results presented here extend the knowledge of the impact of sea salt on atmospheric aerosols above the Southern Hemisphere Ocean. Key Points: Marine aerosols were determined with high‐time‐resolution in the Southern HemisphereSea salt aerosols (SSAs) emissions would be increased with the air temperatureThe concentrations of SSAs do not always increase with the increases of wind speed [ABSTRACT FROM AUTHOR]

The lygaeoid Orsillus depressus Dallas feeds on seeds of several species, mainly cypress. Since the end of the last century, it has extended its range from its native area in the Mediterranean Basin towards northeastern Europe and it is considered an invasive species. In the present work, the presence of O. depressus is reported for the first time from the New World and Southern Hemisphere. Host plants and distribution from central-southern Argentina are given. In addition, morphological characters that allow their identification are provided. [ABSTRACT FROM AUTHOR]

In the Northern Hemisphere, recurrence of transient synoptic-scale Rossby wave packets in the same phase over periods of days to weeks, termed RRWPs, may repeatedly create similar surface weather conditions. This recurrence can lead to persistent surface anomalies. Here, we first demonstrate the significance of RRWPs for persistent hot spells in the Southern Hemisphere (SH) using the ERA-Interim (ERA-I) reanalysis dataset and then examine the role of RRWPs and blocks for heatwaves over south-eastern Australia (SEA). A Weibull regression analysis shows that RRWPs are statistically associated with a significant increase in the duration of hot spells over several regions in the SH, including SEA. Two case studies of heatwaves in SEA in the summers of 2004 and 2009 illustrate the role of RRWPs in forming recurrent ridges (anticyclonic potential vorticity – PV – anomalies), aiding in the persistence of the heatwaves. Then, using a weather-station-based dataset to identify SEA heatwaves, we find that SEA heatwaves are more frequent than climatology during days with extreme RRWPs activity over SEA (high RSEA). On days with both high RSEA and heatwaves, circumglobal zonal wavenumber 4 and 5 (WN4, WN5) anomaly patterns are present in the composite mean of the upper-level PV field, with an anticyclonic PV anomaly over SEA. The Fourier decomposition of the PV and meridional wind velocity fields further reveals that the WN4 and WN5 components in the suitable phase aids in forming the ridge over SEA for days with high RSEA. In addition, we find anomalous blocking over the Indian and the South Pacific oceans during SEA heatwaves, which may help to modulate the phase of RRWPs. [ABSTRACT FROM AUTHOR]

An updated climatology for the occurrence of blockings in the Southern Hemisphere (SH) using daily reanalysis data from 1948–2021 is presented. Geopotential height (z) at 500 hPa was the working variable. The blocking index (BI) was defined for every 2.5° of longitude whenever z (35 °   S) − z (50 °   S) < 0 . The results were organized in longitudinal bands of a width of 10° in order to compare them with previous findings. The primary region for the occurrence of blockings was located around the date line, with a secondary region in southern South America (SSA) and its vicinities, with a third-rank region situated in southern Africa and its surroundings. The results were also stratified by the intensity and duration (persistence) of the events, and the annual and seasonal differences were discussed. Additionally, three different areas were defined to study the distribution of the blockings therein, with the Pacific region (110° E–80° W) having the maximum intensities and longest durations. Linear trends were estimated for the annual and the seasonal time series of the BI and for the number of episodes. On an annual basis, more frequent and the strongest events are expected at 180° E and their surroundings in the future. An alternative BI, using radiosonde data, was built for SSA at 58.50° W. The time evolution of this index was in general agreement with the one estimated from the reanalysis data at some longitudes. [ABSTRACT FROM AUTHOR]

Cold fronts make a significant contribution to cool season rainfall in the extratropics and subtropics. In many regions of the Southern Hemisphere the amount of frontal rainfall has declined in recent decades, but there has been no change in frontal frequency. We show that for southeast Australia this contradiction cannot be explained by changes in frontal intensity or moisture at the latitudes of interest. Rather, declining frontal rainfall in southeast Australia is associated with weakening of the subtropical westerlies in the mid troposphere, which is part of a hemispheric pattern of wind anomalies that modifies the extratropical zonal wave 3. Fronts that generate rainfall are associated with strong westerlies that penetrate well into the subtropics, and the observed decrease in frontal rainfall in southern Australia can be linked to a decrease in the frequency of fronts with strong westerlies at 25° S. [ABSTRACT FROM AUTHOR]

Subantarctic Nothofagus forests are the southernmost forests in the world, with negligible atmospheric nitrogen (N) deposition. Most paradigms about the role of ectomycorrhizal (ECM) fungi in N cycling and plant N uptake at high latitudes have been tested in boreal coniferous forests, while in the southern hemisphere, ECM hosts are primarily angiosperms. Using ITS1 meta-barcoding, we characterized ECM and saprotrophic fungal communities in evergreen and deciduous Nothofagus forests forming monodominant and mixed stands in the archipelago of Tierra del Fuego (Chile and Argentina). We assessed the N economy of Nothofagus by correlating host species with fungal relative abundances, edaphic variables, net N mineralization, microbial biomass N and the activity of eight extracellular soil enzymes activities. The N economy of deciduous N. pumilio forests was strikingly similar to boreal coniferous forests, with the lowest inorganic N availability and net N mineralization, in correlation to higher relative abundances of ECM fungi with enzymatic capacity for organic N mobilization (genus Cortinarius ). In contrast, the N economy of evergreen N. betuloides forests was predominantly inorganic and correlated with ECM lineages from the family Clavulinaceae, in acidic soils with poor drainage. Grassy understory vegetation in deciduous N. antarctica forests likely promoted saprotrophic fungi (i.e., genus Mortierella ) in correlation with higher activities of carbon-degrading enzymes. Differences between Nothofagus hosts did not persist in mixed forests, illustrating the range of soil fertility of these ECM angiosperms and the underlying effects of soil and climate on Nothofagus distribution and N cycling in southern Patagonia., Competing Interests: The authors have no conflict of interest to declare., (© 2024 The Author(s). Ecology and Evolution published by John Wiley & Sons Ltd.)

The Cretaceous “high-fire” period was a global event that reached almost all continental masses during that period in Earth’s history. The extensive wildfires directly affected plant communities. Significant palaeobotanical records in the Antarctic Peninsula have been studied from the James Ross Sub-Basin, especially from the Santa Marta Formation. However, there is no described evidence for palaeo-wildfires in the area so far. Here, we present the first occurrence of fossilized macro-charcoal coming from James Ross Island, confirming that palaeo-wildfires occurred in the Campanian vegetation preserved in the Santa Marta Formation. The new charcoal material has a gymnospermous taxonomic affinity, more specifically with the Araucariaceae, which is in accordance with previous palaeobotanical records from James Ross Island. This occurrence adds new information to the construction of the palaeo-wildfire scenario for Gondwana.

During the COVID-19 pandemic, immunization programs for other respiratory infections, notably influenza continued worldwide but attracted less public or political attention than COVID-19 vaccinations. Due to non-pharmaceutical intervention measures the global influenza burden decreased substantially; but with lifting of restrictions a rebound in other respiratory virus pathogens is both plausible and likely. This article discusses lessons identified from the UK and USA, and provides recommendations for future influenza vaccination programs in light of emerging data from the southern hemisphere and the need for harmonization with COVID-19 vaccination, focusing on operational delivery and messaging to practitioners and the public.

Abstract High‐time resolution (1h) aerosol composition measurements were performed in the Southern Hemisphere during February 2018–April 2018. Na+ was the most abundant water‐soluble ion (WSI) species, accounting for 67% of the total WSIs. The highest Na+ levels were observed in low‐middle latitudes (20–40°S) with an average concentration of 2.69 ± 2.16 μg m−3. This was 2–3 times greater than in other regions. Low temperature (T) and strong short‐term variations of wind speed (WS) were associated with relatively low Na+ concentrations in high‐middle latitudes (40–60°S), where there was a strong mean WS (9.1 m s−1). When WS

Mercury is a toxic pollutant that can negatively impact the population's health and the environment. The research on atmospheric mercury is of critical concern because of the diverse process that this pollutant suffers in the atmosphere as well as its deposition capacity, which can provoke diverse health issues. The Minamata Convention encourages the protection of the adverse effects of mercury, where research is a part of the strategies and atmospheric modelling plays a critical role in achieving the proposed aim. This paper reviews the study of modelling atmospheric mercury based on the southern hemisphere (SH). The article discusses diverse aspects focused on the SH such as the spatial distribution of mercury, its emissions projections, interhemispheric transport, and deposition. There has been a discrepancy between the observed and the simulated values, especially concerning the seasonality of gaseous elemental mercury and total gaseous mercury. Further, there is a lack of research about the emissions projections in the SH and mercury deposition, which generates uncertainty regarding future global scenarios. More studies on atmospheric mercury behaviour are imperative to better understand the SH's mercury cycle. [ABSTRACT FROM AUTHOR]

Most climate models show a poleward shift of the southern hemispheric jet in response to climate change, but the inter-model spread is large. In an attempt to constrain future jet responses, past studies have identified an emergent constraint between the climatological jet latitude and the future jet shift in austral winter. However, we show that the emergent constraint only arises in the zonal mean, and not in separate halves of the hemisphere. This can be explained by the presence of a double jet structure in the Pacific region, making the zonal mean jet latitude a poorly defined quantity that does not represent the latitude of a zonally coherent structure during this season. The usefulness of the emergent constraint is therefore questionable. This finding can further explain the prior finding among CMIP5 and CMIP6 ensembles that the meridional structure of the zonal-mean zonal wind response does not change with climatological jet latitude but stays fixed. [ABSTRACT FROM AUTHOR]

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Abstract Rapid evolution is likely to be an important mechanism allowing native species to adapt to changed environmental conditions. Many Northern Hemisphere species have undergone substantial recent changes in phenology and morphology. However, we have little information about how native species in the Southern Hemisphere are responding to climate change. We used herbarium specimens from 21 native alpine plant species in Kosciuszko National Park, Australia, to make over 1,500 measurements of plant size, leaf thickness, leaf mass per area, leaf shape, and leaf size across the last 126 years. Only two out of 21 species (9%) showed significant changes in any of the measured traits. The number of changes we observed was not significantly different to what we would expect by chance alone, based on the number of analyses performed. This lack of change is not attributable to methodology—an earlier study using the same methods found significant changes in 70% of species introduced to southeast Australia. Australia's native alpine plants do not appear to be adapting to changed conditions, and because of the low elevation of Australia's mountains, they do not have much scope for uphill migration. Thus, our findings suggest that Australia's native alpine plants are at even greater risk in the face of future climate change than was previously understood.