Engineering topics

Merritt, D. C.

Publications and source records attributed to Merritt, D. C..

3 records

NASA NTRS1973

Aerosol physical properties from satellite horizon inversion

The feasibility is investigated of determining the physical properties of aerosols globally in the altitude region of 10 to 100 km from a satellite horizon scanning experiment. The investigation utilizes a horizon inversion technique previously developed and extended. Aerosol physical properties such as number density, size distribution, and the real and imaginary components of the index of refraction are demonstrated to be invertible in the aerosol size ranges (0.01-0.1 microns), (0.1-1.0 microns), (1.0-10 microns). Extensions of previously developed radiative transfer models and recursive inversion algorithms are displayed.

Gray, C. R.↗

NASA NTRS1973

Stratospheric aerosol layer detection.

The earth's daytime horizon was scanned on several occasions between 1963 and 1968. The limb was observed at six wavelengths in the ultraviolet and visible spectrum with a narrow field of view instrument on the X-15 aircraft. The inversion of such horizon observations to yield atmospheric density and the concentrations of ozone and aerosol extinctions is discussed. The most significant features of the X-15 data are effects attributed to stratospheric aerosols. Observations of both the 20-km aerosol layer and a layer at approximately 50 km are inferred from the data. Both layers apparently possess considerable variability. It is pointed out that the existence of substantial aerosol concentrations above 30 km is an important limitation of the nadir technique of determining ozone concentrations in which the earth's radiance is observed at ultraviolet wavelengths from a satellite.

Cunnold, D. M.↗

NASA NTRS1973

Aerosols - A limitation on the determination of ozone from BUV observations.

Evidence is presented for the existence of an aerosol layer in the atmosphere at an altitude of 50 km. It is shown how such a layer can interfere with the determination of the vertical atmospheric ozone profile when satellite measurements of backscattered ultraviolet radiation are used.

Cunnold, D. M.↗