The COADS Sea Level Pressure Signal: A Near-Global El Niño Composite and Time Series View, 1946–1993

Abstract

Abstract Using COADS data for the period 1946–1993, the near-global sea level pressure (SLP) patterns associated with interannual variability and the climatological seasonal march are discussed. A particular focus concerns the patterns associated with the two years before and after the South American sea surface temperatures rise (El Nino). The ten El Nino events in this record are composited, and the robustness of the features of this composite is tested. Many features of the composite are quite robust; they occur during most El Nino events and are infrequent during non-El Nino periods. The most robust feature is an area of negative SLP anomaly (SLPA) in the eastern equatorial Pacific during Year(0) of the composite. This feature exceeds significance thresholds during every El Nino year and never during non-El Nino years; it correlates better with central Pacific SST variability than does the SOI. A west-central North Pacific positive SLPA, occurring late in Year(0) and lasting into the spring of year (+...