Description: New York City has a large steam system for the purposes of heating and cooling high rise buildings and businesses. Steam vents in New York are often the result of outside water coming into contact with pipes from the steam system network; and this is more common in the winter with snow and rain.
Features / Attributes: The steam vents are seen in the UO images as a continuous small plume of grey-white cloud streaming from the tops of buildings, shown in Figure \ref{643439}. As in Figure \ref{416997}, there may be over 10 or more steam vents in a single image.
Source of contamination: Detection of steam vents is dependent on conditions observed over particular time periods. Variables such as wind, temperature, lighting, rain and snow can all impact both the occurrence of steam plumes, along with ability to detect these plumes in the UO images. Whilst rain and snow can make the occurrence of steam vent more common when they come into contact with the hot pipes; they also make their visibility more difficult in the images we have available.
Issues / challenges: A large number of these steam vents appear, particularly on cold winter days. The small and continuous nature of these plumes means complete tagging is time consuming. There may also be days where there is at least one of these steam vents in every single image for the whole day.
Clouds