Southward Expansion Research Articles

How Has the Ferrel Cell Contributed to the Maintenance of Antarctic Sea Ice at Low Levels From 2016 to 2022?

AbstractThis study investigates the specific circulation anomalies that have sustained the low Antarctic sea ice state since 2016. Firstly, we find a significant strengthening and southward shift in the Ferrel Cell (FC) during 2016–2022, resulting in a marked increase in southward transport of heat and moisture. Secondly, this enhanced FC is closely associated with a stronger mid‐latitude wave pattern. This pattern is zonally asymmetric and greatly amplifies the poleward advections of heat and moisture, leading to the increased downward longwave radiation, more liquid precipitation and sea ice retreat in specific regions, including the western Pacific and Indian Ocean sectors, Ross and northern Weddell Seas. The mechanism deduced from the short‐term period is further supported by the results of 40 ensemble members of simulations. The southward expansion of the FC and sea ice decline are closely linked to La Niña‐like conditions but may also be driven by anthropogenic global warming.

Impact of Data Assimilation in Sensitive Features on the Predictability of the 2012 Great Arctic Cyclone

AbstractThe Great Arctic Cyclone 2012 (AC12) is used to understand the role of initial condition errors in the predictability at 2–3‐day forecast range of a high‐impact summer Arctic Cyclone (AC). Ensemble sensitivity analysis (ESA) is first performed to identify potentially sensitive regions of the cyclone evolution using an ensemble baseline forecast with conventional in situ observations assimilated. A pseudo‐observation method is then introduced to investigate impacts of hypothetical observations in these sensitive but unobserved regions. In the baseline experiments with in situ observations assimilated, the forecasted AC12 reaches its peak intensity 18 hr earlier than in the verifying Global Forecast System Analysis (GFS‐ANL) and the cyclone track is biased toward the southwest. Using ESA, the time of peak intensity and the cyclone track error are identified to be sensitive to the upstream trough, downstream ridge, and the tropopause polar vortex (TPV) to the northeast (NE TPV) of the AC12. These features were not observed by the in situ observation networks. To examine the impact of the observation gaps, pseudo‐observations drawn from GFS‐ANL are assimilated. Pseudo‐observations sample the three features separately to study the impact of the initial condition error on the predictability of AC12. The cyclone peak intensity timing error and track error are greatly reduced when the initial condition error is reduced near the NE TPV. A southward expansion of the NE TPV and the corresponding southward shifting low‐level front lead the forecasted AC12 to progress to the east, which better agrees with the verifying GFS‐ANL.

Field monitoring and genetic diversity of the large copper butterfly <i>Lycaena dispar</i> (Lepidoptera: Lycaenidae)

The large copper butterfly Lycaena dispar (Haworth, 1803) (Lepidoptera: Lycaenidae), which is found across Europe and Asia, has been categorized as a near-threatened species (NT) in South Korea from 2012 mainly due to limited distribution. The species has been infrequently observed outside its traditional range in the northwestern region, but no nationwide survey has yet been conducted. In addition, the population genetic data of L. dispar, which is informative to evaluate its vulnerability, remains unknown. In this study, we visited 36 sites spread across all South Korean provinces to verify the distributional range of the species. Mitochondrial cytochrome oxidase subunit I (COI) was also partially sequenced for 53 individuals from nine sites. We observed L. dispar at 15 sites in six provinces, including the two previously known provinces, indicating a southward range expansion. The in-field monitoring and genetic data collectively suggested that L. dispar does not have a limited distribution nor is it isolated, indicating that it should be reclassified as less vulnerable. Our study demonstrates that the combination of field and genetic data can provide a more reliable assessment of the stability of a species.

Molecular phylogeny confirms the subspecies delineation of the Malayan Siamang (Symphalangussyndactyluscontinentis) and the Sumatran Siamang (Symphalangussyndactylussyndactylus) based on the hypervariable region of mitochondrial DNA.

Siamangs (Symphalangussyndactylus) are native to Peninsular Malaysia, Sumatra and southern Thailand and their taxonomical classification at subspecies level remains unclear. Morphologically, two subspecies were proposed as early as 1908 by Thomas namely Symphalangus s.syndactylus and Symphalanguss.continentis. Thus, this study aims to clarify the Siamang subspecies status, based on mtDNA D-loop sequences. Faecal samples were collected from wild Siamang populations at different localities in Peninsular Malaysia. A 600-bp sequence of the mitochondrial D-loop region was amplified from faecal DNA extracts and analysed along with GenBank sequences representing Symphalangus sp., Nomascus sp., Hylobates sp., Hoolock sp. and outgroups (Pongopygmaeus, Macacafascicularis and Papiopapio). The molecular phylogenetic analysis in this study revealed two distinct clades formed by S.s.syndactylus and S.s.continentis which supports the previous morphological delineation of the existence of two subspecies. Biogeographical analysis indicated that the Sumatran population lineage was split from the Peninsular Malaysian population lineage and a diversification occurrred in the Pliocene era (~ 3.12 MYA) through southward expansion. This postulation was supported by the molecular clock, which illustrated that the Peninsular Malaysian population (~ 1.92 MYA) diverged earlier than the Sumatran population (~ 1.85 MYA). This is the first study to use a molecular approach to validate the subspecies statuses of S.s.syndactylus and S.s.continentis. This finding will be useful for conservation management, for example, during Siamang translocation and investigations into illegal pet trade and forensics involving Malayan and Sumatran Siamangs.

Cyclic climate impacts on human activity in northern Central China recorded by varve evidence from the western Loess Plateau

Disentangling the relationship between climate change and human activities is a major challenge in paleoenvironmental research. Here, we report a decadal-resolution sedimentological record from an annually laminated archive from the western Loess Plateau spanning the Middle-Late Holocene, along with a database of archaeological radiocarbon dates in northern central China. Our results reveal the occurrence of 400–600-yr cyclic variations in the climate over the last 6200 years, which correlate well with the periodicities of solar activity and the East Asian summer monsoon. This mode of climate change is associated temporally and regionally with specific prehistoric human activities. More favorable warm-humid environmental conditions may have simultaneously facilitated cultural prosperity and population growth, while less favorable cold-dry periods may have led to cultural alterations and population decline. In addition, we determine that there is a closely coupled relationship between the fluctuations in geopolitical and socioeconomic variables and the cyclicity of the environmental changes in imperial China. That is, the warm-humid cycles are characterized by the northward expansion of agriculturalist empires, a decrease in the number of battles, bumper grain harvests, and economic development, while the cold-dry cycles are characterized by the southward expansion of pastoralist empires, an increase in the number of battles, famines, and economic recession. Further analysis of our study will increase the understanding of human dispersal, cultural exchanges, and climate-human interactions within and beyond northern China.

The influence of glacial landscape evolution on Scandinavian ice-sheet dynamics and dimensions

Abstract. The Scandinavian topography and bathymetry have been shaped by ice through numerous glacial cycles in the Quaternary. In this study, we investigate how the changing morphology has influenced the Scandinavian ice sheet (SIS) in return. We use a higher-order ice-sheet model to simulate the SIS through a glacial period on three different topographies, representing different stages of glacial landscape evolution in the Quaternary. By forcing the three experiments with the same climate conditions, we isolate the effects of a changing landscape morphology on the evolution and dynamics of the ice sheet. We find that early Quaternary glaciations in Scandinavia were limited in extent and volume by the pre-glacial bathymetry until glacial deposits filled depressions in the North Sea and built out the Norwegian shelf. From middle–late Quaternary (∼0.5 Ma) the bathymetry was sufficiently filled to allow for a faster southward expansion of the ice sheet causing a relative increase in ice-sheet volume and extent. Furthermore, we show that the formation of The Norwegian Channel during recent glacial periods restricted southward ice-sheet expansion, only allowing for the ice sheet to advance into the southern North Sea close to glacial maxima. Finally, our experiments indicate that different stretches of The Norwegian Channel may have formed in distinct stages during glacial periods since ∼0.5 Ma. These results highlight the importance of accounting for changes in landscape morphology through time when inferring ice-sheet history from ice-volume proxies and when interpreting climate variability from past ice-sheet extents.

Genetic formation of Sui populations in southwest China

AbstractThe Sui people living in Guizhou province have a unique ethnic culture and population history due to their long‐time isolation from other populations. To investigate the genetic structure of Sui populations in different regions of Guizhou, we genotyped 89 individuals from four Sui populations using genome‐wide single nucleotide polymorphisms arrays. We analyzed the data using principal component analysis, ADMIXTURE analysis, f‐statistics, qpWave/qpAdm, TreeMix analysis, fineSTRUCTURE, and GLOBETROTTER. We found that Sui populations in Guizhou were genetically homogeneous and had a close genetic affinity with Tai‐Kadai‐speaking populations, Hmong‐Mien‐speaking Hmong, and some ancient populations from southern China. The Sui populations could be modeled as an admixture of 33.5%–37.9% of Yellow River Basin farmer‐related ancestry and 62.1%–66.5% of Southeast Asian‐related ancestry, indicating that the southward expansion of northern East Asian‐related ancestry influenced the formation of the Tai‐Kadai‐speaking Sui people. Future publications of more ancient genomics in southern China could effectively provide further insight into the demographic history and population structure of the Sui people.

5-6세기 고구려의 몽촌토성 점유 양상에 관한 연구

This paper aims to examine the processs of regeneration of Mongchontoseong by Goguryeo, following Baekje’s relocation of its capital to Ungjin. Drawing upon the artifacts from 1980s excavation and the recent fieldwork findings, this study explores the spatial and temporal reorganization in the Mongchontoseong after 5th century AD. The spatial distribution of the pottery from the southern part of the inner Mongchontoseong site was first explored. Goguryeo strategically reused places previously built by Baekje, including storage, ponds, and pits, and also altered the built environment. The features, iron weapons, farming tools, and pottery type also reveal the diverse aspects of the long-term occupation of Goguryeo, taking the roles of domestic housing, rituals, agricultural activities, and storage. The radiocarbon dating results from the pits and roadways show Goguryeo’s active engagement in infrastructure reconstruction from the late 5th century to the middle of the 6th century, predating the reoccupation by the allied forces of Baekje and Silla in 550 AD. The material evidence reveals Goguryeo’s prolonged regeneration of the site for the southward expansion, as sociopolitical strategies in the context of warfare in the Korean Peninsula during 5-6th century AD.

Phylogeography and ecological niche modelling of the South American cricetid rodent Graomys griseoflavus, with insights into its chromosomal evolution

Abstract The rodent Graomys griseoflavus has a wide geographical distribution in the Arid Diagonal of South America, showing variation in the diploid number (2n = 33–38) caused by three different Robertsonian (Rb) translocations. Two contrasting hypotheses have been proposed to explain the origin and evolution of this polymorphism: (i) unique and sequential events; or (ii) multiple and independent origins of Rb translocations. Here, we combined phylogeography and ecological niche modelling to elucidate the evolutionary history of G. griseoflavus and help to contrast these hypotheses. The results indicated a demographic increase that would have begun ~150 kya from the High Monte ecoregion. The spatial distributions of these populations were coincident with the areas of highest habitat suitability. The palaeoclimatic projections suggested the presence of two main glacial refugia coincident with the main genetic clusters. Graomys griseoflavus underwent two pulses of southward expansion at ~220 and ~210 kya. More recently (~20 kya), there was a secondary contact between the southern populations (Low Monte ecoregion) expanding northwards and the northern populations (High Monte ecoregion) expanding into marginal areas of the Chaco ecoregion. Combined with the cytogenetic evidence, our results support the multiple and independent origins of Rb translocations.

Whole genome sequencing reveals stepping-stone dispersal buffered against founder effects in a range expanding seabird.

Many species are shifting their ranges in response to climate-driven environmental changes, particularly in high-latitude regions. However, the patterns of dispersal and colonization during range shifting events are not always clear. Understanding how populations are connected through space and time can reveal how species navigate a changing environment. Here, we present a fine-scale population genomics study of gentoo penguins (Pygoscelis papua), a presumed site-faithful colonial nesting species that has increased in population size and expanded its range south along the Western Antarctic Peninsula. Using whole genome sequencing, we analysed 129 gentoo penguin individuals across 12 colonies located at or near the southern range edge. Through a detailed examination of fine-scale population structure, admixture, and population divergence, we inferred that gentoo penguins historically dispersed rapidly in a stepping-stone pattern from the South Shetland Islands leading to the colonization of Anvers Island, and then the adjacent mainland Western Antarctica Peninsula. Recent southward expansion along the Western Antarctic Peninsula also followed a stepping-stone dispersal pattern coupled with limited post-divergence gene flow from colonies on Anvers Island. Genetic diversity appeared to be maintained across colonies during the historical dispersal process, and range-edge populations are still growing. This suggests large numbers of migrants may provide a buffer against founder effects at the beginning of colonization events to maintain genetic diversity similar to that of the source populations before migration ceases post-divergence. These results coupled with a continued increase in effective population size since approximately 500-800 years ago distinguish gentoo penguins as a robust species that is highly adaptable and resilient to changing climate.

Rapid southward range expansion of the Fairy Gerygone – a consequence of climate change?

Until the 1920s, the Australian range of the Fairy Gerygone Gerygone palpebrosa was thought to extend south from Cape York to Cardwell (18.3°S), Queensland. However, by 1981 the species was known to occur as far south as Tin Can Bay (25.9°S), and, by 1990, the Sunshine Coast (26.6°S). Sightings of individuals in the Brisbane region (27.5°S), 170 km south of Tin Can Bay, during 2011 and 2012 prompted a review of the southern range limits of the species, and consideration of causes for its southward range expansion. I collated records south of the 26°S parallel using three databases (eBird, WildNet and Atlas of Living Australia), then selected 30 sites that represented their spatial and temporal extent, noting their elevation, distance to the nearest coastline or watercourse, and vegetation according to the Regional Ecosystem classification. Sightings in the Brisbane region have been mostly along rivers or creeks emptying into Moreton Bay, suggesting that dispersal occurs southward along the coast, then inland via watercourses. Rather than being gradual, range expansion in this species has been characterised by ‘leaps’ of 45–59 km at intervals of 6–16 years. Since the early 1970s, at least five other tropical bird species have expanded their range southwards to Coastal Central Queensland. The most likely explanation for such range expansions is birds exploiting ‘new’ areas with suitable thermal regimes that have become available due to global warming. In the Fairy Gerygone, this process may be facilitated by (1) this species’ partiality for forest edge and riparian habitats, and (2) reduced competition with other gerygone species due to differences in preferred habitats and bill morphology.

Quantitative Assessment of Factors Influencing the Spatiotemporal Variation in Carbon Dioxide Fluxes Simulated by Multi-Source Remote Sensing Data in Tropical Vegetation

Vegetation plays a vital role in the global carbon cycle, a function of particular significance in regulating carbon dioxide fluxes within tropical ecosystems. Therefore, it is crucial to enhance the precision of carbon dioxide flux estimates for tropical vegetation and to explore the determinants influencing carbon sequestration. In this study, Landsat series images and Sentinel-2 Multispectral Instrument satellite data were used to invert vegetation biophysical parameters, thereby improving the timeliness and resolution of state variables from the boreal ecosystem productivity simulator (BEPS). The BEPS model at a 30 m resolution was developed to accurately capture tropical vegetation carbon dioxide fluxes across Hainan Island (HN) over the preceding two decades. The impacts of climate variations and anthropogenic activities on the carbon dioxide fluxes of tropical vegetation were further quantified using quantile regression models and a land-use transfer matrix. Results indicate significant increases in both net primary productivity (NPP) and net ecosystem productivity (NEP) in HN during the period 2000–2020, by 5.81 and 4.29 g C/m2 year, respectively. Spatial trends in vegetation carbon dioxide fluxes exhibited a consistent decline from inland regions to coastal zones. Anthropogenic activities were the dominant factor in the reduced stability of coastal NPP, while the post-2005 vegetation restoration promoted the southward expansion of high NPP (>1200 g C/m2) in the central part of HN. NPP in this tropical island was more sensitive to temperature than to precipitation, with a 1 °C temperature increase resulting in 4.1 g C/m2 reduction in dry-season NPP compared to wet-season NPP. Upgrades of cropland quality and grassland restoration have improved NPP yields, and land use transfers have resulted in a 0.301 Tg C net increase in NPP. This study provides new insight into the improvement of the carbon dioxide flux model at a finer scale for tropical vegetation and highlights ecological construction as an adaptation strategy to enhance the carbon sinks of tropical vegetation under negative climate change conditions.

Environmental evolution of western Tierra del Fuego (∼54°S) since ice-free conditions and its zonal/hemispheric implications

By virtue of its position adjacent to the Drake Passage, Tierra del Fuego in South America allows examining the vegetation and environmental history of the southernmost continental landmass outside Antarctica, and the evolution of the Southern Westerly Winds-Southern Ocean (SWW–SO) coupled system since the Last Glacial Maximum (LGM). For that purpose, we studied sediment cores from Lago Charquito, a small closed-basin lake in central-west Tierra del Fuego with a continuous lacustrine record since ∼17.3 ka. Ice-free conditions at the site imply a ∼70 km retreat of the Bahía Inútil glacier lobe from its LGM position during a ∼800-year interval, a trend that continued until its disappearance ∼100 km upstream from L. Charquito, ∼800 years later. Our palynological data show an open landscape dominated by cold-tolerant shrubs and herbs between ∼17.3–12.9 ka, with increases in precipitation of SWW origin at ∼16.3 ka, ∼14.7 ka, between ∼8.7–7.6 ka, and after ∼6.8 ka. Warming at ∼12.9 ka initiated an abrupt afforestation trend that stalled during the early Holocene (∼12–8.7 ka) owing to a precipitation decline and wildfires, and later resumed in response to invigorated SWW. We hypothesize that sparse Nothofagus tree populations inhabited the periphery of the Patagonian Ice Sheet (PIS) during the LGM and migrated toward the Andes contemporaneous with glacier recession as temperature rose during the Last Glacial Termination (T1). We posit that besides establishing topographic and climatic barriers for land biota, the PIS enabled the connectivity of cold-tolerant hygrophilous plant populations along a humid fringe adjacent to its land-based perimeter, despite the presumably dry conditions downwind from the eastern PIS margin. Our results suggest that southward shifts or expansion of the SWW toward or beyond Tierra del Fuego enhanced upwelling and ventilation of deep waters in the SO, northward shifts or weakening had the opposite effect. We observe that the time evolution of atmospheric CO2 concentrations, high-latitude air and sea-surface temperatures, and sea level during T1 fall short in explaining the timing and abruptness of the Bahía Inútil glacier lobe collapse, and quite possibly multiple other glacier lobes from the PIS.

Forager-farmer transition at the crossroads of East and Southeast Asia 4900 years ago

The southward expansion of East Asian farmers profoundly influenced the social evolution of Southeast Asia by introducing cereal agriculture. However, the timing and routes of cereal expansion in key regions are unclear due to limited empirical evidence. Here we report macrofossil, microfossil, multiple isotopic (C/N/Sr/O) and paleoproteomic data directly from radiocarbon-dated human samples, which were unearthed from a site in Xingyi in central Yunnan and which date between 7000 and 3300 a BP. Dietary isotopes reveal the earliest arrival of millet ca. 4900 a BP, and greater reliance on plant and animal agriculture was indicated between 3800 and 3300 a BP. The dietary differences between hunter-gatherer and agricultural groups are also evident in the metabolic and immune system proteins analysed from their skeletal remains. The results of paleoproteomic analysis indicate that humans had divergent biological adaptations, with and without farming. The combined application of isotopes, archaeobotanical data and proteomics provides a new approach to documenting dietary and health changes across major subsistence transitions.

Hybridization of Atlantic puffins in the Arctic coincides with 20th-century climate change.

The Arctic is experiencing the fastest rates of global warming, leading to shifts in the distribution of its biota and increasing the potential for hybridization. However, genomic evidence of recent hybridization events in the Arctic remains unexpectedly rare. Here, we use whole-genome sequencing of contemporary and 122-year-old historical specimens to investigate the origin of an Arctic hybrid population of Atlantic puffins (Fratercula arctica) on Bjørnøya, Norway. We show that the hybridization between the High Arctic, large-bodied subspecies F. a. naumanni and the temperate, smaller-sized subspecies F. a. arctica began as recently as six generations ago due to an unexpected southward range expansion of F. a. naumanni. Moreover, we find a significant temporal loss of genetic diversity across Arctic and temperate puffin populations. Our observations provide compelling genomic evidence of the impacts of recent distributional shifts and loss of diversity in Arctic communities during the 20th century.

Gray wolves as sentinels for the presence of Echinococcus spp. and other gastrointestinal parasites in France

Over the past 30 years, the gray wolf population has recovered in France, initially to wolves from Italy passing through the Alps. The population is carefully monitored, but little information is available on their helminth fauna, which includes parasites of public health importance: Echinococcus multilocularis and Echinococcus granulosus sensu lato. Capitalizing on the availability of 911 fecal samples collected for the noninvasive genetic monitoring of French wolf populations, along with the intestines from 15 dead wolves, the presence of Echinococcus species among others helminth species was evaluated in French wolves. A copro-PCR approach amplifying a large spectrum of parasites was used for fecal samples while intestines were analyzed using SCT. The fecal occurrences of E. granulosus sensu stricto (2.4%) and E. multilocularis (0.3%), and indeedother parasitic species, are similar to those of other European wolf populations including Taenia hydatigena (7.2%), Taenia krabbei (2.4%), Uncinaria stenocephala (2.4%), Mesocestoides litteratus (1.9%), Taenia ovis (0.3%), Taenia multiceps (0.1%), and Toxascaris leonina (0.1%). The three most abundant species were also found in the intestines. Infections by E. granulosus sensu stricto are in accordance with the overlap of wolf pack areas and sheep breeding pastoral units. However, the wolf does not appear to play a significant role in the lifecycle of E. granulosus sensu stricto. The availability of this opportunistic fecal sampling of wolves in southeastern France means that they can be used as sentinels for the surveillance of E. multilocularis in the context of its southward expansion observed in recent years.

Geographical and morphological changes of conifers in Yunnan, China during the Cenozoic in response to climatic changes

Yunnan province, known as a hot spot of plant diversity, is located in Southwest China and on the southeastern margin of the Qinghai-Tibet Plateau. Today, there are four families, 21 genera and 56 species of conifers found in Yunnan. Three families, 15 genera and 44 species of fossil conifers have been reported from the Cenozoic in Yunnan. In this study, we investigated the fossil conifers from the Cenozoic in Yunnan and their corresponding living species and evaluated the distribution and climatic conditions of the extant genera. Based on this analysis, paleoclimates of the fossils were reconstructed to determine the migration patterns of these conifers in response to climatic changes caused by the uplift of the Qinghai-Tibet Plateau. Our analyses show that the cooling trend led to a southward expansion and migration of conifers to warm and humid climate areas since the early Oligocene. In addition, the drought tendency led to the disappearance of certain conifer species from Yunnan, and the strengthening monsoon climate resulted in the migration of conifers eastward to eastern China or coastal areas, westward to western Yunnan, southeast Tibet and northern Myanmar and northward to dry and cold North China and North Korea. Likely adaptive morphological changes also occurred among the conifer species. The study also revealed that the diversity and composition of conifers in Yunnan have changed significantly since the early Oligocene with the uplift of the Qinghai-Tibet Plateau and climatic changes and that the extant lineages of Yunnan conifers appeared in the late Miocene.

Infectious diseases may have arrested the southward advance of microblades in Upper Palaeolithic East Asia.

An unsolved archaeological puzzle of the East Asian Upper Palaeolithic is why the southward expansion of an innovative lithic technology represented by microblades stalled at the Qinling-Huaihe Line. It has been suggested that the southward migration of foragers with microblades stopped there, which is consistent with ancient DNA studies showing that populations to the north and south of this line had differentiated genetically by 19 000 years ago. Many infectious pathogens are believed to have been associated with hominins since the Palaeolithic, and zoonotic pathogens in particular are prevalent at lower latitudes, which may have produced a disease barrier. We propose a mathematical model to argue that mortality due to infectious diseases may have arrested the wave-of-advance of the technologically advantaged foragers from the north.

Projected Strengthening Impact of the Quasi-Biennial Oscillation on the Southern Hemisphere by CMIP5/6 Models

Abstract Using 20 quasi-biennial oscillation (QBO)-resolving models from phases 5/6 of the Coupled Model Intercomparison Project (CMIP5/6), this study examines the projected Southern Hemisphere (SH) extratropical response to the QBO. Nine of the 22 models simulate decelerated circumpolar westerlies during easterly QBO (EQBO) in the historical climate as is observed, though only ∼30% of the observed change is reproduced in the multimodel ensemble mean (MME) of these high-skill models. These high-skill models project an enhanced stratospheric QBO teleconnection for both emissions scenarios. Further, the stratospheric wind anomaly in high latitudes is projected to move to midlatitudes in future scenarios. The climatological subtropical jet is projected to strengthen, while tropical easterlies are projected to weaken. As a consequence, upward wave activity in the future appears to become more sensitive to the QBO phase. Enhanced upward propagation of waves in mid- to high latitudes during EQBO are much stronger in future scenarios than in historical simulations. The anomalous downwelling over the Antarctic, as part of the Brewer–Dobson deep branch response to EQBO, is also projected to strengthen, corresponding to increased warm anomalies. In future scenarios, the areal extent of the deep convective response to EQBO over the Maritime Continent widens and includes a sharper reduction in outgoing longwave radiation, albeit with southward expansion from Indonesia to Australia. The enhancement and spatial shift in the stratospheric polar vortex pathway and tropical convection pathway subsequently lead to changes in the tropospheric QBO signal. An annular mode–like response forms in the troposphere and near-surface in the present climate, whereas this pattern shifts farther equatorward in future projections with circulation anomalies in the tropical Indian Ocean amplifying. Significance Statement The influence of the equatorial stratospheric quasi-biennial oscillation (QBO) has been reported to intensify in the Northern Hemisphere under climate change, even as the QBO wind magnitude weakens. It is still unknown whether the influence of the QBO on the Southern Hemisphere intensifies or weakens in a warm climate. Using simulations from multiple models, this study finds that the influence of the QBO on the Southern Hemisphere is projected to strengthen in most models even as the QBO weakens. Two QBO pathways are explored, including the stratospheric polar vortex route and the tropical convection pathway, both of which are projected to amplify in both the moderate- and high-emissions scenarios. In addition to the amplification of the QBO signals in the Southern Hemisphere extratropics, an equatorward shift of the maximum anomalies is also projected. That is, the maximum easterly anomalies in the Antarctic stratosphere during easterly QBO and the annular mode–like pattern in the troposphere or the near-surface shifts farther equatorward.

Land use function change and its driving force of the "production-living-ecological" space in Fenhe River Basin from 1980 to 2020.

It is of importance to analyze land use function change and driving factors of the production-living-ecological space of national territory to realize the coordinated development. Based on land use remote sensing data in 1980, 1990, 2000, 2010, and 2020, we used the methods of land use dynamics, transfer matrix, center of gravity shift and geographic detector to analyze the pattern of production-living-ecological space in Fenhe River Basin and explore the influencing factors. The results showed that the area proportion of production-living-ecological space in the basin was ecological space > production space > living space from 1980 to 2020. The ecological space and agricultural production land showed a decreasing trend, with a decrease of 72441.19 and 105882.96 hm2, respectively. The living space and industrial production land showed an upward trend, with an increase of 119503.02 and 58821.13 hm2, respectively. There was significant difference in the land use function change of production-living-ecological space. Agricultural production land had the largest transferred area, accounting for 47.9% of the total. The largest transfer area of industrial land was agricultural land, which accounted for 61.3% of the total from 2000 to 2010. The occupation of agricultural land by urban living land was mainly distributed in the marginal area of various urban areas of Taiyuan Basin. Among them, the increasing area of urban living land in Taiyuan City showed a trend of gradual southward expansion. The center of gravity migration of urban land for living and industrial production land was the most obvious, and that for living showed the trend of first moving south and then moving north, while industrial production land moved northward significantly. The influence of social-economic factors on the land use change was obviously stronger than that of natural factors, while the interaction between social-economic factors had a stronger explanatory power. The results would provide reference for clarifying the relationship between land function transformation and optimizing land use function of production-living-ecological space.