Climate Dynamics

, Volume 22, Issue 5, pp 539–553

Solar irradiance forcing of centennial climate variability during the Holocene

  • S. L. Weber
  • T. J. Crowley
  • G. van der Schrier
Article

DOI: 10.1007/s00382-004-0396-y

Cite this article as:
Weber, S.L., Crowley, T.J. & van der Schrier, G. Climate Dynamics (2004) 22: 539. doi:10.1007/s00382-004-0396-y

Abstract

Centennial climate variability during the Holocene has been simulated in two 10,000 year experiments using the intermediate-complexity ECBilt model. ECBilt contains a dynamic atmosphere, a global 3-D ocean model and a thermodynamic sea-ice model. One experiment uses orbital forcing and solar irradiance forcing, which is based on the Stuiver et al. residual 14C record spliced into the Lean et al. reconstruction. The other experiment uses orbital forcing alone. A glacier model is coupled off-line to the climate model. A time scale analysis shows that the response in atmospheric parameters to the irradiance forcing can be characterised as the direct response of a system with a large thermal inertia. This is evident in parameters like surface air temperature, monsoon precipitation and glacier length, which show a stronger response for longer time scales. The oceanic response, on the other hand, is strongly modified by internal feedback processes. The solar irradiance forcing excites a (damped) mode of the thermohaline circulation (THC) in the North Atlantic Ocean, similar to the loop-oscillator modes associated with random-noise freshwater forcing. This results in a significant peak (at time scales 200–250 year) in the THC spectrum which is absent in the reference run. The THC response diminishes the sea surface temperature response at high latitudes, while it gives rise to a signal in the sea surface salinity. A comparison of the model results with observations shows a number of encouraging similarities.

Copyright information

© Springer-Verlag  2004

Authors and Affiliations

  • S. L. Weber
    • 1
  • T. J. Crowley
    • 2
  • G. van der Schrier
    • 1
  1. 1.Royal Netherlands Meteorological Institute (KNMI)3730 AE De BiltThe Netherlands
  2. 2.Duke UniversityDurhamUSA

Personalised recommendations