The circulation of positive PNA index pattern is prominent in the case of persistent forcing of negative SSTA in West Wind Drift region or positive SSTA in tropical eastern Pacific, which is the typical SSTA Pattern during El Nino peak-mature phase.
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美
- 西風(fēng)漂流區持續負SSTA時(shí)或者熱帶中東太平洋持續正SSTA時(shí)，阿留申低壓均有所加強，正PNA指數型的大氣環(huán)流特征顯著(zhù)。 而當相反符號的SSTA持續作用時(shí)，大氣中阿留申低壓減弱，對應PNA指數為負。
