Effectiveness of Using Calcite as an Aerosol to Remediate the Urban Heat Island

Abstract

The purpose of this study was to develop analytical tools to find the effectiveness of using aerosols to mitigate the urban heat island effect. Specifically, mineral calcite would be placed in a plume over cities to reflect solar radiation. A secondary goal is to compare the relative efficiencies of releasing the particles from tower heights or from aircraft heights. The aim is to reduce daytime temperatures at the surface. The method was to use a one-dimensional model or a single-column model to predict temperatures and weather conditions at all altitudes over a period of one month. The SCAM6 code was altered to incorporate the new capabilities for introduced aerosols. The pre-existing code considered only windblown dust, so the code was enhanced to handle aerosols that were intentionally produced. The key findings are that calcite as an aerosol does affect the weather. The models predict that in humid regions, calcite is less effective because it interacts with water clouds. In arid regions, calcite should be more effective since there are fewer water clouds to interact with. The result is that it is possible to predict reductions in air temperatures if solar insolation can be reduced. It was shown that temperatures can be reduced by 4 °C in arid regions. The conclusions are that calcite aerosol should be effective at mitigating urban heat islands. However, further work is needed related to economic, health, and ecological concerns.