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
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
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?
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).
