Tropical cloud feedbacks and natural variability of climate

Miller, R L; Del Genio, A D

doi:10.1175/1520-0442(1994)007<1388:TCFANV>2.0.CO;2

Title: Tropical cloud feedbacks and natural variability of climate

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Abstract

Simulations of natural variability by two GCMs are examined. One GCM is a sector model, allowing relatively rapid integration without simplification of the model physics, which would potentially exclude mechanisms of variability. Two mechanisms are found in which tropical surface temperature and SST vary on interannual and longer timescales. Both are related to changes in cloud cover that modulate SST through the surface radiative flux. Over the equatorial ocean, SST and surface temperature vary on an interannual timescale, which is determined by the magnitude of the associated cloud cover anomalies. Over the subtropical ocean, variations in low cloud cover drive SST variations. In the sector model, the variability has no preferred timescale, but instead is characterized by a [open quotes]red[close quotes] spectrum with increasing power at longer periods. In the terrestrial GCM, SST variability associated with low cloud anomalies has a decadal timescale and is the dominant form of global temperature variability. Both GCMs are coupled to a mixed layer ocean model, where dynamical heat transports are prescribed, thus filtering out ENSO and thermohaline circulation variability. The occurrence of variability in the absence of dynamical ocean feedbacks suggests that climatic variability on long timescales can arise from atmospheric processes alone.more » 28 refs., 13 figs., 2 tabs.« less

Authors:

Miller, R L; Del Genio, A D ^[1]

NASA Goddard Institute for Space Studies, New York, NY (United States)

Publication Date:: Thu Sep 01 00:00:00 EDT 1994

OSTI Identifier:: 6795348

Resource Type:: Journal Article

Journal Name:: Journal of Climate; (United States)

Additional Journal Information:: Journal Volume: 7:9; Journal ID: ISSN 0894-8755

Country of Publication:: United States

Language:: English

Subject:: 54 ENVIRONMENTAL SCIENCES; CLIMATES; ANNUAL VARIATIONS; CLOUD COVER; GENERAL CIRCULATION MODELS; COMPARATIVE EVALUATIONS; SEAS; TEMPERATURE MEASUREMENT; ATMOSPHERIC CIRCULATION; OCEANIC CIRCULATION; TROPICAL REGIONS; EVALUATION; MATHEMATICAL MODELS; SURFACE WATERS; VARIATIONS; 540110*

Citation Formats


                    Miller, R L, and Del Genio, A D. Tropical cloud feedbacks and natural variability of climate.  United States: N. p., 1994. 
        Web.  doi:10.1175/1520-0442(1994)007<1388:TCFANV>2.0.CO;2.

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                    Miller, R L, & Del Genio, A D. Tropical cloud feedbacks and natural variability of climate.  United States.  https://doi.org/10.1175/1520-0442(1994)007<1388:TCFANV>2.0.CO;2

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                    Miller, R L, and Del Genio, A D. 1994.  
        "Tropical cloud feedbacks and natural variability of climate".  United States.  https://doi.org/10.1175/1520-0442(1994)007<1388:TCFANV>2.0.CO;2.

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@article{osti_6795348,

  title        = {Tropical cloud feedbacks and natural variability of climate},

  author       = {Miller, R L and Del Genio, A D},

  abstractNote = {Simulations of natural variability by two GCMs are examined. One GCM is a sector model, allowing relatively rapid integration without simplification of the model physics, which would potentially exclude mechanisms of variability. Two mechanisms are found in which tropical surface temperature and SST vary on interannual and longer timescales. Both are related to changes in cloud cover that modulate SST through the surface radiative flux. Over the equatorial ocean, SST and surface temperature vary on an interannual timescale, which is determined by the magnitude of the associated cloud cover anomalies. Over the subtropical ocean, variations in low cloud cover drive SST variations. In the sector model, the variability has no preferred timescale, but instead is characterized by a [open quotes]red[close quotes] spectrum with increasing power at longer periods. In the terrestrial GCM, SST variability associated with low cloud anomalies has a decadal timescale and is the dominant form of global temperature variability. Both GCMs are coupled to a mixed layer ocean model, where dynamical heat transports are prescribed, thus filtering out ENSO and thermohaline circulation variability. The occurrence of variability in the absence of dynamical ocean feedbacks suggests that climatic variability on long timescales can arise from atmospheric processes alone. 28 refs., 13 figs., 2 tabs.},

  doi          = {10.1175/1520-0442(1994)007<1388:TCFANV>2.0.CO;2},

  url          = {https://www.osti.gov/biblio/6795348},
  journal      = {Journal of Climate; (United States)},

  issn         = {0894-8755},

  number       = ,

  volume       = 7:9,

  place        = {United States},

  year         = {Thu Sep 01 00:00:00 EDT 1994},

  month        = {Thu Sep 01 00:00:00 EDT 1994}

}

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https://doi.org/10.1175/1520-0442(1994)007<1388:TCFANV>2.0.CO;2

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