Abstract
Localized extreme heat events in high-density urban environments and sensitive agricultural microclimates present urgent public health and economic challenges. Traditional geoengineering methods operate on global or regional scales, lacking the spatial and temporal precision required for targeted microclimate interventions. This paper presents the novel concept of Atmospheric Micro-Sails: aerosolized, highly anisotropic graphene oxide (GO) flakes engineered to temporarily hover in the planetary boundary layer and modulate localized solar radiative forcing. By leveraging the extreme aspect ratio and photothermal properties of single- and few-layer GO flakes, these microscopic membranes can be dispersed via lightweight unmanned aerial vehicles (UAVs) to create transient, optically active shading canopies. Radiative transfer calculations and atmospheric dispersion models indicate that a low-mass concentration canopy of functionalized GO flakes can reflect up to 18% of incident solar shortwave radiation within a 100-meter boundary column, inducing a localized surface cooling effect of 1.8 °C to 3.2 °C. We further outline mechanisms for controlling particle orientation using ambient fluid dynamics and photophoresis, as well as an intrinsic bio-degradation pathway driven by solar UV oxidation and atmospheric humidity. This framework provides a scalable, rapidly deployable paradigm for emergency microclimate thermal management.
