Observational evidence of strengthening of the Brewer-Dobson circulation since 1980
The change of the Brewer-Dobson circulation (BDC) over the period of 1980–2009 is examined through a combined analysis of satellite Microwave Sounding Unit (MSU/AMSU) lower stratospheric temperatures (TLS), ERA-Interim reanalysis data, and observed estimates of changes in ozone, water vapor, well-mi...
| Main Authors: | , , , |
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| Other Authors: | |
| Format: | Article |
| Language: | en_US |
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American Geophysical Union (AGU)
2017
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| Online Access: | http://hdl.handle.net/1721.1/109514 https://orcid.org/0000-0002-2020-7581 |
| _version_ | 1811071295356403712 |
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| author | Fu, Q. Lin, P. Solomon, Susan Hartmann, Dominik Hartmann |
| author2 | Massachusetts Institute of Technology. Department of Chemistry |
| author_facet | Massachusetts Institute of Technology. Department of Chemistry Fu, Q. Lin, P. Solomon, Susan Hartmann, Dominik Hartmann |
| author_sort | Fu, Q. |
| collection | MIT |
| description | The change of the Brewer-Dobson circulation (BDC) over the period of 1980–2009 is examined through a combined analysis of satellite Microwave Sounding Unit (MSU/AMSU) lower stratospheric temperatures (TLS), ERA-Interim reanalysis data, and observed estimates of changes in ozone, water vapor, well-mixed greenhouse gases, and stratospheric aerosols. The MSU/AMSU-observed tropical TLS trend is first empirically separated into a dynamic component associated with the BDC changes and a radiative component due to the atmospheric composition changes. The derived change in the dynamic component suggests that the annual mean BDC has accelerated in the last 30 years (at the 90% confidence interval), with most of the change coming from the Southern Hemisphere. The annual mean Northern Hemisphere contribution to the acceleration is not statistically significant. The radiative component of tropical TLS trends is independently checked using observed changes in stratospheric composition. It is shown that the changes in ozone, stratospheric aerosols, well-mixed greenhouse gases, and water vapor make important contributions to the radiative component of tropical TLS trends. Despite large uncertainties in lower stratospheric cooling associated with uncertainties in observed ozone and water vapor changes, this derived radiative component agrees with the empirically inferred radiative component, both in terms of its average value and small seasonal dependence. By establishing a relationship between tropical residual vertical velocity at 70 hPa and TLS, we show that the relative strengthening of the annual mean BDC is about 2.1% per decade for 1980–2009, supporting the results from state-of-the-art chemistry-climate model simulations. |
| first_indexed | 2024-09-23T08:48:56Z |
| format | Article |
| id | mit-1721.1/109514 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T08:48:56Z |
| publishDate | 2017 |
| publisher | American Geophysical Union (AGU) |
| record_format | dspace |
| spelling | mit-1721.1/1095142022-09-23T14:46:37Z Observational evidence of strengthening of the Brewer-Dobson circulation since 1980 Fu, Q. Lin, P. Solomon, Susan Hartmann, Dominik Hartmann Massachusetts Institute of Technology. Department of Chemistry Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Program in Media Arts and Sciences (Massachusetts Institute of Technology) Solomon, Susan Solomon, Susan Hartmann, Dominik Hartmann The change of the Brewer-Dobson circulation (BDC) over the period of 1980–2009 is examined through a combined analysis of satellite Microwave Sounding Unit (MSU/AMSU) lower stratospheric temperatures (TLS), ERA-Interim reanalysis data, and observed estimates of changes in ozone, water vapor, well-mixed greenhouse gases, and stratospheric aerosols. The MSU/AMSU-observed tropical TLS trend is first empirically separated into a dynamic component associated with the BDC changes and a radiative component due to the atmospheric composition changes. The derived change in the dynamic component suggests that the annual mean BDC has accelerated in the last 30 years (at the 90% confidence interval), with most of the change coming from the Southern Hemisphere. The annual mean Northern Hemisphere contribution to the acceleration is not statistically significant. The radiative component of tropical TLS trends is independently checked using observed changes in stratospheric composition. It is shown that the changes in ozone, stratospheric aerosols, well-mixed greenhouse gases, and water vapor make important contributions to the radiative component of tropical TLS trends. Despite large uncertainties in lower stratospheric cooling associated with uncertainties in observed ozone and water vapor changes, this derived radiative component agrees with the empirically inferred radiative component, both in terms of its average value and small seasonal dependence. By establishing a relationship between tropical residual vertical velocity at 70 hPa and TLS, we show that the relative strengthening of the annual mean BDC is about 2.1% per decade for 1980–2009, supporting the results from state-of-the-art chemistry-climate model simulations. United States. National Aeronautics and Space Administration (grant NNX13AN49G) United States. National Aeronautics and Space Administration (NNX14AB28G) United States. Department of Energy. Office of Science (grant DE-SC0010557) National Science Foundation (U.S.) (grant 1342810) National Science Foundation (U.S.) (grant 1461517) 2017-06-01T18:31:12Z 2017-06-01T18:31:12Z 2015-10 2015-05 Article http://purl.org/eprint/type/JournalArticle 2169897X http://hdl.handle.net/1721.1/109514 Fu, Q., P. Lin, S. Solomon, and D. L. Hartmann. “Observational Evidence of Strengthening of the Brewer-Dobson Circulation Since 1980.” Journal of Geophysical Research: Atmospheres 120, no. 19 (October 12, 2015): 10,214–10,228. https://orcid.org/0000-0002-2020-7581 en_US http://dx.doi.org/10.1002/2015JD023657 Journal of Geophysical Research: Atmospheres Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. application/pdf American Geophysical Union (AGU) Prof. Emanuel via Chris Sherratt |
| spellingShingle | Fu, Q. Lin, P. Solomon, Susan Hartmann, Dominik Hartmann Observational evidence of strengthening of the Brewer-Dobson circulation since 1980 |
| title | Observational evidence of strengthening of the Brewer-Dobson circulation since 1980 |
| title_full | Observational evidence of strengthening of the Brewer-Dobson circulation since 1980 |
| title_fullStr | Observational evidence of strengthening of the Brewer-Dobson circulation since 1980 |
| title_full_unstemmed | Observational evidence of strengthening of the Brewer-Dobson circulation since 1980 |
| title_short | Observational evidence of strengthening of the Brewer-Dobson circulation since 1980 |
| title_sort | observational evidence of strengthening of the brewer dobson circulation since 1980 |
| url | http://hdl.handle.net/1721.1/109514 https://orcid.org/0000-0002-2020-7581 |
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