检索结果-南通市图书馆

Aerosol optical absorption by dust and black carbon in Taklimakan Desert,during no-dust and dust-storm conditions

Particuology 2012年第4期10卷 509-516页

作者： Hui Lu Wenshou Wei Mingzhe Liu Weidong Gao Xi Han Xinjiang Institute of Ecology and Geography Chinese Academy of SciencesUrumqi 830011China Graduate School of the Chinese Academy of Sciences Beijing 100049China Urumqi Institute of Desert meteorology China Meteorological AdministrationUrumqi 830002China School of Resources and Environment University ofJinanJinan 250000China

Aerosol absorption coefficient σap involves the additive contribution of both black carbon aerosol （BC） and dust aerosol. The linear statistical regression analysis approach introduced by Fialho et al. （2005） is used to estimate the absorption exponents of BC and dust aerosol absorption coefficients, and further to separate the contributions of these two types of aerosols from the total light absorption coefficient measured in the hinterland of Taklimakan Desert in the spring of 2006. Absorption coefficients are measured by means of a 7-wavelength Aethalometer from 1 March to 31 May and from 1 November to 28 December, 2006. The absorption exponent of BC absorption coefficient α is estimated as （-0.95 ± 0.002） under background weather （supposing the observed absorption coefficient is due only to BC）; the estimated absorption exponent of dust aerosol absorption coefficient/5 during the 6 dust storm periods （strong dust storm） is （-2.55 ± 0.009）. Decoupling analysis of the measured light absorption coefficients demonstrates that, on average, the light absorptions caused by dust aerosol and BC make up about 50.5% and 49.5% respectively of the total light absorption at 520 nm; during dust weather process periods （dust storm, floating dust, blowing dust）, the contribution of dust aerosol to absorption extinction is 60.6% on average; in the hin- terland of desert in spring, dust aerosol is also the major contributor to the total aerosol light absorption, more than that of black carbon aerosol.

关键词： Black carbonDustAbsorption coefficientAbsorption exponent of absorptioncoefficientDecoupling of absorption coefficient

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

DIAGNOSTIC ANALYSIS OF PERSISTENT DROUGHT/FLOOD EVENTS IN SUMMER OVER THE TWO-LAKE REGION OF CHINA

引用

Journal of Tropical meteorology 2013年第3期19卷 264-275页

作者：吴贤云丁一汇叶成志 Chinese Academy of Meteorological Science Nanjing University of Information Science and Technology Hunan Provincial Climate Center National Climate Center Hunan Meteorological Observatory

Based on the daily regional mean rainfall,the Z-index method is used to identify persistent flood and drought events lasting for at least 10 days over a region where Dongting Lake and Poyang Lake sit(referred to as the"two-lake region"hereafter).The National Centers for Environmental Prediction(NCEP)reanalysis data are then utilized to perform a preliminary diagnostic analysis on these *** results indicate that the composite standardized geopotential height at 500 hPa presents two different meridional wave trains from north to south over the East Asian-Pacific region,i.e.,a"-+-"pattern for the droughts and a"+-+"pattern for the floods,*** developing,maintaining and decaying phases in the drought and flood events are closely related to the intensity and location of a subtropical high and an extra-tropical blocking *** is shown that the East Asian summer monsoon is strong(weak)with the occurrence of persistent drought(flood)***(floods)are accompanied by a weak(strong)tropical convergent system and a strong(weak)subtropical convergent ***,the persistent drought(flood)events are associated with a divergence(convergence)of vertically integrated water vapor *** the vertical profile of water vapor flux,divergence(convergence)in the mid-and lower-levels and convergence(divergence)in the higher levels are evident in the droughts(floods).Both the divergence in the droughts and the convergence in floods are strongest at 850 hPa.

关键词： two-lake region drought/flood East-Asian summer monsoon

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

A Simple Method to Extract Tropical Monsoon Forests Using NDVI Based on MODIS Data:A Case Study in South Asia and Peninsula Southeast Asia

引用

Chinese Geographical Science 2016年第1期26卷 22-34页

作者： LIN Sen LIU Ronggao State Key Laboratory of Resources and Environmental Information System Institute of Geographic Sciences and Natural Resources ResearchChinese Academy of SciencesBeijing 100101China University of Chinese Academy of Sciences Beijing 100049China

Distribution of monsoon forests is important for the research of carbon and water cycles in the tropical regions. In this paper, a simple approach is proposed to map monsoon forests using the Normalized Difference Vegetation lndex （NDVI） derived from the Moderate Resolution Imaging Spectroradiometer （MODIS） data. Owing to the high contrast of greenness between wet season and dry season, the monsoon forest can be easily discriminated from other forests by combining the maximum and minimum annual NDVI. The MODIS-based monsoon forest maps （MODMF） from 2000 to 2009 are derived and evaluated using the ground-truth dataset. The MODMF achieves an average producer accuracy of 80.0% and the Kappa statistic of 0.719. The variability of MODMF among different years is compared with that calculated from MODIS land cover products （MCD 12Q 1）. The results show that the coefficient of variation of total monsoon forest area in MODMF is 7.3%, which is far lower than that in MCD12Q1 with 24.3%. Moreover, the pixels in MODMv which can be identified for 7 to 9 times between 200l and 2009 account for 53.1%, while only 7.9% ofMCD12QI pixels have this frequency. Additionally, the monsoon forest areas estimated in MODMF, Global Land Cover 2000 （GLC2000）, MCDI2Q1 and University of Maryland （UMD） products are compared with the statistical dataset at national level, which reveals that MODMv has the highest R^2 of 0.95 and the lowest RMSE of 14 014 km^2. This algorithm is simple but reliable for mapping the monsoon forests without complex classification techniques.

关键词： monsoon forest Moderate Resolution Imaging Spectroradiometer (MODIS) Normalized Difference Vegetation Index(NDVI) amplitude threshold classification

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

SST biases over the Northwest Pacific and possible causes in CMIP5 models

引用

Science China Earth Sciences 2018年第6期61卷 792-803页

作者： Chenqi WANG Liwei ZOU Tianjun ZHOU LASG Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China University of Chinese Academy of Sciences Beijing 100049 China Jiangsu Collaborative Innovation Center for Climate Change Nanjing 210023 China

In this paper, the features and possible causes of sea surface temperature(SST) biases over the Northwest Pacific are investigated based on a mixed-layer heat budget analysis in 21 coupled general circulation models(CGCMs) from phase 5 of the Coupled Model Inter-comparison Project(CMIP5). Most CMIP5 models show cold SST biases throughout the year over the Northwest Pacific. The largest biases appear during summer, and the smallest biases occur during winter. These cold SST biases are seen at the basin scale and are mainly located in the inner region of the low and mid-latitudes. According to the mixed-layer heat budget analysis, overestimation of upward net sea surface heat fluxes associated with atmospheric processes are primarily responsible for the cold SST biases. Among the different components of surface heat fluxes, overestimated upward latent heat fluxes induced by the excessively strong surface winds contribute the most to the cold SST biases during the spring, autumn, and winter seasons. Conversely, during the summer, overestimated upward latent heat fluxes and underestimated downward solar radiations at the sea surface are equally important. Further analysis suggests that the overly strong surface winds over the Northwest Pacific during winter and spring are associated with excessive precipitation over the Maritime Continent region,whereas those occurring during summer and autumn are associated with the excessive northward extension of the intertropical convergence zone(ITCZ). The excessive precipitation over the Maritime Continent region and the biases in the simulated ITCZ induce anomalous northeasterlies, which are in favor of enhancing low-level winds over the North Pacific. The enhanced surface wind increases the sea surface evaporation, which contributes to the excessive upward latent heat fluxes. Thus, the SST over the Northwest Pacific cools.

关键词： CMIP5 multi-model ensemble SST bias Mixed-layer heat budget analysis Atmospheric processes

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

Strengthened Relationship between the Antarctic Oscillation and ENSO After the Mid-1990s during Austral Spring

引用

Advances in Atmospheric Sciences 2017年第1期34卷 54-65页

作者： Tingting HAN Huijun WANG Jianqi SUN Nansen-Zhu International Research Centre Institute of Atmospheric PhysicsChinese Academy of SciencesBeijing 100029China Climate Change Research Center Chinese Academy of SciencesBeijing 100029China Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters/Key Laboratory of Meteorological Disaster Ministry of EducationNanjing University for Information Science and TechnologyNanjing 210044China University of Chinese Academy of Sciences Beijing 100049China

This paper documents a decadal strengthened co-variability of the Antarctic Oscillation （AAO） and ENSO in austral spring after the mid-1990s. During the period 1979-93, the ENSO （AAO） spatial signatures are restricted to the tropicsmidlatitudes （Antarctic-midlatitudes） of the Southern Hemisphere （SH）, with a weak connection between the two oscillations. Comparatively, after the mid-1990s, the E1 Nifio-related atmospheric anomalies project on a negative AAO pattern with a barotropic structure in the mid-high latitudes of the SH. The expansion of E1 Nifio-related air temperature anomalies have a heightened impact on the meridional thermal structure of the SH, contributing to a weakened circumpolar westerly and strengthened subtropical jet. Meanwhile, the ENSO-related southern three-cell circulations expand poleward and then strongly couple the Antarctic and the tropics. Numerical simulation results suggest that the intensified connection between ENSO and SST in the South Pacific since the mid-1990s is responsible for the strengthened AAO-ENSO relationship.

关键词： ENSO Antarctic Oscillation South Pacific SST austral spring decadal change

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

The Impact of Boreal Autumn SST Anomalies over the South Pacific on Boreal Winter Precipitation over East Asia

引用

Advances in Atmospheric Sciences 2016年第5期33卷 644-655页

作者： Juan AO Jianqi SUN Nansen-Zhu International Research Center Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 University of Chinese Academy of Sciences Beijing 100049

The possible mechanism behind the variability in the dipole pattern of boreal winter precipitation over East Asia is analyzed in this study. The results show that the SST anomalies（SSTAs） over the South Pacific Ocean（SPO） in boreal autumn are closely related to the variability in the dipole pattern of boreal winter precipitation over East Asia. The physical link between the boreal autumn SPO SSTAs and the boreal winter East Asian precipitation dipole pattern is shown to mainly be the seasonal persistence of the SPO SSTAs themselves. The seasonal persistence of the SPO SSTAs can memorize and transport the signal of the boreal autumn SSTAs to the following winter, and then stimulates a meridional teleconnection pattern from the SH to the NH, resulting in a meridional dipole pattern of atmospheric circulation over East Asia in boreal winter. As a major influencing factor, this dipole pattern of the atmospheric circulation can finally lead to the anomalous precipitation dipole pattern over East Asia in boreal winter. These observed physical processes are further confirmed in this study through numerical simulation. The evidence from this study, showing the impact of the SPO SSTAs in boreal autumn,not only deepens our understanding of the variability in East Asian boreal winter precipitation, but also provides a potentially useful predictor for precipitation in the region.

关键词： SST boreal winter precipitation dipolar pattern atmospheric circulation zonal wind

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

Global cooling in the immediate future?

引用

Chinese Science Bulletin 2010年第33期55卷 3847-3852页

作者： WANG ShaoWu WEN XinYu HUANG JianBin Department of Atmospheric and Oceanic Sciences School of Physics Peking University Beijing 100871 China

New perspectives regarding the possible cooling of the Earth's climate as a result of solar changes are reviewed in this *** major findings include:(1)solar activity is weakening to its very low level,which is comparable with the level in the early 20th century;(2)the current grand solar maximum has already lasted for eight 11-year solar cycles and might end in the coming one/two 11-year cycles;(3)a grand solar minimum might prevail in the next 100-200 years;and(4)the number of sunspots in the coming solar maximum(M)-year,around 2013,is an important indicator that needs to be closely monitored.

关键词：全球变冷地球气候变化太阳活动太阳能太阳周期太阳黑子年周期

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

An assessment of global ocean wave energy resources over the last 45 a

引用

Acta Oceanologica Sinica 2014年第1期33卷 92-101页

作者： ZHENG Chongwei SHAO Longtan SHI Wenli SU Qin LIN Gang LI Xunqiang CHEN Xiaobin State Key Laboratory of Structural Analysis of Industrial Equipments Dalian University of Technology College of meteorology and Oceanography People's Liberation Army University of Science & Technology Meteorological Unit No. 92538 People's Liberation Army China Ocean Press

Against the background of the current world facing an energy crisis,and human beings puzzled by the problems of environment and resources,developing clean energy sources becomes the inevitable choice to deal with a climate change and an energy shortage.A global ocean wave energy resource was reanalyzed by using ERA-40 wave reanalysis data 1957–2002 from European Centre for Medium-Range Weather Forecasts（ECMWF）.An effective significant wave height is defined in the development of wave energy resources（short as effective SWH）,and the total potential of wave energy is exploratively *** considering a wave energy density,a wave energy level probability,the frequency of the effective SWH,the stability and long-term trend of wave energy density,a swell index and a wave energy storage,global ocean wave energy resources were reanalyzed and regionalized,providing reference to the development of wave energy resources such as wave power plant location,seawater desalination,heating,pumping.

关键词： global ocean wave energy resources effective significant wave height wave energy storage grade division

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

A Robustness Analysis of CMIP5 Models over the East Asia-Western North Pacific Domain

引用

Engineering 2017年第5期3卷 773-778页

作者： Tianjun Zhou Xiaolong Chen Bo Wu Zhun Guo Yong Sun Liwei Zou Wenmin Man Lixia Zhang Chao He State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics Institute of Atmospheric Physics Chinese Academy of Sciences Beijing 100029 China

The Coupled Model Intercomparison Project （CMIP） is an international community-based infrastructure that supports climate model intercomparison, climate variability, climate prediction, and climate projection. Improving the performance of climate models over East Asia and the western North Pacific has been a challenge for the climate-modeling community. In this paper, we provide a synthesis robustness analysis of the climate models participating in CMIP-Phase 5 （CMIP5）. The strengths and weaknesses of the CMIP5 models are assessed from the perspective of climate mean state, interannual variability, past climate change during the mid-Pliocene （MP） and the last millennium, and climate projection. The added values of regional climate models relative to the driving global climate models are also assessed. Although an encouraging increase in credibility and an improvement in the simulation of mean states, interannual variability, and past climate changes are visible in the progression from CMIP3 to CMIPS, some previously noticed biases such as the ridge position of the western North Pacific subtropical high and the associated rainfall bias are still evident in CMIP5 models. Weaknesses are also evident in simulations of the interannual amplitude, such as El Nino- Southern Oscillation （ENSO）-monsoon relationships. Coupled models generally show better results than standalone atmospheric models in simulating both mean states and interannual variability. Multi-model intercomparison indicates significant uncertainties in the future projection of climate change, although precipitation increases consistently across models constrained by the Clausius-Clapeyron relation. Regional ocean-atmosphere coupled models are recommended for the dynamical downscaling of climate change oroiections over the East Asia-western North Pacific domain.

关键词： East Asian monsoon Western North Pacific climate El Nino-Southern Oscillation Past climate change Climate projection Coupled climate model Regional climate model

来源：

维普期刊数据库评论

在线全文

维普期刊数据库

学校读者我要写书评

暂无评论

Changes in Climate Regionalization Indices in China during 1961–2010

引用

Advances in Atmospheric Sciences 2014年第2期31卷 374-384页

作者： LIU Jing ZHAI Panmao State Key Laboratory of Severe Weather Chinese Academy of Meteorological Sciences

The regionalization of climate in China is based on a three-level classification in terms of lasting days for accumulated temperature （AT）,aridity index,and July mean *** on daily meteorological observational data from 756 stations,trends and interdecadal variation in indices for classifying temperature zones,moisture regions and climatic subregions in the period 1961-2010 are *** reveal that the nationwide AT ≥ 10℃C （AT10） and its lasting days are basically increasing,while aridity in northern Xinjiang is *** increasing trend of July mean temperature in North China is found to be notably larger than in South *** terms of their national averages,a marked step increase of AT10 and its lasting period,as well as July mean temperature occurred around 1997,while the aridity index presents no such clear *** comparing regionalization areas for 1998-2010 with those for 1961-97,it is found that the semi-humid,semi-dry and dry regions in the sub-temperate zone,as well as the humid region in the middle subtropical zone,have experienced substantial shrinkage in terms of *** contrast,the areas of semi-dry and dry regions in the warm temperate zone,as well as the humid region in the south subtropical zone,present drastically increasing *** to the influence of such step changes that took place in 1997,that particular point in time should be given close attention in future studies regarding the regionalization of climate in China.

关键词： climate regionalization climate trends interdecadal variation

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：