Temperature-Dependence of the Clear-Sky Feedback in Radiative-Convective Equilibrium

Link:
Autor/in:
Erscheinungsjahr:
2021
Medientyp:
Text
Schlagworte:
  • atmospheric science
  • climate feedback
  • climate sensitivity
  • radiative transfer
  • radiative-convective equilibrium
  • state-dependence
  • Atmospheric humidity
  • Atmospheric temperature
  • Carbon dioxide
  • Climate models
  • Radiative transfer
  • Surface properties
  • Temperature distribution
  • Water absorption
  • Atmospheric science
  • Clear sky
  • Climate feedbacks
  • Climate sensitivity
  • One-dimensional
  • Radiative forcings
  • Radiative-convective equilibrium
  • State dependence
  • Surface temperatures
  • Temperature dependence
  • Atmospheric radiation
  • air temperature
  • atmospheric convection
  • boundary condition
  • clear sky
  • radiative forcing
  • relative humidity
Beschreibung:
  • We quantify the temperature-dependence of the clear-sky climate sensitivity in a one-dimensional radiative-convective equilibrium model. The atmosphere is adjusted to fixed surface temperatures between 280 and 330 K while preserving other boundary conditions in particular the relative humidity and the CO2 concentration. We show that an out-of-bounds usage of the radiation scheme rapid radiative transfer model for GCMs (RRTMG) can lead to an erroneous decrease of the feedback parameter and an associated “bump” in climate sensitivity as found in other modeling studies. Using a line-by-line radiative transfer model, we find no evidence for a strengthening of the longwave radiative feedback for surface temperatures between 305 and 320 K. However, the line-by-line simulations also show a slight decrease in climate sensitivity when surface temperatures exceed 310 K. This decrease is caused by water-vapor masking the radiative forcing at the flanks of the CO2 absorption band, which reduces the total radiative forcing by about 18%. © 2021. The Authors.
Lizenz:
  • info:eu-repo/semantics/openAccess
Quellsystem:
Forschungsinformationssystem der UHH
Interne Metadaten
Quelldatensatz
oai:www.edit.fis.uni-hamburg.de:publications/80357613-49fa-4a56-8a21-544c23d62514