Simulating the role of subtropical stratocumulus clouds in driving Pacific climate variability

Katinka Bellomo, Amy C Clement, Thorsten Mauritsen, Gaby Rädel, Bjorn Stevens

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

This study examines the influence of the northeast and southeast Pacific subtropical stratocumulus cloud regions on the modes of Pacific climate variability simulated by an atmospheric general circulation model (ECHAM6) coupled to a slab ocean. The sensitivity of cloud liquid water to underlying SST is changed in the radiation module of the atmospheric model to increase the strength of positive low-cloud feedback in the two regions. Enhanced low-cloud feedback increases the persistence and variance of the leading modes of climate variability at decadal and longer time scales. Additional integrations show that the southeast Pacific influences climate variability in the equatorial ENSO region, whereas the effects of the northeast Pacific remain confined to the North Pacific. The results herein suggest that a positive feedback among SST, cloud cover, and large-scale atmospheric circulation can explain decadal climate variability in the Pacific Ocean. In particular, cloud feedbacks over the subtropical stratocumulus regions set the time scale of climate variability. A proper representation of low-level cloud feedbacks in the subtropical stratocumulus regions could therefore improve the simulation of Pacific climate variability.

Original languageEnglish (US)
Pages (from-to)5119-5131
Number of pages13
JournalJournal of Climate
Volume27
Issue number13
DOIs
StatePublished - 2014

Fingerprint

stratocumulus
climate
sea surface temperature
timescale
atmospheric general circulation model
ocean
cloud cover
atmospheric circulation
El Nino-Southern Oscillation
slab
persistence
liquid
simulation

Keywords

  • Atmosphere-ocean interaction
  • Climate models
  • Clouds
  • Feedback
  • Interannual variability
  • Pacific decadal oscillation

ASJC Scopus subject areas

  • Atmospheric Science

Cite this

Simulating the role of subtropical stratocumulus clouds in driving Pacific climate variability. / Bellomo, Katinka; Clement, Amy C; Mauritsen, Thorsten; Rädel, Gaby; Stevens, Bjorn.

In: Journal of Climate, Vol. 27, No. 13, 2014, p. 5119-5131.

Research output: Contribution to journalArticle

Bellomo, Katinka ; Clement, Amy C ; Mauritsen, Thorsten ; Rädel, Gaby ; Stevens, Bjorn. / Simulating the role of subtropical stratocumulus clouds in driving Pacific climate variability. In: Journal of Climate. 2014 ; Vol. 27, No. 13. pp. 5119-5131.
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