Reduced terrestrial evaporation increases atmospheric water vapor by generating cloud feedbacks
Reduced terrestrial evaporation directly warms the surface by reducing latent cooling, but also indirectly modifies surface climate by altering atmospheric processes. We use a global climate model to explore two end cases of terrestrial evaporation, comparing the climate of SwampLand, a world where...
| Main Authors: | , , |
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| Format: | Article |
| Language: | English |
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IOP Publishing
2023-01-01
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| Series: | Environmental Research Letters |
| Subjects: | |
| Online Access: | https://doi.org/10.1088/1748-9326/acdbe1 |
| _version_ | 1827869796539039744 |
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| author | M M Laguë G R Quetin W R Boos |
| author_facet | M M Laguë G R Quetin W R Boos |
| author_sort | M M Laguë |
| collection | DOAJ |
| description | Reduced terrestrial evaporation directly warms the surface by reducing latent cooling, but also indirectly modifies surface climate by altering atmospheric processes. We use a global climate model to explore two end cases of terrestrial evaporation, comparing the climate of SwampLand, a world where land is always fully saturated with water, to that of DesertLand, where land is always completely lacking in soil moisture. When we suppress evaporation to create a desert-like planet, we find that temperatures increase and precipitation decreases in the global mean. We find an increase in atmospheric water vapor over both land and ocean in the DesertLand simulation. Suppressing evaporative cooling over the continents reduces continental cloud cover, allowing more energy input to the surface and increasing surface moist static energy over land. The residence time of atmospheric water vapor increases by about 50 percent. Atmospheric feedbacks such as changes in air temperatures and cloud cover contribute larger changes to the terrestrial surface energy budget than the direct effect of suppressed evaporation alone. Without the cloud feedback, the land surface still warms with suppressed land evaporation, but total atmospheric water vapor decreases, and the anomalous atmospheric circulations over the continents are much shallower than in simulations with cloud changes; that is, the cloud feedback changes the sign of the water vapor response. This highlights the importance of accounting for atmospheric feedbacks when exploring land surface change impacts on the climate system. |
| first_indexed | 2024-03-12T15:49:13Z |
| format | Article |
| id | doaj.art-b4dc31f35ba94921a66f2cb6dbaf2e82 |
| institution | Directory Open Access Journal |
| issn | 1748-9326 |
| language | English |
| last_indexed | 2024-03-12T15:49:13Z |
| publishDate | 2023-01-01 |
| publisher | IOP Publishing |
| record_format | Article |
| series | Environmental Research Letters |
| spelling | doaj.art-b4dc31f35ba94921a66f2cb6dbaf2e822023-08-09T15:18:14ZengIOP PublishingEnvironmental Research Letters1748-93262023-01-0118707402110.1088/1748-9326/acdbe1Reduced terrestrial evaporation increases atmospheric water vapor by generating cloud feedbacksM M Laguë0https://orcid.org/0000-0001-8513-542XG R Quetin1https://orcid.org/0000-0002-7884-5332W R Boos2https://orcid.org/0000-0001-9076-3551Coldwater Lab, Center for Hydrology, University of Saskatchewan , Canmore, AB, Canada; Department of Atmospheric Sciences, University of Utah , Salt Lake City, UT, United States of AmericaDepartment of Geography, University of California , Santa Barbara, CA, United States of AmericaDepartment of Earth and Planetary Science, University of California , Berkeley, CA, United States of America; Climate and Ecosystem Sciences Division, Lawrence Berkeley National Laboratory , Berkeley, CA, United States of AmericaReduced terrestrial evaporation directly warms the surface by reducing latent cooling, but also indirectly modifies surface climate by altering atmospheric processes. We use a global climate model to explore two end cases of terrestrial evaporation, comparing the climate of SwampLand, a world where land is always fully saturated with water, to that of DesertLand, where land is always completely lacking in soil moisture. When we suppress evaporation to create a desert-like planet, we find that temperatures increase and precipitation decreases in the global mean. We find an increase in atmospheric water vapor over both land and ocean in the DesertLand simulation. Suppressing evaporative cooling over the continents reduces continental cloud cover, allowing more energy input to the surface and increasing surface moist static energy over land. The residence time of atmospheric water vapor increases by about 50 percent. Atmospheric feedbacks such as changes in air temperatures and cloud cover contribute larger changes to the terrestrial surface energy budget than the direct effect of suppressed evaporation alone. Without the cloud feedback, the land surface still warms with suppressed land evaporation, but total atmospheric water vapor decreases, and the anomalous atmospheric circulations over the continents are much shallower than in simulations with cloud changes; that is, the cloud feedback changes the sign of the water vapor response. This highlights the importance of accounting for atmospheric feedbacks when exploring land surface change impacts on the climate system.https://doi.org/10.1088/1748-9326/acdbe1evaporationwater vaporland-atmosphere interactionscloud feedbacks |
| spellingShingle | M M Laguë G R Quetin W R Boos Reduced terrestrial evaporation increases atmospheric water vapor by generating cloud feedbacks Environmental Research Letters evaporation water vapor land-atmosphere interactions cloud feedbacks |
| title | Reduced terrestrial evaporation increases atmospheric water vapor by generating cloud feedbacks |
| title_full | Reduced terrestrial evaporation increases atmospheric water vapor by generating cloud feedbacks |
| title_fullStr | Reduced terrestrial evaporation increases atmospheric water vapor by generating cloud feedbacks |
| title_full_unstemmed | Reduced terrestrial evaporation increases atmospheric water vapor by generating cloud feedbacks |
| title_short | Reduced terrestrial evaporation increases atmospheric water vapor by generating cloud feedbacks |
| title_sort | reduced terrestrial evaporation increases atmospheric water vapor by generating cloud feedbacks |
| topic | evaporation water vapor land-atmosphere interactions cloud feedbacks |
| url | https://doi.org/10.1088/1748-9326/acdbe1 |
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