Upper Atmosphere Research Satellite accuracy and spatial resolution, and hence to study the structure and dynamics of the region, (ii) To investigate the distribution and variability of water vapour in the middle atmosphere, to determine its role in the atmospheric general circulation, and its sources and sinks in the middle atmosphere, (iii) To measure the global distribution of oxides of nitrogen and hence to investigate their origins and their roles in catalytic cycles which control the amount of ozone in the stratospheric ozone layer. It also made extensive observations of volcanic aerosols and polar stratospheric clouds in the middle atmosphere. The instrument operated from
Layer by Layer Layer by Layer The Layer by Layer method is a method of solving the 3x3x3 Rubik's Cube. Many beginners' methods use this approach, but it also forms the basis of the CFOP speedcubing technique. The Layer by Layer Method was pioneered by David Singmaster in his 1980 book "Notes on Rubik's "Magic Cube"". The same idea was adopted by James G. Nourse in his "The Simple Solution to Rubik's Cube" which became the bestselling book of 1981, and similar approaches could be found in Don Taylor's "Mastering Rubik's Cube" and Cyril Östrop's "Solving the Cube" from the same era. It