Objective weather classification methods have been extensively applied to identify dominant ozone-favorable synoptic weather patterns(SWPs),however,the consistency of different classification methods is rarely examine...Objective weather classification methods have been extensively applied to identify dominant ozone-favorable synoptic weather patterns(SWPs),however,the consistency of different classification methods is rarely examined.In this study,we apply two widely-used objective methods,the self-organizing map(SOM)and K-means clustering analysis,to derive ozone-favorable SWPs at four Chinese megacities in 2015-2022.We find that the two algorithms are largely consistent in recognizing dominant ozone-favorable SWPs for four Chinese megacities.In the case of classifying six SWPs,the derived circulation fields are highly similar with a spatial correlation of 0.99 between the two methods,and the difference in themean frequency of each SWP is less than 7%.The six dominant ozone-favorable SWPs in Guangzhou are all characterized by anomaly higher radiation and temperature,lower cloud cover,relative humidity,and wind speed,and stronger subsidence compared to climatology mean.We find that during 2015-2022,the occurrence of ozone-favorable SWPs days increases significantly at a rate of 3.2 days/year,faster than the increases in the ozone exceedance days(3.0 days/year).The interannual variability between the occurrence of ozone-favorable SWPs and ozone exceedance days are generally consistent with a temporal correlation coefficient of 0.6.In particular,the significant increase in ozone-favorable SWPs in 2022,especially the Subtropical High type which typically occurs in September,is consistent with a long-lasting ozone pollution episode in Guangzhou during September 2022.Our results thus reveal that enhanced frequency of ozone-favorable SWPs plays an important role in the observed 2015-2022 ozone increase in Guangzhou.展开更多
I.Circle the correct options.1.Nancy is picking what to wear to school on Wednesday.She goes outside and feels the air.Nancy decides to wear a coat.What is the weather like?A.Cool and sunny.C.Cool and cloudy.B.Warm an...I.Circle the correct options.1.Nancy is picking what to wear to school on Wednesday.She goes outside and feels the air.Nancy decides to wear a coat.What is the weather like?A.Cool and sunny.C.Cool and cloudy.B.Warm and sunny.D.Warm and cloudy.2.It was cool and sunny in the morning when Nancy went to school.Now it is the afternoon.She doesn't need her coat anymore.How did the weather change?展开更多
Petrography and mineral chemistry of ninety-eight ordinary chondrites from Grove Mountains （GRV）, Antarctica, were presented and their. Weathering effect, shock metamorphism and type distribution patterns were discu...Petrography and mineral chemistry of ninety-eight ordinary chondrites from Grove Mountains （GRV）, Antarctica, were presented and their. Weathering effect, shock metamorphism and type distribution patterns were discussed in this study. Among them, six are unequilibrated ordinary chondrites, including 3 H3 and 3 L3 ; and 92 meteorites are equilibrated ordinary chondrites, including 24 H-group （ 13 H4, 10 H5, 1 H6）, 64 L-group （2 L4, 44 L5, 18 L6） and 4 LL-group （3 LL4, 1 LL5）. Most GRV ehondrites （ 〉 90% ） displayed minor weathering effect （ W1 and W2）. About half of the meteorites experienced severe shock metamorphism. They commonly contain shock-induced melt veins and pockets. These heavily shocked meteorites provide us with natural samples for study of high-pressure polymorphs of minerals. In addition, the Grove Mountains collection seems to have more abundant unequilibrated and L group ordinary ehondrites compared to the US Antarctic meteorite collection which were mainly found along the Transantarctic Mountains.展开更多
An anomalous phase containing clays and humic acid was found while extraction humic acid from samples of weathering crust of REE-bearing granites by using 0.1 mol/L NaOH solution.Studied by chemical separation experim...An anomalous phase containing clays and humic acid was found while extraction humic acid from samples of weathering crust of REE-bearing granites by using 0.1 mol/L NaOH solution.Studied by chemical separation experiments,column chromatography,ion-exchange chromatography,infrared spectrum.fluorescence spectrum,polarimicroscopic testing and elemental determination by ultraviolet-visible spectrometer and atomic absorption spectrometer.it was proved to be a compound of humic acid and clays which are connected in the form of bridge by heteronuclearpolynuclear complexing ions formed by cations of RE￣(5+),Al￣(3+).Fe￣(3+) etc.The compounding pattern was further proved by the experiment for compounding humic acid,REE and kaolinite.展开更多
Based on the data of hail,gale,thunderstorm and lightning days in 2 481 stations in China from 1961 to 2016,the spatial and temporal distribution characteristics,periodicity and climate abruption characteristics of fo...Based on the data of hail,gale,thunderstorm and lightning days in 2 481 stations in China from 1961 to 2016,the spatial and temporal distribution characteristics,periodicity and climate abruption characteristics of four kinds of disastrous convective weather in China were analyzed by various mathematical statistics methods. The results showed that in time,the days of four kinds of disastrous convective weather in China decreased,and the hail and thunderstorm days were characterized by " increasing firstly and then decreasing" from 1961 to 2016. The hail,gale,thunderstorm and lightning days in China had oscillation cycles of 3-5,2-3,1-2 and 1-4 a respectively,and the hail and thunderstorm days changed suddenly in 2002 and 1992 respectively. In space,the Qinghai-Tibet Plateau and western Sichuan were the highvalue distribution areas of hail,gale and thunderstorm days. The high-value distribution areas of thunderstorm days were also distributed to the south of the Yangtze River. South China and its southwestern regions at the same latitude were the high-value distribution areas of lightning days. In terms of trend,the hail days in China showed a decreasing trend mainly in the Qinghai-Tibet Plateau. The gale days in China decreased in the east,was unchanged in the central region,and increased and decreased alternately in the west. The thunderstorm days in China increased in Tibet,North China,Chongqing,Zhejiang and northwestern Heilongjiang. The lightning days in China decreased obviously to the south of the Yangtze River. In terms of the fluctuation,the hail days fluctuated greatly in the southeast. The gale days fluctuated greatly to the east of Hu Huanyong line. The thunderstorms days in China fluctuated greatly in the northwest and slightly in the southeast. In addition to the small fluctuation in northern Xinjiang and South China,the lightning days fluctuated greatly in other regions of China.展开更多
1.Introduction As global temperatures increase and weather patterns grow more er-ratic,the urgency of adopting climate-smart conservation strategies has intensified(Manyakaidze et al.,2024).Climate-smart conservation ...1.Introduction As global temperatures increase and weather patterns grow more er-ratic,the urgency of adopting climate-smart conservation strategies has intensified(Manyakaidze et al.,2024).Climate-smart conservation com-prises adaptive management practices aimed at bolstering the resilience of ecosystems and species amid climate variability(Birchall et al.,2021;Gabriel-Campos et al.,2021).展开更多
为揭示干旱半干旱地区天气形势与气象要素对大气污染的影响机制,基于2016—2022年欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)提供的第五代大气再分析数据集(ERA5),采用自组织映射神经网络(Self-O...为揭示干旱半干旱地区天气形势与气象要素对大气污染的影响机制,基于2016—2022年欧洲中期天气预报中心(European Centre for Medium-Range Weather Forecasts,ECMWF)提供的第五代大气再分析数据集(ERA5),采用自组织映射神经网络(Self-Organizing Map,SOM)对700 hPa位势高度场和风场进行天气分型,并结合二次曲线拟合解析甘肃不同气候区典型城市气象要素与污染物的非线性关系。结果表明:1)PM_(10)和PM_(2.5)质量浓度与气温整体呈负相关,而O_(3)质量浓度随气温升高非线性增加;低风速(<1 m·s^(-1))和高风速(>4 m·s^(-1))下,PM_(10)和PM_(2.5)质量浓度较高,在静风及强风时分别因局地累积和沙尘输送导致颗粒物质量浓度升高,而1~4 m·s^(-1)的风速有利于前体物积累,导致O_(3)质量浓度升高;25%~75%的相对湿度条件下污染物质量浓度较高,但其影响存在区域差异,如干旱区的酒泉,在湿度小于25%条件下由于易发生沙尘天气PM_(10)质量浓度较高,PM_(2.5)由于吸湿增长作用,质量浓度随相对湿度升高而增加,O_(3)在低湿条件下的消耗降低,其质量浓度随相对湿度升高递减。2)冬春季,以西南高压型和东部低槽型为主导,西南高压型下西部强西北风形成污染物输送通道,东部低压槽型下甘肃地区扩散条件差,其大气形势较为稳定,污染物易积累,导致PM_(10)和PM_(2.5)质量浓度显著升高。3)夏秋季,以高压型为主导,充沛的太阳辐射与高温条件促使边界层高度抬升,配合暖湿气流输送,为光化学反应提供有利环境,导致O_(3)质量浓度较高。展开更多
基金supported by the Guangdong Basic and Applied Basic Research project (No.2020B0301030004)the Key-Area Research and Development Program of Guangdong Province (No.2020B1111360003)+1 种基金the National Natural Science Foundation of China (No.42105103)the Guangdong Basic and Applied Basic Research Foundation (No.2022A1515011554).
文摘Objective weather classification methods have been extensively applied to identify dominant ozone-favorable synoptic weather patterns(SWPs),however,the consistency of different classification methods is rarely examined.In this study,we apply two widely-used objective methods,the self-organizing map(SOM)and K-means clustering analysis,to derive ozone-favorable SWPs at four Chinese megacities in 2015-2022.We find that the two algorithms are largely consistent in recognizing dominant ozone-favorable SWPs for four Chinese megacities.In the case of classifying six SWPs,the derived circulation fields are highly similar with a spatial correlation of 0.99 between the two methods,and the difference in themean frequency of each SWP is less than 7%.The six dominant ozone-favorable SWPs in Guangzhou are all characterized by anomaly higher radiation and temperature,lower cloud cover,relative humidity,and wind speed,and stronger subsidence compared to climatology mean.We find that during 2015-2022,the occurrence of ozone-favorable SWPs days increases significantly at a rate of 3.2 days/year,faster than the increases in the ozone exceedance days(3.0 days/year).The interannual variability between the occurrence of ozone-favorable SWPs and ozone exceedance days are generally consistent with a temporal correlation coefficient of 0.6.In particular,the significant increase in ozone-favorable SWPs in 2022,especially the Subtropical High type which typically occurs in September,is consistent with a long-lasting ozone pollution episode in Guangzhou during September 2022.Our results thus reveal that enhanced frequency of ozone-favorable SWPs plays an important role in the observed 2015-2022 ozone increase in Guangzhou.
文摘I.Circle the correct options.1.Nancy is picking what to wear to school on Wednesday.She goes outside and feels the air.Nancy decides to wear a coat.What is the weather like?A.Cool and sunny.C.Cool and cloudy.B.Warm and sunny.D.Warm and cloudy.2.It was cool and sunny in the morning when Nancy went to school.Now it is the afternoon.She doesn't need her coat anymore.How did the weather change?
基金supported by the Doctor's Foundation of Hunan University of Science and Technology(Grant No.E50806)
文摘Petrography and mineral chemistry of ninety-eight ordinary chondrites from Grove Mountains （GRV）, Antarctica, were presented and their. Weathering effect, shock metamorphism and type distribution patterns were discussed in this study. Among them, six are unequilibrated ordinary chondrites, including 3 H3 and 3 L3 ; and 92 meteorites are equilibrated ordinary chondrites, including 24 H-group （ 13 H4, 10 H5, 1 H6）, 64 L-group （2 L4, 44 L5, 18 L6） and 4 LL-group （3 LL4, 1 LL5）. Most GRV ehondrites （ 〉 90% ） displayed minor weathering effect （ W1 and W2）. About half of the meteorites experienced severe shock metamorphism. They commonly contain shock-induced melt veins and pockets. These heavily shocked meteorites provide us with natural samples for study of high-pressure polymorphs of minerals. In addition, the Grove Mountains collection seems to have more abundant unequilibrated and L group ordinary ehondrites compared to the US Antarctic meteorite collection which were mainly found along the Transantarctic Mountains.
文摘An anomalous phase containing clays and humic acid was found while extraction humic acid from samples of weathering crust of REE-bearing granites by using 0.1 mol/L NaOH solution.Studied by chemical separation experiments,column chromatography,ion-exchange chromatography,infrared spectrum.fluorescence spectrum,polarimicroscopic testing and elemental determination by ultraviolet-visible spectrometer and atomic absorption spectrometer.it was proved to be a compound of humic acid and clays which are connected in the form of bridge by heteronuclearpolynuclear complexing ions formed by cations of RE￣(5+),Al￣(3+).Fe￣(3+) etc.The compounding pattern was further proved by the experiment for compounding humic acid,REE and kaolinite.
基金Supported by National Natural Science Foundation of China (41801064,71790611)Funds for Research of Atmospheric Sciences in Central Asia (CAAS201804)
文摘Based on the data of hail,gale,thunderstorm and lightning days in 2 481 stations in China from 1961 to 2016,the spatial and temporal distribution characteristics,periodicity and climate abruption characteristics of four kinds of disastrous convective weather in China were analyzed by various mathematical statistics methods. The results showed that in time,the days of four kinds of disastrous convective weather in China decreased,and the hail and thunderstorm days were characterized by " increasing firstly and then decreasing" from 1961 to 2016. The hail,gale,thunderstorm and lightning days in China had oscillation cycles of 3-5,2-3,1-2 and 1-4 a respectively,and the hail and thunderstorm days changed suddenly in 2002 and 1992 respectively. In space,the Qinghai-Tibet Plateau and western Sichuan were the highvalue distribution areas of hail,gale and thunderstorm days. The high-value distribution areas of thunderstorm days were also distributed to the south of the Yangtze River. South China and its southwestern regions at the same latitude were the high-value distribution areas of lightning days. In terms of trend,the hail days in China showed a decreasing trend mainly in the Qinghai-Tibet Plateau. The gale days in China decreased in the east,was unchanged in the central region,and increased and decreased alternately in the west. The thunderstorm days in China increased in Tibet,North China,Chongqing,Zhejiang and northwestern Heilongjiang. The lightning days in China decreased obviously to the south of the Yangtze River. In terms of the fluctuation,the hail days fluctuated greatly in the southeast. The gale days fluctuated greatly to the east of Hu Huanyong line. The thunderstorms days in China fluctuated greatly in the northwest and slightly in the southeast. In addition to the small fluctuation in northern Xinjiang and South China,the lightning days fluctuated greatly in other regions of China.
文摘1.Introduction As global temperatures increase and weather patterns grow more er-ratic,the urgency of adopting climate-smart conservation strategies has intensified(Manyakaidze et al.,2024).Climate-smart conservation com-prises adaptive management practices aimed at bolstering the resilience of ecosystems and species amid climate variability(Birchall et al.,2021;Gabriel-Campos et al.,2021).
