Solar Radiative Flux Calculations from Standard Surface Meteorological Observations
Abstract
The flux of solar radiation through a model atmosphere composed of n layers and a ground surface is represented by a system of 2n+2 linear equations. The system is solved in closed form explicitly for the radiation reaching the ground and the radiation reflected back to space, as a function of the vertically incident radiation and specified reflection and transmission coefficients for each of the n layers and the ground. These coefficients vary in time and space as functions of a wide variety of parameters. However, they are primarily dependent upon cloud amount and cloud thickness or type. In spite of some past measurement programs, the cloud coefficients are not very well known. Making use of direct observations of the total solar radiation reaching the ground and simultaneous cloud observations, the model offers the opportunity for determining the mean transmission and reflection characteristics of any individual cloud type. The model is flexible with regard to the number of layers chosen to represent the atmosphere and with regard to the sophistication of the physics to be incorporated. With the use of the SOLMET data tapes, a first approximation calculation is described for the reflection, transmission, and absorption coefficients for a three-layer atmosphere containing high, middle, and low cloud types. Once these coefficients have been determined, the flux of solar radiation is calculated from routine surface meteorological observations. A test of the model on independent data shows no loss in accuracy as compared with that obtained with the developmental data sample.
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 1982
- Accession Number
- ADA118775
Entities
People
- Ralph Shapiro