Weakening of Nonlinear ENSO Under Global Warming
Abstract The amplitude response of the El Niño–Southern Oscillation (ENSO) to global warming is examined in two global climate models with realistic ENSO nonlinearity. Geophysical Fluid Dynamics Laboratory Earth System Model Version 2M (GFDL‐ESM2M) and Model for Interdisciplinary Research on Climate...
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| Format: | Article |
| Language: | English |
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Wiley
2018-08-01
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| Series: | Geophysical Research Letters |
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| Online Access: | https://doi.org/10.1029/2018GL079085 |
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| author | Tsubasa Kohyama Dennis L. Hartmann David S. Battisti |
| author_facet | Tsubasa Kohyama Dennis L. Hartmann David S. Battisti |
| author_sort | Tsubasa Kohyama |
| collection | DOAJ |
| description | Abstract The amplitude response of the El Niño–Southern Oscillation (ENSO) to global warming is examined in two global climate models with realistic ENSO nonlinearity. Geophysical Fluid Dynamics Laboratory Earth System Model Version 2M (GFDL‐ESM2M) and Model for Interdisciplinary Research on Climate version 5 (MIROC5) are the two models that exhibit realistic ENSO nonlinearity. With quadrupled atmospheric carbon dioxide, the ENSO amplitude of GFDL‐ESM2M decreases by about 40%, whereas that of MIROC5 remains almost constant. Because GFDL‐ESM2M exhibits stronger climatological thermal stratification than MIROC5, greenhouse gas forcing increases the upper ocean stability and causes the thermocline to be less sensitive to wind perturbations. The stiffer thermocline inhibits the nonlinear variations of sea surface temperature so that the ENSO amplitude substantially weakens. Idealized nonlinear recharge oscillator model experiments further support climatological thermal stratification as a determinant of the warming response. Observations exhibit stronger thermal stratification than both models, which suggests that the real world may terminate strong, nonlinear El Niños sooner than model‐based projections. |
| format | Article |
| id | doaj-art-d4d77e7672874d2b9ba0c1c56bc37545 |
| institution | DOAJ |
| issn | 0094-8276 1944-8007 |
| language | English |
| publishDate | 2018-08-01 |
| publisher | Wiley |
| record_format | Article |
| series | Geophysical Research Letters |
| spelling | doaj-art-d4d77e7672874d2b9ba0c1c56bc375452025-08-20T02:46:20ZengWileyGeophysical Research Letters0094-82761944-80072018-08-0145168557856710.1029/2018GL079085Weakening of Nonlinear ENSO Under Global WarmingTsubasa Kohyama0Dennis L. Hartmann1David S. Battisti2Department of Earth and Planetary Science The University of Tokyo Tokyo JapanDepartment of Atmospheric Sciences University of Washington Seattle WA USADepartment of Atmospheric Sciences University of Washington Seattle WA USAAbstract The amplitude response of the El Niño–Southern Oscillation (ENSO) to global warming is examined in two global climate models with realistic ENSO nonlinearity. Geophysical Fluid Dynamics Laboratory Earth System Model Version 2M (GFDL‐ESM2M) and Model for Interdisciplinary Research on Climate version 5 (MIROC5) are the two models that exhibit realistic ENSO nonlinearity. With quadrupled atmospheric carbon dioxide, the ENSO amplitude of GFDL‐ESM2M decreases by about 40%, whereas that of MIROC5 remains almost constant. Because GFDL‐ESM2M exhibits stronger climatological thermal stratification than MIROC5, greenhouse gas forcing increases the upper ocean stability and causes the thermocline to be less sensitive to wind perturbations. The stiffer thermocline inhibits the nonlinear variations of sea surface temperature so that the ENSO amplitude substantially weakens. Idealized nonlinear recharge oscillator model experiments further support climatological thermal stratification as a determinant of the warming response. Observations exhibit stronger thermal stratification than both models, which suggests that the real world may terminate strong, nonlinear El Niños sooner than model‐based projections.https://doi.org/10.1029/2018GL079085global warmingENSO amplitudeENSO nonlinearity |
| spellingShingle | Tsubasa Kohyama Dennis L. Hartmann David S. Battisti Weakening of Nonlinear ENSO Under Global Warming Geophysical Research Letters global warming ENSO amplitude ENSO nonlinearity |
| title | Weakening of Nonlinear ENSO Under Global Warming |
| title_full | Weakening of Nonlinear ENSO Under Global Warming |
| title_fullStr | Weakening of Nonlinear ENSO Under Global Warming |
| title_full_unstemmed | Weakening of Nonlinear ENSO Under Global Warming |
| title_short | Weakening of Nonlinear ENSO Under Global Warming |
| title_sort | weakening of nonlinear enso under global warming |
| topic | global warming ENSO amplitude ENSO nonlinearity |
| url | https://doi.org/10.1029/2018GL079085 |
| work_keys_str_mv | AT tsubasakohyama weakeningofnonlinearensounderglobalwarming AT dennislhartmann weakeningofnonlinearensounderglobalwarming AT davidsbattisti weakeningofnonlinearensounderglobalwarming |