Cloud and radiation variability associated with El Niño
Abstract
The El Niño Southern Oscillation (ENSO) is the dominant form of variability in the tropics, causing both local and global variations in radiation, clouds, and precipitation. In this study we examine the response of the atmosphere, during El Niño events, in both observations and GFDL's atmosphere-only models: AM2, AM3 and HiRAM. Locally, both shortwave and longwave top-of-atmosphere (TOA) fluxes show strong correlation with ENSO, but in the tropical and global mean the correlation is strong only for the longwave. This implies strong cancellation of induced geographical shifts in cloud distributions. All models reasonably reproduce longwave TOA, but show large deficiencies for shortwave fluxes in the tropical/global average. We show that biases in cloud amount in the models mean state translate linearly to biases in anomalies. The same scaling argument works for precipitation but not TOA radiation fluxes. Implications of these results are discussed.
- Publication:
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AGU Fall Meeting Abstracts
- Pub Date:
- December 2012
- Bibcode:
- 2012AGUFM.A51C0051R
- Keywords:
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- 0321 ATMOSPHERIC COMPOSITION AND STRUCTURE / Cloud/radiation interaction