Stratospheric water vapor: an important climate feedback

The role of stratospheric water vapor (SWV) changes, in response to increasing , as a feedback component of quantitative significance for climate sensitivity has remained controversial. Here, we calculate the SWV climate feedback under abrupt quadrupling in the CMIP5 ensemble of models. All models r...

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Detalles Bibliográficos
Autores: Banerjee, Antara, Chiodo, Gabriel, Previdi, Michael, Ponater, Michael, Conley, Andrew J., Polvani, Lorenzo M.
Tipo de recurso: artículo
Estado:Versión aceptada para publicación
Fecha de publicación:2019
País:España
Institución:Consejo Superior de Investigaciones Científicas (CSIC)
Repositorio:DIGITAL.CSIC. Repositorio Institucional del CSIC
OAI Identifier:oai:digital.csic.es:10261/415315
Acceso en línea:http://hdl.handle.net/10261/415315
https://api.elsevier.com/content/abstract/scopus_id/85068825943
Access Level:acceso abierto
Palabra clave:Climate change
Climate feedback
CMIP5 models
Partial radiative perturbation
Radiative kernel
Stratospheric water vapor
Descripción
Sumario:The role of stratospheric water vapor (SWV) changes, in response to increasing , as a feedback component of quantitative significance for climate sensitivity has remained controversial. Here, we calculate the SWV climate feedback under abrupt quadrupling in the CMIP5 ensemble of models. All models robustly show a moistening of the stratosphere, causing a global mean net stratosphere adjusted radiative perturbation of at the reference tropopause. The stratospheric temperature adjustment is a crucial component of this radiative perturbation. The associated climate feedback is , with a considerable inter-model range of 0.12–0.28 . Taking into account the rise in tropopause height under slightly reduces the feedback to , with a range of 0.10– . The SWV radiative perturbation peaks in the midlatitudes and not the tropics: this is due primarily to increases in SWV in the extratropical lowermost stratosphere, which cause the majority (over three quarters) of the global mean feedback. Based on these results, we suggest an increased focus on understanding drivers of water vapor trends in the extratropical lowermost stratosphere. We conclude that the SWV feedback is important, being on the same order of magnitude as the global mean surface albedo and cloud feedbacks in the multi-model mean.