Measuring and Modeling Twilight's Purple Light
Abstract
During many clear twilights, much of the solar sky is dominated by pastel purples. This purple light's red component has long been ascribed to transmission through and scattering by stratospheric dust and other aerosols. Clearly the vivid purples of post-volcanic twilights are related to increased stratospheric aerosol loading. Yet our time-series measurements of purple-light spectra, combined with radiative transfer modeling and satellite soundings, indicate that background stratospheric aerosols by themselves do not redden sunlight enough to cause the purple light's reds. Furthermore, scattering and extinction in both the troposphere and the stratosphere are needed to explain most purple lights.
Document Details
- Document Type
- Technical Report
- Publication Date
- Jan 20, 2003
- Accession Number
- ADA526105
Entities
People
- Javier Hernandez-andres
- Raymond L. Lee Jr.