HALOE was designed to carefully monitor hydrogen fluoride and hydrogen chloride, byproducts of CFC destruction in the stratosphere. HALOE operates by observing the absorption of infrared radiation by these molecules against the rising and setting sun. When UARS was first launched, measurements by HALOE showed that CFC byproducts were still increasing in the stratosphere. But the newest HALOE measurements now show that CFC by-products are no longer increasing. UARS has shown that the stratosphere is starting to respond to the international ban on CFC manufacture.
Video slate image reads, "The Upper Atmosphere Research Satellite Graph Animations A graph showing the HALOE instrument results of CFC byproducts in the stratosphere, within an 8-year period of monitoring the atmostphere."