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Comparative Analysis of Energy Characteristics of Two Southwest Vortices in Sichuan Under Similar Circulation Backgrounds
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作者 周春花 张驹 肖红茹 《Journal of Tropical Meteorology》 SCIE 2024年第2期168-179,共12页
Based on ERA5 reanalysis data,the present study analyzed the thermal energy development mechanism and kinetic energy conversion characteristics of two extreme rainstorm processes in relation to the shallow southwest v... Based on ERA5 reanalysis data,the present study analyzed the thermal energy development mechanism and kinetic energy conversion characteristics of two extreme rainstorm processes in relation to the shallow southwest vortex in the warm-sector during a“rain-generated vortex”process and the deep southwest vortex in a“vortex-generated rain”process.The findings were as follows:(1)During the extreme rainstorm on August 11,2020(hereinafter referred to as the“8·11”process),intense surface heating and a high-energy unstable environment were observed.The mesoscale convergence system triggered convection to produce heavy rainfall,and the release of latent condensation heat generated by the rainfall promoted the formation of a southwest vortex.The significant increase(decrease)in atmospheric diabatic heating and kinetic energy preceded the increase(decrease)in vorticity.By contrast,the extreme rainstorm on August 16,2020(hereinafter referred to as the“8·16”process)involved the generation of southwest vortex in a low-energy and highhumidity environment.The dynamic uplift of the southwest vortex triggered rainfall,and the release of condensation latent heat from rainfall further strengthened the development of the southwest vortex.The significant increase(decrease)in atmospheric diabatic heating and kinetic energy exhibited a delayed progression compared to the increase(decrease)in vorticity.(2)The heating effect around the southwest vortex region was non-uniform,and the heating intensity varied in different stages.In the“8·11”process,the heating effect was the strongest in the initial stage,but weakened during the vortex's development.On the contrary,the heating effect was initially weak in the“8·16”process,and intensified during the development stage.(3)The available potential energy of the“8·11”process significantly increased in kinetic energy converted from rotational and divergent winds through baroclinic action,and the divergent wind energy continued to convert into rotational wind energy.By contrast,the“8·16”process involved the conversion of rotational wind energy into divergent wind energy,which in turn converted kinetic energy back into available potential energy,thereby impeding the further development and maintenance of the southwest vortex. 展开更多
关键词 southwest vortex similar circulation background diabatic heating kinetic energy spatial non-uniform heating effect
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The Spatial-Temporal Characteristics of Meteorological Disasters in the Southwest Region of Zhejiang Province during 1953-2022
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作者 Qi Zhang Yifan Wang +3 位作者 Zhidan Zhu Hongxia Shi Wenhao Yang Shujie Yuan 《Journal of Geoscience and Environment Protection》 2024年第3期16-27,共12页
Meteorological disasters are some of the most serious and costly natural disasters, which have larger effects on economic and social activity. Liuchun Lake is an ecotourism area in the southwest region of Zhejiang pro... Meteorological disasters are some of the most serious and costly natural disasters, which have larger effects on economic and social activity. Liuchun Lake is an ecotourism area in the southwest region of Zhejiang province, where also has experienced meteorological disasters including rainstorm and cold wave. Understanding the temporal-spatial characteristics of meteorological disasters is important for the local tourism and economic development. Based on the daily temperature and precipitation from 18 meteorological stations in the southwest of Zhejiang province during 1953-2022 and some statistical approaches, the temporal and spatial characteristics of meteorological disasters (Freezing, Rainstorm, Cold wave) are analyzed. The results indicate that 1) Rainstorm occurred frequently around the Liuchun lake, the frequency was about 8 times/a, it can also reach about 3 times/a in the other region. Freezing and cold wave (including strong cold wave and extremely cold wave) had the same spatial distribution as rainstorm, however, except for Liuchun lake, they occurred less than one time in the other regions;2) The trend of rainstorm had larger spatial difference, it increased in all the study area, but it increased more significantly around the study area than around Liuchun lake. Freezing was on the downtrend in the whole region, with 93.3% of the stations passed the 95% significant level. Cold wave also showed a declined trend, but it was insignificantly at most of the stations, only 33% of the stations passed the 90% significant level. Compared with cold wave, strong cold wave and extremely strong cold wave had weaker decline in all the regions. In general, from 1953 to 2022 rainstorm showed an increasing trend, it was the main meteorological disaster in the study area, cold wave displayed a decreasing trend, but it still occurred about 2 - 3 times/a in most regions. 展开更多
关键词 southwest of Zhejiang Province RAINSTORM Cold Wave Spatial Distribution Trend Analysis
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Deep learning-based subseasonal to seasonal precipitation prediction in southwest China:Algorithm comparison and sensitivity to input features 被引量:1
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作者 GuoLu Gao Yang Li +3 位作者 XueYun Zhou XiaoMing Xiang JiaQi Li ShuCheng Yin 《Earth and Planetary Physics》 CAS CSCD 2023年第4期471-486,共16页
The prediction of precipitation at subseasonal to seasonal(S2S)timescales remains an enormous challenge because of the gap between weather and climate predictions.This study compares three deep learning algorithms,nam... The prediction of precipitation at subseasonal to seasonal(S2S)timescales remains an enormous challenge because of the gap between weather and climate predictions.This study compares three deep learning algorithms,namely,the long short-term memory recurrent(LSTM),gated recurrent unit(GRU),and recurrent neural network(RNN),and selects the optimal algorithm to establish an S2S precipitation prediction model.The models were evaluated in four subregions of the Sichuan Province:the Plateau,Valley,eastern Basin,and western Basin.The results showed that the RNN model had better performance than the LSTM and GRU models.This could be because the RNN model had an advantage over the LSTM model in the transformation of climate indices with positive and negative variations.In the validation of test datasets,the RNN model successfully predicted the precipitation trend in most years during the wet season(May-October).The RNN model had a lower prediction bias(within±10%),higher sign accuracy of the precipitation trend(~88.95%),and greater accuracy of the maximum precipitation month(>0.85).For the prediction of different lead times,the RNN model was able to provide a stable trend prediction for summer precipitation,and the time correlation coefficient score was higher than that of the National Climate Center of China.Furthermore,this study proposed a method to measure the sensitivity of the RNN model to different input features,which may provide unprecedented insights into the nonlinear relationship and complicated feedback process among climate systems.The results of the sensitivity distribution are as follows.First,the Niño 4 and Niño 3.4 indices were equally important for the prediction of wet season precipitation.Second,the sensitivity of the snow cover on the Tibetan Plateau was higher than that in the Northern Hemisphere.Third,an opposite sensitivity appeared in two different patterns of the Indian Ocean and sea ice concentrations in the Arctic and the Barents Sea. 展开更多
关键词 recurrent neural network long short-term memory recurrent sensitivity analysis artificial intelligence explainability complex terrain southwest China
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Genomic analysis of indigenous goats in Southwest Asia reveals evidence of ancient adaptive introgression related to desert climate
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作者 Hojjat Asadollahpour Nanaei Yudong Cai +8 位作者 Akil Alshawi Jiayue Wen Tanveer Hussain Wei-Wei Fu Nai-Yi Xu Abdulameer Essa Johannes ALenstra Xihong Wang Yu Jiang 《Zoological Research》 SCIE CAS CSCD 2023年第1期20-29,共10页
Understanding how evolutionary pressures related to climate change have shaped the current genetic background of domestic animals is a fundamental pursuit of biology. Here, we generated wholegenome sequencing data fro... Understanding how evolutionary pressures related to climate change have shaped the current genetic background of domestic animals is a fundamental pursuit of biology. Here, we generated wholegenome sequencing data from native goat populations in Iraq and Pakistan. Combined with previously published data on modern, ancient(Late Neolithic to Medieval periods), and wild Capra species worldwide, we explored the genetic population structure, ancestry components, and signatures of natural positive selection in native goat populations in Southwest Asia(SWA). Results revealed that the genetic structure of SWA goats was deeply influenced by gene flow from the eastern Mediterranean during the Chalcolithic period, which may reflect adaptation to gradual warming and aridity in the region. Furthermore, comparative genomic analysis revealed adaptive introgression of the KITLG locus from the Nubian ibex(C. nubiana) into African and SWA goats. The frequency of the selected allele at this locus was significantly higher among goat populations located near northeastern Africa. These results provide new insights into the genetic composition and history of goat populations in the SWA region. 展开更多
关键词 GOAT Adaptation KITLG southwest Asia Nubian ibex
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An extraordinary multielement apparatus of conodont Nicoraella from the Middle Triassic Luoping Biota,southwest China
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作者 Jin-yuan Huang 《China Geology》 CAS CSCD 2023年第1期183-184,共2页
Conodont animal is an extinct group of marine animals.The conodont elements and their hard skeletal remains are originally from the head region of this kind of animal,and they are considered to be functioned as“teeth... Conodont animal is an extinct group of marine animals.The conodont elements and their hard skeletal remains are originally from the head region of this kind of animal,and they are considered to be functioned as“teeth”.The“multielement apparatus”can also be called the“(conodont)apparatus”,“multimembrate(skeletal)apparatus”. 展开更多
关键词 apparatus southwest MIDDLE
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Record of hydrothermal activity in the Yuhuang hydrothermal field and its implications for the Southwest Indian Ridge:evidence from sulfide chronology
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作者 Weifang Yang Chunhui Tao +6 位作者 Shili Liao Jin Liang Wei Li Teng Ding Ágata Alveirinho Dias Xuefeng Wang Lisheng Wang 《Acta Oceanologica Sinica》 SCIE CAS CSCD 2023年第11期59-68,共10页
The Yuhuang hydrothermal field(YHF)is located between the Indomed and Gallieni fracture zones near the top of the off-axis slope on the south rift wall of Segment 29 on the ultraslow Southwest Indian Ridge(SWIR).Previ... The Yuhuang hydrothermal field(YHF)is located between the Indomed and Gallieni fracture zones near the top of the off-axis slope on the south rift wall of Segment 29 on the ultraslow Southwest Indian Ridge(SWIR).Previous studies have shown that sulfides in the YHF formed during different mineralization episodes and the YHF has the greatest potential for the formation of large-scale seafloor massive sulfide deposits.However,the sulfide chronology and hydrothermal activity of the YHF remain poorly constrained.In this study,mineralogical analyses and 230Th/U dating were performed.Hydrothermal activity may start about(35.9±2.3)ka from the southwest part of the YHF and may cease about(708±81)a ago from the northeast part of the YHF.The 74 nonzero chronological data from hydrothermal sulfide samples provide the first quantitative characterization of the spatial and temporal history along the SWIR.Hydrothermal activity in the SWIR has been relatively active over the past20 ka.In contrast,between 40 ka and 100 ka,hydrothermal activity was relatively infrequently and short in duration.The maximum activity occurred at 15–11 ka,9–7 ka,6–0.2 ka.There was a slight positive correlation between the maximal age and estimated surface area or estimated tonnage.The minimum mass accumulation rate of YHF is about 278 t/a,which is higher than most HFs related to ultramafic systems.The ultraslow spreading SWIR has the greatest potential to form large-scale seafloor massive sulfides(SMS)deposits.The results of this study provide new insights into the metallogenic mechanism of hydrothermal sulfides along ultraslow-spreading ridges. 展开更多
关键词 southwest Indian Ridge seafloor massive sulfides 230Th/U dating hydrothermal activity mass accumulation
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Evaluation and Quantitative Attribution Analysis of Water Yield Services in the Peak-cluster Depression Basins in Southwest of Guangxi,China
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作者 WANG Donghua TIAN Yichao +5 位作者 ZHANG Yali HUANG Liangliang TAO Jin YANG Yongwei LIN Junliang ZHANG Qiang 《Chinese Geographical Science》 SCIE CSCD 2023年第1期116-130,共15页
Karst environmental issues have become one of the hot spots in contemporary international geological research. The same problem of water shortage is one of the hot spots of global concern. The peak-cluster depression ... Karst environmental issues have become one of the hot spots in contemporary international geological research. The same problem of water shortage is one of the hot spots of global concern. The peak-cluster depression basins in southwest of Guangxi is an important water connotation and ecological barrier areas in the Pearl River Basin of China. Thus, studying the spatial and temporal variations and the influencing factors of its water yield services is critical to achieve the sustainable development of water resources and ecological environmental protection in this region. As such, this paper uses the Integrated Valuation of Ecosystem Services and Tradeoffs(InVEST) model to assess the spatial and temporal variabilities of water yield services and its trends in the peak-cluster depression basins in southwest of Guangxi from 2000 to 2020. This work also integrates precipitation(Pre), reference evapotranspiration(ET), temperature(Tem), digital elevation model(DEM), slope, normalized difference vegetation index(NDVI), land use/land cover(LULC) and soil type to reveal the main factors that influence water yield services with the help of Geodetector. Results show that: 1) in time scale,the total annual water yield in the study area show a fluctuating and increasing trend from 2000 to 2020, with a growth rate of 7.3753 × 10^(8)m^(3)/yr, and its multi-year average water yield was 538.07 mm;2) in spatial pattern, with high yield areas mainly distributed in the south of the study area(mainly including Shangsi County, Pingxiang City, Ningming County, Longzhou County and Jingxi County), and low yield areas mainly distributed in Baise City and Nanning City;3) the dominant factor of water yield within karst and non-karst landforms is not necessarily controlled by precipitation, and the explanation degree of DEM factors in karst areas is significantly higher than that in non-karst areas;4) amongst the climatic factors, Pre, ET and Tem are dominant in the spatial pattern of region water yield capacity. among which Pre has the highest explanatory power for the spatial heterogeneity of annual water production, with q values above0.8, and each driver showed a significant interaction on the spatial distribution of water yield, with Pre exhibiting the strongest interaction with LULC. 展开更多
关键词 water yield Integrated Valuation of Ecosystem Services and Trade-offs(InVEST) Geodetector peak-cluster depression basins in southwest of Guangxi China
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A comparative study of seismic tomography models of Southwest China
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作者 Xuezhen Zhang Xiaodong Song Feiyi Wang 《Earthquake Science》 2023年第1期15-39,共25页
The margin of the Tibetan Plateau of Southwest China is one of the most seismically active regions of China and is the location of the China Seismic Experimental Site(CSES).Many studies have developed seismic velocity... The margin of the Tibetan Plateau of Southwest China is one of the most seismically active regions of China and is the location of the China Seismic Experimental Site(CSES).Many studies have developed seismic velocity models of Southwest China,but few have compared and evaluated these models which is important for further model improvement.Thus,we compared six published seismic shear-wave velocity models of Southwest China on absolute velocity and velocity perturbation patterns.The models are derived from different types of data(e.g.,surface waves from ambient noise and earthquakes,body-wave travel times,receiver functions) and inversion methods.We interpolated the models into a uniform horizontal grid(0.5° × 0.5°) and vertically sampled them at 5,10,20,30,40,and 60 km depths.We found significant differences between the six models.Then,we selected three of them that showed greater consistency for further comparison.Our further comparisons revealed systematic biases between models in absolute velocity that may be related to different data types.The perturbation pattern of the model is especially divergent in the shallow part,but more consistent in the deep part.We conducted synthetic and inversion tests to explore possible causes and our results imply that systematic differences between the data,differences in methods,and other factors may directly affect the model.Therefore,the Southwest China velocity model still has considerable room for improvement,and the impact of inconsistency between different data types on the model needs further research.Finally,we proposed a new reference shear-wave velocity model of Southwest China(SwCM-S1.0) based on the three selected models with high consistency.We believe that this model is a better representation of more robust features of the models that are based on different data sets. 展开更多
关键词 model comparison shear-wave velocity model southwest China
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Moisture Sources and Their Contributions to Summer Precipitation in the East of Southwest China
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作者 李永华 黄丁安 +3 位作者 卢楚翰 向波 周杰 何卷雄 《Journal of Tropical Meteorology》 SCIE 2023年第2期153-167,共15页
Complex topography,special geographical location and sea-land-air interactions lead to high interannual variability of summer precipitation in the east of Southwest China(ESWC).However,the contributions,influencing fa... Complex topography,special geographical location and sea-land-air interactions lead to high interannual variability of summer precipitation in the east of Southwest China(ESWC).However,the contributions,influencing factors and mechanisms of remote and local evaporation remain to be further investigated.Using clustering analysis and Hybrid Single-Particle Lagrangian Integrated Trajectory version 5 model,we analyze the contributions of remote moisture transport and local evaporation to summer precipitation in the ESWC and their causes.There are mainly five remote moisture channels in the ESWC,namely the Arabian Sea channel,Bay of Bengal channel,western Pacific channel,Northwest channel 1 and Northwest channel 2.Among the five channels,the western Pacific channel has the largest number of trajectories,while the Bay of Bengal channel has the largest contribution rate of specific humidity(33.33%)and moisture flux(33.14%).The amount of regional average precipitation is close to that of the precipitation caused by remote moisture transport,and both are considerably greater than the rainfall amount caused by local evaporation.However,on interannual time scales,precipitation recirculation rates are negatively correlated to regional average precipitation and precipitation caused by remote moisture transport but are consistent with that caused by local evaporation.An apparent"+-+"wave train can be found on the height anomaly field in East Asia,and the sea surface temperature anomalies are positive in the equatorial Middle-East Pacific,the South China Sea,the Bay of Bengal and the Arabian Sea.These phenomena cause southwest-northeast moisture transport with strong updrafts,thereby resulting in more precipitation in the ESWC. 展开更多
关键词 east of southwest China summer precipitation moisture sources local evaporation contributions of moisture
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Prevalence, Aetiology, and Clinical Profile of Acute Abdomen in Pregnancy in Southwest Cameroon: A 5-Year Retrospective Study
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作者 Yannick Mahamat Ekani Boukar Divine Mokake +9 位作者 Felix Adolphe Elong Terence Dze Enah Moussa Adam Adami Eric Patrick Savom Anutebeh Verdo Zisuh Guy Aristide Bang Alain Chichom Mefire Arthur Essomba Marcellin Ngowe Ngowe Maurice Aurelien Sosso 《Surgical Science》 2023年第1期1-9,共9页
Background: Acute abdomen is one of the commonest reasons for presentation at the emergency department. The physiologic changes of pregnancy increase the chances of developing acute abdomen. The global incidence of ac... Background: Acute abdomen is one of the commonest reasons for presentation at the emergency department. The physiologic changes of pregnancy increase the chances of developing acute abdomen. The global incidence of acute abdomen in pregnancy range from 1 in 500 to 1 in 635 pregnant women. In 2018, a study in Azerbaijan reported a prevalence of 25%. However, to the best of our knowledge, very few studies have been carried out on this subject in Cameroon. Objectives: To determine the prevalence, assess the aetiologies, and review clinical profile of acute abdomen in pregnancy in the Southwest Cameroon. Methods: We conducted a 5-year retrospective study at the Obst/Gyn and Surgical units of Kumba, Buea, and Limbe Regional Hospitals. We included all files of pregnant women that were admitted for acute abdomen within the study period (1<sup>st</sup> Jan 2017 to 31<sup>st</sup> Dec 2021). Data was collected using a structured checklist adapted from previous studies. Descriptive statistics and statistical testing was done using SPSS version 25.0. Chi-square was used to compare categorical variables. p Results: Over 14,106 pregnant women were admitted to the aforementioned hospitals within the study period. 335 (2.4%) met our inclusion criteria. The patients’ age ranged from 17 to 43 years. The mean age was 27 years. Acute abdomen was more frequent (65%) in the first trimester. Ectopic pregnancy was the commonest obstetric aetiology while appendicitis was the commonest non obstetric surgical aetiology. Abdominal pain and tenderness were the most common presentation. Conclusion: The prevalence of acute abdomen in pregnancy in the Southwest Cameroon is 10 times higher than the global prevalence. Our study also confirmed the numerous aetiologies and varied clinical presentations of acute abdomen in pregnancy. Hence a wake-up call for primary care physicians. 展开更多
关键词 Acute Abdomen PREGNANCY southwest Cameroon
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The Spatial-Temporal Change of Extreme Precipitation in the Southwest Region of Zhejiang Province during 1953-2022
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作者 Wenhao Yang Shujie Yuan Hongxia Shi 《Journal of Geoscience and Environment Protection》 2023年第11期91-102,共12页
Based on the daily precipitation from 17 meteorological stations in the southwest of Zhejiang from 1953 to 2022, 11 extreme precipitation indices were calculated, and the temporal-spatial characteristic of extreme pre... Based on the daily precipitation from 17 meteorological stations in the southwest of Zhejiang from 1953 to 2022, 11 extreme precipitation indices were calculated, and the temporal-spatial characteristic of extreme precipitation were analyzed. The results indicate that 1) Except for the number of consecutive dry days (CDD), all the other extreme precipitation indices had low values in the northeast of the study area and high value around Liuchun Lake;2) CDD had a decreasing trend in most part of study area, while the other indices were on the rise, especially at Suichang (SC) and Tonglu (TL) stations, the change was significant (p 0.05);3) The annual variation showed that CDD declined with the trend of 0.83 d/10a, however, all the other indices increased, especially after 2000, the increase was more obvious. In general, the extreme precipitation mount, the extreme precipitation days showed an increasing trend, drought was less likely to happen, and the possibility of heavy precipitation is less, however, at some individual station such as SC, heavy precipitation and storm is much more likely to occur. 展开更多
关键词 southwest of Zhejiang Province Extreme Precipitation Indices Temporal-Spatial Characteristic
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Contribution of external forcing to summer precipitation trends over the Qinghai-Tibet Plateau and Southwest China
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作者 Yuying Xiang Tao Wang +1 位作者 Hongna Xu Huijun Wang 《Atmospheric and Oceanic Science Letters》 CSCD 2023年第5期29-34,共6页
在过去的60年中,全球气候经历了快速变暖和短暂的变暖停滞,而中国的区域降水也经历了多样而复杂的变化.本文分析了1961年至2014年外强迫因子对青藏高原和中国西南地区夏季降水趋势的影响.观测数据显示,青藏高原的夏季降水呈增加趋势,而... 在过去的60年中,全球气候经历了快速变暖和短暂的变暖停滞,而中国的区域降水也经历了多样而复杂的变化.本文分析了1961年至2014年外强迫因子对青藏高原和中国西南地区夏季降水趋势的影响.观测数据显示,青藏高原的夏季降水呈增加趋势,而中国西南地区的夏季降水呈减少趋势,这两个相邻地区的夏季降水变化趋势相反.利用CMIP6数据,本文研究了不同外强迫因子对两个区域夏季降水趋势的影响.结果表明,温室气体对青藏高原夏季降水的增加具有显著影响,而气溶胶在中国西南地区夏季降水减少中起主要作用。 展开更多
关键词 夏季降水 青藏高原 中国西南 CMIP6 外强迫因子
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The dry and hot American Southwest under the present and future climates
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作者 Wei Zhang 《Atmospheric and Oceanic Science Letters》 CSCD 2023年第6期48-51,共4页
由于正在持续的特大干旱,更频繁的洪水,热浪以及导致空气污染的山火,美国西南部目前正在经历气候危机.这些气候危机主要与水文气候过程相关,尤其是气候系统各圈层之间的水汽通量.本研究主要讨论目前一些水文系统的科学基站以及物理驱动... 由于正在持续的特大干旱,更频繁的洪水,热浪以及导致空气污染的山火,美国西南部目前正在经历气候危机.这些气候危机主要与水文气候过程相关,尤其是气候系统各圈层之间的水汽通量.本研究主要讨论目前一些水文系统的科学基站以及物理驱动因素,比如北美夏季风以及太平洋北美遥相关.本研究指出降水以及气温对于干旱的相对作用的理论和工具.确定内部变率和外部强迫对于美国西南部水文气候系统的相对作用尤为重要.展望未来,需要研究高分辨率模拟系统,加强降水以及温度对于水文气候系统相对作用的理解,外部强迫的作用以及通过科学家以及其他利益相关者之间的合作. 展开更多
关键词 美国西南部 热浪 干旱 气候变化 内部变率 外部强迫
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Relationships among the Monsoon-like Southwest Australian Circulation,the Southern Annular Mode, and Winter Rainfall over Southwest Western Australia 被引量:1
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作者 FENG Juan LI Jianping +2 位作者 Yun LI ZHU Jianlei XIE Fei 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2015年第8期1063-1076,共14页
This study examines the relationships among the monsoon-like southwest Australian circulation (SWAC), the South- ern Annular Mode (SAM), and southwest Western Australia winter rainfall (SWR), based on observed r... This study examines the relationships among the monsoon-like southwest Australian circulation (SWAC), the South- ern Annular Mode (SAM), and southwest Western Australia winter rainfall (SWR), based on observed rainfall, reanalysis datasets, and the results of numerical modeling. By decomposing the SWAC into two components using a linear model, i.e. the component related to SAM (RSAM) and the component unrelated to SAM (SWACI*), we find it is the SWACI* that shows a significant influence on SWR. Similarly, it is the component of SAM associated with SWAC that exhibits an impact on SWR, whereas the component unrelated to SAM. A similar result is obtained in terms of the circulation associated with SWAC and the SAM. These facts suggest the SAM plays an indirect role in influencing SWR, and raise the possibility that SWAC acts as a bridge between the SAM and SWR, by which the SAM passes its influences onto SWR. This is due to the fact that the variations of SWAC are closely linked to the thermal contrast between land and sea across the southern Indian Ocean and southwest Australia. By contrast, the SAM does not significantly relate to this thermal structure, particularly for the component unrelated to SWAC. The variations of surface sea temperature over the southern Indian Ocean contribute to the favored rainfall circulation patterns. This finding is supported by the numerical modeling results. The strong coupling between SWAC and SWR may be instrumental for understanding the interactions between SWR and the southern Indian Ocean, and provides another perspective in examining the variations in SWR. 展开更多
关键词 monsoon-like southwest Australian Circulation Southern Annular Mode southwest Western Australian winterrainfall
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Assessment of Future Drought in Southwest China Based on CMIP5 Multimodel Projections 被引量:26
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作者 WANG Lin CHEN Wen ZHOU Wen 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2014年第5期1035-1050,共16页
In the last decade, a series of severe and extensive droughts have swept across Southwest China, resulting in tremendous economic losses, deaths, and disruption to society. Consequently, this study is motivated by the... In the last decade, a series of severe and extensive droughts have swept across Southwest China, resulting in tremendous economic losses, deaths, and disruption to society. Consequently, this study is motivated by the paramount importance of as- sessing future changes in drought in Southwest China. Precipitation is likely to decrease over most parts of Southwest China around the beginning of the century, followed by widespread precipitation increases; the increase in potential evapotran- spiration (PET), due to the joint effects of increased temperature and surface net radiation and decreased relative humidity, will overwhelm the whole region throughout the entire 21st century. In comparative terms, the enhancement of PET will outweigh that of precipitation, particularly under Representative Concentration Pathway (RCP) 8.5, resulting in intensified drought. Generally, the drying tendency will be in the southeast portion, whereas the mountainous region in the northwest will become increasingly wetter owing to abundant precipitation increases. Droughts classified as moderate/severe according to historical standards will become the norm in the 2080s under RCP4.5/RCP8.5. Future drought changes will manifest different characteristics depending on the time scale: the magnitude of change at a time scale of 48 months is nearly twice as great as that at 3 months. Furthermore, we will see that not only will incidences of severe and extreme drought increase dramatically in the future, but extremely wet events will also become more probable. 展开更多
关键词 DROUGHT Standardized Precipitation Evapotranspiration Index spatial disaggregation southwest China
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Drought in Southwest China: A Review 被引量:19
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作者 WANG Lin CHEN Wen +1 位作者 ZHOU Wen HUANG Gang 《Atmospheric and Oceanic Science Letters》 CSCD 2015年第6期339-344,共6页
The clustering of severe and sustained droughts in Southwest China(SWC)during the last decade has resulted in tremendous losses,including crop failure,a lack of drinking water,ecosystem destruction,health problems,and... The clustering of severe and sustained droughts in Southwest China(SWC)during the last decade has resulted in tremendous losses,including crop failure,a lack of drinking water,ecosystem destruction,health problems,and even deaths.Various attempts have been made to explore the variability and causes of drought in SWC.Here,the authors summarize and integrate this accumulated but fragmented knowledge.On the whole,general agreement has been reached on the evolution of drought in SWC,which has become more frequent and intense during the past 50 years and is projected to continue throughout the 21st century.However,it is unclear and even disputable as to what and how sea surface temperatures and circulation oscillation patterns affect the drought condition.Meanwhile,the presence of strong nonlinearity places considerable challenges in both understanding and predicting drought in SWC.Therefore,much remains to be learned concerning the mechanisms responsible for drought disasters in SWC and accurate forecast practice.In addition to pursuing research on factors and processes involved in drought formation,above all,there is an urgent need to develop appropriate strategies and plans for mitigating the threats of drought. 展开更多
关键词 DROUGHT southwest China HISTORICAL CHANGE FUTURE s
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Geochemistry and SHRIMP Zircon U-Pb Age of Post-Collisional Granites in the Southwest Tianshan Orogenic Belt of China:Examples from the Heiyingshan and Laohutai Plutons 被引量:19
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作者 LONG Lingli GAO Jun +5 位作者 WANG Jingbin QIAN Qing XIONG Xianming WANG Yuwang WANG Lijuan GAO Liming 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2008年第2期415-424,共10页
The Heiyingshan granite and the Laohutai granite plutons exposed in the Southwest Tianshan resemble A-type granites geochemically. Analysis shows that the both are ferron calc-alkalic peraluminous or ferron alkali-cal... The Heiyingshan granite and the Laohutai granite plutons exposed in the Southwest Tianshan resemble A-type granites geochemically. Analysis shows that the both are ferron calc-alkalic peraluminous or ferron alkali-calcic peraluminous with a relatively high concentration of SiO2 (〉70%), high alkali contents (Na20 + K20 = 7.14%-8.56%; K20〉N20; A/CNK = 0.99-1.20), and pronounced negative anomales in Eu, Ba, St, P and Ti. A SHRIMP zircon U-Pb age of 285±4 Ma was obtained for the Heiyingshan hornblende biotite granite intrusion. The geochemical and age dating data reported in this paper indicate that these granites were formed during the post-collisional crustal extension of the Southwest Tianshan orogenic belt, in agreement with the published data for the granites in the South Tianshan. 展开更多
关键词 Xinjiang southwest Tianshan granite GEOCHEMISTRY SHRIMP zircon U-Pb age
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Late Silurian to Early Devonian Palynomorphs from Qujing,Yunnan,Southwest China 被引量:12
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作者 TIAN Jiajie ZHU Huaicheng +1 位作者 HUANG Min LIU Feng 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2011年第3期559-568,共10页
Well-preserved and diversified spores,cryptospores,and acritarchs have been recorded from a relatively continuous sequence that encompasses the Silurian-Devonian boundary in Qujing, Yunnan,southwest China.Four spore a... Well-preserved and diversified spores,cryptospores,and acritarchs have been recorded from a relatively continuous sequence that encompasses the Silurian-Devonian boundary in Qujing, Yunnan,southwest China.Four spore assemblage zones from Late Silurian to Early Devonian in age are proposed based on the first appearance datum(FAD)of characteristic spore species.In ascending stratigraphic order,they are Ambitisporites dilutus-Apiculiretusispora synorea(DS;Late Ludfordian to Early Pridoli),Synorisporites verrucatus-Apiculiretusispora plicata(VP;Pridoli),Apiculiretusispora minuta-Leiotriletes ornatus(MO;Lochkovian),and Verrucosisporites polygonalis-Dibolisporites wetteldorfensis(PW;Pragian).The acritarch assemblage from the upper part of the Yulongsi Formation,the Xiaxishancun Formation,and the lower-middle parts of the Xitun Formation indicates an age of Late Silurian.Based on palynological evidence,the upper part of the Yulongsi Formation is considered Late Ludfordian to Early Pridoli in age;the Xiaxishancun Formation is believed to be Pridoli in age;the Xitun Formation is considered Late Pridoli to Early Lochkovian in age;the Guijiatun Formation is considered Lochkovian in age;and the Xujiachong Formation is Late Lochkovian to Pragian in age.The Silurian-Devonian boundary is recognized between the VP and the MO spore biozones,and occurs within the middle part of the Xitun Formation. 展开更多
关键词 SPORE cryptospore ACRITARCH SILURIAN DEVONIAN Qujing southwest China
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Observational Facts Regarding the Joint Activities of the Southwest Vortex and Plateau Vortex after Its Departure from the Tibetan Plateau 被引量:25
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作者 Shuhua YU Wenliang GAO +1 位作者 Dixiang XIAO Jun PENG 《Advances in Atmospheric Sciences》 SCIE CAS CSCD 2016年第1期34-46,共13页
Using atmospheric observational data from 1998 to 2013,station rainfall data,TRMM(Tropical Rainfall Measuring Mission) data,as well as annual statistics for the plateau vortex and shear line,the joint activity featu... Using atmospheric observational data from 1998 to 2013,station rainfall data,TRMM(Tropical Rainfall Measuring Mission) data,as well as annual statistics for the plateau vortex and shear line,the joint activity features of sustained departure plateau vortexes(SDPVs) and southwest vortexes(SWVs) are analyzed.Some new and useful observational facts and understanding are obtained about the joint activities of the two types of vortex.The results show that:(1) The joint active period of the two vortexes is from May to August,and mostly in June and July.(2) The SDPVs of the partnership mainly originate near Zaduo,while the SWVs come from Jiulong.(3) Most of the two vortexes move in almost the same direction,moving eastward together with the low trough.The SDPVs mainly act in the area to the north of the Yangtze River,while the SWVs are situated across the Yangtze River valley.(4) The joint activity of the two vortexes often produces sustained regional heavy rainfall to the south of the Yellow River,influencing wide areas of China,and even as far as the Korean Peninsula,Japan and Vietnam.(5) Most of the two vortexes are baroclinic or cold vortexes,and they both become strengthened in terms of their joint activity.(6) When the two vortexes move over the sea,their central pressure descends and their rainfall increases,especially for SWVs.(7) The two vortexes might spin over the same area simultaneously when there are tropical cyclones in the eastern and southern seas of China,or move southward together if a tropical cyclone appears near Hainan Island. 展开更多
关键词 plateau vortex southwest vortex observational study
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Biostratigraphy of Triassic Marine Reptiles in Southwest Guizhou and Its Adjacent Area 被引量:17
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作者 WANG Liting, LI Jinling, WANG Xinjin, LI Chun,WU Tianzhuang and LIU Jun Bureau of Geology and Mineral Exploration and Development of Guizhou ProvinceGuiyang 550004 Institute of Vertebrate Palaeontology and Palaeoanthropology,Chinese Academy of Sciences, Beijing 100044 Guizhou Museum, Guiyang 550004 《Acta Geologica Sinica(English Edition)》 SCIE CAS CSCD 2001年第4期349-353,共5页
This paper briefly reviews the Triassic marine reptile fossils in Guizhou Province, especially the fossils that have been recently found in the Guanling area. Based on three sections at Guanling and Xingyi, Guizhou Pr... This paper briefly reviews the Triassic marine reptile fossils in Guizhou Province, especially the fossils that have been recently found in the Guanling area. Based on three sections at Guanling and Xingyi, Guizhou Province and Luoping, Yunnan Province, four horizons with vertebrate fossils are recognized in the Middle and Upper Triassic of this area; They are from bottom to top: Member I and Member II of the Guanling Formation, and the Zhuganpo Member and the Wayao Member of the Falang Formation. 展开更多
关键词 southwest Guizhou Middle and Upper Triassic marine reptiles Guanling Formation Falang Formation
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