Anu Dudhia

Abstract:

Data from the Stratospheric and Mesospheric Sounder (SAMS) on the Nimbus 7 satellite, for the three years from January 1979-December 1981, are used to prepare a reference model for the long-lived trace gases methane (CH4) and nitrous oxide (N2O) in the stratosphere. The model is presented in tabular form on seventeen pressure surfaces from 20 to 0.1 mb, in 10° latitude bins from 50S to 70N, and for each month of the year. The means by which the data quality and interannual variability, and some of the more interesting globally and seasonally variable features of the data are discussed briefly. © 1987.

Abstract:

This paper describes the pressure-modulation technique, which is employed by the stratospheric and mesospheric sounder (SAMS) experiment on the satellite Nimbus 7, and by an advanced version (the improved stratospheric and mesospheric sounder or ISAMS) now under construction for the forthcoming Upper Atmosphere Research Satellite programme. SAMS measurements of methane and nitrous oxide for the three-year period from 1 January 1979 to 31 December 1981 are presented, and show the latitudinal and seasonal variability of the average concentration of these long-lived minor constituents. From the observed behaviour, some aspects of the circulation of the middle atmosphere are identified and their possible origins discussed. -from Authors