The climate time scale in the approach to radiative-convective equilibrium
In this paper, we discuss the importance of the surface boundary condition (fixed versus interactive surface temperature) for the long time scale of approach to Radiative-Convective Equilibrium (RCE). Using a simple linearized two-variable model for surface-atmosphere interaction, we derive an analy...
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| Format: | Article |
| Language: | en_US |
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American Geophysical Union (AGU)
2015
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| Online Access: | http://hdl.handle.net/1721.1/97933 https://orcid.org/0000-0002-7807-2878 https://orcid.org/0000-0002-2066-2082 |
| _version_ | 1826204706207170560 |
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| author | Emanuel, Kerry Andrew Cronin, Timothy Wallace |
| author2 | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences |
| author_facet | Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Emanuel, Kerry Andrew Cronin, Timothy Wallace |
| author_sort | Emanuel, Kerry Andrew |
| collection | MIT |
| description | In this paper, we discuss the importance of the surface boundary condition (fixed versus interactive surface temperature) for the long time scale of approach to Radiative-Convective Equilibrium (RCE). Using a simple linearized two-variable model for surface-atmosphere interaction, we derive an analytic expression for τ[subscript C], a long climate relaxation time scale that remains well defined and much longer than either mixing time scale of Tompkins and Craig (1998b), even in the limit that the heat capacity of the surface vanishes. We show that the size of τ[subscript C] is an intrinsic property of the coupling between the atmosphere and surface, and not a result of the thermal inertia of the surface alone. When the surface heat capacity is low, τ[subscript C] can be several times longer than expected, due to the effects of moisture on the effective heat capacity of the atmosphere. We also show that the theoretical expression for τ[subscript C] is a good predictor of best fit exponential relaxation time scales in a single-column model with full physics, across a range of surface temperatures and surface heat capacities. |
| first_indexed | 2024-09-23T12:59:45Z |
| format | Article |
| id | mit-1721.1/97933 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T12:59:45Z |
| publishDate | 2015 |
| publisher | American Geophysical Union (AGU) |
| record_format | dspace |
| spelling | mit-1721.1/979332024-05-15T08:04:58Z The climate time scale in the approach to radiative-convective equilibrium Emanuel, Kerry Andrew Cronin, Timothy Wallace Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences Massachusetts Institute of Technology. Program in Atmospheres, Oceans, and Climate Woods Hole Oceanographic Institution Cronin, Timothy W. Emanuel, Kerry Andrew In this paper, we discuss the importance of the surface boundary condition (fixed versus interactive surface temperature) for the long time scale of approach to Radiative-Convective Equilibrium (RCE). Using a simple linearized two-variable model for surface-atmosphere interaction, we derive an analytic expression for τ[subscript C], a long climate relaxation time scale that remains well defined and much longer than either mixing time scale of Tompkins and Craig (1998b), even in the limit that the heat capacity of the surface vanishes. We show that the size of τ[subscript C] is an intrinsic property of the coupling between the atmosphere and surface, and not a result of the thermal inertia of the surface alone. When the surface heat capacity is low, τ[subscript C] can be several times longer than expected, due to the effects of moisture on the effective heat capacity of the atmosphere. We also show that the theoretical expression for τ[subscript C] is a good predictor of best fit exponential relaxation time scales in a single-column model with full physics, across a range of surface temperatures and surface heat capacities. National Science Foundation (U.S.) (Grant 1136480) 2015-07-31T17:11:49Z 2015-07-31T17:11:49Z 2013-10 2013-09 Article http://purl.org/eprint/type/JournalArticle 19422466 http://hdl.handle.net/1721.1/97933 Cronin, Timothy W., and Kerry A. Emanuel. “The Climate Time Scale in the Approach to Radiative-Convective Equilibrium.” Journal of Advances in Modeling Earth Systems 5, no. 4 (October 29, 2013): 843–849. © 2013 American Geophysical Union https://orcid.org/0000-0002-7807-2878 https://orcid.org/0000-0002-2066-2082 en_US http://dx.doi.org/10.1002/jame.20049 Journal of Advances in Modeling Earth Systems 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) MIT web domain |
| spellingShingle | Emanuel, Kerry Andrew Cronin, Timothy Wallace The climate time scale in the approach to radiative-convective equilibrium |
| title | The climate time scale in the approach to radiative-convective equilibrium |
| title_full | The climate time scale in the approach to radiative-convective equilibrium |
| title_fullStr | The climate time scale in the approach to radiative-convective equilibrium |
| title_full_unstemmed | The climate time scale in the approach to radiative-convective equilibrium |
| title_short | The climate time scale in the approach to radiative-convective equilibrium |
| title_sort | climate time scale in the approach to radiative convective equilibrium |
| url | http://hdl.handle.net/1721.1/97933 https://orcid.org/0000-0002-7807-2878 https://orcid.org/0000-0002-2066-2082 |
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