DOI: 10.1175/JCLI-D-17-0561.1
Scopus记录号: 2-s2.0-85050203395
论文题名: Characterization of dry conditions across the U.S.-Affiliated Pacific Islands during near-neutral ENSO phases
作者: Ludert A. ; Wang B. ; Merrifield M.A.
刊名: Journal of Climate
ISSN: 8948755
出版年: 2018
卷: 31, 期: 16 起始页码: 6461
结束页码: 6480
语种: 英语
英文关键词: Atmosphere
; ENSO
; La Nina
; Pacific Ocean
; Precipitation
Scopus关键词: Earth atmosphere
; Nickel compounds
; Oceanography
; Precipitation (chemical)
; Rain
; Tropics
; Wind effects
; Anticyclonic circulation
; ENSO
; La nina
; Negative correlation
; Pacific ocean
; Seasonal forecasts
; Tropical Western Pacific
; Western North Pacific
; Drought
; anticyclone
; dry season
; El Nino-Southern Oscillation
; La Nina
; precipitation (climatology)
; rainfall
; regional climate
; sea surface temperature
; temperature anomaly
; weather forecasting
; Pacific islands
; Pacific Ocean
; Pacific Ocean (Central)
; Pacific Ocean (North)
; Pacific Ocean (West)
; United States
英文摘要: The U.S.-Affiliated Pacific Islands (USAPIs), located in the tropical western Pacific, are very susceptible to severe drought. Dry season (December-May) rainfall anomalies have different relationships to ENSO for USAPIs north and south of 7°N. South of 7°N, rainfall exhibits a canonical negative correlation with the Oceanic Niño Index (ONI) (i.e., dry conditions during warm periods). To the north, the dry season falls into either "canonical" or "noncanonical" (positively correlated with ONI) regimes. Noncanonical years pose an important forecasting challenge as severe droughts have occurred during cool ONI conditions (referred to here as "cool dry" cases). Composite analysis of the two regimes shows that for noncanonical cool dry years, anticyclonic circulation anomalies over the tropical western North Pacific (TWNP), with a band of anomalous dry conditions extending from the central Pacific toward Micronesia, result in unexpected droughts. In contrast, canonical "cool wet" events show cyclonic TWNP circulation and increased rainfall over the northern USAPIs. Maximum SST anomalies are located near the date line during noncanonical years, and farther east during canonical years. While both regimes show negative rainfall and TWNP anticyclonic circulation anomalies before the onset of the December-May dry season, during the dry season these anomalies persist during noncanonical events but rapidly reverse sign during canonical events. SST anomalies in the noncanonical regime extend eastward from the central Pacific rather than intensify in place over the eastern Pacific in the canonical regime. Differences in the evolution of circulation, precipitation, and SST anomalies suggest distinct physical mechanisms governing the two ENSO regimes, with possible ramifications for seasonal forecasts. © 2018 American Meteorological Society. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/111423
Appears in Collections: 气候减缓与适应
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作者单位: Department of Atmospheric Science, University of Hawai'i at Manoa, Honolulu, HI, United States; Pacific ENSO Applications Climate Center, University of Hawai'i at Manoa, Honolulu, HI, United States; Earth System Modeling Center, Nanjing University of Information Science and Technology, Nanjing, China; Department of Oceanography, University of Hawai'i at Manoa, Honolulu, HI, United States
Recommended Citation:
Ludert A.,Wang B.,Merrifield M.A.. Characterization of dry conditions across the U.S.-Affiliated Pacific Islands during near-neutral ENSO phases[J]. Journal of Climate,2018-01-01,31(16)