Oscillations and teleconnections - The Global Climate System: Patterns, Processes, and Teleconnections - page 54

emerging is one of interacting phenomena operating on QB to multidecadal
time frames, with ENSO to ''ENSO-like'' characteristics. Not surprisingly,
these climatic features display similarities and differences in their physical
patterns and structures. Theoretical and modeling studies suggest that they are
powered by dynamical processes inherent in the climate system, with the QB,
LF ENSO, and quasi-decadal features all showing evidence of the operation of
delayed action oscillator physics in their nature. However, the physics under-
lying lower frequency PDO/IPO and AMO fluctuations has not yet been
explained.
Possible modulation of ENSO by the enhanced greenhouse effect remains
an area of considerable debate in the scientific community. Although this
debate will continue, there is growing evidence that natural ''ENSO-like''
variability on decadal to multidecadal time scales plays a very significant role
in observed climatic patterns.
Acknowledgments
This essay is British Crown Copyright. I would like to thank David Parker,
Hadley Centre, Met Office, for his comments and suggestions on the text.
2.9 Examples of oscillations and teleconnections websites
(Note: many significant sites are given in the text of this chapter)
The Climate Prediction Center is linked to www.nws.noaa.gov. Teleconnec-
tions provide the main topic and the site provides a comprehensive account of the
indices used.
Interannual forecast/climate dynamics is located at www.cdc.noaa.gov/
seasonal/dynamics.html. Details and links to many sites including ENSO,
index values and monsoons are provided.
2.10 References
Agrawala, S., Barlow, M., Cullen, H. and Lyon, B., 2001. The Drought and Humanitarian
Crisis in Central and Southwest Asia: A Climate Perspective. IRI Special Report 01-11,
Lamont-Doherty Earth Observatory of Columbia University, Palisades, New York, 20pp.
Allan, R. J., 2000. ENSO and climatic variability in the last 150 years. In H. F. Diaz and
V. Markgraf, eds., El Nino and the Southern Oscillation: Multiscale Variability and its
Impacts on Natural Ecosystems and Society. Cambridge: Cambridge University Press,
pp. 3-55.
2003. El Ni ˜o - A world perspective and what it means in Australia. In P. Attiwell and
B. Wilson, eds., Ecology: An Australian Perspective. Melbourne, Australia: Oxford
University Press.
Allan, R. J. and D'Arrigo, R. D., 1999. 'Persistent' ENSO Sequences: How unusual was the
1990-1995 El Ni ˜o? Holocene, 9, 101-118.