Eastern Central Asia Research Articles

Re-evaluating the origins of sands in the Gurbantunggut Desert and its role as an aeolian dust contributor

We analyzed the trace and rare earth element contents of the desert sands and loess deposits in the Junggar Basin. Combined with previously published data, and using principal component analysis, our results provide insights into the sand provenances of the Gurbantunggut Desert in eastern Central Asia (CA); the genetic links between deserts and loess deposits in CA; and the specific sources in CA for the aeolian dust in North Pacific Ocean sediments. The results demonstrate the spatial heterogeneity of the geochemistry of sand across the Gurbantunggut Desert. The desert sands in the northern and western parts of this desert are mainly derived from the Altai and Junggar mountains, respectively, as supported by the directions of sand fluxes. However, Beitashan Mountain makes a negligible contribution due to the lack of fluvial transport and westward sand fluxes. However, more sediment samples need to be collected to confirm the contribution of Tianshan Mountains. Our findings also indicate that the Gurbantunggut Desert did not contribute significantly to loess accumulation on the northern slopes of the Tianshan Mountains, in accordance with the weak genetic relationships between loess deposits and deserts in western CA. We attribute this to the limited ability of the CA deserts to produce and supply dust-sized particles. Additionally, using the Metropolis-Hastings sampling approach, we find that the Gurbantunggut Desert is not the source region in CA for the fine dust particles in North Pacific Ocean sediments. Overall, our results contribute to a deeper understanding of the aeolian systems in CA and their impacts on the dust cycle at a hemispheric scale.

Changes in alcohol, tobacco, cannabis, and other substance use and its association with mental health during the COVID-19 pandemic among sexual minority men in Eastern European and Central Asian countries

BackgroundThe COVID-19 pandemic had a particularly negative impact on mental wellbeing of vulnerable individuals, such as sexual minority men (SMM) living in Eastern Europe and Central Asia (EECA), where the social-political climate may be restrictive for SMM. Alcohol, tobacco, and other drugs (ATOD) use may be another factor contributing to exacerbated mental health among SMM in this region. MethodsSecondary analyses were conducted using data collected as part of the COVID-19 disparities survey from active users of Hornet, a popular geo-social networking app for SMM in late 2020. Using a subset of SMM living in EECA (n = 3209) and pre-validated scales (AUDIT-C and PHQ-4), we used multivariable logistic regression models to examine the relationship between changes in participants' use of ATOD and their mental wellbeing. ResultsBased on AUDIT-C, 35.1 % SMM screened for alcohol use disorder (AUD), 18.6 % reported an increase in alcohol use since the pandemic began. Over 30 % screened for depressive symptoms and anxiety based on PHQ-4 (30.4 % and 30.7 %, respectively). In multivariable models, AUD was significantly associated with screening positive for depressive symptoms and anxiety. Other factors associated with mental distress included lower socioeconomic status, unemployment, ethnic minority identity, IPV victimization, and financial and economic vulnerability. LimitationsCross-sectional data cannot be used to infer causality. ConclusionsOur results support the needs for integrated substance use reduction and mental health services tailored for SMM in EECA. Programs aimed at promoting mental wellbeing among SMM in EECA must consider both interpersonal and structural barriers.

Forecasting sustainable development goals scores by 2030 using machine learning models

AbstractThe Sustainable Development Goals (SDGs) set by the United Nations are a worldwide appeal to eliminate poverty, preserve the environment, address climate change, and guarantee that everyone experiences peace and prosperity by 2030. These 17 goals cover various global issues concerning health, education, inequality, environmental decline, and climate change. Several investigations have been carried out to track advancements toward these goals. However, there is limited research on forecasting SDG scores. This research aims to forecast SDG scores for global regions by 2030 using ARIMAX and LR (Linear Regression) smoothed by HW (Holt‐Winters') multiplicative technique. To enhance model performance, we used predictors identified from the SDGs that are more likely to be influenced by Artificial Intelligence (AI) in the future. The forecast results for 2030 show that “OECD countries” (80) (with a 2.8% change) and “Eastern Europe and Central Asia” (74) (with a 2.37% change) are expected to achieve the highest SDG scores. “Latin America and the Caribbean” (73) (with a 4.17% change), “East and South Asia” (69) (with a 2.64% change), “Middle East and North Africa” (68) (with a 2.32% change), and “Sub‐Saharan Africa” (56) (with a 7.2% change) will display lower levels of SDG achievement, respectively.

TURKIC SOURCES ABOUT THE PROTECTORATE OF THE OTTOMAN EMPIRE IN KASHGARIA (SECOND HALF OF THE 19TH CENTURY)

The article, based on information from the works of East Turkestan historians, examines the relationship of the Ottoman Empire with the state of Yakup Beg, which arose in Kashgaria in the second half of the 19th century. The purpose of the study is to conduct an in-depth study and conduct a source study, textual analysis of information from East Turkistan historians, which contain important and valuable information about the connections of the Ottoman Empire with Kashgaria and its neighbouring regions of Central Asia (Kazakhstan, Uzbekistan, Kyrgyzstan, etc.). The study is based on conclusions formed during a comparative analysis of information from Turkic written sources with archival materials and data from unique scientific literature. In the course of preparing the article, to determine the completeness and reliability of the information provided, comparative-contrastive, comparative-historical and problem-chronological methods, methods of analysis, collection, and synthesis of information were also used. This technique was used to compare essential documents on the records management of the Ottoman and Russian Empires of the period under study, stored in the archives and funds of various countries, with information from local East Turkestan historians. It should be noted that relations between the two states developed in the context of the “Great Game” policy of the great powers towards Central Asia. The works of local East Turkestan historians provide extensive information on events related to the relationship between the Zhetyshar state (the state of Yakup-bek) and the Ottoman Sultanate. The authors describe these events with tremendous verve and enthusiasm. The unity of the Turkic-speaking peoples, who for centuries nourished each other with great faith and hope, is reflected in the works of historians.

Magnesium Isotopes of Carbonate Reveal Seasonal Climate Variation in the Central East Asia During the Middle Eocene

AbstractIt is debated whether there was strong climate seasonality during the Eocene, which provides a close geological analogy for near‐future scenarios of greenhouse gas emissions. Lithological data suggest the existence of a broad arid zone centered around 30°N paleo‐latitude, while a humid climate was supported by palaeobotanic assemblages in East Asia. Here, we report the occurrence of massive primary lacustrine dolomite and magnesite in the central East Asia during the middle Eocene. We provide a novel perspective from magnesium isotopes to link the formation of Mg‐carbonates to seasonal dry‐wet cycles. Rapid magnesium input during the rainy season and intense evaporation in the dry season likely caused the formation of magnesium carbonates in an enclosed lake. These findings provide insights into hydroclimatic seasonality during the Eocene, contributing to our understanding of the hydrological cycle response to a greenhouse climate.

Studies on the Assessment of Hair Cortisol Concentration in Dogs by Radioimmunoassay (RIA)

Background: Hair cortisol Concentration (HCC) is often used as a measure of chronic stress responses in humans. The use of Radioimmunoassay (RIA) and HCC to assess stress in hospitalized dogs has been poorly reported in the literature in India and Central East Asia. This paper presents a modified protocol for measuring HCC in dog hair samples for stress assessment using RIA. Methods: Estimation of HCC concentrations of healthy (n=20) and hospitalized (n=20) dogs was done using RIA. Hair samples were collected from a dog’s nape region and weighed to measure HCC concentration. The study used RIA-enabled dissevered spiking and detectable concentration-based modifications to measure HCC. Five known cortisol concentration standards (viz 19.0 nmol/l, 47.9 nmol/l, 190 nmol/l, 238.66 nmol/l and 713.33 nmol/l) were used, with the first three readily available with a cortisol RIA kit. The samples were spiked with 50 µL of the standard and analysed in a gamma counter to take counts per minute (CPM). The final concentration of HCC was estimated in nmol/l and derived in pg/mg as per standard methods. Result: Healthy dogs had a mean HCC of 6.24±0.84 pg/mg, while hospitalized dogs had 31.65±5.87 pg/mg. A significant deviation was observed in both groups. A box and whisker graph showed an HCC range of 0.36 to 13.78 pg/mg for healthy dogs and 8.70 to 65.25 pg/mg for hospitalized dogs. The interquartile range (25th to 75th percentile) was 3.55 to 9.24 pg/mg for healthy dogs and 14.43 to 46.22 for hospitalized dogs. The observed median for healthy dogs was 6.16 pg/mg and 22.62 pg/mg for hospitalized dogs. The study shows higher HCC in hospitalized sick dogs compared to clinically healthy ones, suggesting hair sample collection as a simple stress assessment method and RIA as a promising HCC detection technique.

Extreme precipitation and temperature indices under future climate change in central Asia based on CORDEX-CORE

The present study analyzes the projected changes of extreme climate indices over Central Asia using regional climate model (RCM) simulations from the Coordinated Regional Climate Downscaling Experiment (CORDEX) - Coordinated Output for Regional Evaluations (CORE). The extreme indices are based on precipitation and temperature and are inspected for present (1981–2005) and future periods - near- (2031–2055) and far-future (2071–2095) - to assess the long-term climate change under the representative concentration pathway RCP8.5. Projected changes are analyzed for three different model ensembles. These ensembles are based on CORDEX-Central Asia (ENS_CAS, four ensemble members) and CORDEX-East Asia (ENS_EAS, six ensemble members), and a combination of both (ENS, ten ensemble members) for our study area centered over high mountain Asia, called Central East Asia (CEAS). For precipitation indices, an increase of consecutive dry days (CDD) in ENS_EAS and a slight to moderate decrease in northern parts in ENS_CAS during near-future is observed. Consecutive wet days (CWD), very heavy precipitation events (R20mm), maximum one-day precipitation (RX1day), and very wet days (R95p) are projected to increase in most areas. All indices show a further intensification towards the end of the century over large parts of the domain, e.g., + 7.8% / +5.6 days for CDD, + 96.6% / +0.26 days for R20mm, and + 19.7% for RX1day as median of ENS over CEAS. For temperature indices, the ensembles project a strong increase over the high mountain regions and southern parts for consecutive summer days (CSU, + 108.5% / +38.3 days), heat wave duration index (HWDI, + 1379.1% / +91.37 days), and the percentage of very hot days (TX90p, + 391.1% / +34.54 days). Accordingly, the number of consecutive frost days (CFD, -43.7% / -25.2 days) and the percentage of very cold days (TX10p, -83.4% / -8.13 days) are projected to decrease. The first-time usage of CORDEX-CORE and the larger ensemble size by considering simulations from overlapping domains increase the robustness of the findings from earlier studies. However, some discrepancies in the projected changes prevail among the different RCMs being part of the two CORDEX-domains and in specific landscapes like complex mountainous or lake areas. These uncertainties may be tackled by further model development with improved land-surface processes and potentially higher spatial resolution.

International donors as agents of policy transfer in influencing water legislation: The adoption of the river basin principle by transition economies in Eastern Europe, Caucasus and Central Asia

Over the past decades, political scientists have studied how the policies and ideas of one political setting are used in the development of policies in another political setting, a process known as ‘policy transfer’. In the case of such transfer from one country to another, the role of various institutions and networks as ‘agents’ of policy transfer becomes central. Many researchers have mapped the role of the international donor community as an agent of transfer of Integrated Water Resources Management (IWRM) principles in developing economies. This article examines the case of 11 transition economies from Eastern Europe, Caucasus and Central Asia (EECCA) to establish whether the role of the international donor community has been similar in exporting the IWRM concept, along with its key river basin principle, into national legislation. Roughly a decade after these 11 former Soviet republics gained independence in 1991, a ‘window of opportunity’ emerged when the need arose to revise the national water legislation that had been developed according to old Soviet approaches. The present analysis finds that international donors such as the EU, the US and UN agencies have played a significant role as transfer agents, being involved in shaping at least 18 out of 23 key national water laws, programmes or concepts in the selected countries between 2002 and 2023. The article concludes that 10 countries have adopted IWRM basin management principle and one is expected to follow soon as a result of a process involving international donor engagement.

Neoarchean and Paleoproterozoic magmatism in the Longjiang area, NE China: Implications for the recycling history of supracrustal components in the eastern Central Asian Orogenic Belt

Substantial Phanerozoic crustal growth and reworking in the eastern Central Asian Orogenic Belt has partly obscured the Precambrian geological record. Accurate identification of such Precambrian magmatism and its petrogenesis is paramount to unveiling the early crustal evolution of the eastern Central Asian Orogenic Belt. Two outcrops of Neoarchean and Paleoproterozoic magmatism in the Longjiang area of NE China, eastern Central Asian Orogenic Belt, were recently discovered. The Kaoquantun outcrop consists of monzogranites that yield a zircon 207Pb/206Pb age of 2568 ± 8 Ma and are similar to peraluminous A1-type granites. They were derived from the partial melting of a hybrid crustal source comprising newly accreted Mesoarchean crust and abundant supracrustal metapelites in a post-collisional extensional setting. Such metapelites were initially part of the upper crust but were buried in the middle−lower crust due to crustal thickening prior to ca. 2.6 Ga. In the Zhanbeitun outcrop, basaltic andesites overlie monzogranites, and both have been intruded by syenogranites. The monzogranites and syenogranites yield zircon 207Pb/206Pb ages of 1881 ± 10 Ma and 1843 ± 3 Ma, respectively, whereas the basaltic andesites are inferred to have formed at 1.88−1.84 Ga. The 1.88 Ga monzogranites have relatively enriched zircon Hf-O isotopic compositions and were derived from a hybrid melt of mafic rocks in the lower crust and ancient metabasalts that had undergone low-temperature alteration at supracrustal depths. The 1.88−1.84 Ga basaltic andesites are Nb-rich and were generated by the partial melting of a mantle wedge that was metasomatized by subduction-derived fluids, recycled sediments, and slab-derived melts. The 1.84 Ga syenogranites are peraluminous and K-rich, and record a profound mixing and assimilation process involving melts derived from supracrustal sediments and the lower crust. Three stages of Paleoproterozoic magmatism emerged from subduction-related crustal thickening, slab breakoff, and collision, respectively. The zircon Hf isotopic data further indicate that the eastern Central Asian Orogenic Belt underwent at least one stage of proto-crustal growth at ca. 3.0 Ga, followed by multiple phases of crustal reworking during the Neoarchean and Paleoproterozoic, with dominant involvement of supracrustal components.

Discovery of Late Permian Adakite in Eastern Central Asian Orogenic Belt: Implications for Tectonic Evolution of Paleo-Asian Ocean

The Permian to Triassic period represents a pivotal phase in the evolution of the Paleo-Asian Ocean, marked by significant tectonic transitions from subduction, collision, and post-orogenic extension. The timing of closure of the Paleo-Asian Ocean in northeastern China has always been controversial. In this contribution, the petrology, zircon U-Pb geochronology and geochemistry are conducted on granite found in well HFD1, Songliao Basin, eastern part of Central Asian orogenic belt. Zircon U-Pb dating indicates that granite crystallized at 258.9 ± 2.2 Ma, as the product of magmatism occurred in the early Late Permian. The rocks have high SiO2, Al2O3, Na2O content, negative Eu anomaly, light enrichment of rare-earth elements, depletion of heavy rare-earth elements, high Sr (448.29–533.11 ppm, average 499.68 ppm), low Yb (0.49–0.59 ppm, average 0.54 ppm), Y (4.23–5.19 ppm, average 4.49 ppm), and high Sr/Y ratios (98–125, average 112) and can be classified as O-type adakite. This is the first discovery of late Paleozoic adakite in the Songliao Basin and the neighboring areas. The geochemistry of adakite indicates derivation by partial melting of MORB-type subducted oceanic crust, indicating that the subduction of the Paleo-Asian Oceanic lithosphere lasted until at least 258.9 Ma.

The Naqshbandiyya Mujaddidiyya in China

AbstractThe Naqshbandiyya Mujaddidiyya order is among the world's largest and most geographically widespread Sufi orders, but it has long been assumed to be absent among Chinese-speaking Muslims. Despite a handful of isolated references to local Chinese Mujaddidī groups in studies of particular communities, comprehensive histories of Chinese Islams make no mention of the Mujaddidiyya, and histories of the Naqshbandiyya Mujaddidiyya make no reference to Chinese-speaking Muslims. This article demonstrates that the Mujaddidiyya order has not only been present at various times and places among Chinese Muslims, but has also played a role in the development of nearly all major strains of Islam in China proper, including those commonly known as the Gedimu, Jahriyya, Khāfiyya, Qādiriyya, and Ikhwān. The article also uses new primary sources to provide an account of how a Mujaddidī order expanded into Eastern Turkistan and was transmitted from there to Muslims in China proper. It shows that adaptation to local environments created distinctive forms of Mujaddidī Sufism, highlights Hui-Uyghur connections, and argues that South Asia deserves a central place in any account of Islam in China.

Toll-Like Receptor Gene Polymorphisms in a Population-Based Study of HIV and Tuberculosis Patients from Eastern Europe and Central Asia

Toll-Like Receptor Gene Polymorphisms in a Population-Based Study of HIV and Tuberculosis Patients from Eastern Europe and Central Asia

Wither the Greater Eurasian Partnership? Challenges from the East in an evolving world order

AbstractThe idea of the Greater Eurasian Partnership (GEP) has gained increasing currency in Russian foreign policy. The Russia–China partnership has been presented as its bedrock through a partnership between the Eurasian Economic Union and the Belt and Road Initiative, further expanding to include other regional powers from across East Asia, South Asia, Central Asia, and Middle East as well as nonwestern multilateral groupings (SCO, ASEAN). Given the centrality of Asia‐Pacific to this expansive concept, GEP has to deal with the challenges posed by the evolving regional geopolitics of the East and the rise of the Indo‐Pacific amidst heightened US–China rivalry. The paper seeks to conduct a policy review of GEP and its proposed development format in light of ongoing changes in the East to determine the likely future of the concept in a contested region that also remains at the center of this expansive Russian vision.

Features of the Karakhanid craftsmanship

The establishment of Karakhanid rule in Mawarannahr (942-1212) led to the political unification of vast territories from East Turkestan to Khorezm. Political integrity, economic stability and intensive trade between the urban and steppe communities provided an environment conducive to developing local craftsmanship.This article analyses the mutual influences and common features observed in the craftsmanship of the settled population and nomads in Mawarannahr under the Karakhanids. It demonstrates preservation of the ‘Turkic motifs’ in the new cultural environment. Although the vast territory of the Karakhanid state from Jetisu to Amu-Darya preserved local cultural peculiarities, the formation of universal cultural forms was conspicuous. This article demonstrates the innovations and transformation processes of the Karakhanid era’s craftsmanship, focusing on metal and ceramic products, as well as jewelry. During this period, unglazed pottery of an archaic type, similar to Bronze Age vessels, was widely used, along with fine pottery. These handmade vessels are painted with gray or red engobe. In addition to traditional products of high quality, there are also metal vessels and female jewelry decorated with zoomorphic images. However the presence of these products does not necessarily indicate a decline in the overall quality of craftsmanship in the region.

The Prevalence and Vaccination Coverage Rates of COVID-19 in Asia: A Cross-sectional Study after Four Years

Asia is the largest and most populous continent and is divided into five regions: Eastern Asia, South-eastern Asia, Central Asia, Southern Asia, and Western Asia. Understanding the pattern of the coronavirus disease 2019 (COVID-19) prevalence in Asia could help researchers and decision-makers learn how to respond to public health emergencies more effectively. By the end of 2023, it would have been nearly four years since the first cases of COVID-19 were detected. In this article, COVID-19 data, including the vaccination coverage rate, were used to examine the COVID-19 prevalence across Asia by the end of 2023 based on income and geographic division. Data on COVID-19, including the vaccination coverage rates, for various Asian countries were collected from reliable, publicly available websites. Then, COVID-19 data were analyzed based on income and geographic division. An analysis of variance (ANOVA) test and an Independent Samples t-test were also performed to assess the variation of the means of COVID-19 data across the continent. As of January 1, 2024, COVID-19 data across Asia's five regions were inconsistent. West Asia was most affected, with the highest cases and deaths per million and most tests performed per population. Eastern Asia had the lowest deaths per million, tests per population, and case-fatality rates (CFRs). The COVID-19 vaccination rates range between 2.39% and 105.7%, while the booster vaccination rates varied from 0% in Kyrgyzstan and Laos to 141.7% in Japan. The ANOVA test showed significant variance in the mean, median age, mean vaccination coverage rates, and mean booster vaccination rates, where Eastern Asia had higher averages than the other parts. The independent t-test revealed significant differences in COVID-19 data means, except for CFRs, where low- and lower-middle-income countries had lower averages than upper-middle and high-income countries. Inconsistent COVID-19 data, including vaccination coverage, across Asia highlights the need for uniform standards in case identification and diagnosis, ensuring equitable vaccine distribution, and providing essential diagnostic resources to all countries for future emergencies.

The role of intra-oceanic arc in the growth of continental crust: Evidence from the Early Paleozoic Bainaimiao arc

The Early Palaeozoic arc-related formations in the northern margin of the North China Craton (NCC) belonging to the Bainaimiao arc belt is an important part of the eastern Central Asian Orogenic Belt (CAOB). The tectonic evolution of this belt remains controversial. Here we present detailed data on the geochronology and geochemistry on a newly identified Early Palaeozoic igneous suite from the Faku area in northern Liaoning. Zircon U–Pb dating of the Faku volcanic and intrusive rocks yielded weighted mean 206Pb/238U ages of ca. 458 Ma and 433–405 Ma, respectively, which represent their crystallization (eruption) times. Zircon Hf isotopic analyses show a low negative to positive εHf (t) values of − 0.33 to + 12.4, implying depleted characteristics of the source. The geochemical features of Laolingshan basaltic andesites display higher TiO2 and lower P2O5 contents, similar to that of mid-ocean ridge basalts, and relatively high Zr/Y and low Ta/Yb ratios, suggesting oceanic island arc basalt affinity. Therefore, we suggest that the Laolingshan basaltic andesites were formed in an intra-oceanic environment. The Bachagou granodiorites, with adakitic geochemical signatures, belong to the calc-alkaline and high-K calc-alkaline series, implying formation in an active continental margin tectonic setting. The Baerhushan granodiorites, which geochemically belong to S-type granites, were probably formed in a syn-collisional environment influenced by arc–continent collision. The Donggou granitoids, which have higher SiO2 and alkali and lower MgO and P2O5, show A-type granite features. Geochemical characteristics of the Donggou A-type granite suggest formation in an extensional setting caused by orogenic intermittent extension. The Baerhushan gabbro diorites, which display properties of both mid-ocean ridge and continental rift basalts, were produced under post-orogenic extensional tectonic setting after the arc–continent collision. Our study traces the Early Palaeozoic tectonic evolution of the south-eastern segment of the CAOB and the related accretionary tectonics.

Hydroclimatic changes on multiple timescales since 7800 y BP in the winter precipitation–dominated Central Asia

Central Asia (CA) is one of the world's most significant arid regions, which is markedly impacted by global warming. A better understanding of the dynamical processes governing its Holocene climate variability is critical for a better understanding of possible future impacts of climate change in the region. To date, most of the existing CA paleoclimate records are from the summer precipitation-dominated eastern CA (ECA), with few records from the winter precipitation-dominated western CA (WCA). Here, we present a precisely dated (~6‰) and highly resolved (<4-y) record of hydroclimatic variations from the WCA covering the period between 7,774 and 656 y BP. Utilizing multiple proxies (δ18O, δ13C, and Sr/Ca) derived from a stalagmite from the Fergana Valley, Kyrgyzstan, we reveal a long-term drying trend in WCA, which is in contrast with the wetting trend in ECA. We propose that different responses of winter and summer westerly jets to seasonal solar insolation over the past 8,000 y may have resulted in an antiphased precipitation relationship between the WCA and ECA. Our data contain dominant quasiperiodicities of 1,400, 50 to 70, and 20 to 30 y, indicating close connections between the WCA climate and the North Atlantic. We further identified a series of droughts and pluvials on centennial-to-decadal timescales, which may have influenced regional societies and trans-Eurasian culture exchanges during historical and prehistorical times.

Modulation of the impact of winter-mean warm Arctic-cold Eurasia pattern on Eurasian cold extremes by the subseasonal variability

Utilizing ERA5 data, this study provides evidence that both the winter-mean state and subseasonal variability (SSV) of the warm Arctic-cold Eurasia (WACE) pattern significantly influence the frequency of cold extremes in Eurasia. The positive phase of winter-mean WACE (WACEMean) or a stronger SSV of WACE (WACESSV) corresponds to a higher occurrence of cold extremes over central Eurasia and East Asia. Furthermore, the study reveals that the impact of WACEMean on the cold extremes is modulated by WACESSV. During years characterized by a positive WACEMean and enhanced WACESSV, the associated winter-mean anticyclonic anomalies, combined with amplified subseasonal circulation fluctuations over the northern Eurasia continent, contribute to a significant increase in the blocking frequency over the Ural–Siberia region. This, in turn, contributes to an intensified occurrence of cold extremes in central Eurasia and East Asia. In contrast, during the years with a positive WACEMean but reduced WACESSV, in the absence of significant changes in the subseasonal circulation fluctuations, the winter-mean anticyclonic anomalies over the northern Eurasia continent do not exert a significant impact on Ural–Siberian blocking frequency by themselves. Consequently, there are no notable anomalies in the frequency of cold extremes over central Eurasia and East Asia. Finally, this study reveals that the differences in the distribution of the frequency anomalies in the blocking between the two sets of years are attributed to the constructive and destructive superposition of anomalies in subseasonal circulation fluctuations related to the WACEMean and WACESSV.

Concurrent drought and heatwave events over the Asian monsoon region: insights from a statistically downscaling CMIP6 dataset

Concurrent drought and heatwave (CONDH) can cause tremendous ramifications on socioeconomic activities and human health, and the drought-heatwave (D-H) dependence was revealed to be one of the major factors of the CONDH across most global land regions. However, insufficient attention has been paid on the CONDH over the Asian monsoon region, and the impact of the D-H dependence is even more rarely considered. Based on a statistically downscaling the Coupled Model Intercomparison Project Phase 6 (CMIP6) dataset, we explore the spatial distributions of the intensity, frequency, and duration of the CONDH. In addition, the qualitative impacts of D-H dependence on the intensity, frequency, and duration of the CONDH have been further investigated via comparing these three metrics of the CONDH with those of heatwave. In the period of 1961–2014, the spatial pattern of intensity and duration of the CONDH bear a large resemblance to that of heatwave, with more severe CONDH (heatwave) occurring over South Asia, and relatively long-lasting CONDH (heatwave) occupying over the low latitudes of the Asian monsoon region. The frequency of the CONDH presents large discrepancies with that of heatwave. East Asia (South Asia) is hit by more frequent CONDH (heatwave) than other sub-regions. The D-H dependence is conducive to the intensity, frequency, and duration of the CONDH, especially over the East Asia, Eastern Siberia, and Western Siberia. In the period of 2015–2100, the intensity and duration of the CONDH and heatwave maintain the historical spatial structures. The frequency of the CONDH and heatwave change remarkably relative to 1961–2014, with largest value over eastern central Asia. The D-H dependence is conducive to the three features of the CONDH, and such positive contributions would weaken in response to global warming, especially under higher emission scenario.

Kazakhstan and Eastern Turkestan in the 17th – 19th centuries from the history of political interaction

Kazakhstan and Eastern Turkestan in the 17th – 19th centuries from the history of political interaction