Evaluation of UV and Visible radiation influence on dynamics and chemistry of the atmosphere with CCM SOCOL.
Abstract
To separate the influence of UV and visible radiation on the global atmosphere and to investigate the effects of solar variability during 11-year solar cycle we have carried out four 20-year long steady state simulations with observed spectral solar fluxes: (1) Solar minimum; (2) Solar maximum; (3) Solar maximum for UV radiation only; and (4) Solar maximum for Visible radiation only. As a modeling tool we have used the chemistry-climate model SOCOL. The obtained results for experiment runs have been compared with the solar minimum case. The simulated ozone response is positively correlated with solar irradiance in the tropical stratosphere and negatively correlated in the mesosphere, which is in an agreement with theoretical expectation. For the experiment 2 the model suggests a weak acceleration of the polar night jets resulting in a dipole structure in the temperature response over the high latitudes of both hemispheres. These dynamical changes lead to an alternation of the tropospheric circulation, which in turn, influences the surface air temperature resulting in a statistically significant warming of 1 K in the annual mean surface air temperature over North America and Siberia. The pattern in surface temperature changes resembles the signal of positive AO phases, which implies downward propagation of the solar signal via intensification of the polar night jets. For the simulation where only the visible radiation was enhanced we have also obtained a stratospheric response. This response appears only over the high latitudes and is caused by upward propagating dynamical perturbations. Our analysis of the surface air temperature response shows that the visible and UV radiation dominates in different geographical regions providing a substantial combined effect.
- Publication:
-
35th COSPAR Scientific Assembly
- Pub Date:
- 2004
- Bibcode:
- 2004cosp...35..718E