A Climate Index Derived from Satellite Measured Spectral Infrared Radiation.
Abstract
This thesis introduces a climate index based on radiative transfer theory and derived from the spectral radiances typically used to retrieve temperature profiles. It is assumed that clouds and climate are closely related and a change in one will result in a change in the other. Because the index developed in this paper is primarily a function of the cloud distribution and also dependent upon temperature and moisture distributions, it may be used as a climate index. The advantage is that the index is more accurately retrieved from satellite data than cloudiness per se. This index, hereafter referred to as the VIRES index (for Vertical Infrared Radiative Emitting Structure), is based upon the shape and relative magnitude of the broadband weighting function of the infrared radiative transfer equation. The broadband weighting curves (VIRES curves) are retrieved from simulated satellite infrared sounder data (spectral radiances). the VIRES index is a useful means of classifying the VIRES curves. This thesis describes the retrieval procedure and investigates error sensitivities of this method. Advantages of the approach include; day and night capability, no need to know cloud radiative properties, retrieval ability when cloud fraction or cloud emittance is less than 1.0, retrieved information below sensor resolution, minimum influence on the index from low tropospheric retrieval errors, and the ability to statistically discriminate between VIRES curves retrieved from different scenes. Operational VIRES index retrieval strategies and a number of specific applications are also proposed. (Author)
Document Details
- Document Type
- Technical Report
- Publication Date
- Apr 01, 1981
- Accession Number
- ADA106733
Entities
People
- Michael David Abel
Organizations
- Air Force Institute of Technology