Abstract: A method is provided to reduce the surface temperature at high latitudes beneath mixed-phase low-level clouds. The clouds are seeded by ice crystals from dry ice pellets or from water droplets sprayed by effervescent nozzles or by injection of silver iodide. The ice crystals convert supercooled liquid water in the clouds into ice crystals by the Wegener-Bergeron-Findeisen process. Ice-only clouds are more transmissive to long wavelength radiation than mixed-phase clouds, thereby allowing more surface long wavelength radiation to escape into space or into higher, colder regions of the atmosphere.

Abstract: A system is provided to discharge heat from a reservoir of water inside an unventilated greenhouse. Heat is transferred from the greenhouse air to the reservoir during the day by a droplet system. During the cool hours of the night and morning, the same droplet system transfers reservoir heat back into the air within a restricted volume above the reservoir while the air is simultaneously circulated through an air-to-air heat exchanger outside the building.

Abstract: An unventilated greenhouse is cooled during the day by transferring most of the solar energy entering the greenhouse into one or more large reservoirs of water using a droplet dispensing system. Cool reservoir water is pumped from the reservoirs into the droplet dispensing system above the reservoirs. As the droplets fall back into the reservoirs they exchange heat and water vapor with the greenhouse air, gradually warming the reservoir water during the day. During the night and morning the reservoirs are cooled for the next day by enclosing the reservoirs and droplet dispensing system so that the air above the reservoirs is isolated from the air in the remainder of the greenhouse. With the droplets activated the air enclosed above the reservoirs is circulated through banks of tubes outside the greenhouse building that serve as heat exchangers. Heat is transferred from the warm droplets to the cool air above the reservoirs, cooling the reservoirs and saturating the air.