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A Radiation Coursebased upon Numerical Methods

Björn-Martin Sinnhuber & Stefan Bühler

University of Bremen

Summer semester 2005

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Björn-Martin Sinnhuberbms@iup.physik.uni-bremen.deNW1 - W3190

Stefan Bühlersbuehler@uni-bremen.deNW1 - N3371

Contact

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Aim and Scope of the Course

The aim of the course is to:

• understand the processes and

• learn how to calculate the transfer of radiation in the atmosphere.

Main applications of atmospheric radiative transfer are:

• Impact of radiation on climate

• Atmospheric remote sensing

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Organisation of the Course

The course will consist of:• About 7 introductory lectures• About 7 practical exercises at the computers

For the Diploma students:

Kriterium um einen Schein über„erfolgreiche Teilnahme“ zu bekommen:

• Aktive Teilnahme an den praktischen Übungen(höchstens zweimal fehlen)

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Outline of the Next Few Weeks

1. Introduction

2. Radiative Transfer, Part 1

3. Spectroscopy

4. Radiative Transfer, Part 2

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Introduction

• What are numerical methods?

• Why use numerical methods?

• How does this look like in practise?

7SZA = 87.0°

8SZA = 89.5°

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1.0 Blackbody Radiation

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1.1 Planetary Equilibrium Temperature

• Heating by absorption of (shortwave) solar radiation

• Cooling by emission of (longwave) terrestrial radiation

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1.1 Planetary Equilibrium Temperature

• Incoming solar radiation needs to be balanced by outgoing terrestrial radiation.

• Solar constant at top of Earth‘s atmosphere:1376 W m-2

• Outgoing longwave radiation:42

Earth4 Tr

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1.2 A Simple Model of the Greenhouse Effect

Assumptions:

• Single layer atmosphere with constant temperature

• Atmosphere is transparent for shortwave solar radiation

• Atmosphere is a blackbody for longwave radiation

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1.3 Outgoing Longwave Radiation