92nd American Meteorological Society Annual Meeting (January 22-26, 2012)

Monday, 23 January 2012
Process-Resolving Decomposition of the Global Temperature Response to El Niño
Hall E (New Orleans Convention Center )
Yi Deng, Georgia Institute of Technology, Atlanta, GA; and T. W. Park and M. Cai

Adopting the coupled atmosphere-surface climate feedback-responses analysis method (CFRAM), the global land-ocean surface temperature and 3-dimensional atmospheric temperature responses to El Niño are decomposed into partial temperature changes associated with various thermodynamical and dynamical feedbacks including radiative forcing associated with changes in ozone concentration, albedo feedback, cloud feedback, water vapor feedback, surface sensible/latent heat flux and atmospheric/oceanic energy transport. The decomposition is first validated by following the “additive” nature of the CFRAM. The key findings include 1) changes in ozone concentration during El Niño contribute significantly to the stratospheric temperature response, 2) radiative feedbacks related to albedo, cloud, and water vapor anomalies are mainly confined to the equatorial Pacific, 3) non-radiative feedbacks play an essential role in setting up temperature responses in the extratropics, and 4) near-surface oceanic energy transport has pronounced positive contributions to atmospheric and surface temperature responses in the tropics, and 5) atmospheric energy transport is the primary driver of temperature response in the extratropics at high altitude. In addition, the sea surface temperature anomalies over the tropical central and eastern Pacific during El Niño are found to be mainly driven by near-surface oceanic energy transport and water vapor feedback while offset by other feedback processes. The implications of these results for further understanding of ENSO dynamics, coupled-model evaluation and projection of future ENSO variability in a warming climate will be discussed.

Supplementary URL: