Temporal Variability of Tropospheric NO_(2) over Cities in the United States,Western Europe and China from 2005 to 2022

Anthropogenic Nitrogen oxides(NO_(x)=NO_(2)+NO)emissions are highly concentrated in urban area,and the weekly cycles,seasonal patterns and long-term trends of tropospheric NO_(2) columns over cities differ from region to region due to different emission sectoral compositions and human activities.In this study,we used satellite observed tropospheric NO_(2) column data to compare the longand short-term NO_(2) column density time series over cities in the United Sates(the U.S.),western Europe and China.The results showed that in all the targeted cities,the outbreak of the Corona Virus Disease in 2019(COVID-19)moved the December peak of the city-level NO_(2)columns forward to November and October or even earlier in 2020 and 2021.On weekly level,cities in the U.S.show the lowest NO_(2) columns ratio on weekend/work day,then come the western European cities,and a weak weekly pattern is seen in Chinese cities.For all the cites,we find a higher weekend/work day NO_(2) ratio in cold seasons than in warm seasons,indicating a higher contribution from NOx emission sectors of residential,industry and power plants in the warm seasons.In the long-term,NO_(2) columns over the U.S.and western European cities declined by a fraction twice that of the regional mean level from 2004 to 2021.In China,NO_(2) columns started to decrease since 2012,at a similar rate between the city and regional level.This work confirms the importance to quantify and control NOx emissions from cities.

New Discovery in The Western Part of South China Sea

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Spatiotemporal Changes of Snow Depth in Western Jilin,China from 1987 to 2018

Seasonal snow cover is a key global climate and hydrological system component drawing considerable attention due to glob-al warming conditions.However,the spatiotemporal snow cover patterns are challenging in western Jilin,China due to natural condi-tions and sparse observation.Hence,this study investigated the spatiotemporal patterns of snow cover using fine-resolution passive mi-crowave(PMW)snow depth(SD)data from 1987 to 2018,and revealed the potential influence of climate factors on SD variations.The results indicated that the interannual range of SD was between 2.90 cm and 9.60 cm during the snowy winter seasons and the annual mean SD showed a slightly increasing trend(P>0.05)at a rate of 0.009 cm/yr.In snowmelt periods,the snow cover contributed to an increase in volumetric soil water,and the change in SD was significantly affected by air temperature.The correlation between SD and air temperature was negative,while the correlation between SD and precipitation was positive during December and March.In March,the correlation coefficient exceeded 0.5 in Zhenlai,Da’an,Qianan,and Qianguo counties.However,the SD and precipitation were neg-atively correlated over western Jilin in October,and several subregions presented a negative correlation between SD and precipitation in November and April.

A New Troodontid (Theropoda: Troodontidae) from the Lower Cretaceous Yixian Formation of Western Liaoning, China

A specimen collected from the Lower Cretaceous Yixian Formation of western Liaoning, China, represents a new genus and species of troodontid theropod. The new taxon is named and described on the basis of the holotype and the only known specimen, which comprises an articulated skeleton with the presacral vertebral, shoulder girdle and forelimbs missing as preserved. Diagnostic features of the new species include nasals that are sinusoid in lateral view, absence of a passage connecting the antorbital and maxillary fenestrae, relatively large teeth, plate-like chevrons forming a band along most of the length of the tail, and a long neck between the femoral head and shaft. The temporal constraints of the three paravian groups (Troodontidae, Dromaeosauridae and Aves) combined with the character distributions among the earliest known troodontids indicate a rapid evolution at the base of the Troodontidae.

Causes of the Extreme Hot Midsummer in Central and South China during 2017:Role of the Western Tropical Pacific Warming

This study investigates why an extreme hot midsummer occurred in Central and South China(CSC) during 2017. It is shown that the western North Pacific subtropical high(WNPSH) was abnormally intensified and westward-extending,resulting in anomalous high pressure and consequent extreme heat over CSC. The abnormal WNPSH was favored by the warming of the western tropical Pacific(WTP), which was unrelated to ENSO and manifested its own individual effect.The WTP warming enhanced the convection in-situ and led to anomalous high pressure over CSC via a local meridional circulation. The influence of the WTP was confirmed by CAM4 model experiments. A comparison between the 2017 midsummer and 2010 midsummer(with a stronger WNPSH but weaker extreme heat) indicated that the influence of the WNPSH on extreme heat can be modulated by the associated precipitation in the northwestern flank.The role of the WTP was verified by regression analyses on the interannual variation of the WTP sea surface temperature anomaly(SSTA). On the other hand, the WTP has undergone prominent warming during the past few decades, resulting from decadal to long-term changes and favoring extreme warm conditions. Through a mechanism similar to the interannual variation, the decadal to long-term changes have reinforced the influence of WTP warming on the temperature over CSC,contributing to the more frequent hot midsummers recently. It is estimated that more than 50% of the temperature anomaly over CSC in the 2017 midsummer was due to the WTP warming, and 40% was related to the decadal to long-term changes of the WTP SSTA.

A New Darwinopterid Pterosaur from the Middle Jurassic of Western Liaoning,Northeastern China and its Ecological Implications

A new species of Darwinopterus,D.robustodens sp.nov.is described and named.Based on the new specimen,the diagnostic characters of Darwinopterus are amended and include：rostral dentition composed of well-spaced,spike-like teeth;the longest teeth are confined to the anterior half of the tooth row;tooth alveoli have raised margins;nasoantorbital fenestra confluent;inclined quadrate;elongate cervical vertebrae with low neural spine and reduced or absent ribs;long tail of more than 20 caudals partially enclosed by filiform extensions of the pre-and postzygapophyses;short metacarpus less than 60 per cent length of humerus,fifth toe with two elongate phalanges and curved second pedal phalanx of the fifth toe with the angle between the proximal and distal segments about 130 degrees.The complete specimen of the new pterosaur D.robustodens sp.nov.provides much more osteological information.The differences in tooth morphologies between Darwinopterus modularis and D.robustodens sp.nov.suggest that they filled different ecological niches.The hard integument-bearing Coleoptera may have been the main food source of Darwinopterus robustodens.

Impact of the Thermal State of the Tropical Western Pacific on Onset Date and Process of the South China Sea Summer Monsoon

Since the early or late onset of the South China Sea summer monsoon （SCSM） has a large impact on summer monsoon rainfall in East Asia, the mechanism and process of early or late onset of the SCSM are an worthy issue to study. In this paper, the results analyzed by using the observed data show that the onset date and process of the SCSM are closely associated with the thermal state of the tropical western Pacific in spring. When the tropical western Pacific is in a warming state in spring, the western Pacific subtropical high shifts eastward, and twin cyclones are early caused over the Bay of Bengal and Sumatra before the SCSM onset. In this case, the cyclonic circulation located over the Bay of Bengal can be early intensified and become into a strong trough. Thus, the westerly flow and convective activity can be intensified over Sumatra, the Indo-China Peninsula and the South China Sea （SCS） in mid-May. This leads to early onset of the SCSM. In contrast, when the tropical western Pacific is in a cooling state, the western Pacific subtropical high anomalously shifts westward, the twin cyclones located over the equatorial eastern Indian Ocean and Sumatra are weakened, and the twin anomaly anticyclones appear over these regions from late April to mid-May. Thus, the westerly flow and convective activity cannot be early intensified over the Indo-China Peninsula and the SCS. Only when the western Pacific subtropical high moves eastward, the weak trough located over the Bay of Bengal can be intensified and become into a strong trough, the strong southwesterly wind and convective activity can be intensified over the Indo-China Peninsula and the SCS in late May. Thus, this leads to late onset of the SCSM. Moreover, in this paper, the influencing mechanism of the thermal state of the tropical western Pacific on the SCSM onset is discussed further from the Walker circulation anomalies in the different thermal states of the tropical western Pacific.

Association of Late Paleozoic Adakitic Rocks and Shoshonitic Volcanic Rocks in the Western Tianshan, China

The late Paleozoic adakitic rocks are closely associated with the shoshonitic volcanic rocks in the western Tianshan Mountains, China, both spatially and temporally. The magmatic rocks were formed during the period from the middle to the late Permian with isotopic ages of 248-268 Ma. The 87Sr/86Sr initial ratios of the rocks are low in a narrow variation range (-0.7050). The 143Nd/144Nd initial ratios are high (-0.51240) with positive εND(t) values (+1.28-+4.92). In the εNd(t)-(87Sr/86Sr)i diagram they fall in the first quadrant. The association of the shoshonitic and adakitic rocks can be interpreted by a two-stage model: the shoshonitic volcanic rocks were formed through long-term fractional crystallization of underplated basaltic magma, while the following partial melting of the residual phases formed the adakitic rocks.

Spatial-temporal Dynamics and Driving Forces of Land Development Intensity in the Western China from 2000 to 2015

The change in land development intensity is an important perspective to reflect the variation in regional social and economic development and spatial differentiation.In this paper,spatial statistical analysis,Ordinary Least Squares(OLS),and Geographically weighted regression(GWR)methods are used to systematically analyse the spatial-temporal characteristics and driving forces of land development intensity for 131 spatial units in the western China from 2000 to 2015.The findings of the study are as follows:1)The land development intensity in the western China has been increasing rapidly.From 2000 to 2015,land development intensity increased by 3.4 times on average.2)The hotspot areas have shifted from central Inner Mongolia,northern Shaanxi and the Beibu Gulf of Guangxi to the Guanzhong Plain and the Chengdu-Chongqing urban agglomeration.The areas of cold spots were mainly concentrated in the Qinghai-Tibet Plateau,Yunnan,and Xinjiang.3)Investment intensity and the natural environment have always been the main drivers of land development intensity in the western China.Investment played a powerful role in promoting land development intensity,while the natural and ecological environment distinctly constrained such development.The effect of the economic factors on land development intensity in the western China has changed,which is reflected in the driving factor of construction land development shifting from economic growth in 2000 to economic structure,especially industrial structure,in 2015.

Dongbeititan dongi,the First Sauropod Dinosaur from the Lower Cretaceous Jehol Group of Western Liaoning Province,China

We herein describe a partial postcranial skeleton of a sauropod dinosaur recovered from the Lower Cretaceous Jehol Group in the Beipiao area of western Liaoning Province, northeastern China. A suite of features it possesses, including the camellate internal structure of its presacral elements, the existence of pneumatocoels on the proximal ends of the dorsal ribs, and especially the medially deflected proximal portion of the femur, definitively establish the titanosauriform affinities of the specimen. It differs from other titanosauriforms in having a craniocaudally elongate coracoid with a squared cranioventral extreme and a long, smooth, and slightly convex acetabular edge of the pubis. It represents a new taxon, Dongbeititan dongi gen. et sp. nov. Comparative studies suggest that Dongbeititan is a basal titanosauriform, more derived than Euhelopus, Fusuisaurus, and Huanghetitan, but less derived than Gobititan and Jiutaisaurus. Dongbeititan represents the first sauropod dinosaur reported from the Lower Cretaceous Jehol Group of western Liaoning Province.

The characteristic differences of tropical cyclones forming over the western North Pacific and the South China Sea

The best track dataset of tropical cyclones in the western North Pacific （WNP） and the South China Sea （SCS） from 1977 to 2005 during the satellite era, the NCEP/NCAR reanalysis dataset and the extended reconstructed sea surface temperature dataset are employed in this study. The main climatological characteristics of tropical cyclone formation over the WNP and the SCS are compared. It is found that there is obviously different for the locations of tropical cyclone origins, achieving the lowest central pressure and termination points between over the WNP and over the SCS. The annual number of tropical cyclones forming over the SCS is obviously less than over the WNP, and there is a significant negative correlation with the correlation coefficient being - 0.36 at the 5% significance level between over the WNP and over the SCS. The mean speed of tropical cyclone moving is 6.5 m/s over the WNP and 4.6 m/s over the SCS. The mean lowest central pressure of tropical cyclones is obviously weaker over the SCS than over the WNP. The tropical cyclone days per year, mean total distance and total displacement of tropical cyclone traveled over the WNP are all obviously longer than those over the SCS. Tropical cyclone may intensify to Saffir - Simpson hurricane scale 5 over the WNP, but no tropical cyclone can intensify to Saffir - Simpson hurricane scale 3 over the SCS. The changing ranges of the radii （R15,R16） of the 15.4 m/s winds them and the 25.7 m/s winds over the WNP are obviously wider than those over the SCS, and the median values of the radii over the WNP are also larger than those over the SCS. For the same intensity of tropical cyclones, both radii have larger medians over the WNP than over the SCS. The correlations of annual mean tropical cyclone size parameters between over the WNP and over the SCS are not significant. At the same time, the asymmetric radii of tropical cyclones over the WNP are different from those over the SCS.

New Bivalved Arthropods from the Cambrian(Series 3, Drumian Stage) of Western Hunan, South China

We report two new three-dimensionally phosphatized microfossils, Cambrolongispina reticulata gen. et sp. nov. and Cambrolongispina glabra gen. et sp. nov., from the middle Cambrian （Series 3, Drumian Stage） at Wangcun, Yongshun County, western Hunan, South China. They are bivalved arthropods, with thin, pliable, originally chitinous or chitin-calcareous shields （c. 350-517 I1 m long）. The shields are equipped with a pair of antero-dorsal spines. The spines are internally hollow, varying in length from 1/2 of to as long as the shield length in C. reticulata, and uniformly longer than the shield length in C. glabra. The spines of C. reticulata are ornamented with a longitudinal row of conical or blade-shaped denticles along the posterior edge. Cambrolongispina lacks marginal rims, valve lobation and sulci which are diagnostic of the Bradoriida sensu stricto. It also lacks a donblure/duplicature characteristic of phosphatocopids and some bradoriids. It could be related to the Monasteriidae （which may belong to Bradoriida sensu lato）, both characterized by a pair of antero-dorsal spines. Cambrolongispina may have been meiofaunai detritus feeders that lived on or within sediments. The antero-dorsal spines may have been sensory organs to detect nearby predators. The posterior denticles on these spines might have facilitated the sensory function of the spines.

Impact of the South China Sea Throughflow on the Pacific Low-Latitude Western Boundary Current:A Numerical Study for Seasonal and Interannual Time Scales

Prior studies have revealed that,as a part of the Pacific tropical gyre,the South China Sea throughflow（SCSTF） is strongly influenced by the Pacific low-latitude western boundary current（LLWBC）.In this study,ocean general circulation model（OGCM） experiments with and without connection to the South China Sea（SCS） were performed to investigate the impact of the SCSTF on the Pacific LLWBC.These model experiments show that if the SCS is blocked,seasonal variability of the Kuroshio and Mindanao Current becomes stronger,and the meridional migration of the North Equatorial Current（NEC） bifurcation latitude is enhanced.Both in seasonal and interannual time scales,stronger Luzon Strait transport（LST） induces a stronger Kuroshio transport combined with a southward shift of the NEC bifurcation,which is unfavorable for a further increase of the LST;a weaker LST induces a weaker Kuroshio transport and a northward shifting NEC bifurcation,which is also unfavorable for the continuous decrease of the LST.

STUDY ON INDEX SYSTEM OF ASSESSMENT OF PUBLIC DISASTER PERCEPTION IN THE WESTERN CHINA

The study on humanity response to global environment change is a new direction in the research of global change science, of which an important aspect is to study the adaptation strategies of human being to environmental changes in different regions. One reasonable and scientific adaptation strategy is based on not only scientific assessment of the impact of environmental change on society, but also correct estimation of the public perception of environmental change, whereas the research on the latter is terribly weak. This paper intends to understand the personality difference in public perception of environment in the western China primarily by establishing the assessment index system of nation environmental perception and analyzing the results of questionnaire survey in some regions of Shaanxi Province. The conclusions are as follows: 1) The state of public perception of disaster is one of the foundations of constituting and enforcing reasonable adaptation strategy to environmental change. 2) The personality differences of public perception of disaster appear as follows: female disaster perception is stronger than male;the order of disaster perception from strong to weak from the point of age characteristics is 20-30, 0-20, 40-50, 30-40, 50-60, 60 year old or over in turns; the order of disaster perception from strong to weak from the point of educational characteristics is senior high school, college, illiterate, junior high school, primary school, in turns; the order of disaster perception from strong to weak from the point of occupation characteristics is student, farmer, teacher, worker and functionary, in turns; the order of disaster perception from strong to weak from the point of habitat characteristics is city, countryside, towns, and metropolis in turns.

The Crustal Structure and Assembly of Terranes in the Qaidam-Qilian-Beishan Area, Western China

Abstract: Through a study of the geotransect from Golmud to Ejin Qi published recently, the tectonics of the crust beneath the area from the northern Qinghai-Tibet plateau (Qaidam and the Qilian Mountains) to the border between China and Mongolia and its structure, composition and tectonic evolution have been revealed, and abundant information about the deep structures has been provided. Based on the research into the geotransect, it is suggested that the crust in this area was formed by the assembly of the terranes in different geological stages. Following the formation of the Palaeo-Asian continent, the north part of the corridor of the transect became a part of the huge unifying continent by the end of the Early Permian. In the Mesozoic and Cenozoic, as a result of the compression mainly by the push of the Qinghai-Tibet plateau on the south, the unique crustal structure and geomorphologic features on the northern Qinghai-Tibet plateau were formed. This geotransect together with the Yadong-Golmud geotransect constitutes a long geotransect which runs across the western Chinese continent.

The winter western boundary current of the South China Sea:physical structure and volume transport in December 1998

The unique survey in December 1998 mapped the entire western boundary area of the South China Sea（SCS）,which reveals the three-dimensional structure and huge volume transport of the swift and narrow winter western boundary current of the SCS（SCSwwbc） in full scale. The current is found to flow all the way from the shelf edge off Hong Kong to the Sunda Shelf with a width around 100 km and a vertical scale of about 400 m. It appears to be the strongest off the Indo-China Peninsula, where its volume transport reached over 20×10~6 m^3/s. The current is weaker upstream in the northern SCS to the west of Hong Kong. A Kuroshio loop or detached eddy intruded through the Luzon Strait is observed farther east where the SCSwwbc no more exists. The results suggest that during the survey the SCSwwbc was fed primarily by the interior recirculation of the SCS rather than by the＂branching＂ of the Kuroshio from the Luzon Strait as indicated by surface drifters, which is likely a near-surface phenomenon and only contributes a minor part to the total transport of the SCSwwbc. Several topics related to the SCSwwbc are also discussed.

Influence of Tropical Western Pacific Warm Pool Thermal State on the Interdecadal Change of the Onset of the South China Sea Summer Monsoon in the Late-1990s

An interdecadal shift in the onset date of the South China Sea summer monsoon(SCSSM) is identified during the late 1990 s by using the European Centre for Medium-Range Weather Forecasts Interim Reanalysis dataset. The mean onset date was brought forward by two pentads during 1999–2013 compared to that during 1979–1998. The large-scale atmospheric and oceanic change associated with this shift exhibits a significant interdecadal variation signal around 1998/1999, indicating that the shift during the late 1990 s is robust. Different from the well-known mid-1990 s shift, this shift carried more important systematical significance. Diagnostic analysis suggests that the earlier outbreak of the SCSSM was due to the interdecadal warming of the warm pool, which brought stronger convection anomalies and led to a weak western Pacific subtropical high(WPSH) during boreal spring(March–May). The earlier retreat of the WPSH was a direct cause of this shift.

Assessment on the Effects of Hepatitis B Prevention and Control Measures in Western China:A Comparison of Three Population-based Serosurveys

Objective Despite the remarkable progress in efforts to control disease spread,the nationwide elimination of hepatitis B in China is still hindered by the persistently high rate of hepatitis B virus(HBV)infection in Western China.This study aimed to evaluate the strategy of hepatitis B prevention and control in Western China and identify potential areas and strategies for improvement.Methods Susceptible population vaccination,health education,professional training of doctors,and other prevention and control measures have been implemented in Wuwei city since 2010.Data were obtained from three representative cross-sectional serosurveys conducted in 2010,2013,and 2015.The serum samples were subjected to enzyme-linked immunosorbent assays to detect the following seromarkers:HBV surface antigen(HBsAg),antibody against hepatitis B surface antigen(anti-HBs),and antibody against hepatitis B core antigen(anti-HBc).Estimates of variance were determined using Taylor series linearization methods.Results The three serosurveys revealed decreases in the prevalence of HBsAg(7.19% in 2010 vs.6.51% in 2013 vs.5.87% in 2015)and anti-HBc positivity(43.89%vs.32.87%vs.28.46%)and an increase in the prevalence of anti-HBs positivity(49.07%vs.53.66%vs.53.72%)over time.From 2010 to 2015,the legally reported incidence of hepatitis B in Wuwei city decreased from 686.53/100,000 to 53.72/100,000.Notably,persistently high HBsAg-positive rates(above 5.40%)were observed among subjects aged 20–69 years old in the three serosurveys;the prevalence of HBsAg was above 1% among children younger than 10 years old.Furthermore,rural subjects had higher rates of HBsAg and anti-HBc positivity than their urban counterparts(6.04%vs.4.83% and 30.26%vs.20.35%,respectively)in 2015 but had a lower rate of anti-HBs positivity(49.68 vs.55.18%).Multivariate regression analysis showed that age,urban and rural areas,and education level were the main factors affecting HBV infection.Conclusion Although vaccine-based prevention and control measures reduced the rate of HBV infection in Wuwei City over time,the hepatitis B infection rate in children younger than 10 years was still higher than the national average level.Therefore,the prevention and control of mother-to-child transmission and the management of the infected should be the focus of future prevention and control work.

On the Impact of Western Festivals on Traditional Festivals in China and the Reform of Chinese Festivals

As China steps up its reform and opening up to the outside world,Chinese,especially the young,are becoming increasingly interested in western festivals.However,some traditional festivals in China are left out in the cold.This paper is mainly on the effect of west ern festivals on traditional festivals in China,trying to analyze the reason why it becomes this and it will lead us to face the communion and mixture between the two parties rationally.From the perspective of folk culture,it is necessary for us to find the motive of reform of Chinese traditional festivals.

Neoproterozoic Trench-arc System in the Western Segment of Jiangnan Orogenic Belt, South China

The Jiangnan orogenic belt is a key to understanding of the Neoproterozoic tectonic evolution of the South China Block. We investigate the mafic-ultramafic suites of lherzolite, pyroxenite, gabbro, pillow basalt and gabbroic diorite as well as red jasper interbedded with marine marbles that are mainly exposed as fault-trapped blocks in the Yuanbaoshan and Longsheng domains of the western Jiangnan belt. The postcollisional granite plutons that intruded the ultramafic-mafic rocks are developed well. Zircons in the gabbro yield crystallization ages of 867±10 Ma, 863±8 Ma, 869±9 Ma and 855±5 Ma whereas those from the granites show ages of 823±5 Ma, 831±5 Ma, 824±5 Ma and 833±6 Ma. The Neoproterozoic serpentinited ultramafic samples display minor REE enriched pattern with depletion of Rb, Ba, Nb, Ta and Ti, similar to those of SSZ type ophiolite. The coeval gabbro shows tholeiitic features and is characterized by negative Ba, Nb, Ta, Zr, Hf and Sr anomalies and LREE enriched patterns, with a minor negative Eu anomaly. Some zircon grains from the Longshen gabbro yield Neoarchean-Paleoproterozoic ages(2859–2262 Ma), suggesting its continental arc setting. Geochemical signature of the maficultramafic rocks is consistent with subduction related setting. The pyroxene-bearing diorite exhibits a distinctive arc affinity. The zircons from the gabbro show positive εHf(t) values ranging from 3.9 to 13.8. The granitoids are typical S–type granites with high ACNK values(1.15–1.40) and negative εHf(t) values(–15.1 to –3.2), and are classified as collision–related granites. Combined with the occurrences of mafic-ultramafic rocks, siliceous marble and red jasper mixed with basalt, our new results suggest the presence of a Tonian(863–869 Ma) SSZ ophiolite system and continental arc-type magmatism in the western Jiangnan orogen.