检索结果-南通市图书馆

Seasonal Forecasts of Precipitation during the First Rainy Season in South China Based on NUIST-CFS1.0

Advances in Atmospheric Sciences 2023年第10期40卷 1895-1910页

作者： Sinong LI Huiping YAN Jing-Jia LUO Institute for Climate and Application Research(ICAR)/cic-femd/klme/ilcec Nanjing University of Information Science and TechnologyNanjing 210044China

Current dynamical models experience great difficulties providing reliable seasonal forecasts of regional/local rainfall in South China.This study evaluates seasonal forecast skill for precipitation in the first rainy season(FRS,i.e.,April–June)over South China from 1982 to 2020 based on the global real-time Climate Forecast System of Nanjing University of Information Science and Technology(NUIST-CFS1.0,previously known as SINTEX-F).The potential predictability and the practical forecast skill of NUIST-CFS1.0 for FRS precipitation remain low in general.But NUIST-CFS1.0 still performs better than the average of nine international models in terms of correlation coefficient skill in predicting the interannual precipitation anomaly and its related circulation index.NUIST-CFS1.0 captures the anomalous Philippines anticyclone,which transports moisture and heat northward to South China,favoring more precipitation in South China during the FRS.By examining the correlations between sea surface temperature(SST)and FRS precipitation and the Philippines anticyclone,we find that the model reasonably captures SST-associated precipitation and circulation anomalies,which partly explains the predictability of FRS precipitation.A dynamical downscaling model with 30-km resolution forced by the large-scale circulations of the NUIST-CFS1.0 predictions could improve forecasts of the climatological states and extreme precipitation events.Our results also reveal interesting interdecadal changes in the predictive skill for FRS precipitation in South China based on the NUIST-CFS1.0 hindcasts.These results help improve the understanding and forecasts for FRS precipitation in South China.

关键词： seasonal forecast of precipitation first rainy season in South China global climate model prediction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Urban Impact on Landfalling Tropical Cyclone Precipitation:A Numerical Study of Typhoon Rumbia(2018)

引用

Advances in Atmospheric Sciences 2023年第6期40卷 988-1004页

作者： Xinguan DU Haishan CHEN Qingqing LI Xuyang GE KLME/ILCEC/CIC-FEMD Nanjing University of Information Science and TechnologyNanjing 210044China School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjing 210044China

Coastal urban areas are prone to serious disasters caused by landfalling tropical cyclones(TCs). Despite the crucial role of urban forcing in precipitation, how fine-scale urban features impact landfalling TC precipitation remains poorly understood. In this study, high-resolution ensemble simulations of Typhoon Rumbia(2018), which crossed the Yangtze River Delta urban agglomeration, were conducted to analyze the potential urban impact on TC precipitation. Results show that the inner-core rainfall of Rumbia is strengthened by approximately 10% due to the urban impact near the landfall,whereas minor differences in outer-core rainfall are found when the urban impact is excluded. Further diagnostic analyses indicate that low-level upward motion is crucial for precipitation evolution, as both co-vary during landfall. Moreover, the frictionally induced upward motion plays a decisive role in enhancing the rainfall when the urban impacts are included.Urban surface friction can decelerate the tangential wind and therefore destroy the gradient balance and strengthen the radial wind within the boundary layer and thus can enhance upward motion. This study demonstrates that urban surface friction and related physical processes make the most significant contribution to landfalling TC rainfall enhancement.

关键词： landfalling tropical cyclone urban agglomeration quantitative diagnosis rainfall physical mechanisms surface friction

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Downscaling Seasonal Precipitation Forecasts over East Africa with Deep Convolutional Neural Networks

引用

Advances in Atmospheric Sciences 2024年第3期41卷 449-464页

作者： Temesgen Gebremariam ASFAW Jing-Jia LUO Institute for Climate and Application Research(ICAR)/cic-femd/klme/ilcec Nanjing University of Information Science and TechnologyNanjing 210044China Institute of Geophysics Space Science and Astronomy Addis Ababa UniversityAddis Ababa 1176Ethiopia

This study assesses the suitability of convolutional neural networks(CNNs) for downscaling precipitation over East Africa in the context of seasonal forecasting. To achieve this, we design a set of experiments that compare different CNN configurations and deployed the best-performing architecture to downscale one-month lead seasonal forecasts of June–July–August–September(JJAS) precipitation from the Nanjing University of Information Science and Technology Climate Forecast System version 1.0(NUIST-CFS1.0) for 1982–2020. We also perform hyper-parameter optimization and introduce predictors over a larger area to include information about the main large-scale circulations that drive precipitation over the East Africa region, which improves the downscaling results. Finally, we validate the raw model and downscaled forecasts in terms of both deterministic and probabilistic verification metrics, as well as their ability to reproduce the observed precipitation extreme and spell indicator indices. The results show that the CNN-based downscaling consistently improves the raw model forecasts, with lower bias and more accurate representations of the observed mean and extreme precipitation spatial patterns. Besides, CNN-based downscaling yields a much more accurate forecast of extreme and spell indicators and reduces the significant relative biases exhibited by the raw model predictions. Moreover, our results show that CNN-based downscaling yields better skill scores than the raw model forecasts over most portions of East Africa. The results demonstrate the potential usefulness of CNN in downscaling seasonal precipitation predictions over East Africa,particularly in providing improved forecast products which are essential for end users.

关键词： East Africa seasonal precipitation forecasting downscaling deep learning convolutional neural networks(CNNs)

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Alternation of the Atmospheric Teleconnections Associated with the Northeast China Spring Rainfall during a Recent 60-Year Period

引用

Advances in Atmospheric Sciences 2023年第1期40卷 168-176页

作者： Zhiwei ZHU Rui LU Shanshan FU Hua CHEN Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)Nanjing University of Information Science and TechnologyNanjing 210044China

Northeast China(NEC)is China’s national grain production base,and the local precipitation is vital for agriculture during the springtime.Therefore,understanding the dynamic origins of the NEC spring rainfall(NECSR)variability is of socioeconomic importance.This study reveals an interdecadal change in the atmospheric teleconnections associated with the NECSR during a recent 60-year period(1961-2020).Before the mid-1980s,NECSR had been related to a Rossby wave train that is coupled with extratropical North Atlantic sea surface temperature(SST),whereas,since the mid-1980s,NECSR has been linked to a quite different Rossby wave train that is coupled with tropical North Atlantic SST.Both Rossby wave trains could lead to enhanced NECSR through anomalous cyclones over East Asia.The weakening of the westerly jet over North America is found to be mainly responsible for the alternation of the atmospheric teleconnections associated with NECSR during two epochs.

关键词： Northeast China spring rainfall Rossby wave train interdecadal change westerly jet stream

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Important role of the ENSO combination mode in the maintenance of the anomalous anticyclone over the western North Pacific in boreal summer

引用

Science China Earth Sciences 2022年第7期65卷 1379-1387页

作者： Wenjun ZHANG Zuoli YU Feng JIANG Xin GENG Renhe ZHANG cic-femd/ilcec Key Laboratory of Meteorological Disaster of Ministry of Education(KLME)/School of Atmospheric SciencesNanjing University of Information Science and TechnologyNanjing 210044China Zhangjiagang Meteorological Bureau Suzhou 215600China Institute of Atmospheric and Oceanic Sciences Fudan UniversityShanghai 200433China

This study demonstrates the main physical mechanism for the maintenance of the western North Pacific(WNP)anomalous anticyclone(WNPAC)during the El Niño decaying summer by analyzing the respective effects of the cold sea surface temperature(SST)anomalies in the WNP,the warm SST anomalies in the Indian Ocean(IO),and the El Niño and Southern Oscillation(ENSO)combination mode.We find that the WNPAC is usually accompanied by significant cold WNP SST anomalies in the El Niño mature winter and following spring,which almost disappear in the decaying summer and cannot explain the maintenance of the WNPAC in summer.The influence of the IO warm SST anomalies on the WNPAC exhibits conspicuous decadal differences.Before the 2000 s,the IO warm SST anomalies played a role in the WNPAC maintenance through the response of the baroclinic atmospheric Kelvin wave;however,this effect cannot be evidently detected after the 2000 s.This decadal difference may be related to changes in the decaying speed of ENSO events.In contrast to El Niño events before the 2000 s,El Niño events after the 2000 s decay more rapidly,and the associated tropical central-eastern Pacific SST features a La Ni?a-like condition in the El Niño decaying summer.Concomitantly,no significant warm SST anomalies appear over the tropical Indian Ocean,exerting a weak influence on the WNPAC.Relative to the cold WNP SSTanomalies and warm IO SST anomalies,the ENSO combination mode,originating from the nonlinear interaction between ENSO and the annual cycle,has a relatively stable relationship with the WNPAC during the El Niño decaying summer,which exhibits a crucial role in the maintenance of the WNPAC.Considering the persistence of the ENSO combination mode,the WNPAC and associated climate variability during the El Niño decaying summer can be skillfully predicted at least one season in advance based on the ENSO combination mode.

关键词： ENSO WNP anomalous anticyclone ENSO combination mode

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Key regions where land surface processes shape the East Asian climate

引用

Atmospheric and Oceanic Science Letters 2022年第3期15卷 64-66页

作者： Haishan Chen KLME/ILCEC/CIC-FEMD Nanjing University of Information Science and TechnologyNanjingChina School of Atmospheric Sciences Nanjing University of Information Science and TechnologyNanjingChina

陆气相互作用是影响东亚大气环流和气候的一个关键过程,受到了越来越多的关注.然而,关于陆面过程影响东亚气候的相关机理的理解还有待提升.在已有研究基础上,提出了陆面过程影响东亚气候研究值得关注的青藏高原,欧亚中高纬地区,中国东... 详细信息

陆气相互作用是影响东亚大气环流和气候的一个关键过程,受到了越来越多的关注.然而,关于陆面过程影响东亚气候的相关机理的理解还有待提升.在已有研究基础上,提出了陆面过程影响东亚气候研究值得关注的青藏高原,欧亚中高纬地区,中国东部季风区,中南半岛,中亚中纬度区域,西亚等6个关键区,期待为加强陆面过程与东亚气候研究提供一定参考.

关键词：陆面过程东亚气候关键区

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Interdecadal Variations of ENSO Impacts over the Indo-Northwest Pacific Region and the Related Mechanisms

引用

Journal of Meteorological Research 2024年第2期38卷 235-248页

作者： Hongxia LAN Jing MA Haiming XU Jingjia LUO Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(cic-femd)/Key Laboratory of Meteorological Disaster Ministry of Education/Joint International Research Laboratory of Climate and Environment Change(KLME/ILCEC)Nanjing University of Information Science&TechnologyNanjing 210044 School of Atmospheric Sciences Nanjing University of Information Science&TechnologyNanjing 210044

Owing to limited observations,it remains unknown whether the impact of El Niño-Southern Oscillation(ENSO)on the Indian Ocean-Northwest Pacific(IO-NWP)climate showed decadal changes in the early 20th century.Using multi-source reanalysis and hindcast datasets from the ECMWF and NOAA extending back to 1901,this study investigates interdecadal variations of the impact of ENSO on the IO-NWP climate from 1901 to 2009.It is found that the influence of ENSO on the IO-NWP climate shows“strong-weak-strong”interdecadal change during 1901-2009.This is characterized by much weaker Indian Ocean sea surface temperature(SST)warming and a weaker NWP subtropical anticyclone(NWPSA)in the following summer of El Ni?o during 1946-1967,compared with those in the other two periods(1901-1945 and 1968-2009).Analyses of the datasets indicate that the interdecadal variation is mainly associated with the change in ENSO amplitude.In contrast to the period of 1946-1967,a greater SST variance occurred in the central-eastern equatorial Pacific during 1901-1945 and 1968-2009.A stronger El Ni?o tends to generate more significant anticyclonic anomalies over the southeast Indian Ocean through teleconnection.The northwesterly anomalies to the south of the anticyclone weaken the southeast trade winds and warm the south Indian Ocean SST via wind-evaporation-SST feedback,and the positive south Indian Ocean SST anomalies trigger westward-propagating oceanic Rossby waves to induce stronger warming of the southwest Indian Ocean,leading to a significant asymmetric wind pattern across the equator in spring.The profound northeastward winds on the north side weaken the southwest monsoon,leading to a“second warming”over the north Indian Ocean in summer,which anchors the eastward-propagating warm Kelvin waves and results in a stronger NWPSA by inducing surface divergence and suppressing deep convection.

关键词： ENSO Indo-Northwest Pacific Northwest Pacific subtropical anticyclone decadal changes

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Relationship between the Stratospheric Arctic Vortex and Surface Air Temperature in the Midlatitudes of the Northern Hemisphere

引用

Journal of Meteorological Research 2024年第1期38卷 39-52页

作者： Xue RAN Dingzhu HU Yang ZHANG Mei-Chen LIU Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environmental Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science&TechnologyNanjing 210044 School of Atmospheric Sciences Nanjing UniversityNanjing 210023

It is known that different relationships exist between the strength and displacement of the stratospheric polar vortex(SPV),and the surface air temperature(SAT)patterns in Eurasia and North America,but the mechanisms behind these relationships remain unclear,especially on an interannual timescale.Based on empirical orthogonal function(EOF)analysis using NCEP reanalysis data over 1958–2018,this study attempts to ascertain the relationship between the SPV intensity and displacement over the Arctic and the SATs in the midlatitudes of the Northern Hemisphere.Our results indicate that a strengthened SPV corresponds to an SAT increase in Eurasia and a decrease in eastern North America and Greenland.When the SPV is shifted towards Eurasia,however,a corresponding SAT increase occurs in both North America and Eurasia,with a larger increase in North America than in Eurasia.Specifically,a strengthened SPV tends to correspond to a positive North Atlantic Oscillation-like circulation in the troposphere with negative geopotential height(GH)anomalies in Greenland and eastern North American continent and positive GH anomalies to the north of 45°N in Eurasia,which corresponds to lower SATs in North America than in Eurasia.However,when the SPV shifted towards Eurasia,it was accompanied by a positive Pacific/North American-like pattern with a deepened Aleutian low,which corresponds to the increasing SATs in North America.These tropospheric circulation changes are related to the response of tropospheric planetary wave activity to the SPV.A strengthened SPV corresponds to the weakening of tropospheric planetary wave-1 waves,which is accompanied by a negative GH in North America but a positive GH in Eurasia.If the SPV shifted towards Eurasia,the tropospheric planetary wave-1(-2)waves strengthened(weakened),and the combined effects of the planetary wave-1 and wave-2 waves would cause positive GH anomalies in both Eurasia and North America.

关键词： stratospheric polar vortex surface air temperature teleconnection patterns planetary waves

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Intra-seasonal Features of an Extreme High Temperature Event in 2011 in Eastern China and Its Atmospheric Circulation

引用

Journal of Tropical Meteorology 2021年第4期27卷 437-446页

作者：高庆九李岩韩彤欣 Key Laboratory of Meteorological Disaster Ministry of Education(KLME)Joint International Research Laboratory of Climate and Environment Change(ILCEC)and Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science and TechnologyNanjing 210044 China

Based on the daily maximum air temperature(T_(max))data from the China Meteorological Data Network and the NCEP/DOE reanalysis data,the intra-seasonal circulation and evolution of an extreme high temperature event(EHTE)in the middle reaches of the Yangtze River(MYR)from August 9-21,2011 were explored,as well as the influence of diabatic heating on the position variation of the Western Pacific subtropical high(WPSH).Results show that the daily T_(max) in the MYR exhibits a vigorous intraseasonal oscillation(ISO)of 10-25 days in the extended summer of 1980-2018.The main factors affecting the EHTE in the summer of 2011 are the low-frequency wave train propagating southeastward in the mid-latitude of the upper troposphere and the low-frequency anticyclone moving northwestward in the lowlatitude of the mid-lower troposphere.The diagnosis of 925hPa thermodynamic equation indicates that the ISO features of the T_(max) in the core region is determined by the intra-seasonal variation of the adiabatic variation.In addition,the variations of the WPSH correspond well to the distribution of apparent heat source.In the early stage of the high temperature process,the apparent heat source in the north of the Bay of Bengal is a certain indicator for the westward extension of the WPSH.

关键词： extreme high temperature event intra-seasonal oscillation diagnosis Western Pacific subtropical high complete form of vertical vorticity tendency equation

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

Observational Subseasonal Variability of the PM_(2.5) Concentration in the Beijing-Tianjin-Hebei Area during the January 2021 Sudden Stratospheric Warming

引用

Advances in Atmospheric Sciences 2022年第10期39卷 1623-1636页

作者： Qian LU Jian RAO Chunhua SHI Dong GUO Ji WANG Zhuoqi LIANG Tian WANG Key Laboratory of Meteorological Disaster Ministry of Education(KLME)/Joint International Research Laboratory of Climate and Environment Change(ILCEC)/Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters(CIC-FEMD)Nanjing University of Information Science and TechnologyNanjing 210044China Key Laboratory of Meteorology and Ecological Environment of Hebei Province Shijiazhuang 050021China Beijing Regional Climate Center Beijing 100089China

It is still not well understood if subseasonal variability of the local PM_(2.5) in the Beijing-Tianjin-Hebei(BTH)region is affected by the stratospheric state.Using PM_(2.5) observations and the ERA5 reanalysis,the evolution of the air quality in BTH during the January 2021 sudden stratospheric warming(SSW)is explored.The subseasonal variability of the PM_(2.5) concentration after the SSW onset is evidently enhanced.Stratospheric circumpolar easterly anomalies lasted for 53 days during the January-February 2021 SSW with two evident stratospheric pulses arriving at the ground.During the tropospheric wave weakening period and the intermittent period of dormant stratospheric pulses,the East Asian winter monsoon weakened,anomalous temperature inversion developed in the lower troposphere,anomalous surface southerlies prevailed,atmospheric moisture increased,and the boundary layer top height lowered,all of which favor the accumulation of pollutant particulates,leading to two periods of pollution processes in the BTH region.In the phase of strengthened East Asian winter monsoon around the very beginning of the SSW and another two periods when stratospheric pulses had reached the near surface,opposite-signed circulation patterns and meteorological conditions were observed,which helped to dilute and diffuse air pollutants in the BTH region.As a result,the air quality was excellent during the two periods when the stratospheric pulse had reached the near surface.The increased subseasonal variation of the regional pollutant particulates after the SSW onset highlights the important role of the stratosphere in the regional environment and provides implications for the environmental prediction.

关键词： sudden stratospheric warming(SSW) PM_(2.5) Beijing-Tianjin-Hebei(BTH) East Asian winter monsoon boundary layer meteorological conditions

来源：

维普期刊数据库

同方期刊数据库评论

在线全文

学校读者我要写书评

暂无评论

欢迎您,

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案：

请选择收藏分类：

通借通还

欢迎您,

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

在线全文

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：