Impact of ENSO events on the interannual variability of Hadley circulation extents in boreal winter

The interannual variability of the boreal winter Hadley circulation extents during the period of 1979e2014 and its links to El Ni^no-Southern Oscillation(ENSO) were investigated by using reanalysis datasets. Results showed that the El Ni^no(La Ni^na) events can induce the shrinking(expansion) of Hadley circulation extent in the Southern Hemisphere. For the Northern Hemisphere, El Ni^no(La Ni^na) mainly leads to shrinking(expansion) of the Hadley circulation extent in the middle and lower troposphere and expansion(shrinking) of the Hadley circulation extent in the upper troposphere. The ENSO associated meridional temperature gradients have close relationship with the Hadley circulation extents in both Hemispheres. But in the Northern Hemisphere, the ENSO associated eddy momentum flux divergence plays more important role in affecting the Hadley circulation extent than the meridional temperature gradient because of the small local Rossby number. In the Southern Hemisphere, as the ENSO induced eddy momentum flux divergence is small, the meridional temperature gradient dominates the change of the Hadley circulation extent.

A progressive framework for rotary motion deblurring

The rotary motion deblurring is an inevitable procedure when the imaging seeker is mounted in the rotating missiles.Traditional rotary motion deblurring methods suffer from ringing artifacts and noise,especially for large blur extents.To solve the above problems,we propose a progressive rotary motion deblurring framework consisting of a coarse deblurring stage and a refinement stage.In the first stage,we design an adaptive blur extents factor(BE factor)to balance noise suppression and details reconstruction.And a novel deconvolution model is proposed based on BE factor.In the second stage,a triplescale deformable module CNN(TDM-CNN)is designed to reduce the ringing artifacts,which can exploit the 2D information of an image and adaptively adjust spatial sampling locations.To establish a standard evaluation benchmark,a real-world rotary motion blur dataset is proposed and released,which includes rotary blurred images and corresponding ground truth images with different blur angles.Experimental results demonstrate that the proposed method outperforms the state-of-the-art models on synthetic and real-world rotary motion blur datasets.The code and dataset are available at https://github.com/JinhuiQin/RotaryDeblurring.

Four-to Six-Year Periodic Variation of Arctic Sea-Ice Extent and Its Three Main Driving Factors

Besides the rapid retreating trend of Arctic sea-ice extent(SIE),this study found the most outstanding low-frequency variation of SIE to be a 4-6-year periodic variation.Using a clustering analysis algorithm,the SIE in most ice-covered regions was clustered into two special regions:Region-1 around the Barents Sea and Region-2 around the Canadian Basin,which were located on either side of the Arctic Transpolar Drift.Clear 4-6-year periodic variation in these two regions was identified using a novel method called“running linear fitting algorithm”.The rate of temporal variation of the Arctic SIE was related to three driving factors:the regional air temperature,the sea-ice areal flux across the Arctic Transpolar Drift,and the divergence of sea-ice drift.The 4-6-year periodic variation was found to have always been present since 1979,but the SIE responded to different factors under heavy and light ice conditions divided by the year 2005.The joint contribution of the three factors to SIE variation exceeded 83%and 59%in the two regions,respectively,remarkably reflecting their dynamic mechanism.It is proven that the process of El Niño-Southern Oscillation(ENSO)is closely associated with the three factors,being the fundamental source of the 4-6-year periodic variations of Arctic SIE.

Joint Probability Analysis and Prediction of Sea Ice Conditions in Liaodong Bay

Sea ice conditions in Liaodong Bay of China are often described by sea ice grades,which classify annual sea ice conditions based on the annual maximum sea ice thickness(AM-SIT)and annual maximum floating ice extent(AM-FIE).The joint probability distribution of AM-SIT and AM-FIE was established on the basis of their data pairs from 1949/1950 to 2019/2020 in Liaodong Bay.The joint intensity index of the sea ice condition in the current year is calculated,and the joint classification criteria of the sea ice grades in past years are established on the basis of the joint intensity index series.A comparison of the joint criteria with the 1973 and 2022 criteria revealed that the joint criteria of the sea ice grade match well,and the joint intensity index can be used to quantify the sea ice condition over the years.A time series analysis of the sea ice grades and the joint intensity index sequences based on the joint criteria are then performed.Results show a decreasing trend of the sea ice condition from 1949/1950 to 2019/2020,a mutation in 1990/1991,and a period of approximately 91 years of the sea ice condition.In addition,the Gray-Markov model(GMM)is applied to predict the joint sea ice grade and the joint intensity index of the sea ice condition series in future years,and the error between the results and the actual sea ice condition in 2020/2021 is small.

From partial to complete:Wing-and tail-feather moult sequence and intensity depend on species,life-cycle stage,and moult completeness in passerines

Passerines moult during various life-cycle stages.Some of these moults involve the retention of a variable quantity of wing and tail feathers.This prompts the question whether these partial moults are just arrested complete moults or follow different processes.To address it,I investigated whether three relevant features remain constant across partial and complete moults:1) moult sequence(order of activation) within feather tracts(e.g.,consecutive outward moult of primaries) and among tracts(e.g.,starting with marginal coverts,followed by greater coverts second,tertials,etc.);2) dynamics of moult intensity(amount of feathers growing along the moult progress);and 3) protection of wing quills by overlapping fully grown feathers.To study the effect of moult completeness on these three features,I classified moults of 435 individuals from 61 species in 3 groups:i) complete and partial,ii) without and iii) with retention of feathers within tracts.To study the effect of life-cycle stage,I used postbreeding,postjuvenile,and prebreeding moults.I calculated phylogenetically corrected means to establish feather-moult sequence within tracts.I applied linear regression to analyse moult sequence among tracts,and polynomial regression to study the dynamics of moult intensity as moult progresses.Sequence and intensity dynamics of partial moults tended resemble those of the complete moult as moult completeness increased.Sequence within and among feather tracts tended to shift as moult intensity within tracts and number of tracts increased.Activation of primaries advanced in relation to the other feather tracts as number of moulted primaries increased.Tertial quills were protected by the innermost greater covert regardless of moult completeness.These findings suggest that moult is a self-organised process that adjusts to the degree of completeness of plumage renewal.However,protection of quills and differences among species and between postjuvenile-and prebreeding-moult sequences also suggest an active control linked to feather function,including protection and signalling.

Survival Analysis of Patients Undergoing Intraoperative Contrast-enhanced Ultrasound in the Surgical Treatment of Malignant Glioma

Objective:Complete resection of malignant gliomas is often challenging.Our previous study indicated that intraoperative contrast-enhanced ultrasound(ICEUS)could aid in the detection of residual tumor remnants and the total removal of brain lesions.This study aimed to investigate the survival rates of patients undergoing resection with or without the use of ICEUS and to assess the impact of ICEUS on the prognosis of patients with malignant glioma.Methods:A total of 64 patients diagnosed with malignant glioma(WHO grade HI and IV)who underwent surgery between 2012 and 2018 were included.Among them,29 patients received ICEUS.The effects of ICEUS on overall survival(OS)and progression-free survival(PFS)of patients were evaluated.A quantitative analysis was performed to compare ICEUS parameters between gliomas and the surrounding tissues.Results:The ICEUS group showed better survival rates both in OS and PFS than the control group.The univariate analysis revealed that age,pathology and ICEUS were significant prognostic factors for PFS,with only age being a significant prognostic factor for OS.In multivariate analysis,age and ICEUS were significant prognostic factors for both OS and PFS.The quantitative analysis showed that the intensity and transit time of microbubbles reaching the tumors were significantly different from those of microbubbles reaching the surrounding tissue.Conclusion:ICEUS facilitates the identification of residual tumors.Age and ICEUS are prognostic factors for malignant glioma surgery,and use of ICEUS offers a better prognosis for patients with malignant glioma.

Changes in snow cover extent in the Central Taurus Mountains from 1981 to 2021 in relation to temperature, precipitation, and atmospheric teleconnections

The snow cover over the Taurus Mountains affects water supply, agriculture, and hydropower generation in the region. In this study, we analyzed the monthly Snow Cover Extent(SCE) from November to April in the Central Taurus Mountains(Bolkar, Aladaglar, Tahtali and Binboga Mountains) from 1981 to 2021. Linear trends of snow cover season(November to April) over the last 41 years showed decreases in SCE primarily at lower elevations. The downward trend in SCE was found to be more pronounced and statistically significant for only November and March. SCE in the Central Taurus Mountains has declined about-6.3% per decade for 2500-3000 m in November and about-6.0% per decade for 1000-1500 m and 3000+ m in March over the last 41 years. The loss of SCE has become evident since the 2000s, and the lowest negative anomalies in SCE have been observed in 2014, 2001, and 2007 in the last 41 years, which are consistent with an increase in air temperature and decreased precipitation. SCE was correlated with both mean temperature and precipitation, with temperature having a greater relative importance at all elevated gradients. Results showed that there is a strong linear relationship between SCE and the mean air temperature(r =-0.80) and precipitation(r = 0.44) for all elevated gradients during the snow season. The Arctic Oscillation(AO), the North Atlantic Oscillation(NAO), and the Mediterranean Oscillation(MO) winter indices were used to explain the year-to-year variability in SCE over the Central Taurus Mountains. The results showed that the inter-annual variability observed in the winter SCE on the Central Taurus Mountains was positively correlated with the phases of the winter AO, NAO and MO, especially below 2000 m elevation.

Optimizing the LSTM Deep Learning Model for Arctic Sea Ice Melting Prediction

The National Oceanic and Atmospheric Administration reports a 95% decline in the oldest Arctic ice over the last 33 years [1], while the National Aeronautics and Space Administration states that summer Arctic Sea Ice Extent (SIE) is shrinking by 12.2% per decade since 1979 due to warmer temperatures [2]. Given the rapidly changing Arctic conditions, accurate prediction models are crucial. Deep learning models developed for Arctic forecasts primarily focus on exploring convolutional neural networks (CNN) and convolutional Long Short-Term Memory (LSTM) networks, while the exploration of the power of LSTM networks is limited. In this research, we focus on enhancing the performance of an LSTM network for predicting monthly Arctic SIE. We leverage five climate and atmospheric variables, validated for their correlation with SIE in prior studies [3]. We utilize the Spearman’s rank correlation and ExtraTrees regressor to enhance our understanding of the importance of the five variables in predicting SIE. We further enhance our predictor variables with seasonal information, lagged time steps, and a linear regression simulated SIE that accounts for the influence of past SIE on current SIE. Statistical methods guide our selection of data scalers and best evaluation metrics for our model. By experimenting with hyperparameter optimization and advanced deep learning training techniques, such as batch sizes, number of neurons, early stopping, and model checkpoint, our model achieved a Mean Absolute Error (MAE) of 0.191 and R2 of 0.996, underscoring its ability to account for nearly all the variance in our data and holds great promise for the prediction of SIE.

Temporal and spatial variation characteristics of Antarctic sea ice and the causes of its record decline during 2015–2016: a review

Satellite observations over the past four decades have shown that the long-term trend of Antarctic sea ice extent(SIE)is opposite to the trend of sea ice extent in the Arctic.Arctic sea ice extent continues to decline while Antarctic SIE is generally on the rise except for a dramatic decline in 2015–2016.Based on the 40-year climatology from 1981 to 2020,Antarctic SIE anomaly in December 2016 is–2.1×10^(6) km^(2),reaching the minimum since 1979.There are many studies on the cause of this record decline.This present review summarizes the spatial and temporal characters of Antarctic sea ice and recaps major findings on the causes of record decline in 2015–2016 from the perspective of direct thermodynamic and dynamic process of atmosphere and ocean as well as the modulation of climate modes.Finally,the challenges and key scientific problems to be solved in the future of Antarctic sea ice research are presented.

Proposal of a modified classification for hilar cholangiocarcinoma

Hilar cholangiocarcinoma is a malignant tumor that originates from the left and right hepatic ducts and their confluence.It is highly malignant and associated with a poor prognosis.Surgical resection is the only available curative treatment option.A scientific classification system can aid in the preoperative assessment of resectability and guide the development of appropriate surgical strategies.Several classification systems are available,with the Bismuth-Corlette(BC)classification being the earliest and most widely used.Similar to many other classifications,the BC classification relies on the secondary branching of the bile ducts as an important anatomical landmark,making it unsuitable for cases with variations in the bile duct anatomy.With advances in understanding the hepatic plate and anatomical structures at the hilum,the secondary bile ducts are no longer considered important anatomical landmarks.Therefore,modifications to the BC classification are needed to align with modern anatomical improvements and advancements in surgical techniques.Herein,we propose a modification to the BC classification.In this new system,the boundary of the hilar plate is considered as limit of the proximal ductal margin and used as an anatomical landmark,rather than the concept of“secondary bile ducts”in the BC classification.

栓式附着体固位义齿在双侧后牙游离缺失修复中的应用

目的探讨栓式附着体固位义齿对双侧后牙游离缺失修复的临床应用及其效果。方法应用Acrylock栓式附着体固位义齿修复治疗双侧后牙游离缺失患者23例,通过患者主观感觉、临床观测、X线检查等方法,对义齿的美观、舒适、固位及稳定、咀嚼功能、基牙及牙槽嵴状况等方面进行定期评价。结果Acrylock栓氏附着体固位义齿的美观、舒适性、固位及稳定性、咀嚼功能等各项,患者主观评价的满意率均达80%以上;经过12～18月随访观察,所有义齿的固位及稳定性良好,基牙牙周状况良好,X线根尖片及口腔全景片检测基牙及游离缺牙区牙槽嵴高度没有降低改变。结论对双侧后牙游离缺失牙列的修复,栓式附着体固位义齿是较为理想的修复方法。

基于EXT4文件系统的数据恢复方法研究

研究EXT4文件系统中删除文件的恢复方法对计算机取证工作有重要意义。文章研究了在EXT4文件系统中通过日志中的备份信息进行数据恢复的方法。采用了实例式研究方法,分析了EXT4文件系统中extent树的构成,分析了文件被删除之后extent树的变化,研究了通过inode编号定位inode结点所在数据块的方法,研究了通过日志恢复被删除文件的方法。文章得出的结论是在日志文件和删除数据未被完全覆盖的情况下,可以通过日志有效恢复EXT4文件系统中被删除的文件。文章的研究成果可以应用在公安机关的电子数据鉴定工作中,也可用于公安院校的《电子物证检验》课程教学。

基于Ext4文件系统的数据提取方法研究

大多数Linux系统下的发行版主要还是应用于X86平台,磁盘的分区结构仍然支持MBR和GPT磁盘分区,目前常见的文件系统有Ext3及Ext4。本文借助Winhex及R-Studio,详细介绍Ext4文件系统的结构,并举例说明手工提取文件的方法。

基于内容的智能视频监控文件系统

针对传统文件系统碎片化会严重影响存储性能的问题,结合视频监控具有的基于内容检索的特点,提出一种应用于智能视频监控的专用文件系统。基于Extent的逻辑卷索引结构,以特征录像段为单位进行特征内容的索引,采用B+树和位图提高索引效率。在索引策略中,基于数据簇回收最原始数据,实现循环存储。通过控制数据连续存储的时间,优化数据块的分配,保证数据的连续、顺序存储。测试结果表明,该文件系统索引策略对存储带宽的下降比例仅为2.4%,在1 Mb/s的典型视频码率下,存储带宽相比传统文件系统提高了24.5%,存储空间利用率达到了99%。

基于Ext4元数据Extent树重构的数据恢复研究

为了解决计算机取证中Ext4文件系统的数据恢复问题,提出了一种基于文件头尾特征元数据Extent重构的恢复方法。在Extent树完整性遭到破坏的情况下提出了重构的方法,通过扫描磁盘扇区定位文件头尾特征所在的磁盘位置,确定文件大小,并根据ext4_extent_header中魔数信息实现对Extent的重建,进而实现对文件的恢复。实验结果表明,经该方法设计的软件在文件恢复的时间效率和成功率方面有了较大的提高。

Possible Impacts of Winter Arctic Oscillation on Siberian High, the East Asian Winter Monsoon and Sea-Ice Extent

Using the NCEP/ NCAR reanalysis dataset covering a 40-year period from January 1958 to December 1997, sea surface temperature (1950-1992), and monthly sea-ice concentration dataset for the period from 1953 to 1995, we investigate connections between winter Arctic Oscillation (AO) and Siberian high (SH), the East Asian winter monsoon (EAWM), and winter sea-ice extent in the Barents Sea. The results indicate that winter AO not only influences climate variations in the Arctic and the North Atlantic sector, but also shows possible effects on winter SH, and further influences EAWM, When winter AO is in its positive phase, both of winter SH and the EAWM are weaker than normal, and air temperature from near the surface to the middle troposphere is about 0.5-2degreesC higher than normal in the southeastern Siberia and the East Asian coast, including eastern China, Korea, and Japan. When AO reaches its negative phase, an opposite scenario can be observed. The results also indicate that winter SH has no significant effects on climate variations in Arctic and the North Atlantic sector. Its influence intensity and extent are obviously weaker than AO, exhibiting a 'local, feature in contrast to AO. This study further reveals the possible mechanism of how the winter AO is related to winter SH. It is found that winter SH variation is closely related to both dynamic processes and air temperature variations from the surface to the middle troposphere. The western SH variation mainly depends on dynamic processes, while its eastern part is more closely related to air temperature variation. The maintaining of winter SH mainly depends on downward motion of airflow of the nearly entire troposphere. The airflow originates from the North Atlantic sector, whose variation is influenced by the AO. When AO is in its positive (negative) phase, downward motion remarkably weakened (strengthened), which further influences winter SH. In addition, winter AO exhibits significant influences on the simultaneous sea-ice extent in the Barents Sea.

Study on the Tectonic Setting for the Ophiolites in Xigaze, Tibet

The Xigaze ophiolite is located in the middle section of the Yarlung Zangbo River ophiolite belt and includes a well-preserved sequence section of seven ophiolite blocks. The relatively complete ophiolitic sequence sections are represented by Jiding, Dejixiang, Baigang, and Dazhuqu ophiolites and consist of three-four units. The complete ophiolite sequence in order from the bottom to top consists of mantle peridotite, cumulates, sheeted sill dike swarms, and basic lavas±radiolarian chert. These cumulates are absent in the remaining blocks of Dejixiang and Luqu. The age of radiolaria in the radiolarian chert is Late Jurassic-Cretaceous. The basalt and ultramafic rock of the ophiolite also are overlaid by Tertiary Liuqu conglomerate, which contains numerous pebble components of ophiolite, indicating that the Tethys Ocean began to close at the end of Cretaceous Period. The isotopic data of gabbro, diabase, and albite granite in the Xigaze ophiolite are approximately 126-139 Ma, which indicates that the ophiolite formed in the Early Cretaceous. The K-Ar age of amphibole in garnet amphibolite in the ophiolite melange is 81 Ma, indicating that tectonic ophiolite emplacement occurred at the end of Late Cretaceous. Research in petrology, petrological chemistry, mineralogy, and geochemistry of volcanic rocks and dikes of the Xigaze ophiolite indicate the following characteristics： （1） They are mainly composed of basalt, basaltic andesite, dolerite, and diabase and are characterized by high TiO2 （0.7-1.47%）, low MgO （mostly less than 8%）, and low SiO2 （mostly less than 53%）. （2） The volcanic rocks and dikes of the Xigaze ophiolite show light rare earth element （LREE）-depleted rare earth element （REE） patterns. （3） The spider diagrams of the volcanic rocks and dikes of the Xigaze ophiolite exhibit LILE depletion relative to high-field-strength element （HFSE） patterns with left oblique features. （4） No protogenetic olivine and clinoenstatite was detected. （5） Some dikes show low TiO2 and high MgO, in which a few of Cr-enriched spinels and a very few pseudomorphs of olivine, orthopyroxene can be seen. They show more distinctive affinity as boninitic rock and canbe classified to boninite series rock. The previously mentioned features of the volcanic rocks and dikes in the Xigaze ophiolite implies that these ophiolites formed in a mid-ocean ridge （MOR） in the earlier stage and than forearc extension of subduction initiation occurred once at the later stage of the evolution of the Xigaze ophiolite. The forearc extention caused further melting of the residue-depleted mantle, resulting in the formation of melts with lower TiO2 and higher MgO. These melts formed as dikes and intruded into the oceanic crust formed in the earlier stage, resulting in a close association of mid-ocean ridge basalt and the boninite rock of the Xigaze ophiolite.

Glacier extent changes and possible causes in the Hala Lake Basin of Qinghai-Tibet Plateau

Glacier is a common sensitivity indicator of environmental and global climate change.Examining the relationship between glacier area and climate change will help reveal glacier change mechanisms and future trends.Glacier changes are also of great significance to the regulation of regional water resources.This study selected the Hala Lake Basin in the northeastern Qinhai-Tibet Plateau as a study area,and examined the relationships between the temporal and spatial change of glaciers in the northeastern Qinghai-Tibet Plateau and climate change based on remote sensing imagery,climatological data,and topographic data during the past 30 years.Results showed that glacier area in the Hala Lake basin fluctuated and decreased from106.24 km2 in 1986 to 78.84 km2 in 2015,with a decreasing rate of 0.94 km2·yr-1.The number of glacier patches,mean patch area,and largest patch index all decreased from 1986 to 2015,while the splitting index increased from 1986 to 2015,indicating that the landscape fragmentation of glacier in the Hala Lake Basin was increasing significantly during the study period.Glacier area change was mainly concentrated in the slopes>25°with an altitude of 4500-5000 m,and the retreating rate of glacier of sunny slope was obviously higher than that of shady slope.Geometric center of glacier in the basin moved from southwest to northeast towards high altitude.Results of the response of glacier extent to climate change showed that temperature was the dominant factor affecting glacier area dynamic change in the Hala Lake Basin.It is predicted that in future several years,the glacier area will decrease and fragment continually as a result of global warming on the Tibetan Plateau.

Sea ice extent retrieval with HY-2A scatterometer data and its assessment

A sea ice extent retrieval algorithm over the polar area based on scatterometer data of HY-2A satellite has been established. Four parameters are used for distinguishing between sea ice and ocean with Fisher＇s linear discriminant analysis method. The method is used to generate polar sea ice extent maps of the Arctic and Antarctic regions of the full 2013-2014 from the scatterometer aboard HY-2A （HY-2A-SCAT） backscatter data. The time series of the ice mapped imagery shows ice edge evolution and indicates a similar seasonal change trend with total ice area from DMSP-F17 Special Sensor Microwave Imager/Sounder （SSMIS） sea ice concentration data. For both hemispheres, the HY-2A-SCAT extent correlates very well with SSMIS 15% extent for the whole year period. Compared with Synthetic Aperture Radar （SAR） imagery, the HY-2A-SCAT ice extent shows good correlation with the Sentinel-1 SAR ice edge. Over some ice edge area, the difference is very evident because sea ice edges can be very dynamic and move several kilometers in a single day.

Combining CLUE-S and SWAT Models to Forecast Land Use Change and Non-point Source Pollution Impact at a Watershed Scale in Liaoning Province, China

Non-point source(NPS) pollution has become a major source of water pollution. A combination of models would provide the necessary direction and approaches designed to control NPS pollution through land use planning. In this study, NPS pollution load was simulated in urban planning, historic trends and ecological protection land use scenarios based on the Conversion of Land Use and its Effect at Small regional extent(CLUE-S) and Soil and Water Assessment Tool(SWAT) models applied to Hunhe-Taizi River Watershed, Liaoning Province, China. Total nitrogen(TN) and total phosphorus(TP) were chosen as NPS pollution indices. The results of models validation showed that CLUE-S and SWAT models were suitable in the study area. NPS pollution mainly came from dry farmland, paddy, rural and urban areas. The spatial distribution of TN and TP exhibited the same trend in 57 sub-catchments. The TN and TP had the highest NPS pollution load in the western and central plains, which concentrated the urban area and farm land. The NPS pollution load would increase in the urban planning and historic trends scenarios, and would be even higher in the urban planning scenario. However, the NPS pollution load decreased in the ecological protection scenario. The differences observed in the three scenarios indicated that land use had a degree of impact on NPS pollution, which showed that scientific and ecologically sound construction could effectively reduce the NPS pollution load in a watershed. This study provides a scientific method for conducting NPS pollution research at the watershed scale, a scientific basis for non-point source pollution control, and a reference for related policy making.