NASA and NOAA scientists work together to study the ozone layer, monitoring the hole over Antarctica as it fluctuates with the seasons. Scientists use computer models to simulate and help understand Earth’s physical, chemical, and weather processes, including the complex interactions between UV light, temperature and upper atmospheric chemical constituents such as ozone. Atmospheric models need accurate UV measurements over a wide range of wavelengths to correctly simulate the effects of changing UV on the atmosphere. Understanding these natural variations is vital when studying the effects of human influence on Earth’s atmosphere, including ozone loss from human-made ozone depleting chemicals and climate change from greenhouse gases.
Scientists have studied the links between solar activity and climate and say the small variations in the Sun's irradiance over the last century – estimated to be about the same magnitude of a typical solar cycle variation – cannot explain the intensity and speed of warming trends seen on Earth over this time.