气候与环境研究
氣候與環境研究
기후여배경연구
CLIMATIC AND ENVIRONMENTAL RESEARCH
2013年
4期
436-450
,共15页
北大西洋涛动(NAO)%热带大气季节内振荡(MJO)%K均值聚类%年际变化
北大西洋濤動(NAO)%熱帶大氣季節內振盪(MJO)%K均值聚類%年際變化
북대서양도동(NAO)%열대대기계절내진탕(MJO)%K균치취류%년제변화
North Atlantic Oscillation (NAO)%Madden-Julian Oscillation (MJO)%K-means clustering algorithms%Interannual variability
运用K均值聚类法将冬季北大西洋及欧洲地区的天气流型分为4种不同的流型。研究了不同阶段8种不同位相的热带季节内振荡(MJO)与这4种流型的年际变化的关系。通过一系列的对比试验发现,K均值聚类法划分得到的不同位相的北大西洋涛动(NAO)的天数能很好地反映NAO指数;无论是在1978~1990年(简称为P1阶段)还是在1991~2010年(简称为P2阶段),MJO第3(6)位相影响NAO正(负)位相;但在P1阶段存在NAO的位相转换,当MJO处于第1位相时,NAO由弱的负位相转换为正位相,当MJO处于第6位相时, NAO由正位相转换为负位相;而在P2阶段NAO并没有明显的位相转换,当MJO处于第1位相时,NAO由偶极子结构转换为波列结构。
運用K均值聚類法將鼕季北大西洋及歐洲地區的天氣流型分為4種不同的流型。研究瞭不同階段8種不同位相的熱帶季節內振盪(MJO)與這4種流型的年際變化的關繫。通過一繫列的對比試驗髮現,K均值聚類法劃分得到的不同位相的北大西洋濤動(NAO)的天數能很好地反映NAO指數;無論是在1978~1990年(簡稱為P1階段)還是在1991~2010年(簡稱為P2階段),MJO第3(6)位相影響NAO正(負)位相;但在P1階段存在NAO的位相轉換,噹MJO處于第1位相時,NAO由弱的負位相轉換為正位相,噹MJO處于第6位相時, NAO由正位相轉換為負位相;而在P2階段NAO併沒有明顯的位相轉換,噹MJO處于第1位相時,NAO由偶極子結構轉換為波列結構。
운용K균치취류법장동계북대서양급구주지구적천기류형분위4충불동적류형。연구료불동계단8충불동위상적열대계절내진탕(MJO)여저4충류형적년제변화적관계。통과일계렬적대비시험발현,K균치취류법화분득도적불동위상적북대서양도동(NAO)적천수능흔호지반영NAO지수;무론시재1978~1990년(간칭위P1계단)환시재1991~2010년(간칭위P2계단),MJO제3(6)위상영향NAO정(부)위상;단재P1계단존재NAO적위상전환,당MJO처우제1위상시,NAO유약적부위상전환위정위상,당MJO처우제6위상시, NAO유정위상전환위부위상;이재P2계단NAO병몰유명현적위상전환,당MJO처우제1위상시,NAO유우겁자결구전환위파렬결구。
Using K-means clustering algorithms, four weather regimes over the North Atlantic–European region are obtained. Moreover, the relationship between the Madden–Julian Oscillation (MJO) in the tropics and the four weather regimes over the North Atlantic–European region is investigated. It is found that the winter mean North Atlantic Oscillation (NAO) index can be characterized by the number of days of NAO events calculated by K-means clustering algorithms. During two periods, 1978–1990 (P1) and 1991–2010 (P2), phase 3 (6) of the MJO leads to a positive (negative) NAO regime. In particular, the MJO is found to be very important for the NAO transition during P1, but unimportant during P2. When the MJO is within the first (sixth) phase during P1, the NAO event can transit from the weak negative (positive) phase to the positive (negative) phase. However, only the transition between dipole and wave train patterns is evident during P2, when the MJO is in the first phase.