Solar Radiative Transfer and Global Climate Modelling
No Thumbnail Available
Date
2021-12-10
Authors
Journal Title
Journal ISSN
Volume Title
Publisher
Addis Ababa University
Abstract
In this project we have studied Solar radiative transfer and global climate modelling.
We consider a parallel beam of electromagnetic radiation incident on a slab of thickness
ds. As this radiation passes through the atmosphere it interacts and is being
absorbed by the atmospheric gases, the continental lands and oceans and large water
bodies. In this project work, we describe the optical depth or optical thickness,
the intensity or spectral radiance, absorption, reflection, scattering of particles by
applying Beer’s law or Lambert’s law. The intensity of the incident radiation decreases
exponentially as a function of solar zenith angle, fraction of absorbers in the
atmosphere, the scattering coefficient, scale height, altitude and density of the atmosphere.
The absorption and emission of radiation by the atmospheric gases causes
climate changes. More over the major climate system components (atmosphere, land
surface, ocean, and sea ice), and their interactions are described using the basic equations
that govern the atmosphere. These can be formulated as a set of seven equations
with seven unknowns such as the three velocity components (u, v, w), the pressure
p, the temperature T, the specific humidity q and the density _. These equations,
solved numerically by computers, are used to produce our weather forecasts. While
there are details about these equations which are uncertain (for example, how we
parameterize processes smaller than the grid size of the models), the equations for
the most part are accepted as fact. The radiation that passes through the atmosphere
is absorbed by the lands and ocean surfaces and is re-emitted as infrared back into
the atmosphere so as to heat it and this causes climatic changes.
Description
Keywords
Solar, Radiative Transfer, Global, Climate Modelling