The burden and long-term trends of breast cancer by different menopausal status in China

Background: The burden of breast cancer in women of different menopausal status has not been assessed in China previously. We aim to evaluate and project the burden of breast cancer in different menopausal status in China. Methods: The incidence and mortality of breast cancer were estimated using the data of 554 cancer registries in 2017 and the trends of incidence and mortality of 112 cancer registries from 2010 to 2017. Data from 22 continued cancer registries from 2000 to 2017 were applied for long-term trend projection to 2030 using the Bayesian age- period-cohort model. Menopausal status was stratified by age, with premenopause defined as chronological age < 45 years, perimenopause defined as 45-54 years, and postmenopause defined as ≥ 55 years. Results: Approximately 352,300 incident cases and 74,200 deaths of breast cancer occurred in China in 2020, contributing to 2.6 million disability-adjusted life years (DALYs). Perimenopausal women had the highest inci- dence, prevalence, and DALYs rates, with the rates being 100.3 per 100,000, 819.2 per 100,000 and 723.1 per 100,000 persons. While postmenopausal women had the highest mortality rates (25.5 per 100,000 persons). From 2000 to 2017, the largest increase in incidence and mortality for breast cancer was observed in postmenopausal women with an average annual percentage change (AAPC) of 5.6% and 2.94%. The number of breast cancer cases and deaths will increase to 452,000 and 98,800 in 2030, resulting in 3.2 million DALYs. Conclusions: The burden of breast cancer is rapidly increasing in China and varies among different menopausal status. Specific prevention and control strategies for women in different menopausal status will be more helpful in reducing the rapidly growing trends of breast cancer.

Long-term trends in the abundance and breeding performance in Adélie penguins:the Argentine Ecosystem Monitoring Program

In this work,we report long-term trends in the abundance and breeding performance of Adélie penguins(Pygoscelis adeliae)nesting in three Antarctic colonies(i.e.,at Martin Point,South Orkneys Islands;Stranger Point/Cabo Funes,South Shetland Islands;and Esperanza/Hope Bay in the Antarctic Peninsula)from 1995/96 to 2022/23.Using yearly count data of breeding groups selected,we observed a decline in the number of breeding pairs and chicks in crèche at all colonies studied.However,the magnitude of change was higher at Stranger Point than that in the remaining colonies.Moreover,the index of breeding success,which was calculated as the ratio of chicks in crèche to breeding pairs,exhibited no apparent trend throughout the study period.However,it displayed greater variability at Martin Point compared to the other two colonies under investigation.Although the number of chicks in crèche of Adélie penguins showed a declining pattern,the average breeding performance was similar to that reported in gentoo penguin colonies,specifically,those undergoing a population increase(even in sympatric colonies facing similar local conditions).Consequently,it is plausible to assume a reduction of the over-winter survival as a likely cause of the declining trend observed,at least in the Stranger Point and Esperanza colonies.However,we cannot rule out local effects during the breeding season affecting the Adélie population of Martin Point.

Long-Term Trends in Photosynthetically Active Radiation in Beijing

A long-term dataset of photosynthetically active radiation （Qp） is reconstructed from a broadband global solar radiation （Rs） dataset through an all-weather reconstruction model. This method is based on four years＇ worth of data collected in Beijing. Observation data of Rs and Qp from 2005-2008 are used to investigate the temporal variability of Qp and its dependence on the clearness index and solar zenith angle. A simple and effcient all-weather empirically derived reconstruction model is proposed to reconstruct Qp from Rs. This reconstruction method is found to estimate instantaneous Qp with high accuracy. The annual mean of the daily values of Qp during the period 1958-2005 period is 25.06 mol m-2 d-1. The magnitude of the long-term trend for the annual averaged Qp is presented （-0.19 mol m-2 yr-1 from 1958-1997 and -0.12 mol m-2 yr-1 from 1958-2005）. The trend in Qp exhibits sharp decreases in the spring and summer and more gentle decreases in the autumn and winter.

Long-Term Trends in the Probability of Different Grades of Haze Days in China from 1960 to 2013

The number of haze days and daily visibility data for 543 stations in China were used to define the probabilities of four grades of haze days:slight haze(SLH)days;light haze(LIH)days;moderate haze(MOH)days;and severe haze(SEH)days.The change trends of the four grades of haze were investigated and the following results were obtained.The highest probability was obtained for SLH days(95.138%),which showed a decreasing trend over the last54 years with the fastest rate of decrease of-0.903%·(10 years)-1 and a trend coefficient of-0.699,passing the 99.9%confidence level.The probabilities of LIH and MOH days increased steadily,whereas the probability of SEH days showed a slight downward trend during that period.The increasing probability of SLH days was mainly distributed to the east of 105°E and the south of 42°N and the highest value of the trend coefficient was located in the Pearl River Delta and Yangtze River Delta regions.The increasing probability of LIH days was mainly distributed in eastern China and the southeastern coastal region.The probabilities of MOH and SEH days was similar to the probability of LIH days.An analysis of the four grades of haze days in cities with different sizes suggested that the probability of SLH days in large cities and medium cities clearly decreased during the last 54 years.However,the probabilities of LIH days was<10%and increased steadily.The probability of MOH days showed a clear interdecadal fluctuation and the probability of SEH days showed a weak upward trend.The probability of SLH days in small cities within 0.8°of large or medium cities decreased steadily,but the probability of LIH and MOH days clearly increased,which might be attributed to the impact of large and medium cities.The probability of SLH days in small cities>1.5°from a large or medium city showed an increasing trend and reached 100%after 1990;the probability of the other three grades was small and decreased significantly.

Long-Term Trends and Its Best Functional Form Estimation of Yearly Maximum and Minimum Temperatures at Cotonou City by Improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise Method

The understanding of the long-term trend in climatic variables is necessary for the climate change impacts studies and for modeling several processes in environmental engineering. However, for climatic variables, long-term trend is usually unknown whether there is a trend component and, if so, the functional form of this trend is also unknown. In this context, a conventional strategy consists to assume randomly the shape of the local trends in the time series. For example, the polynomial forms with random order are arbitrarily chosen as the shape of the trend without any previous justification. This study aims to 1) estimate the real long-term nonlinear trend and the changing rate of the yearly high temperature among the daily minimum (YHTaDMinT) and maximum temperatures (YHTaDMaxT) observed at Cotonou city, 2) find out for these real trend and trend increment, the best polynomial trend model among four trend models (linear, quadratic, third-order and fourth-order polynomial function). For both time series, the results show that YHTaDMinT and YHTaDMaxT time series are characterized by nonlinear and monotonically increasing trend. The trend increments present different phases in their nonmonotone variations. Among the four trend estimations models, the trend obtained by third-order and fourth-order polynomial functions exhibits a close pattern with the real long-term nonlinear trend given by the Improved Complete Ensemble Empirical Mode Decomposition with Adaptive Noise (ICEEMDAN). But, the fourth-order polynomial function is optimal, therefore, it can be used as the functional form of trend. In the trend increment case, for the YHTaDMaxT time series, the fourth-order fit is systematically the best among the four proposed trend models. Whereas for the YHTaDMinT time series, the third-order and fourth-order polynomial functions present the same performance. They can both be used as the functional form of trend increments. Overall, the fourth-order polynomial function presents a good performance in terms of trend and trend increments estimation.

Long-Term Trends in Extreme Temperatures in Hong Kong and Southern China

The observed long-term trends in extreme temperatures in Hong Kong were studied based on the meteorological data recorded at the Hong Kong Observatory Headquarters from 1885-2008. Results show that, over the past 124 years, the extreme daily minimum and maximum temperatures, as well as the length of the warm spell in Hong Kong, exhibit statistically significant long-term rising trends, while the length of the cold spell shows a statistically significant decreasing trend. The time-dependent return period analysis also indicated that the return period for daily minimum temperature at 4°C or lower lengthened considerably from 6 years in 1900 to over 150 years in 2000, while the return periods for daily maximum temperature reaching 35°C or above shortened drastically from 32 years in 1900 to 4.5 years in 2000. Past trends in extreme temperatures from selected weather stations in southern China from 1951-2004 were also assessed. Over 70% of the stations studied yielded a statistically significant rising trend in extreme daily minimum temperature, while the trend for extreme maximum temperatures was found to vary, with no significant trend established for the majority of stations.

CLIMATE CHANGE:LONG-TERM TRENDS AND SHORT-TERM OSCILLATIONS

Identifying the Northern Hemisphere （NH） temperature reconstruction and instrumental data for the past 1000 years shows that climate change in the last millennium includes long-term trends and varioas oscillations. Two long-term trends and the quasi-70-year oscillation were detected in the global temperature series tbr the last 140 years and the NH millennium series. One important feature was emphasized that temperature decreases slowly but it increases rapidly based on the analysis of different series. Benefits can be obtained of climate change from understanding various long-term trends and oscillations. Millennial temperature proxies from the natural climate system and time series of nonlinear model system are used in understanding the natural climate change and recognizing potential benefits by using the method of wavelet transform analysis. The results from numerical modeling show that major oscillations contained in numerical solutions on the interdecadal timescale are consistent with that of natural proxies. It seems that these oscillations in the climate change are not directly linked with the solar radiation as an external tbrcing. This investigation may conclude that the climate variability at the interdecadal timescale strongly depends on the internal nonlinear effects in the climate system.

Long-Term Trends in Near-Surface Wind Speed over the Southern Hemisphere: A Preliminary Analysis

Many studies that discuss observed trends in wind speed focus primarily on regions of the Northern Hemisphere, so there is little research directed to the Southern Hemisphere. This paper pre- sents a preliminary investigation of possible statistically significant trends in wind speed over the Southern Hemisphere, with a detailing on the South American continent, between 1961 and 2008. Thus, data from the 20th Century Reanalysis V2 were examined with statistical tests of Mann- Kendall and Sen’s Bend in order to establish the significance and the magnitude of detected trends. The previous results indicate statistically significant trends of increase in average wind speedover the equatorial region of the planet, as well as in the eastern sector of the South Pacific and South Atlantic Oceans. In South America, the most significant trends of decrease in wind speed were noted in some areas of the southern sector of the continent, even as in the adjacent Atlantic Ocean to Argentina. Further studies should be performed to physically support the occurrence of these trends in wind speed. In addition, other observed and reanalysis data sets should be explored to update and corroborate these primary analyzes.

Long-Term Trends of Carbon Monoxide Total Columnar Amount in Urban Areas and Background Regions:Ground-and Satellite-based Spectroscopic Measurements

A comparative study was carried out to explore carbon monoxide total columnar amount（CO TC） in background and polluted atmosphere, including the stations of ZSS（Zvenigorod）, ZOTTO（Central Siberia）, Peterhof, Beijing, and Moscow,during 1998–2014, on the basis of ground-and satellite-based spectroscopic measurements. Interannual variations of CO TC in different regions of Eurasia were obtained from ground-based spectroscopic observations, combined with satellite data from the sensors MOPITT（2001–14）, AIRS（2003–14）, and IASI Met Op-A（2010–13）. A decreasing trend in CO TC（1998–2014） was found at the urban site of Beijing, where CO TC decreased by 1.14% ± 0.87% yr^（-1）. Meanwhile, at the Moscow site, CO TC decreased remarkably by 3.73% ± 0.39% yr^（-1）. In the background regions（ZSS, ZOTTO, Peterhof）, the reduction was 0.9%–1.7% yr^（-1） during the same period. Based on the AIRSv6 satellite data for the period 2003–14, a slight decrease（0.4%–0.6% yr^（-1）） of CO TC was detected over the midlatitudes of Eurasia, while a reduction of 0.9%–1.2% yr^（-1） was found in Southeast Asia. The degree of correlation between the CO TC derived from satellite products（MOPITTv6 Joint, AIRSv6 and IASI Met Op-A） and ground-based measurements was calculated, revealing significant correlation in unpolluted regions.While in polluted areas, IASI Met Op-A and AIRSv6 data underestimated CO TC by a factor of 1.5–2.8. On average, the correlation coefficient between ground-and satellite-based data increased significantly for cases with PBL heights greater than 500 m.

Long-Term Trends in Pre-Summer Daytime and Nocturnal Extreme Hourly Rainfall in a Coastal City of South China

The long-term trends in the occurrence frequency of pre-summer daytime and nocturnal extreme hourly rainfall(EXHR) during 1988-2018 in Hong Kong and their spatial distributions are examined and analyzed. Despite a significant increasing trend observed in the occurrence frequency of pre-summer EXHRs during the investigated period,the increase in daytime and nocturnal EXHRs show distinct spatial patterns. Nocturnal EXHRs show uniform increasing trends over the entire Hong Kong. However, the increase in daytime EXHRs is concentrated over the northern or eastern areas of Hong Kong, indicating a downstream shift of pre-summer EXHRs in Hong Kong with regard to the prevailing southwesterly monsoonal flows in south China. The clustering of weather types associated with daytime and nocturnal EXHRs further reveals that the increase in EXHRs over Hong Kong are mainly contributed by the increase of the events associated with southwesterly monsoonal flows with relatively high speeds. During the past few decades, the southwesterly monsoonal flows at coastal south China have undergone a substantial weakening due to the increased surface roughness induced by the urbanization over the Guangdong-Hong Kong-Macao Greater Bay Area since 1990s,leading to enhanced low-level convergence and thus significant increase in EXHRs at coastal south China. Meanwhile,daytime sea-wind circulation at coastal south China is markedly enhanced during the investigated period, which is the main reason for the northward shift of daytime EXHRs in Hong Kong. In addition, the blocked southwesterly monsoonal flows at coastal south China are detoured eastward, leading to stronger convergence and increase in EXHRs at eastern coast of Hong Kong, especially during daytime, when the easterly sea winds prevail at the region.

Gender disparities and woman-specific trends in Barrett’s esophagus in the United States:An 11-year nationwide populationbased study

BACKGROUND Barrett's esophagus(BE)is a known premalignant precursor to esophageal adenocarcinoma(EAC).The prevalence rates continue to rise in the United States,but many patients who are at risk of EAC are not screened.Current practice guidelines include male gender as a predisposing factor for BE and EAC.The population-based clinical evidence regarding female gender remains limited.AIM To study comparative trends of gender disparities in patients with BE in the United States.METHODS A nationwide retrospective study was conducted using the 2009-2019 National Inpatient Sample(NIS)database.Patients with a primary or secondary diagnosis code of BE were identified.The major outcome of interest was determining the gender disparities in patients with BE.Trend analysis for respective outcomes for females was also reported to ascertain any time-based shifts.RESULTS We identified 1204190 patients with BE for the study period.Among the included patients,717439(59.6%)were men and 486751(40.4%)were women.The mean age was higher in women than in men(67.1±0.4 vs 66.6±0.3 years,P<0.001).The rate of BE per 100000 total NIS hospitalizations for males increased from 144.6 in 2009 to 213.4 in 2019(P<0.001).The rate for females increased from 96.8 in 2009 to 148.7 in 2019(P<0.001).There was a higher frequency of obesity among women compared to men(17.4%vs 12.6%,P<0.001).Obesity prevalence among females increased from 12.3%in 2009 to 21.9%in 2019(P<0.001).A lower prevalence of smoking was noted in women than in men(20.8%vs 35.7%,P<0.001).However,trend analysis showed an increasing prevalence of smoking among women,from 12.9%in 2009 to 30.7%in 2019(P<0.001).Additionally,there was a lower prevalence of alcohol abuse,Helicobacter pylori(H.pylori),and diabetes mellitus among females than males(P<0.001).Trend analysis showed an increasing prevalence of alcohol use disorder and a decreasing prevalence of H.pylori and diabetes mellitus among women(P<0.001).CONCLUSION The prevalence of BE among women has steadily increased from 2009 to 2019.The existing knowledge concerning BE development has historically focused on men,but our findings show that the risk in women is not insignificant.

Long-term trends of fine particulate matter and chemical composition in the Pearl River Delta Economic Zone （PRDEZ）, China

Understanding essential for formulating the trends in PM2.5 levels is clean air plans. This paper analyzes PM2.5 data from various published sources for the years 2000 to 2010 in the Pearl River Delta Economic Zone （PRDEZ）. The long-term variation in PM2.5 mass concentration is analyzed. Results show that PM2.5, organic carbon （OC）, elemental carbon （EC）, and SO24 show a similar trend, increasing before 2005 and then decreasing slightly. The annual average PM2.5 concentra- tion ranges from 49.1 μg·m-3 in 2000 to 64.3 μg·m-3 in 2010, with a peak of 84.1 μg· m3 in 2004. None of these 11 years meets the new National Ambient Air Quality standard （NAAQS） for PM2.5 （35 μg· m-3）. Overall average concentrations of OC, EC, and SO2/4 are 13.0, 6.5, and 11.8μg·m-3, respectively. NO3 and NH＋ respectively have concentrations of 1.5 μg·m-3 and 2.9 μg·m-3 in 2000 and 6.4 μg·m 3 and 5.3μg·m-3 in 2010, with a statistically significant average annual trend of＋ 0.2 μg·m-3 ·yr-1 and ＋ 0.1 μg· m-3. yr-1. In certain geographic regions, OC and EC contribute most of the PM2.5, while in other regions secondary water-soluble ions are more important. In general, OC and SO2/4- are the dominant components of PM2.5, contributing 20.6% and 18.6%, respectively. These results provide, for the first time, a better understanding of the long-term PM2.5 characteristics and trends, on a species-by-species basis, in the PRDEZ. The results indicate that PM2.5 abatement needs to prioritize secondary species.

Analysis of seasonal signals and long-term trends in the height time series of IGS sites in China

The seasonal signal and long-term trend in the height time series of 10 IGS sites in China are investigated in this paper. The offset detection and outlier removal as well as the removal of common mode error are performed on the raw GPS time-series data developed by the Scripps Orbit and Permanent Array Center(SOPAC). The seasonal-trend decomposition procedure based on LOESS(STL) is utilized to extract precise seasonal signals, followed by an estimation of the long-term trend with the application of maximum likelihood estimation(MLE) to the seasonally adjusted time series. The Up-compo- nents of all sites are featured by obvious seasonal variations, with significant phase and amplitude modulation on some sites. After Kendall's tau test, a significant trend(99% confidence interval) for all sites is achieved. Furthermore, the trends at sites TCMS and TNML have significant changes at epochs 2009.5384 and 2009.1493(95% confidence interval), respectively, using the Breaks For Additive Seasonal and Trend test. Finally, the velocities and their uncertainties for all sites are estimated using MLE with the white noise plus flicker noise model. And the results are analyzed and compared with those announced by SOPAC. The results obtained in this paper have a higher precision than the SOPAC results.

从Google Trends看“一带一路”倡议的国际反响

[目的/意义]2013年中国提出“一带一路”倡议,这对推动我国继续繁荣发展并为全球提供中国治理体系方案等具有重大意义。[方法/过程]利用Google Trends,分析中国“一带一路”倡议的国际反响及其潜在阻碍因子。[结果/结论]“一带一路”倡议受到国际上绝大多数国家民众的支持和关注;个别国家为了压制中国的国际影响力,通过“债务陷阱外交”“珍珠链战略”以及环境问题等方面抹黑“一带一路”,行动上提出“重建更好世界”等企图替代中国的“一带一路”倡议。得益于“一带一路”倡议投资没有附加条件以及G7国家内部自身问题,“一带一路”倡议仍然获得了广大第三世界国家的支持,并将继续是推动世界经济发展的重要力量。

Human brain organoid:trends,evolution,and remaining challenges

Advanced brain organoids provide promising platforms for deciphering the cellular and molecular processes of human neural development and diseases.Although various studies and reviews have described developments and advancements in brain organoids,few studies have comprehensively summarized and analyzed the global trends in this area of neuroscience.To identify and further facilitate the development of cerebral organoids,we utilized bibliometrics and visualization methods to analyze the global trends and evolution of brain organoids in the last 10 years.First,annual publications,countries/regions,organizations,journals,authors,co-citations,and keywords relating to brain organoids were identified.The hotspots in this field were also systematically identified.Subsequently,current applications for brain organoids in neuroscience,including human neural development,neural disorders,infectious diseases,regenerative medicine,drug discovery,and toxicity assessment studies,are comprehensively discussed.Towards that end,several considerations regarding the current challenges in brain organoid research and future strategies to advance neuroscience will be presented to further promote their application in neurological research.

Long-term ocean temperature trend and marine heatwaves

Marine heatwaves(MHWs)can cause irreversible damage to marine ecosystems and livelihoods.Appropriate MHW characterization remains difficult,because the choice of a sea surface temperature(SST)temporal baseline strongly influences MHW identification.Following a recent work suggesting that there should be a communicating baseline for long-term ocean temperature trends(LTT)and MHWs,we provided an effective and quantitative solution to calculate LTT and MHWs simultaneously by using the ensemble empirical mode decomposition(EEMD)method.The long-term nonlinear trend of SST obtained by EEMD shows superiority over the traditional linear trend in that the data extension does not alter prior results.The MHWs identified from the detrended SST data exhibited low sensitivity to the baseline choice,demonstrating the robustness of our method.We also derived the total heat exposure(THE)by combining LTT and MHWs.The THE was sensitive to the fixed-period baseline choice,with a response to increasing SST that depended on the onset time of a perpetual MHW state(identified MHW days equal to the year length).Subtropical areas,the Indian Ocean,and part of the Southern Ocean were most sensitive to the long-term global warming trend.

Long-term survival trends of gastric cancer patients between 1972 and 2011 in Qidong

Background:There have been few reports on long-term survival of gastric cancer patients.This study analyzed the survival data of gastric cancer patients obtained from the population-based Qidong Cancer Registry between 1972 and 2011,providing a basis for evaluation of gastric cancer treatment and prognosis.Methods:The cumulative observed survival rate and relative survival rate of gastric cancer patients were calculated using Hakulinen's method via the SURV3.01 software,which was developed by the Finnish Cancer Registry.The date of the last follow-up for the survival status of the 15,401 registered cases was April 30,2012.Results:The 1-,5-,10-,20-,and 30-year observed survival rates were 33.82%,14.18%,10.35%,6.63%,and 4.19%,respectively,and the 1-,5-,10-,20-,and 30-year relative survival rates were 35.43%,18.13%,17.50%,21.96%,and32.84%,respectively.For males,the corresponding observed survival rates were 34.50%,14.40%,10.42%,6.46%,and4.05%,and the corresponding relative survival rates were 36.23%,18.67%,18.28%,23.73%,and 38.61%.For females,the corresponding observed survival rates were 32.62%,13.80%,10.22%,6.95%,and 4.46%,and the corresponding relative survival rates were 34.03%,17.21%,16.28%,19.70%,and 26.78%.Significant differences in relative survival rates were observed between sexes(P=0.003).For the 15-34,35-44,45-54,55-64,65-74,and 75+ age groups,the 5-year relative survival rates were 16.13%,21.77%,18.63%,12.61%,7.99%,and 2.94%,respectively,and the 10-year relative survival rates were 16.49%,22.83%,20.50%,15.97%,15.88%,and 15.73%,respectively.Remarkable improvement could be observed for the 5-,10-,and 15-year relative survival rates in Qidong beginning in the 1980 s.Conclusion:The survival outcome of registered gastric cancer cases in Qidong showed gradual progress over the past two decades.

Long-term trends of precipitation in the North China Plain

The North China Plain (NCP) is the most important food grain producing area in China and has suffered from serious water shortages. To capture variation water availability, it is necessary to have an analysis of changing trends in precipitation. This study, based on daily precipitation data from 47 representative stations in NCP records passed the homogeneity test, analyzed the trend and amplitude of variation in monthly, seasonal and annual precipitation, annual maximum continuous no-rain days, annual rain days, rainfall intensity, and rainfall extremes from 1960 to 2007, using the MannKendall (M-K) test and Sen's slope estimator. It was found that monthly precipitation in winter had a significant increasing trend in most parts, while monthly precipitation in July to September showed a decreasing trend in some parts of NCP. No significant changing trend was found for the annual, dry and wet season precipitation and rainfall extremes in the majority of NCP.A significant decreasing trend was detected for the maximum no-rain duration and annual rain days in the major part of NCP. It was concluded that the changing trend of precipitation in NCP had an apparent seasonal and regional pattern, i.e., precipitation showed an obvious increasing trend in winter, but a decreasing trend in the rainy season (July to September), and the changing trend was more apparent in the northern part than in the southern and middle parts. This implies that with global warming, seasonal variation of precipitation in NCP tends to decline with an increasing of precipitation in winter season, and a decreasing in rainy season, particularly in the sub-humid northern part.

Analysis of Temperature Trends and Variations in the Arabian Peninsula’s Upper Atmosphere

In this study, the trends of upper-air temperatures are analysed by utilising radiosonde observations for the barometric levels at 700, 500, 300, 200, 150, 100 and 50 hPa from five meteorological stations within the Arabian Peninsula from January 1986 to August 2015. The mean monthly variations of the temperatures at these levels are characterised and established. The magnitudes of the annual trends of the mean temperatures for each site for the selected barometric levels are studied and statistically tested using Mann-Kendall rank statistics at different significance levels. The temperature trends at different pressure levels show that the upper troposphere and lower stratosphere are warming, while the middle troposphere is cooling which is consistent with the findings of other studies. The variations in upper air temperature observed in this study can be attributed to a range of factors, including increasing greenhouse gas concentrations, changes in atmospheric circulation patterns, variations in solar activity, aerosols and volcanic eruptions, and land use and land cover change.

Effects of temperature and precipitation on drought trends in Xinjiang, China

The characteristics of drought in Xinjiang Uygur Autonomous Region(Xinjiang),China have changed due to changes in the spatiotemporal patterns of temperature and precipitation,however,the effects of temperature and precipitation—the two most important factors influencing drought—have not yet been thoroughly explored in this region.In this study,we first calculated the standard precipitation evapotranspiration index(SPEI)in Xinjiang from 1980 to 2020 based on the monthly precipitation and monthly average temperature.Then the spatiotemporal characteristics of temperature,precipitation,and drought in Xinjiang from 1980 to 2020 were analyzed using the Theil-Sen median trend analysis method and Mann-Kendall test.A series of SPEI-based scenario-setting experiments by combining the observed and detrended climatic factors were utilized to quantify the effects of individual climatic factor(i.e.,temperature and precipitation).The results revealed that both temperature and precipitation had experienced increasing trends at most meteorological stations in Xinjiang from 1980 to 2020,especially the spring temperature and winter precipitation.Due to the influence of temperature,trends of intensifying drought have been observed at spring,summer,autumn,and annual scales.In addition,the drought trends in southern Xinjiang were more notable than those in northern Xinjiang.From 1980 to 2020,temperature trends exacerbated drought trends,but precipitation trends alleviated drought trends in Xinjiang.Most meteorological stations in Xinjiang exhibited temperature-dominated drought trend except in winter;in winter,most stations exhibited precipitation-dominated wetting trend.The findings of this study highlight the importance of the impact of temperature on drought in Xinjiang and deepen the understanding of the factors influencing drought.