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Über dieses Buch

Forests and vegetation emit biogenic volatile organic compounds (BVOCs) into the atmosphere which, once oxidized, can partition into the particle phase, forming secondary organic aerosols (SOAs). This thesis reports on a unique and comprehensive analysis of the impact of BVOC emissions on atmospheric aerosols and climate. A state-of-the-art global aerosol microphysics model is used to make the first detailed assessment of the impact of BVOC emissions on aerosol microphysical properties, improving our understanding of the role of these emissions in affecting the Earth’s climate. The thesis also reports on the implications for the climate impact of forests. Accounting for the climate impacts of SOAs, taken together with the carbon cycle and surface albedo effects that have been studied in previous work, increases the total warming effect of global deforestation by roughly 20%.

Inhaltsverzeichnis

Frontmatter

Chapter 1. Introduction

Abstract
Vegetation emits biogenic volatile organic compounds (BVOCs) into the atmosphere which, once oxidised, may partition into the particle-phase forming secondary organic aerosol (SOA). In this thesis, the climatic impacts of biogenic SOA are quantified, using a detailed global aerosol microphysics model, and the sensitivity of these radiative effects to the representation of various atmospheric processes is examined.
Catherine E. Scott

Chapter 2. Model Description

Abstract
This chapter describes the global aerosol microphysics model (GLOMAP-mode) used in Chaps. 36. An offline radiative transfer model and land-surface model are introduced and described in Chaps. 4 and 6, respectively.
Catherine E. Scott

Chapter 3. The Impact of Biogenic SOA on Particle and Cloud Condensation Nuclei Concentration

Abstract
As described in Chap. 1, the presence of biogenic SOA affects the number and size of particles in the atmosphere. Organic oxidation products may condense onto existing particles and aid their growth to larger sizes (e.g., [30]), enhance particle solubility [27], and contribute to new particle formation (e.g., [25]).
Catherine E. Scott

Chapter 4. The Radiative Impact of Biogenic SOA

Abstract
Despite the ubiquity of organic material in the particle phase over much of the world (e.g., [12, 30]), its impact on the climate is not well understood [17].
Catherine E. Scott

Chapter 5. The Impact of Volatility Treatment on the Radiative Effect of Biogenic SOA

Abstract
The multi-step oxidation of BVOCs yields products with lower volatility, which allows their partitioning to the particle phase and the formation of SOA. The manner in which this SOA adds to the existing aerosol distribution will influence its impact on the number, size and composition of particles in the atmosphere; in particular, the number of particles that are able to act as CCN.
Catherine E. Scott

Chapter 6. The Radiative Effects of Deforestation

Abstract
In this chapter, a land-surface model is used to explore the impact of several idealised deforestation scenarios on BVOC emission levels. The subsequent change in aerosol properties is then calculated using GLOMAP-mode, and the first AIE is evaluated using the Edwards-Slingo (ES) radiative transfer model.
Catherine E. Scott

Chapter 7. Conclusions, Implications and Further Work

Abstract
This thesis has explored the role of biogenic secondary organic aerosol (SOA) in the present-day, and pre-industrial, atmosphere. Chapters 35 examined the behaviour of SOA, and the radiative impact of its presence, whilst Chap. 6 focussed on the climatic significance of forest-derived SOA.
Catherine E. Scott
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