Sun-synchronous orbital dust ring to reduce climate change at the polar caps

Abstract

As a geoengineering strategy to attenuate the solar insolation and offset the impacts of global warming at the polar regions, this study proposes a Sun-pointing vertical Earth ring comprised of dust grains to shade mainly the Earth’s poles and to reduce climate change at the polar regions. A dust ring from 1.1 to 1.17 Earth radii passing above both poles of the Earth is designed, taking into account the effects of solar radiation pressure and the Earth’s $J_2$ oblateness perturbation. Perturbations including atmospheric drag, third-body gravitational forces and shaded regions are neglected. A family of circular polar orbits, with inclinations about $98^{\circ }$, is considered for the passive cloud of particles with radii less than 50 $\mu \hbox {m}$. We state that the coupled effect of solar radiation pressure and $J_2$ perturbation in the orbital dynamics of small particles is essential to ensure that the side of the dust ring will be pointing to the Sun. An analytical ring shadow model is used to evaluate its performance and to estimate the mass of the ring. The results of this study shows that the attenuation of solar isolation at the polar regions is about twice the attenuation computed in the rest of the regions of the Earth. Finally, an estimate of about $5.5 \times 10^{12}$ kg of material is computed as the total mass required to offset the impacts of climate change at the Earth’s poles.