Seasonal Loops Between Local Outgoing Longwave Radiation and Surface Temperature
The relationship between outgoing longwave radiation (OLR) and the surface temperature has a major influence on Earth's climate sensitivity. Studies often assume that this relationship is approximately linear, but it is unclear whether the approximation always holds. Here we show that, on seaso...
| Main Authors: | , , |
|---|---|
| Other Authors: | |
| Format: | Article |
| Language: | English |
| Published: |
American Geophysical Union (AGU)
2022
|
| Online Access: | https://hdl.handle.net/1721.1/140401 |
| _version_ | 1826213525324824576 |
|---|---|
| author | Richards, Benjamin D. G. Koll, Daniel D. B. Cronin, Timothy W. |
| 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 Richards, Benjamin D. G. Koll, Daniel D. B. Cronin, Timothy W. |
| author_sort | Richards, Benjamin D. G. |
| collection | MIT |
| description | The relationship between outgoing longwave radiation (OLR) and the surface temperature has a major influence on Earth's climate sensitivity. Studies often assume that this relationship is approximately linear, but it is unclear whether the approximation always holds. Here we show that, on seasonal timescales, clear-sky OLR is a multivalued function of local surface temperature. In many places, the OLR-temperature relationship is better approximated by a loop than a line and we quantify the resulting “OLR loopiness”, that is, how much clear-sky OLR varies between different seasons with the same surface temperature. Based on offline radiative calculations, in the tropics OLR loops are mainly caused by seasonal variations in relative humidity that are out of phase with surface temperature; in the extratropics, OLR loops are mainly due to variations in lapse rates. Our work provides a mechanism through which Earth's climate feedback can differ between seasonal and long-term time scales. |
| first_indexed | 2024-09-23T15:50:37Z |
| format | Article |
| id | mit-1721.1/140401 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T15:50:37Z |
| publishDate | 2022 |
| publisher | American Geophysical Union (AGU) |
| record_format | dspace |
| spelling | mit-1721.1/1404012024-06-06T20:07:24Z Seasonal Loops Between Local Outgoing Longwave Radiation and Surface Temperature Richards, Benjamin D. G. Koll, Daniel D. B. Cronin, Timothy W. Massachusetts Institute of Technology. Department of Earth, Atmospheric, and Planetary Sciences The relationship between outgoing longwave radiation (OLR) and the surface temperature has a major influence on Earth's climate sensitivity. Studies often assume that this relationship is approximately linear, but it is unclear whether the approximation always holds. Here we show that, on seasonal timescales, clear-sky OLR is a multivalued function of local surface temperature. In many places, the OLR-temperature relationship is better approximated by a loop than a line and we quantify the resulting “OLR loopiness”, that is, how much clear-sky OLR varies between different seasons with the same surface temperature. Based on offline radiative calculations, in the tropics OLR loops are mainly caused by seasonal variations in relative humidity that are out of phase with surface temperature; in the extratropics, OLR loops are mainly due to variations in lapse rates. Our work provides a mechanism through which Earth's climate feedback can differ between seasonal and long-term time scales. 2022-02-16T15:20:57Z 2022-02-16T15:20:57Z 2021-08-06 Article http://purl.org/eprint/type/JournalArticle 0094-8276 1944-8007 https://hdl.handle.net/1721.1/140401 Richards, B. D. G., Koll, D. D. B., & Cronin, T. W. (2021). Seasonal loops between local outgoing longwave radiation and surface temperature. Geophysical Research Letters, 48, e2021GL092978. en http://dx.doi.org/10.1029/2021gl092978 Geophysical Research Letters Creative Commons Attribution-Noncommercial-Share Alike http://creativecommons.org/licenses/by-nc-sa/4.0/ application/pdf American Geophysical Union (AGU) Wiley |
| spellingShingle | Richards, Benjamin D. G. Koll, Daniel D. B. Cronin, Timothy W. Seasonal Loops Between Local Outgoing Longwave Radiation and Surface Temperature |
| title | Seasonal Loops Between Local Outgoing Longwave Radiation and Surface Temperature |
| title_full | Seasonal Loops Between Local Outgoing Longwave Radiation and Surface Temperature |
| title_fullStr | Seasonal Loops Between Local Outgoing Longwave Radiation and Surface Temperature |
| title_full_unstemmed | Seasonal Loops Between Local Outgoing Longwave Radiation and Surface Temperature |
| title_short | Seasonal Loops Between Local Outgoing Longwave Radiation and Surface Temperature |
| title_sort | seasonal loops between local outgoing longwave radiation and surface temperature |
| url | https://hdl.handle.net/1721.1/140401 |
| work_keys_str_mv | AT richardsbenjamindg seasonalloopsbetweenlocaloutgoinglongwaveradiationandsurfacetemperature AT kolldanieldb seasonalloopsbetweenlocaloutgoinglongwaveradiationandsurfacetemperature AT cronintimothyw seasonalloopsbetweenlocaloutgoinglongwaveradiationandsurfacetemperature |