文档介绍：Is SBDART on Target?: An Analysis of the Radiative Transfer Model to Observations
Daniel P. Tyndall
Department of Marine and Environmental Systems
Florida Institute of Technology
20 July 2005
Overview
What is radiative transfer?
What is SBDART?
How did we evaluate SBDART?
How well does SBDART do?
What can we conclude?
What is radiative transfer?
Transfer of radiant (or ic) energy through a medium
The four types of basic radiative transfer processes:
Transmission
Absorption
Reflection
Scattering
All radiative transfer processes are based on these four processes
Solar radiation strikes cloud droplet
Reflection
Scattering
Absorption
Transmission as infrared radiation
Components of Radiative Transfer
SBDART
Why do we care about radiative transfer?
Radiative transfer drives the puting all interactions for the entire thickness of atmosphere is impossible
Santa Barbara DISORT Atmospheric Radiative Transfer model
Written by P. hiazzi et al. at the Institute putational Earth Systems Science, University of California, Santa Barbara
FORTRAN code piled in 1998
Code continuously improved
SBDART Input Parameters
75 input parameters
Atmospheric profile sounding input
Changes in temperature, pressure, water vapor and ozone concentrations with height
Cloud layer input
Particulate pollution input
Aerosol profile input
Ground albedo parameters
Geographical location, date, and time input
SBDART Output
Verification of the Model
Goal: Verification of SBDART
Clear sky
Cloudy sky (well developed cumulus)
Methods of verification
Measuring total downward flux using a radiometer
Measuring the effective temperature of an object in a specific wavelength
Cloud and Sky Temperature Measurements
Heitronics IIP infrared pyrometer (supported by 2005 ACITC faculty grant)
Sensitive to radiation between and micrometers
Pyrometer pointed to clouds and clear sky
Temperatures recorded every second
Source: Heitronics
Pyrometer Calibration