Linear Relation of Central and Eastern North American Precipitation to Tropical Pacific Sea Surface Temperature Anomalies

Abstract

In past research the Southern Oscillation index has often been used as an indicator of the tropical Pacific climate, notably for El Niño and La Niña event occurrences. This study identifies calendar monthly teleconnection signals in central and eastern North American precipitation associated with an alternative tropical Pacific indicator, sea surface temperature anomaly (SSTA) patterns. Using an approximate 1° resolution set of monthly precipitation totals for 1950–92, the work identifies monthly teleconnection relationships and their intraseasonal evolution. This builds upon previous studies that were limited to seasonal timescales. Here, a unique two-way statistical analysis is used to delineate linear SSTA–precipitation teleconnection patterns. First, a principal component analysis (PCA) is performed on a monthly tropical Pacific SSTA dataset for 1950–92 to identify the coherent modes of variability. The principal component (PC) score time series representing the most significant modes of SSTA... Abstract In past research the Southern Oscillation index has often been used as an indicator of the tropical Pacific climate, notably for El Niño and La Niña event occurrences. This study identifies calendar monthly teleconnection signals in central and eastern North American precipitation associated with an alternative tropical Pacific indicator, sea surface temperature anomaly (SSTA) patterns. Using an approximate 1° resolution set of monthly precipitation totals for 1950–92, the work identifies monthly teleconnection relationships and their intraseasonal evolution. This builds upon previous studies that were limited to seasonal timescales. Here, a unique two-way statistical analysis is used to delineate linear SSTA–precipitation teleconnection patterns. First, a principal component analysis (PCA) is performed on a monthly tropical Pacific SSTA dataset for 1950–92 to identify the coherent modes of variability. The principal component (PC) score time series representing the most significant modes of SSTA...