Thermosphere gas and the ionospheric plasma. The International Space Station orbits the Earth within the middle of the thermosphere, between . It is convenient to separate the atmospheric regions according to the two temperature minima at about 12 km altitude (the tropopause) and at about 85 km (the mesopause) (Figure 1). The thermosphere (or the upper atmosphere) is the height region above 85 km, while the region between the tropopause and the mesopause is the middle atmosphere (stratosphere and mesosphere) where absorption of solar UV radiation generates the temperature maximum near 45 km altitude and causes the ozone layer. The density
Lauriston S. Taylor Lauriston S. Taylor Lauriston S. Taylor (1 June 1902 – 26 November 2004) was an American physicist known for his work in the field of radiation protection and measurement. He established standards for X-ray radiation exposure for the first time in the 1920s, which eventually led to a group of government organizations that set the standards over the next 50 years. Taylor remained active in debates about radiation exposure into his 80s, often advocating the viewpoint that small doses of radiation were not important. He served as president of the Health Physics Society (HPS) from 1958 to 1959. He was