AUTHOREA
Log in Sign Up Browse Preprints
LOG IN SIGN UP
Keith P Shine
Keith P Shine
Professor
Joined Sep 2022 · Reading
Member of: University of Reading

Public Documents 1
Methane's Solar Radiative Forcing
Rachael Emily Byrom
Keith P Shine

Rachael Emily Byrom

and 1 more

February 23, 2022
Methane (CH4) has significant absorption bands at wavelengths of 1.7, 2.3, 3.3 and 7.6 µm which absorb incoming solar ‘shortwave’ (SW) radiation and cause a radiative forcing (RF) of climate. This letter presents a comprehensive quantification of CH4 SW RF using a narrow-band radiative transfer model to calculate spatially and monthly resolved estimates of the direct CH4 SW effect and its impact on longwave (LW) RF via stratospheric temperature change. This significantly extends previous assessments. Calculations include satellite measurements of CH4 distribution, spectrally-varying surface albedo and absorption of solar mid-infrared radiation by methane’s 7.6 µm band. These factors substantially influence the SW effect; all-sky CH4 SW tropopause instantaneous RF is significantly smaller than previous estimates at 0.002 W m-2 (±25%). In total, the CH4 SW effect enhances CH4 LW-only RF by 7% from 0.574 W m-2 to 0.613 W m-2 for a 750-1800 ppb perturbation.
Authorea
  • Home
  • About
  • Product
  • Preprints
  • Pricing
  • Blog
  • Twitter
  • Help
  • Terms of Use
  • Privacy Policy