The Microwave Limb Sounder (MLS) is an instrument on board the Upper Atmosphere Research Satellite (UARS) which measured global ClO, O3, H2O, temperature and SO2. Data are version 4 and public (gridded in time or latitude along the satellite track) between 80S - 80N, approximately 10-60 km in the vertical, from October 1991 to June 1997. This directory tree now contains Version 4 MLS data files, in subdirectories for constituent and year, for FTP to remote machines. The data is held in IEEE binary files as supplied by the Goddard DAAC. Remember to switch to BINARY mode when transferring these files by FTP. New software to read the data files is also available.

The Microwave Limb Sounder (MLS) was a satellite-borne instrument(on UARS satellite) making limb sounding measurements of atmospheric composition at microwave frequencies. The water vapour data was collected by the 183 GHz radiometer which was developed in the UK by Heriot-Watt University and the Rutherford Appleton Laboratory. This data set is a prototype version of the MLS water vapour data developed by Dr Hugh Pumphrey in the Meteorology Department at the University of Edinburgh. This work was funded by the NERC. Data generally cover wider altitude range than "official" MLS version 4 retrievals and are available at a higher vertical resolution. The data coverage extends from 80°S to 80°N, but at any one time this is restricted to 34°S to 80°N or 34°N to 80°S. In the vertical, measurements are usually available between 68hPa and 0.031hPa and may extend down 100hPa and up to 0.0031hPa. The data set covers the time period from UARS day 8 (19th September 1991) to UARS day 580 (13th April 1993). IMPORTANT NOTE: V0006 is EXACTLY THE SAME DATA as V0104. Please refer to the "MLS-H2O-versions-explained" documentation under "Docs" for details.