6 January 2018 | ZEROGeoengineering.com | “Abstract: In spite of its short period of existence, a great deal was accomplished during the Hurricane-Aerosol-Microphysics Program (HAMP). The research supports the original hypotheses that seeding with high concentrations of pollution sized aerosols in the outer rainbands of hurricanes can lead to significant weakening of a storm. This was demonstrated by simulations of both idealized storms and actual case studies and with advanced bin-emulating microphysics and spectral bin microphysics. It was also evident in satellite analysis of actual storms. There still remains much to unravel about the intricacies of aerosol interactions with tropical cyclones. First we need to understand the causal mechanisms for storm weakening at very high concentrations of CCN as storm rainfall and cold-pools are substantially reduced. Second, the aerosol influence has to be put in perspective of other factors influencing TC intensity including SST, wind shear, and the moisture content of the lower troposphere. Research under HAMP has also spun-off a strategy for parameterizing sea-spray generation in tropical cyclones, a process that is not only important to aerosol generation by the storm but also to the bulk thermodyamics of the storm system.”