Oral Presentation AMOS Annual Meeting and International Conference on Tropical Meteorology and Oceanography

Multi-year to decadal variability in the tropical Pacific: characteristics, causes, predictability and prospects (#207)

scott power 1 , matthieu lengaigne 2 , antonietta capotondi 3 , kim cobb 4 , shayne mcgregor 5 , jeong-seon kug 6 , Eric Guilyardi 7 , Myriam Khodri 8 , Andrew Wittenberg 9 , Jérôme Vialard 10 , Wenju Cai 11 , Michael McPhaden 12 , Magdalena Balmaseda 13 , Pascale Braconnot 14 , Christine Chung 1 , Julia Cole 15 , Julien Cretat 16 , Francois Delage 17 , Rene Garreau 18 , Aaron Levine 12 , Matt Newman 19 , Yuko Okumura 20 , Yann Planton 10 , Janet Sprintall 21 , Daniel Vimont 22 , Guojian Wang 11 , Xuebin Zhang 11
  1. Bureau of Meteorology, Melbourne, Australia
  2. IRD, Paris, France
  3. University of Colorado, Boulder, CO, USA
  4. Georgia Tech, Atlanta, GA, USA
  5. Monash University, Melbourne, Australia
  6. Hanyang University, Hanyang, Korea
  7. University of Reading, Reading, UK
  8. LOCEAN, IRD/IPSL, Sorbonne University, Paris, France
  9. GFDL, Princeton, NJ, USA
  10. LOCEAN, Paris, France
  11. CSIRO, Melbourne, Vic, Australia
  12. NOAA/PMEL, Seattle, USA
  13. ECMWF, Reading, UK
  14. IPSL, Paris, France
  15. University of Michigan, Michigan, USA
  16. LSCE-IPSL, Paris, France
  17. Bureau of Meteorology, 3001, VIC, Australia
  18. University of Chile, Santiago, Chile
  19. NOAA/ESRL/CIRES, Seattle, USA
  20. Univeristy of Texas, Austin, USA
  21. Scripps Institute of Oceanography, La Jolla, USA
  22. University of Wisconin-Madison, Madison, USA

 

Multi-year to decadal climate variability in the tropical Pacific (MDVTP) is a major driver of variability in precipitation, river flow, flooding and the incidence of extreme weather in many parts of the world. MDVTP also modulates the rate at which global temperature increases in response to anthropogenic forcing, as exemplified by the recent global warming slowdown. Here we provide an overview of the spatial and temporal characteristics of MDVTP. Evidence is drawn from instrumental data, paleo data, climate models and theory.

There are two kinds of MDVTP – internally generated natural variability and externally forced variability. Internal MDVTP may arise from instabilities within the tropical Pacific, as well as from interactions with higher latitudes and other basins via atmospheric or oceanic teleconnections. The internal sources of MDVTP within the tropical Pacific include oceanic adjustment processes as well as nonlinear interactions between El Niño-Southern Oscillation and the tropical Pacific mean state. Externally forced MDVTP can either be natural (e.g., intermittent volcanic eruptions) or anthropogenic (e.g., anthropogenic increases in greenhouse gas concentrations and sulphate aerosols). We will describe our current knowledge of the characteristics of MDVTP, and discuss how the different mechanisms can affect its predictability. While the emphasis is on synthesizing the relevant scientific literature, some new analyses will also be presented. Key issues where understanding is lacking, and how understanding can be improved, will also be discussed. We will conclude by outlining what the prospects are for the Pacific over the coming decade.