Springtime ENSO phase evolution and its relation to rainfall in the continental U.S.

Sang Ki Lee, Brian E. Mapes, Chunzai Wang, David B. Enfield, Scott J. Weaver

Research output: Contribution to journalArticle

25 Scopus citations

Abstract

Springtime El Niño-Southern Oscillation (ENSO) phase evolution and associated U.S. rainfall variability are explored by performing composite analysis of observational data. Although the tropical Pacific ENSO sea surface temperature anomalies are weaker and less coherent in boreal spring compared to those in winter, there are unique and significant patterns of U.S. rainfall anomalies frequently appearing during the onset and decay phases of ENSO. In early spring of a decaying El Niño, the atmospheric jet stream and associated storm track shift southward, causing more frequent wet conditions across the southern U.S. and dry conditions in a belt south and east of the Ohio River. In late spring of a developing El Niño, the synoptic activity over the U.S. reduces overall and the southwesterly low-level winds that carry moist air from the Gulf of Mexico to the U.S. shift westward, causing a similar dipole of rainfall anomalies between the southern U.S. and the Ohio Valley. Key Points Springtime ENSO phase evolution and its relation to U.S. rainfall is explored Coherent springtime ENSO SST anomalies exist in the central tropical Pacific Significant patterns of U.S. rainfall anomalies covary with ENSO phase in spring

Original languageEnglish (US)
Pages (from-to)1673-1680
Number of pages8
JournalGeophysical Research Letters
Volume41
Issue number5
DOIs
StatePublished - Mar 16 2014

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Keywords

  • ENSO evolution in spring
  • ENSO teleconnection
  • U.S. rainfall in spring

ASJC Scopus subject areas

  • Geophysics
  • Earth and Planetary Sciences(all)

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