Impacts of Increasing Model Resolutions and Shortening Forecast Lead Times on QPFs in South China During the Rainy Season

This study investigated the impacts of increasing model resolutions and shortening forecast lead times on the quantitative precipitation forecast(QPF)for heavy-rainfall events over south China during the rainy seasons in 2013-2020.The control experiment,where the analysis-forecast cycles run with model resolutions of about 3 km,was compared to a lower-resolution experiment with model resolutions of about 9 km,and a longer-term experiment activated 12 hours earlier.Rainfall forecasting in the presummer rainy season was significantly improved by improving model resolutions,with more improvements in cases with stronger synoptic-scale forcings.This is partially attributed to the improved initial conditions(ICs)and subsequent forecasts for low-level jets(LLJs).Forecasts of heavy rainfall induced by landfalling tropical cyclones(TCs)benefited from increasing model resolutions in the first 6 hours.Forecast improvements in rainfall due to shortening forecast lead times were more significant at earlier(1-6 h)and later(7-12 h)lead times for cases with stronger and weaker synoptic-scale forcings,respectively,due to the area-and case-dependent improvements in ICs for nonprecipitation variables.Specifically,significant improvements mainly presented over the northern South China Sea for low-level onshore wind of weak-forcing cases but over south China for LLJs of strong-forcing cases during the presummer rainy season,and over south China for all the nonprecipitation variables above the surface during the TC season.However,some disadvantages of higher-resolution and shorter-term forecasts in QPFs highlight the importance of developing ensemble forecasting with proper IC perturbations,which include the complementary advantages of lower-resolution and longer-term forecasts.

Application of the predictable model ofregional time-magnitude to North and Southwest China region

In this paper, the method which can combine different seismic data with the different precision and completeness, even the palaeo-earthquake data, has been applied to estimate the yearly seismic moment rate in the seismic region. Based on this, the predictable model of regional time-magnitude has been used in North China and Southwest China. The normal correlation between the time interval of the events and the magnitude of the last strong earthquake shows that the model is suitable. The value of the parameter c is less than the average value of 0.33 that is obtained from the events occurred in the plate boundary in the world. It is explained that the correlativity between the recurrence interval of the earthquake and the magnitude of the last strong event is not obvious. It is shown that the continental earthquakes in China are different from that occurred in the plate boundary and the recurrence model for the continental events are different from the one for the plate boundary events. Finally the seismic risk analysis based on this model for North China and Southwest China is given in this paper.

Velocity model and time-depth conversion for the northwestern South China Sea deepwater areas

There are rich natural gas resources in the northwestern South China Sea deepwater areas, with poor degree of exploration. Because of the unique tectonic, sedimentary background of the region, velocity model building and time-depth conversion have been an important and difficult problem for a long time. Recent researches in this direction have revealed three major problems for deepwater areas, i.e., the way to determine error correction for drilling velocity, the optimization of velocity modeling, and the understanding and analysis of velocity variations in the slope areas. The present contribution proposes technical solutions to the problems：（1） velocity correction version can be established by analyzing the geology, reservoir, water depths and velocity spectrum characteristics;（2） a unified method can be adopted to analyze the velocity variation patterns in drilled pale structural positions;and （3） across-layer velocity is analyzed to establish the velocity model individually for each of the layers. Such a solution is applicable, as shown in an example from the northwestern South China Sea deepwater areas, in which an improved prediction precision is obtained.

Time Series Analysis of Energy Intensity, Value Added Tax and Corporate Income Tax: A Case Study of the Non-Ferrous Metal Industry, Jiangxi Province, China

Unprecedented industrialization and urbanization have led to China’s poor energy efficiency. In response, the Chinese government has set goals to reduce energy consumption that may include implementing new tax policies. In this paper, we investigate the relationship between energy intensity, an indicator that measures the efficiency of energy consumption, and two sources of government revenue in China (i.e., value-added tax (VAT) and corporate income tax). As a case study, we developed a Granger co-integration model to analyze the dynamic relationship of energy intensity, VAT and corporate income tax in the non-ferrous metal industry, Jiangxi Province, China, between 1996 and 2010. Augmented Dickey-Fuller tests were used to validate the model. In our time series analyses, we found when controlling for corporate income tax, a one log unit increase of VAT resulted in a decrease of 1.17 log units of energy intensity. However, when controlling for VAT, a one log unit increase of corporate income tax resulted in an increase of 0.34 log units of energy intensity. Understanding the relationship between energy intensity and taxation in industries that consume high volumes of energy can greatly enhance China’s goal to reduce energy consumption. We believe our findings add to this on-going discussion.

太行山复杂地形下华北暖季极端降水的时空分布特征

基于2012—2021年5—9月华北五省的逐日降水资料和台站地形高度数据,统计分析了华北全区及各子区域极端降水事件的降水量及其强度和频次的时空分布特征;并运用地理加权回归(GWR)模型分析得到极端降水事件的降水量、强度及频次与海拔高度之间的关系。结果表明:1)华北区域极端降水量的时间变化均呈多波动特征且区域差异性显著,太行山以西高原和以东平原降水频次多、波动明显且强度较弱,太行山南段以南平原降水频次少、变化平缓而强度明显偏强。2)极端降水量的空间分布呈现南北少、中间多的型态分布,降水量大值区分别位于燕山东南侧和太行山南段晋冀豫三省交界处;极端降水高频站点主要聚集在晋东南地区;日最大降水量超过300 mm的站点主要集中在太行山脉和燕山山脉与华北平原的过渡地带。3)华北区域38°N以北,极端降水量、降水频次、强度和日最大降水量均随海拔高度的升高而减小;38°N以南,山西南部临运地区降水量随海拔高度的升高而显著增加。由于降水频次和强度与地形均存在正相关而导致,太行山附近降水量随海拔高度的升高而减小的贡献主要在于降水强度而非降水频次。

1950-2015年中国布鲁菌病空间流行病学分析

目的:分析布鲁氏菌病(布病)流行趋势,包括地区和空间分布特征,为布病的早期防治提供依据。方法:采用Excel 2010构建1950-2015年布病数据库,绘制60年间布病发病率、死亡率和月平均发病例数趋势图作趋势分析。通过Arcgis 10.2软件空间统计工具,对2000-2015年布病发病率作空间自相关分析。结果:1950-2009年60年间,中国共报告布病发病927987例,死亡547例,年平均发病率为0.2012(1/100000),年平均死亡率为0.0003(1/100000);布病发病率较高的为内蒙古、黑龙江、山西、新疆等省、自治区;2008-2013年中国布病发病情况的全局空间分布关系为离散模式(Moran′s I<0,P<0.05),2014-2015发病情况的全局空间分布关系为随机模式(P>0.05);高高空间关联模式存在于山西、新疆和宁夏,高低空间关联模式多存在于内蒙古和山西。结论:中国布病发病呈现全局空间负相关关系,高低空间关联模式多存在于内蒙古,高高空间关联模式多存在于山西、新疆和宁夏,应加大对这几个省和自治区布病的监控和防治。

China’s Energy Transition Pathway in a Carbon Neutral Vision

China’s energy system requires a thorough transformation to achieve carbon neutrality.Here,leveraging the highly acclaimed the Integrated MARKAL-EFOM System model of China(China TIMES)that takes energy,the environment,and the economy into consideration,four carbon-neutral scenarios are proposed and compared for different emission peak times and carbon emissions in 2050.The results show that China’s carbon emissions will peak at 10.3–10.4 Gt between 2025 and 2030.In 2050,renewables will account for 60%of total energy consumption(calorific value calculation)and 90%of total electricity generation,and the electrification rate will be close to 60%.The energy transition will bring sustained air quality improvement,with an 85%reduction in local air pollutants in 2050 compared with 2020 levels,and an early emission peak will yield more near-term benefits.Early peak attainment requires the extensive deployment of renewables over the next decade and an accelerated phasing out of coal after 2025.However,it will bring benefits such as obtaining better air quality sooner,reducing cumulative CO_(2) emissions,and buying more time for other sectors to transition.The pressure for more ambitious emission reductions in 2050 can be transmitted to the near future,affecting renewable energy development,energy service demand,and welfare losses.

Simulation of Suspended Sediment in the Yellow and East China Seas

Described is an initial attempt to simulate the suspended sediment dynamics relating to tidal and wave forcing during summertime in June 1980 and August 1981 for the Yellow and East China Seas continental shelf. The cohesive/non-cohesive sediment resuspension and movement generated by the interaction between current and wave are modeled by use of ECOMSED and WAM Cycle 4. Model results are compared with observations in US-China Marine Sedimentation Dynamics Program performed for 1980-81 at off the Changjiang estuary. The main features of simulations show that suspended sediment concentrations during the summer decreased markedly offshore as observed during the simulation periods. As for some discrepancies for the mouth of the estuary with high river discharges, i.e., the Changjiang River, the model did not properly reproduce the over-mixing situation in the summer; thus distinct vertical concentration variation in this local region is not agreeable with observation. However, general dispersal patterns of suspended sediment movement seem to be agreeably reproduced for the nearshore shallow region. Some of the procedures of simulation and results are presented and discussed.

Prediction of Farmers' Income and Selection of Model ARIMA

Based on the research technology of scholars' prediction of farmers' income and the data of per capita annual net income in rural households in Henan Statistical Yearbook from 1979 to 2009,it is found that time series of farmers' income is in accordance with I(2)non-stationary process.The order-determination and identification of the model are achieved by adopting the correlogram-based analytical method of Box-Jenkins.On the basis of comparing a group of model properties with different parameters,model ARIMA(4,2,2)is built up.The testing result shows that the residual error of the selected model is white noise and accords with the normal distribution,which can be used to predict farmers' income.The model prediction indicates that income in rural households will continue to increase from 2009 to 2012 and will reach the value of 2 282.4,2 502.9,2 686.9 and 2 884.5 respectively.The growth speed will go down from fast to slow with weak sustainability.

信息基础设施建设对城际技术转移的影响研究——基于“宽带中国”战略试点的准自然实验

基于IncoPat全球专利数据库,以2008—2019年间发生在中国273个地级及以上城市的185752件城际发明专利转让事件为研究样本,借助“宽带中国”战略试点政策和多期DID模型,评估信息基础设施建设对城际技术转移的影响。研究发现:(1)信息基础设施建设显著促进了城际技术转移,且可通过市场化效应、知识产权保护效应、城市联通效应进行正向调节。(2)在市场规模效应、政府创新驱动效应和技术差距效应的影响下,信息基础设施建设对东部地区城市、南方地区城市和中心城市城际技术转移的促进作用更强。(3)信息基础设施建设的技术转移效应存在空间地理距离衰减特征,有效空间半径为900千米,最优空间半径为400千米。因此,中国应完善全国信息技术交易平台,解决科技成果定价的难题,健全人工智能技术下的知识产权保护机制,培育区域发展新动能。

中国大陆基于BPT模型的时间相依地震危险性分析

概率地震危险性分析是地震区划图编制、重大工程场地地震安全性评估以及地震风险管理等领域的重要依据,地震时间活动性模型则是概率地震危险性分析的主要理论基础.本研究中基于布朗过程时间(Brownian passage time(BPT))模型,计算了不同情况下中国大陆特征地震震源区时间相依的地震发生率,采用概率地震危险性计算方法,选择合适的地震动模型,评估了中国大陆地区时间相依的地震危险性,并与基于泊松模型的地震危险性做了比较.结果表明,时间相依的地震活动特征对概率地震危险性具有显著影响,在那些地震离逝时间相对较长,离逝率较大(大于1)的震源区,时间相依的地震危险性结果相较于基于泊松模型的地震危险性结果显著增大,增大幅度最大可达50%以上.相反,在那些刚发生地震不久,地震离逝时间较短的震源区,时间相依的地震危险性结果相较于泊松模型显著减小,减小幅度最大可达50%左右.地震复发间隔的变异系数对地震危险性结果也有显著影响,选择合适的变异系数对时间相依地震危险性分析十分重要,后续应该加强对地震复发间隔不确定性的研究.研究结果还表明,时间相依的地震活动特征对不同超越概率下的地震危险性结果的影响是一致的,不随超越概率水平的变化而变化.本文研究结果对地震风险管理、地震保险以及相关防震减灾政策的制定等方面具有重要的应用价值.

中欧班列对中国与哈萨克斯坦可达性的影响研究

哈萨克斯坦是中国重要的贸易伙伴,在中欧班列开通后两国双边贸易额不断攀升,对两国经济产生了积极的影响。以中欧班列国内沿线城市与哈萨克斯坦各州域为研究对象,构建经济潜力与加权平均旅行时间模型,量化中欧班列国内沿线城市与哈萨克斯坦州域间的可达性。结果表明中欧班列使中哈加权平均旅行时间减少90.6%,经济潜能平均增大15.08倍,促进了中哈两国的可达性。中欧班列对中国与哈萨克斯坦的可达性改善作用存在差异性,对国内沿线城市可达性促进作用强于哈萨克斯坦各州域,国内地区中加权平均旅行时间改善程度呈内陆向沿海、北部向南部递减的特点,西北地区的经济潜力得到明显改善;哈萨克斯坦州域改善程度呈由东向西递减的地域特征。

华中华东陆态网坐标时序噪声模型及环境负载分析

针对目前华中、华东地区陆态网坐标时序噪声模型及速度场研究还不全面和深入,时间跨度未满足要求的问题,同时也为了进一步研究环境负载对噪声模型和速度场的影响,提出一种分析方法:利用赫克托(Hector)软件解算陆态网华中和华东地区34个连续站10 a的时间序列数据确定最优噪声模型,并经过环境负载改正,比较改正前后最优噪声模型的变化;然后获得基于有色噪声以及环境负载改正后的速度场,并分析噪声和环境负载对其的影响。结果表明,在北(N)和东(E)方向的最优噪声模型均为“幂律噪声(PL)+白噪声(WN)”,在高(U)方向的最优噪声模型为“闪烁噪声(FN)+白噪声(WN)”;环境负载改正只是改变了其在整体噪声模型中的占比,但其仍占主要地位;考虑有色噪声及环境负载后,速度场精度明显更高。

中国共产党红色血脉的内涵、样态及价值

红色血脉的主流意识形态本质特性,规定了其在中国人民尤其是中国共产党的精神世界里占据着重要的地位。对特定时空所生成的红色血脉进行内涵勘定,是引导全体中国人民理解、认同进而赓续红色血脉的现实需求。中国共产党红色血脉之科学内涵,主要表现在革命决心的红色比喻、革命传承的红色借喻以及革命成果的红色隐喻等。物质、文化和理论是其基本存在样态。它们具有凝聚中华民族共识、把准中国前进方向、汇聚中国人民力量等方面的现实意义。

中国台湾地震对福建平潭站的影响

为了分析福建平潭(FJPT)站监测到的坐标时间序列数据是否受到中国台湾地震的影响.通过对TNML(中国台湾新竹)站和FJPT站的相关性进行分析发现,TNML站和FJPT站之间有着较强的正相关,其中E方向上最为显著.通过对FJPT站坐标时间序列进行汉明窗功率谱分析及拟合,得出其噪声主要为随机游走噪声+白噪声.通过进一步对FJPT站坐标时间序列进行小波系数多时间尺度分析,得出震前、震后对FJPT站存在运动特征存在短期的影响,影响时间约为地震前后3d左右,但对FJPT站的周期性和趋势性并未造成实质性的影响.震前、后对FJPT站在高程方向的沉降较明显,因此在FJPT站坐标时间序列数据的实际应用,需要考虑台湾地区地震对其短期的影响.

基于BCC_CSM模式的中国东部夏季降水预测检验及订正

基于国家气候中心第二代季节预测模式的历史回报试验数据,检验了模式对我国东部夏季降水的预测能力,探讨了预测误差形成的可能原因,并应用降尺度方法提高了模式的降水预测技巧。分析表明:(1)模式能在一定程度上把握我国东部夏季降水时空变率的两个主要模态(偶极子型模态和全区一致型模态),但是不同超前时间的预测在刻画模态方差贡献、异常空间分布特征、时间系数的年际变化等方面存在明显误差;(2)模式能够合理预测大尺度环流和海表温度(SST)的变化特征,但是对中国东部夏季降水的总体预测技巧有限,这与模式不能准确刻画西太平洋副热带高压、大陆高压、中高纬阻塞高压等环流系统以及热带太平洋、印度洋SST变率对中国东部降水模态的影响有关;(3)针对1991~2003年回报试验数据中的500 h Pa位势高度、850 h Pa纬向风和经向风、SST变量,在全球范围内寻找并定位与中国东部站点降水关系最密切的预报因子,进而建立针对降水预测的单因子线性回归、多因子逐步和多元回归模型。采用2004~2013年回报试验对所建立的降水预测模型进行了独立检验,结果表明:所建立的降尺度预测模型能显著提高中国东部地区夏季降水的预报技巧。以6月1日起报试验为例,预测的第一模态(第二模态)与观测的空间相关系数由原始的0.12(0.48)提高到了0.58(0.80),时间相关系数则从0.47(0.15)提高到0.80(0.67);其它超前时间的预测试验中,降尺度预测模型的降水预测技巧相比模式原始预测技巧也同样明显提高。

ARIMA模型在我国体育用品出口预测中的应用

为了客观把握目前我国体育用品出口的发展现状,准确预测未来我国体育用品出口的发展趋势。收集了2004年1月至2006年8月我国体育用品出口的月度数据,进行了时间序列分析,建立了体育用品月出口额的自回归求和移动平均模型(即ARIMA模型)。结果显示:模型ARIMA(0,1,2)(0,1,1)能较为准确地预测我国体育用品出口额的月度数据,模型的预测值与实际观测值非常接近,说明时间序列模型在我国体育用品出口状况预测中具有较好的应用价值。

东海磷营养盐变动模型的建立与应用

基于磷营养盐的变动由线性趋势和周期性波动构成的假设,构建了东海磷营养盐变动模型;提出了对非等间隔时间序列实测数据求解周期等模型参数的逐步选择法。运用模型对东海磷营养盐的历史调查资料进行验证及预测检验均取得了良好效果。分析还表明,周期性成分引起的波动对东海磷酸盐变动的影响要比相应的趋势项成分大得多;模型的构成周期中并没有特别卓越的成分在其中起支配作用,决定东海磷酸盐变动的是多个时间尺度上的周期性现象的共同作用。

西北地区东部短时强降水概念模型

利用2001-2011年NCEP/NCAR 1°×1°再分析资料对影响西北地区东部的天气环流形势进行分型,分析了各类天气型下短时强降水的时空特征和气候特征,以短时强降水发生的时间和环流状态为着眼点,结合能量天气学理论分类建立了西北地区东部短时强降水的低涡型、低槽型、两高切变型和西南气流型等4类天气学中尺度概念模型。结果表明:西北地区东部区域性短时强降水事件的天气型有明显的季节性特点和区域性特征。时间上,春末夏初和秋季主要为低槽型短时强降水,而盛夏主要为西南气流型和两高切变型;空间上,戈壁荒漠区以低槽型短时强降水为主,青藏高原东北边坡区以西南气流型为主,而黄土高原区和秦岭以南区以西南气流型和低槽型为主。

基于WRF-SWAN耦合模式的台风“威马逊”波浪场数值模拟

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