Climate change and the need for mitigation

For more info about our services contact : help@bestpfe.com

Table of contents

1 Introduction 
1.1 Climate change and the need for mitigation
1.2 Climate engineering
1.2.1 Overview of proposed climate engineering techniques
1.2.2 Stratospheric aerosol injection
1.3 Atmospheric aerosols
1.3.1 Aerosol properties
1.3.2 Tropospheric aerosols
1.3.3 Stratospheric aerosols
1.3.4 Numerical modelling of aerosols
1.4 Outline of the thesis
2 The physics of stratospheric aerosol injection 
2.1 The aerosol distribution and its properties
2.2 Competing radiative effects
2.3 Efficacy and scalability
2.4 Short term impact on the atmosphere
2.5 Climate impact
2.6 Aerosol reaching the Earth’s surface
2.7 Tailored climate engineering techniques
2.8 Weaknesses of previous studies
2.9 Research questions addressed in this thesis
3 Description of the LMDZ-S3A atmosphere-aerosol model 
3.1 Overview of previous modelling efforts
3.2 The host atmospheric model LMDZ
3.2.1 Model physics and resolution
3.2.2 Tropopause recognition
3.2.3 Quasi-biennial oscillation in the stratosphere
3.2.4 Nudging to meteorological reanalysis
3.3 The sectional stratospheric sulphate aerosol module S3A
3.3.1 Prognostic variables
3.3.2 Semi-prognostic sulphur chemistry
3.3.3 Nucleation
3.3.4 Condensation and evaporation of sulphuric acid
3.3.5 Competition between nucleation and condensation
3.3.6 Coagulation
3.3.7 Aerosol chemical composition and density
3.3.8 Sedimentation
3.3.9 Aerosol optical properties
3.3.10 Model code availability
3.4 Conclusions on the model
4 Evaluation of the LMDZ-S3A model 
4.1 Validation of aerosol optics and radiative transfer
4.2 Non-volcanic background aerosol
4.3 Mount Pinatubo 1991 eruption
4.3.1 Aerosol distribution and size
4.3.2 Stratospheric temperature anomaly
4.4 Sensitivity studies under Pinatubo conditions
4.4.1 Sensitivity to van der Waals coagulation enhancement factor
4.4.2 Sensitivity to the sulphur dioxide chemical lifetime
4.5 Conclusions on the model evaluation
5 Studying stratospheric aerosol injection with LMDZ-S3A 
5.1 Simulation setup
5.2 Results from the reference experiment
5.3 Sensitivity to the injected sulphur dioxide mass
5.4 Comparison with results from Niemeier and Timmreck [2015]
5.5 Sensitivity to injection height
5.6 Sensitivity to spatio-temporal injection pattern
5.7 Effect of radiatively interactive aerosol
5.8 Impact on the quasi-biennial oscillation
5.9 Rapid adjustments and effective radiative forcing
5.10 Impact of aerosol optical properties on the results
5.11 Sulphate impact at the Earth’s surface
5.12 Conclusions on the stratospheric aerosol injection simulation results
6 Combining stratospheric aerosol injection (SAI) and marine cloud brightening (MCB) 
6.1 Simulation setup
6.2 Aerosol direct vs. indirect effect in the MCB experiment
6.3 Rapid adjustments and effective radiative forcing of MCB
6.4 Spatial differences between instantaneous and effective radiative forcing
6.5 Additivity and complementarity between SAI and tropical MCB
6.6 Conclusions on simulations of SAI and MCB
7 Conclusions 
7.1 Summary
7.2 Perspectives
Acknowledgements
List of acronyms
Publications
Bibliography