West Central Asia Research Articles

Indian Summer Monsoon Precipitation Dominates the Reproduction of Circumglobal Teleconnection Pattern: A Comparison of CMIP5 and CMIP6 Models

Abstract The zonal wavenumber-5 circumglobal teleconnection (CGT) pattern is one of the most critical atmospheric teleconnection patterns during boreal summer over the Northern Hemisphere (NH). CGT can exert significant climatic impact across NH including Europe, East Asia, and North America, but how reliable coupled climate models simulate the characteristics of CGT is poorly understood. Here, 20 coupled models with their respective versions in phase 5 of the Coupled Model Intercomparison Project (CMIP5) and CMIP6 are selected to evaluate their performance on CGT simulation. We find that while both CMIP5 and CMIP6 models are able to capture the basic features of CGT in multimodel mean (MMM), there are large intermodel discrepancies in the simulation of CGT pattern among CMIP5 and CMIP6 models. High-skill models exhibit strong action center over west-central Asia, coinciding with the pattern derived from reanalysis, while the corresponding action center in low-skill models is weaker. Further analyses demonstrate that high-skill models are capable of simulating more realistic Indian summer monsoon (ISM) precipitation anomalies related to CGT. The resultant anomalous upper-tropospheric divergence over west-central Asia, acting as a Rossby wave source, can therefore excite the abovementioned action center. This high- and low-skill model difference on CGT–ISM relationship is consistent in both CMIP5 and CMIP6. It is also found that high-skill models tend to simulate more realistic CGT–ENSO relationship. The relationship between simulation skills of CGT–ENSO correlation and CGT spatial pattern is attributed to the remote impact of ENSO on CGT wave train through affecting ISM precipitation anomalies.

Unveiling the role of climate in spatially synchronized locust outbreak risks.

Desert locusts threaten crop production and food security. Spatially synchronized locust outbreaks further exacerbate these crises. Continental-scale understanding of such compound locust risks and underlying climatic drivers is crucial to designing coordinated and predictive control strategies but remains elusive. Here, we develop a data-driven framework to assess the compound risk of locust outbreaks in the Middle East and North Africa (MENA) and elucidate the role of climate in locust dynamics. We find that more than one-fifth of high-risk country pairs faced spatially synchronized locust risks from 1985 to 2020, dominated by concurrent winds or inundations. Individual locusts are more prone to infest arid areas punched by extreme rainfall. The spatial prevalence of locusts is strongly modulated by climate variability such as El Niño-Southern Oscillation. A warming climate will lead to widespread increases in locust outbreaks with emerging hotspots in west central Asia, posing additional challenges to the global coordination of locust control.

Dipole pattern of Indian Summer Monsoon precipitation modulated by the Circumglobal Teleconnection during the Last Deglaciation

Modern observations have demonstrated that the Indian Summer Monsoon (ISM) rainfall shows a west-east dipole pattern influenced by the Circumglobal Teleconnection (CGT). In this study, we investigated the temporal evolution of the ISM rainfall and the dynamic mechanisms using a set of transient simulations (TraCE-21 ka, simulation of Transient Climate Evolution over the past 21,000 years) during the Last Deglaciation. The results show that, the responses of ISM rainfall always present west-east dipole patterns under different forcing factors and such responses are closely related to the CGT-like wave trains in the Northern Hemisphere summer. During the Last Deglaciation, the ISM is strengthened and summer precipitation is increased over northwestern India but decreased over northeastern India. With increased solar insolation and atmospheric CO2, as well as reduced global ice volume, the positive-phase CGT-like wave trains, characterized by an anticyclonic anomaly over west-central Asia (WCA) and a cyclonic anomaly over the Tibetan Plateau (TP), tends to shift the South Asian High (SAH) westward and strengthens (weakens) the divergence in the upper-troposphere over northwestern (northeastern) India. Simultaneously, the intensification of the monsoon trough (MT) due to the local baroclinic atmospheric circulations over Arabian Peninsula-Iranian Plateau leads to the moisture convergence (divergence) over northwestern (northeastern) India in the lower troposphere. For the Younger Dryas (YD) cooling event, the pattern of CGT-like wave trains and Indian summer rainfall do the reverse. Theses rainfall responses highlight the spatial complexity of multi-scale Indian monsoon evolution and it should be cautious when explaining geological proxies.

Is leishmaniasis the new emerging zoonosis in the world?

Leishmania is a genus of parasitic protozoa that causes a disease called leishmaniasis. Leishmaniasis is transmitted to humans through the bites of infected female sandflies. There are several different species of Leishmania that can cause various forms of the disease, and the symptoms can range from mild to severe, depending on species of Leishmania involved and the immune response of the host. Leishmania parasites have a variety of reservoirs, including humans, domestic animals, horses, rodents, wild animals, birds, and reptiles. Leishmaniasis is endemic of 90 countries, mainly in South American, East and West Africa, Mediterranean region, Indian subcontinent, and Central Asia. In recent years, cases have been detected in other countries, and it is already an infection present throughout the world. The increase in temperatures due to climate change makes it possible for sandflies to appear in countries with traditionally colder regions, and the easy movement of people and animals today, facilitate the appearance of Leishmania species in new countries. These data mean that leishmaniasis will probably become an emerging zoonosis and a public health problem in the coming years, which we must consider controlling it from a One Health point of view. This review summarizes the prevalence of Leishmania spp. around the world and the current knowledge regarding the animals that could be reservoirs of the parasite.

Estimating the Global Geographical Distribution Patterns of the Invasive Crop Pest Diuraphis noxia Kurdjumov under Current and Future Climatic Scenarios

Invasive crop pests (ICPs) are a major cause of crop losses and adversely affect global food security. Diuraphis noxia Kurdjumov is a significant ICP that feeds on the sap of crops, reducing crop yield and quality. Although estimating the geographical distribution patterns of D. noxia under climate change is critical for its management and global food security, such information remains unclear. Based on 533 global occurrence records and 9 bioclimatic variables, an optimized MaxEnt model was used to predict the potential global geographical distribution of D. noxia. The results showed that Bio1, Bio2, Bio7, and Bio12 were significant bioclimatic variables that influenced the potential geographical distribution of D. noxia. Under current climatic conditions, D. noxia was mainly distributed in west-central Asia, most of Europe, central North America, southern South America, southern and northern Africa, and southern Oceania. Under the SSP 1-2.6, SSP 2-4.5, and SSP 5-8.5 scenarios for the 2030s and 2050s, the potential suitable areas increased, and the centroid migrated to higher latitudes. The early warning of D. noxia in northwestern Asia, western Europe, and North America should be attended to further. Our results provide a theoretical basis for early monitoring and warning of D. noxia worldwide.

Phylogeography and Genetic Diversity of Duck Mussel Anodonta anatina (Bivalvia: Unionidae) in Eurasia

The duck mussel Anodonta anatina is widely distributed throughout the freshwater basins of Northern, Central, and Western Eurasia, and it has a comprehensive genetic structure. This study was devoted to the analysis of lineages, which are defined based on COI gene sequences. Our new dataset was expanded by samples from freshwater basins of Northern and Central Eurasia. It allowed us to reveal a high level of genetic diversity for the widely distributed trans-Eurasian lineage of A. anatina for the first time. As for results, representative samples from the Russian Plain, Southern Siberia, and the Ural region showed the presence of multiple interactions between duck mussel populations, indicating the existence of connections between freshwater basins in this region during the Late Quaternary. The genetic group from the freshwater basins of Northern Eurasia may be divided into two sub-lineages, which have differences in genetic structure and distribution patterns. It was revealed that there was a post-glacial expansion of duck mussels in the freshwater basins of Northern Eurasia after deglaciations of these territories and that the wide distribution of this species in this region was shaped via ancient connections between periglacial waterbodies. The lineage of A. anatina from the Ponto-Caspian region is a genetically rich and diverged group, which is present in the riverine basins of West-Central Asia related to the Caspian Sea.

Varieties of Fossil Resins of the West Central Asia and Features of Their Molecular Structure

This article provides the first modern overview of fossil resin finds in West Central Asia – far beyond the traditional resin-bearing areas, both in Russia and in northern Western Europe. Based on little-known facts and random references scattered in the geological literature, the main locations of fossil resins have been revisited and described, and the level of their study has been assessed. Peculiarities of molecular structure of fossil resins of Priaralie using IR spectroscopy has been studied for the first time. It is shown that the resins of this region, previously described as amber (in modern understanding – succinite), are not such, but are represented by exclusively fragile varieties – retinite, gedanite and do not represent practical interest as jeweller raw material.

Joint effect of the Indian Ocean Dipole and the Silk Road Pattern on Indian rainfall during summer to autumn transition

Variations in Indian summer rainfall pose a threat to water security that can cause widespread socio-economic impacts. Summer rainfall is affected by both tropical and extratropical circulation anomalies owing to India's particular geographical location. Using observational, reanalysis, and CMIP6 model datasets, this study reveals the individual and joint effects of the Indian Ocean Dipole (IOD) and Silk Road Pattern (SRP) on the interannual variability of Indian rainfall during the summer to autumn transition (i.e., September). The results indicate that there is a consistent positive correlation between the IOD and SRP and the second mode of the Indian rainfall anomaly, which features a north–south inverse dipole pattern. During the positive phase of the IOD, the zonal sea surface temperature anomaly (SSTA) gradient of warm west and cold east in the equatorial Indian Ocean drives a Gill-type response, with an anticyclonic anomaly over southern India. This suppresses local convection and results in precipitation deficit across southern India. The SRP exhibits a baroclinic structure over west-central Asia, with an upper (lower) tropospheric anticyclonic (cyclonic) anomaly over west-central Asia (northern India) during its positive phase. This lower-level cyclonic anomaly is drastically amplified under the easterly vertical shear condition, favoring stronger moisture convergence and increased precipitation over northern India. The joint effect of the IOD and SRP explains nearly 29% of the Indian rainfall anomaly, higher than the individual contributions of the IOD (17%) or SRP (12%). These results highlight the need to consider the joint effects of tropical and mid-latitude anomalous drivers on precipitation patterns and provide the basis for more accurate simulation and prediction of Indian rainfall.

Exploring the circum-global teleconnection—Indian summer monsoon interactions in the interannual and multidecadal timescales

The Northern hemispheric circum global teleconnection (CGT) pattern is thought to be maintained by two main forcings—viz-diabatic heating associated with the Indian summer monsoon (ISM) and barotropic instability generation over the jet exit region over the North Atlantic. The CGT and ISM impacts one another through the circulation responses over West central Asia (WCA). In this study we revisit the CGT-ISM interactions focusing on the WCA region and try to understand whether the downstream impact of CGT on ISM dominates over the ISM feedback on CGT. Analysis indicates that the Atlantic forced CGT responses play a lead role in modulating the ISM in the interannual timescale, by modulating the upper-level anticyclones over WCA and in turn affecting the ISM easterly vertical wind shear. Atlantic multi-decadal oscillation (AMO) is a major driver of ISM variability in the multi-decadal time scale and the AMO is associated with an arching wave-train of teleconnection across Eurasia. Our analysis indicates significant modulation of WCA anomalies by the AMO in the multi-decadal time scale, implying that the Atlantic-CGT-WCA-ISM pathway of teleconnection has a low frequency counterpart. We further demonstrate that the observed out of phase relationship between AMO and ISM in the recent decades, may be attributed to the relatively stronger high latitude warming over the north Atlantic during the recent AMO warm phase. The equivalent barotropic responses to the extra-tropical north Atlantic sea surface temperature (SST) anomalies alter the entire downstream teleconnection pattern producing cyclonic anomalies over WCA and in turn weakening the ISM.

Multi‐proxy climate and environmental records from a Holocene eutrophic mire, southern taiga subzone, West Siberia

Palaeoenvironmental reconstructions from peat are strongly focused on ombrotrophic mires, but this study demonstrates that eutrophic mires can also be used. A multi‐proxy approach was applied to a eutrophic mire on a floodplain terrace in the southern taiga of West Siberia. The results of the reconstruction were considered in the wide geographic context of the surrounding regions, including Siberia and Central Asia. Different palaeoecological proxies (analysis of plant macrofossils, testate amoebae, oribatid mites, molluscs, peat humification, ash content and spectral characteristics of humic acids) were used in this study. The results of different proxies showed a high level of consistency among themselves, which allowed for a robust interpretation of Holocene mire development. Throughout the ~7800 years history of the mire, there was a high level of surface wetness. The presence of mineral matter in the peat between 7800 and 5100 cal. a BP indicates regular flooding caused by the intensive fluvial activity, apparently resulting from increased precipitation. This was followed by a trend towards a gradual decrease in surface wetness from conditions of high surface moisture (stagnant water) between 5100 and 3000 cal. a BP to present day conditions of moderate surface moisture with a water table slightly below the mire surface. This pattern is consistent with the well‐documented long‐term trend from palaeoecological records throughout the taiga and arctic zones in West Siberia and central arid Asia. Our data further support the idea that the westerlies were the dominant driver of climate for the southern taiga of West Siberia during the Middle to Late Holocene.

S02-2 Socioeconomic determinants of physical activity, sleep and screen time among children aged 6-9 years of age in Europe

Abstract Background Physical activity is key for preventing obesity and development of noncommunicable diseases later in life. Previous research suggests that socioeconomic factors, such as parental education or income, may influence a child’s risk of obesity. However, previous research on this has provided heterogeneity in results. Our aim was to investigate the socioeconomic disparities between physical activity, sedentary behaviour and sleep patterns in school-aged children aged 6 to 9 years in 24 European countries, using a large nationally-representative sample of children from 24 countries (Albania, Bulgaria, Croatia, Czechia, Denmark, France, Georgia, Ireland, Italy, Kazakhstan, Kyrgyzstan, Lithuania, Latvia, Malta, Montenegro, Poland, Portugal, Romania, Russian Federation – only Moscow, San Marino Republic, Spain, Tajikistan, Türkiye and Turkmenistan). Methods COSI collected information on physical activity patterns of children, sedentary behaviour and sleep duration through a questionnaire filled by parents. Among these, the paper focused on the following behaviours: Transportation to and from schools, Time spent on practising sports, Time spent on actively/vigorously playing, Time spent watching TV or using electronic devices and Hours of sleep per night. For the paper purpose, countries were grouped in 4 macro-regions according to United Nations “Standard Country or Area Codes for Statistical Use”. Results Findings indicated that a high prevalence of motorized school transport among children of employed parents in Southern Europe. The highest prevalence of insufficient sports and active play was among families from West-Central Asia who meet the end of the month with troubles, the highest prevalence of excessive screen time is among families from Eastern Europe, where both parents have a low level of education and the highest prevalence of insufficient sleep is among families from West-Central Asia where both parents have a high level of education. Conclusions There are important differences in the socioeconomic determinants of PA, sleep and screen related behaviours both between countries and sub-regions across the WHO European Region. This analysis of results from the COSI survey provides important insights that can help guide policy makers to take action to address the childhood obesity epidemic.

Borders before Nations: Encounters in the Akan and Dzungar Borderlands, 1450–1750

Abstract This article combines the methodological approaches and insights of two scholars working in distinct regions of the early modern world, namely West Africa and Central Asia, to consider border-making outside of Europe before the nation state. Using borders to understand historical developments is not unprecedented and decades of borderland studies have shown how borders result from, and are affected by, political, emotional, economic, and social processes. The field has also shown that borders can be permeable and solid simultaneously and has offered fruitful new perspectives for historians examining the gradual consolidation of nation states. However, using the history of border-making to understand how nations were formed is a comparatively modern, and regionally limited, line of inquiry. Instead, by adopting a comparative analysis, underpinned by a common theoretical approach, this article combines the examination of two understudied early modern regions to offer an alternative approach for understanding border-making, situated in a global context. Comparisons of this nature show the potential of global history to break up categories taken for granted and open up new venues for research; in doing so, they can generate novel approaches that serve to connect diverse spaces, historiographies, and archives.

Climatic Effects of the Indian Ocean Tripole on the Western United States in Boreal Summer

Abstract The Indian Ocean tripole (IOT) is an independent mode of ocean–atmosphere circulation centered on the tropical Indian Ocean. This study explores the physical mechanisms of the IOT affecting the western United States climate variation during the boreal summer. We find that the IOT is significantly correlated with both western United States summer surface temperature and precipitation anomalies. During positive IOT events, the westerly wind anomalies over the northern Indian Ocean are intensified by two cross-equator airflows over the tropical eastern Indian Ocean and the east coast of Africa. The resulting convergence of air over the northern Bay of Bengal–Indochina Peninsula–northern South China Sea (NBB–IP–NSCS) region (15°–25°N, 80°–125°E) exacerbates the surplus precipitation there. Serving as a heat source, these NBB–IP–NSCS precipitation anomalies can excite a circumglobal teleconnection (CGT)-like pattern that propagates eastward from west-central Asia toward North America along the Asia subtropical westerly jet, further influencing local circulation anomalies. Development of strong anticyclonic circulation over the western United States enhances descending motion and divergence there, resulting in negative precipitation anomalies. This circulation anomaly also induces the diabatic heating anomalies through allowing more solar radiation to reach the ground surface, further increasing the surface temperature anomalies. Meanwhile, the increased tropospheric temperature also raises local surface temperatures by modulating the adiabatic air expansion and compression. Ultimately, the CGT-like pattern associated with NBB–IP–NSCS precipitation anomalies sets up an atmospheric bridge by which the IOT can impact summer climate in the western United States.

Phylogenetics and Biogeography of Lilium ledebourii from the Hyrcanian Forest

Lilium ledebourii (Baker) Boiss is one of the most endangered lilies, restricted to only a few small and fragmented areas in the Hyrcanian forest. This study aimed at evaluating the taxonomy of this unique Iranian lily and reconstructing divergence time from other species of the genus Lilium to address the role of this region in its diversification. Phylogenetic trees based on nuclear ITS and chloroplastic matK strongly supported the monophyly of the genus Lilium and division into subclades hardly matching prior morphological classifications. Biogeographic analyses using S-DIVA revealed East Asia as the ancestral range from where Lilium presented a multidirectional expansion towards North America, West-Central Asia, North Asia, and Europe. Diverging from ancestral Lilium during the beginning of Eocene (50 Ma; 95% HDP: 68.8–36.8). Specific members of Lilium colonized Iran (Western Asia) separated from the Clade IV (West-Central Asia and Europe lineage), and then yielded the Iranian L.ledebourri. Accordingly, the north of Iran appears to have promoted both long-term persistence and migration of Lily species from Asia to the Europe.

Assessment and influencing factors analysis of economic system vulnerability of the Belt and Road Initiative countries.

Economic vulnerability is an important indicator to measure regional coordination, health and stability. Despite the importance of vulnerabilities, this is the first study that presents 26 indicators selected from the dimensions of the domestic economic system, external economic system and financial system in the Belt and Road Initiative (BRI) countries. A quantitative analysis is conducted to analyze the characteristics of spatial heterogeneity of vulnerability of the economic subsystems and the comprehensive economic system of the BRI countries and the main influencing factors of the comprehensive economic system vulnerability (CESV) are identified based on obstacle degree model. The results show that the CESV of the East Asia, South Asia and ASEAN countries are lower than that of the Middle Eastern Europe, Central Asia and West Asia countries. The CESV of the BRI countries are generally in the middle level and the average vulnerability index of highly vulnerable countries is twice as much as that of lowly vulnerable countries. In addition, in terms of the vulnerability of the three subsystems, the spatial distribution of vulnerability of the domestic economic system (DESV) and financial system (FSV) is basically consistent with the spatial distribution pattern of CESV, both of which are low in East Asia and South Asia and high in West Asia and Central Asia. While, the vulnerability of external economic system (EESV) shows a different spatial pattern, with vulnerability of West Asia, Central Asia and ASEAN higher than that of East Asia and South Asia. The main obstacle factors influencing the CESV of BRI countries include GDP growth rate, saving ratio, ratio of bank capital to assets, service industry level, industrialization level and loan rate. Therefore, the key way to maintain the stability and mitigate the vulnerability of the economic system of BRI countries is to focus on the macroeconomic development and operation, stimulate the economy and market vitality, promote the development of industries, especially the service and secondary industries, and optimize the economic structure, banking system and financial system.

Non-technological and behavioral options for decarbonizing buildings – A review of global topics, trends, gaps, and potentials

Worldwide, energy use in buildings with the same function differed by a factor of 3–10, owing to behavioral issues. Future lifestyle changes in developed countries are expected to result in significant energy use reductions of up to 50% by 2050, with a correspondingly large impact on greenhouse gas (GHG) emissions. However, neither clear categorizations of behavioral or nontechnological (NT) climate mitigation solutions (CMS), nor corresponding estimates of global potentials for energy savings and GHG mitigation are available. Using a systematic map methodology, review of frameworks, and topic modeling, we propose a taxonomy that conceptually covers various demands (maintained/reduced), perspectives (individual/collective), and direct energy use (yes/no), resulting in five types of NT solutions: active and passive management and operation (MO), demand flexibility, sufficient comfort levels, circular and sharing economy, and organizational and social innovations. A knowledge glut for active and passive MO has been identified, with clusters in Europe and North America. Furthermore, evidence gaps were discovered in terms of geographical scope (with very little literature available about Africa and the Middle East, Latin America and the Caribbean, and Eastern Europe and West-Central Asia), stakeholder perspectives, and some measures (circular and sharing economy, flexibility of demand over time, social and organizational innovations). There was insufficient evidence on current NT CMS adoption and implementation costs. Quantified potentials were mostly found for developed countries and residential buildings, with more energy savings than GHG mitigation studies. Whereas these potentials are substantial, they vary largely among regions and solutions. The potential energy-saving ranges between 5% and 40% for most regions and CMS. The greatest potential GHG emissions reductions are seen in the circular and sharing category (25% to 70%). For other actions, most potentials range from 5% to 30%. More research is needed to provide evidence on rebound effects that can offset the climate benefits of NT solutions, business models that demonstrate their financial viability, and policy actions that trigger the already identified climate mitigation potentials of NT solutions.

Dynamical mechanisms linking Indian monsoon precipitation and the circumglobal teleconnection

The circumglobal teleconnection (CGT) is an important mode of circulation variability, with an influence across many parts of the northern hemisphere. Here, we examine the excitation mechanisms of the CGT in the ECMWF seasonal forecast model, and the relationship between the Indian summer monsoon (ISM), the CGT and the extratropical northern hemisphere circulation. Results from relaxation experiments, in which the model is corrected to reanalysis in specific regions, suggest that errors over northwest Europe are more important in inhibiting the model skill at representing the CGT, in addition to northern hemisphere skill more widely, than west-central Asia and the ISM region, although the link between ISM precipitation and the extratropical circulation is weak in all experiments. Thermal forcing experiments in the ECMWF model, in which a heating is applied over India, suggest that the ISM does force an extratropical Rossby wave train, with upper tropospheric anticyclonic anomalies over east Asia, the North Pacific and North America associated with increased ISM heating. However, this eastward-propagating branch of the wave train does not project into Europe, and the response there occurs largely through westward-propagating Rossby waves. Results from barotropic model experiments show a response that is highly consistent with the seasonal forecast model, with similar eastward- and westward-propagating Rossby waves. This westward-propagating response is shown to be important in the downstream reinforcement of the wave train between Asia and North America.

The Evolution Characteristics of Daily-Scale Silk Road Pattern and Its Relationship with Summer Temperature in the Yangtze River Valley

By employing multi-reanalysis daily datasets and station data, this study focuses on the evolution characteristics of the daily-scale Silk Road pattern (SRP) and its effect on summer temperatures in the Yangtze River Valley (YRV). The results manifest that the evolution characteristics of positive- and negative-phase SRP (referred to SRP+ and SRP−) exhibit marked distinctions. The anomaly centers of SRP+ over West Central Asia (WCA) and Mongolia emerge firstly, vanishing simultaneously one week after peak date; however, the Far East (FE) anomaly centers can persist for a longer period. The SRP− starts with the WCA and FE centers, with a rapid decline in the strength of the WCA center and preservation of other anomaly centers after its peak. In the vertical direction, daily-scale SRP mainly concentrates in the mid-to-upper troposphere. Baroclinicity accounts for its early development and barotropic instability process favors the maintenance. Moreover, the SRP+ (SRP−) is inextricably linked to heat wave (cool summer) processes in the YRV. Concretely, before the onset of SRP+ events, an anomalous anticyclone and significant negative vorticities over East Asia related to SRP+ favor the zonal advance between the South Asia high (SAH) and western Pacific subtropical high (WPSH), inducing local descents over YRV area. The sinking adiabatic warming and clear-sky radiation warming can be considered as the possible causes for the YRV heat waves. The adiabatic cooling with the local ascents leads to more total cloud cover (positive precipitation anomalies) and less solar radiation incident to surface of the YRV, inducing the cool summer process during SRP−.

Characteristics of dissolved organic carbon and nitrogen in precipitation in the northern Tibetan Plateau

Dissolved organic carbon (DOC) and nitrogen (N) play essential roles in global C and N cycles. To address the possible role of DOC and N in precipitation and enrich the related global database, the characteristics of DOC and N in precipitation were investigated in a typical remote permafrost region (upper Heihe River Basin) of the northern Tibetan Plateau (TP) from February 2019 to March 2020. The results demonstrated that the average DOC and total dissolved N (TDN) concentrations in the precipitation were 1.41 ± 1.09 μg mL−1 and 0.84 ± 0.48 μg mL−1, respectively, with relatively lower concentrations in the summer. The annual DOC and TDN fluxes were estimated to be 6.42 kg ha−1 yr−1 and 3.39 kg ha−1 yr−1, respectively, indicating that precipitation was a significant factor in C and N deposition. The light-absorbing properties of precipitation DOC from the SUVA254 and spectral slope revealed that precipitation DOC containing more aromatic components and lower molecular weights mostly was present during the summer; the mass cross-section (at the wavelength of 365 nm) ranged 0.26–1.84 m2 g−1, suggesting the potential impact of DOC on climatic forcing in the area. The principal component analysis combined with air mass backward trajectories indicated that the air masses from west Siberia, Central Asia, and northwestern China most significantly influenced the precipitation C and N in the study area. The WRF-Chem simulations and aerosol vertical distributions further illustrated the air mass transport pathways, demonstrating that dust and anthropogenic emissions could be transported over the studied area by westerlies and monsoonal winds. In the study basin, the precipitation deposition of DOC and N contributed largely to the riverine DOC and N exportation during the summer and had potential ecological effects. These results highlight the importance of DOC and N deposition from precipitation in the northern TP.

Imagining Alfalfastan: Plant Exploration, Technopolitics, Colonialism, and the Environment in the American West and Russian Central Asia, 1897–1930

Imagining Alfalfastan: Plant Exploration, Technopolitics, Colonialism, and the Environment in the American West and Russian Central Asia, 1897–1930