Role of spatial and temporal variations in the computation of radiative forcing due to sulphate aerosols: A regional study

Abstract A high‐resolution regional model for sulphate aerosols is used to investigate the effects of spatial and temporal averaging of radiative forcing. Mie theory is used to calculate the aerosol optical properties. The strong hygroscopic growth with increasing relative humidity is taken into acc...

Full description

Bibliographic Details
Published in:Quarterly Journal of the Royal Meteorological Society
Main Authors: Myhre, Gunnar, Jonson, Jan E., Bartnicki, Jerzy, Stordal, Frode, Shine, Keith P.
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2002
Subjects:
Online Access:http://dx.doi.org/10.1256/0035900021643610
https://api.wiley.com/onlinelibrary/tdm/v1/articles/10.1256%2F0035900021643610
https://rmets.onlinelibrary.wiley.com/doi/pdf/10.1256/0035900021643610
Description
Summary:Abstract A high‐resolution regional model for sulphate aerosols is used to investigate the effects of spatial and temporal averaging of radiative forcing. Mie theory is used to calculate the aerosol optical properties. The strong hygroscopic growth with increasing relative humidity is taken into account. The results for the regional area selected in our study (Europe and much of the North Atlantic) show that earlier global studies may have underestimated the magnitude of the radiative forcing due to sulphate aerosols by up to 30–40% due to coarse spatial and/or temporal resolution, at least over certain regions. This underestimation in global models of the water uptake is important for all strongly scattering hygroscopic aerosols. Our results imply that representation of relative humidity at even higher spatial resolution than used in this study may be of importance. This could be incorporated in models using subgrid‐scale parametrizations of the relative humidity. Copyright © 2002 Royal Meteorological Society.