We investigate the characteristics and mechanisms of persistent wet–cold events(PWCEs)with different types of coldair paths.Results show that the cumulative single-station frequency of the PWCEs in the western part o...We investigate the characteristics and mechanisms of persistent wet–cold events(PWCEs)with different types of coldair paths.Results show that the cumulative single-station frequency of the PWCEs in the western part of South China is higher than that in the eastern part.The pattern of single-station frequency of the PWCEs are“Yangtze River(YR)uniform”and“east–west inverse”.The YR uniform pattern is the dominant mode,so we focus on this pattern.The cold-air paths for PWCEs of the YR uniform pattern are divided into three types—namely,the west,northwest and north types—among which the west type accounts for the largest proportion.The differences in atmospheric circulation of the PWCEs under the three types of paths are obvious.The thermal inversion layer in the lower troposphere is favorable for precipitation during the PWCEs.The positive water vapor budget for the three types of PWCEs mainly appears at the southern boundary.展开更多
Strom surges are not only determined by the atmospheric forcing,but also influenced by the coastal geometry and bathymetry.The Bohai Sea,as one of China’s marginal seas,is seriously harmed by storm surges,especially ...Strom surges are not only determined by the atmospheric forcing,but also influenced by the coastal geometry and bathymetry.The Bohai Sea,as one of China’s marginal seas,is seriously harmed by storm surges,especially those caused by cold-air outbreaks.As the coastline of the Bohai Sea has changed evidently these years,storm surges may have new characteristics due to the changes in the local geometry.This paper aims to find out these new characteristics by primarily investigating the influence of the changes in the local geometry on storm surges with numerical methods.20 scenarios were constructed based on the track and inten-sity of the cold-air outbreaks to describe the actual situation.By analyzing the model results of the control scenarios,it is found that the main changes of the maximum surge elevation occur in the Bohai Bay and the Laizhou Bay.At the top of the Bohai Bay,the maximum surge elevation is obviously decreased,while in the Laizhou Bay,it is enhanced by the growing Yellow River Delta.This,however,does not suggest that the storm surges in the Laizhou Bay become more serious.A comparison of the risk assessment of storm surges in the Tanggu,Huanghua and Yangjiaogou regions shows that the risk of storm surges in these coastal areas is lightened by the evolvement of the coastal geometry.Particularly near Yangjiaogou,though the maximum surge elevation becomes higher to subject more areas to risk,the risk is still reduced by the evolvement of the Yellow River Delta.展开更多
A 24-h simulation with the Advanced Regional Prediction System （ARPS） nonhydrostatic model is performed for the heavy snowfall event of 3-4 February 1998 along the eastern coast of Korean Peninsula; the results are ...A 24-h simulation with the Advanced Regional Prediction System （ARPS） nonhydrostatic model is performed for the heavy snowfall event of 3-4 February 1998 along the eastern coast of Korean Peninsula; the results are used to understand the snowfall process, including why the precipitation maxima formed along the Yeongdong coastal region rather than over the mountain slope and ridge top during. The numerical simulation with a 4-kin horizontal grid spacing and 43 levels reproduces very well the narrow snowband located off the eastern Korean coast, away from, instead of over, the Yeongdong coastal mountain range. The general evolution of the snowband agrees quite well with radar observations, while the water-equivalent precipitation amount agrees reasonably well with radar precipitation estimate. The simulation results clearly show that the snow band developed due to the lifting by a coastal front that developed because of the damming of cold air against the eastern slope of the coastal mountain range. The damming was enhanced by the advection of cold air by a tow-level mountain-parallel jet from the north, formed due to geostrophic adjustment as the on-shore upslope air was decelerated by the mountain blocking. As the onshore flow weakened later due to synoptic-scale flow pattern change, the cold front propagated off shore and the precipitation dissipated.展开更多
为促进风电消纳,减少火电机组的碳排放,解决综合能源系统(Integrated Energy System,IES)低碳经济运行问题,文中引入变掺氧富氧燃烧技术对燃气机组进行改造,并结合利用液化天然气(Liquefied Natural Gas,LNG)冷能的液化空气储能(Liquid ...为促进风电消纳,减少火电机组的碳排放,解决综合能源系统(Integrated Energy System,IES)低碳经济运行问题,文中引入变掺氧富氧燃烧技术对燃气机组进行改造,并结合利用液化天然气(Liquefied Natural Gas,LNG)冷能的液化空气储能(Liquid Air Energy Storage,LAES),提出了一种电热气冷IES低碳经济优化策略。首先,构建含变掺氧富氧燃烧燃气机组、利用LNG冷能的LAES、电转气(Power To Gas,P2G)设备、中央空调和溴化锂制冷机的IES架构,并建立各设备的数学模型;其次,引入阶梯式碳交易机制,建立了以系统运行成本最小为目标的电热气冷IES低碳经济调度模型;最后,采用MATLAB调用GUROBI求解器对多个场景进行求解,验证了文中提出的低碳经济优化调度策略可以提高系统的风电消纳、有效降低系统运行成本,实现碳减排。展开更多
目的探讨合肥市极端气温对居民循环系统疾病死亡的影响及不同人群的敏感性分析。方法收集合肥市2016—2021年逐日气象资料、大气污染物监测资料及循环系统疾病死亡数据。采用基于广义相加模型的分布滞后非线性模型(distributed lag non-...目的探讨合肥市极端气温对居民循环系统疾病死亡的影响及不同人群的敏感性分析。方法收集合肥市2016—2021年逐日气象资料、大气污染物监测资料及循环系统疾病死亡数据。采用基于广义相加模型的分布滞后非线性模型(distributed lag non-linear model,DLNM),评估极端气温对不同性别、年龄人群循环系统疾病死亡影响以及对循环系统主要疾病死亡的滞后效应和累积效应。以日均气温中位数(17.7℃)为对照,计算极端气温的相对危险度(RR)。结果合肥市极端气温对居民循环系统疾病死亡具有显著影响。极端低温对循环系统疾病死亡影响滞后时间长,lag4时达到最大,RR(95%CI)为1.067(1.039,1.095),且不同人群的死亡风险均明显增加。极端高温对循环系统疾病死亡的影响在当天达到最大,RR(95%CI)为1.088(1.020,1.160),持续时间短;≥65岁、女性和脑血管病患者也均在当日效应最大,且效应具有统计学意义,而对其他人群无明显影响。极端气温对不同人群的冷效应均高于热效应,低温对<65岁人群的死亡风险明显高于≥65岁人群,热效应则相反;女性冷效应和热效应均高于男性;脑血管病人群冷效应和热效应也均高于缺血性心脏病人群。结论合肥市极端气温可能增加居民循环系统疾病死亡风险,冷效应影响更大,不同人群对冷热效应的敏感性有差别。展开更多
基金supported by the National Key Research and Development Program of China (Grant No. 2018YFC1505602)the National Natural Science Foundation of China (Grant No. 41705055)+2 种基金the Graduate Innovation Project of Jiangsu Province (Grant No. CXZZ11_0485)the Creative Teams of Jiangsu Qinglan Projectthe Priority Academic Program Development of Jiangsu Higher Education Institutions (PAPD)
文摘We investigate the characteristics and mechanisms of persistent wet–cold events(PWCEs)with different types of coldair paths.Results show that the cumulative single-station frequency of the PWCEs in the western part of South China is higher than that in the eastern part.The pattern of single-station frequency of the PWCEs are“Yangtze River(YR)uniform”and“east–west inverse”.The YR uniform pattern is the dominant mode,so we focus on this pattern.The cold-air paths for PWCEs of the YR uniform pattern are divided into three types—namely,the west,northwest and north types—among which the west type accounts for the largest proportion.The differences in atmospheric circulation of the PWCEs under the three types of paths are obvious.The thermal inversion layer in the lower troposphere is favorable for precipitation during the PWCEs.The positive water vapor budget for the three types of PWCEs mainly appears at the southern boundary.
基金supported by the National Science and Technology Pillar Program during China's Eleventh Five-Year Plan Period (2006BAC03B01)
文摘Strom surges are not only determined by the atmospheric forcing,but also influenced by the coastal geometry and bathymetry.The Bohai Sea,as one of China’s marginal seas,is seriously harmed by storm surges,especially those caused by cold-air outbreaks.As the coastline of the Bohai Sea has changed evidently these years,storm surges may have new characteristics due to the changes in the local geometry.This paper aims to find out these new characteristics by primarily investigating the influence of the changes in the local geometry on storm surges with numerical methods.20 scenarios were constructed based on the track and inten-sity of the cold-air outbreaks to describe the actual situation.By analyzing the model results of the control scenarios,it is found that the main changes of the maximum surge elevation occur in the Bohai Bay and the Laizhou Bay.At the top of the Bohai Bay,the maximum surge elevation is obviously decreased,while in the Laizhou Bay,it is enhanced by the growing Yellow River Delta.This,however,does not suggest that the storm surges in the Laizhou Bay become more serious.A comparison of the risk assessment of storm surges in the Tanggu,Huanghua and Yangjiaogou regions shows that the risk of storm surges in these coastal areas is lightened by the evolvement of the coastal geometry.Particularly near Yangjiaogou,though the maximum surge elevation becomes higher to subject more areas to risk,the risk is still reduced by the evolvement of the Yellow River Delta.
基金supported by the National Research Foundation of Korea(NRF) grant funded by the Korea government (MEST)(Grant No. 2011-0013879)supported by NSF (Grant Nos. AGS-0802888,AGS-1046171,and EEC-0313747)
文摘A 24-h simulation with the Advanced Regional Prediction System （ARPS） nonhydrostatic model is performed for the heavy snowfall event of 3-4 February 1998 along the eastern coast of Korean Peninsula; the results are used to understand the snowfall process, including why the precipitation maxima formed along the Yeongdong coastal region rather than over the mountain slope and ridge top during. The numerical simulation with a 4-kin horizontal grid spacing and 43 levels reproduces very well the narrow snowband located off the eastern Korean coast, away from, instead of over, the Yeongdong coastal mountain range. The general evolution of the snowband agrees quite well with radar observations, while the water-equivalent precipitation amount agrees reasonably well with radar precipitation estimate. The simulation results clearly show that the snow band developed due to the lifting by a coastal front that developed because of the damming of cold air against the eastern slope of the coastal mountain range. The damming was enhanced by the advection of cold air by a tow-level mountain-parallel jet from the north, formed due to geostrophic adjustment as the on-shore upslope air was decelerated by the mountain blocking. As the onshore flow weakened later due to synoptic-scale flow pattern change, the cold front propagated off shore and the precipitation dissipated.
文摘为促进风电消纳,减少火电机组的碳排放,解决综合能源系统(Integrated Energy System,IES)低碳经济运行问题,文中引入变掺氧富氧燃烧技术对燃气机组进行改造,并结合利用液化天然气(Liquefied Natural Gas,LNG)冷能的液化空气储能(Liquid Air Energy Storage,LAES),提出了一种电热气冷IES低碳经济优化策略。首先,构建含变掺氧富氧燃烧燃气机组、利用LNG冷能的LAES、电转气(Power To Gas,P2G)设备、中央空调和溴化锂制冷机的IES架构,并建立各设备的数学模型;其次,引入阶梯式碳交易机制,建立了以系统运行成本最小为目标的电热气冷IES低碳经济调度模型;最后,采用MATLAB调用GUROBI求解器对多个场景进行求解,验证了文中提出的低碳经济优化调度策略可以提高系统的风电消纳、有效降低系统运行成本,实现碳减排。
文摘目的探讨合肥市极端气温对居民循环系统疾病死亡的影响及不同人群的敏感性分析。方法收集合肥市2016—2021年逐日气象资料、大气污染物监测资料及循环系统疾病死亡数据。采用基于广义相加模型的分布滞后非线性模型(distributed lag non-linear model,DLNM),评估极端气温对不同性别、年龄人群循环系统疾病死亡影响以及对循环系统主要疾病死亡的滞后效应和累积效应。以日均气温中位数(17.7℃)为对照,计算极端气温的相对危险度(RR)。结果合肥市极端气温对居民循环系统疾病死亡具有显著影响。极端低温对循环系统疾病死亡影响滞后时间长,lag4时达到最大,RR(95%CI)为1.067(1.039,1.095),且不同人群的死亡风险均明显增加。极端高温对循环系统疾病死亡的影响在当天达到最大,RR(95%CI)为1.088(1.020,1.160),持续时间短;≥65岁、女性和脑血管病患者也均在当日效应最大,且效应具有统计学意义,而对其他人群无明显影响。极端气温对不同人群的冷效应均高于热效应,低温对<65岁人群的死亡风险明显高于≥65岁人群,热效应则相反;女性冷效应和热效应均高于男性;脑血管病人群冷效应和热效应也均高于缺血性心脏病人群。结论合肥市极端气温可能增加居民循环系统疾病死亡风险,冷效应影响更大,不同人群对冷热效应的敏感性有差别。
基金supported by the Strategic Priority Research Program of Chinese Academy of Sciences[grant numbers XDA23090102]the National Natural Science Foundation of China[grant numbers 42175078 and 42075040]+1 种基金the Health Meteorological Project of Hebei Province[grant number FW202150]the National Key Research and Development Program of China[grant number 2018YFA0606203].
