Climate Dynamics

, Volume 41, Issue 5, pp 1671–1683

The seasonal footprinting mechanism in CFSv2: simulation and impact on ENSO prediction

Authors

    • Cooperative Institute for Research in Environmental SciencesUniversity of Colorado
    • Physical Sciences Division, Earth System Research LaboratoryNational Oceanic and Atmospheric Administration
  • Michael Alexander
    • Physical Sciences Division, Earth System Research LaboratoryNational Oceanic and Atmospheric Administration
Article

DOI: 10.1007/s00382-013-1887-5

Cite this article as:
Pegion, K. & Alexander, M. Clim Dyn (2013) 41: 1671. doi:10.1007/s00382-013-1887-5

Abstract

The seasonal footprinting mechanism (SFM) is thought to be a pre-cursor to the El Nino Southern Oscillation (ENSO). Fluctuations in the North Pacific Oscillation (NPO) impact the ocean via surface heat fluxes during winter, leaving a sea-surface temperature (SST) “footprint” in the subtropics. This footprint persists through the spring, impacting the tropical Pacific atmosphere–ocean circulation throughout the following year. The simulation of the SFM in the National Centers for Environmental Prediction (NCEP)/Climate Forecast System, version 2 (CFSv2) is likely to have an impact on operational predictions of ENSO and potentially seasonal predictions in the United States associated with ENSO teleconnection patterns. The ability of the CFSv2 to simulate the SFM and the relationship between the SFM and ENSO prediction skill in the NCEP/CFSv2 are investigated. Results indicate that the CFSv2 is able to simulate the basic characteristics of the SFM and its relationship with ENSO, including extratropical sea level pressure anomalies associated with the NPO in the winter, corresponding wind and SST anomalies that impact the tropics, and the development of ENSO-related SST anomalies the following winter. Although the model is able to predict the correct sign of ENSO associated with the SFM in a composite sense, probabilistic predictions of ENSO following a positive or negative NPO event are generally less reliable than when the NPO is not active.

Copyright information

© Springer-Verlag Berlin Heidelberg 2013