Antarctic Specific Features of the Greenhouse Effect

101 Pages·2014·28.48 MB·English

by  Holger Schmithüsen

Antarctic Specific Features
of the Greenhouse Effect:
A Radiative Analysis Using
Measurements and Models
Holger Schmithüsen

Dissertation
zur Erlangung des Grades
Doktor der Naturwissenschaften (Dr. rer. nat.)
durch den
Fachbereich 1 (Physik/ Elektrotechnik)
Institut für Umweltphysik
Universität Bremen
gemäß der Promotionsordnung vom 25. April 2012.
1. Gutachter: Prof. Dr. Peter Lemke
2. Gutachter: Prof. Dr. Justus Notholt
Die Dissertation wurde angefertigt am
Alfred-Wegener-Institut
Helmholtz-Zentrum
für Polar- und Meeresforschung (AWI)
in Betreuung durch die Gutachter und
Dr. Gert König-Langlo
Bremerhaven, den 10. Dezember 2014

Hiermit erkläre ich, dass ich
1. die Arbeit ohne unerlaubte fremde Hilfe angefertigt habe,
2. keine anderen als die von mir angegebenen Quellen und
Hilfsmittel benutzt habe und
3. die den benutzten Werken wörtlich oder inhaltlich
entnommenen Stellen als solche kenntlich gemacht habe.
Bremerhaven, den 10. Dezember 2014

Abstract
CO is the strongest anthropogenic forcing agent for climate change since
2
pre-industrial times. Like other greenhouse gases, CO absorbs terrestrial
2
surface radiation and causes emission from the atmosphere to space. As
the surface is generally warmer than the atmosphere, the total long-wave
emission to space is commonly less than the surface emission. However,
this does not hold true for the high elevated areas of central Antarctica. For
this region, it is shown that the greenhouse effect of CO is around zero or
2
even negative. Moreover, for central Antarctica an increase in CO
2
concentration leads to an increased long-wave energy loss to space, which
cools the earth-atmosphere system. These unique findings for central
Antarctica are in contrast to the well known general warming effect of
increasing CO . The work contributes to explain the non-warming of central
2
Antarctica since 1957.
Contents
Contents
Abstract...........................................................................................................7
Chapter 1: Scientific background...............................................................11
1.1 The structure of the Earth's atmosphere..............................................................11
1.2 The role of radiation in climate..............................................................................13
1.3 Anthropogenic impact on climate.........................................................................16
1.4 Topography of Antarctica.......................................................................................18
1.5 Antarctic temperature records...............................................................................20
1.5.1 Station records.............................................................................................................20
1.5.2 Spatially interpolated analyses.....................................................................................24
1.6 Current explanations of the non-warming of central Antarctica........................29
Chapter 2: A theory why central Antarctica is currently not warming....31
2.1 Objectives and content of the thesis....................................................................31
2.2 Top of atmosphere measurements........................................................................34
2.2.1 Quantification of greenhouse effect from satellite.........................................................34
2.2.2 Sensor used: Tropospheric Emission Spectrometer (TES)...........................................37
2.2.3 Results.........................................................................................................................38
2.2.4 Discussion....................................................................................................................45
2.3 Two layer model considerations............................................................................48
2.4 Radiative transfer calculations for central Antarctic conditions.......................50
2.4.1 Radiative transfer model (ALFIP).................................................................................50
2.4.2 Estimation of surface emission from BSRN measurements.........................................51
2.4.3 Construction of temperature profiles.............................................................................52
2.4.4 Construction of trace gas profiles.................................................................................57
2.4.5 Results: Top of atmosphere calculations......................................................................61
2.4.6 Results: Surface calculations.......................................................................................66
2.4.7 Discussion....................................................................................................................70
2.5 General circulation model analysis.......................................................................71
2.5.1 ECMWF experiment with quadrupled CO ....................................................................71
2
2.5.2 Climate model intercomparison (CMIP5)......................................................................76
2.5.3 Discussion....................................................................................................................81
2.6 Comparison of measurements and models.........................................................82
8
Contents
Chapter 3: Conclusion and outlook...........................................................85
3.1 A thought experiment on negative greenhouse effect........................................85
3.2 Greenhouse effect of CO over Antarctica...........................................................86
2
3.3 Instantaneous radiative forcing of CO over Antarctica.....................................87
2
3.4 Effect of CO on LWD under strong inversion conditions..................................88
2
3.5 Outlook.....................................................................................................................89
Bibliography.................................................................................................90
List of figures...............................................................................................94
List of tables.................................................................................................95
Acronyms......................................................................................................96
Mathematical symbols.................................................................................98
Acknowledgements...................................................................................101
9