Sökning: "Aerosol climate effects"

Visar resultat 16 - 20 av 39 avhandlingar innehållade orden Aerosol climate effects.

1. 16. Modelling the effects of organic aerosol phase partitioning processes on cloud formation

   Författare :Samuel Joseph Lowe; Ilona Riipinen; Daniel Partridge; Harri Kokkola; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Cloud droplet activation; organic aerosol; cloud parcel modelling; Köhler theory; Sensitivity and Uncertainty analysis; Applied Environmental Science; tillämpad miljövetenskap;

   Sammanfattning : Atmospheric aerosols particles may act as cloud condensation nuclei (CCN) that provide sites for condensation of water vapour for the formation of cloud droplets, called cloud droplet activation. Whether aerosol particles are CCN is determined by their size, composition and the ambient humidity. LÄS MER

3. 17. A large-eddy simulation perspective on Arctic airmass transformation and low-level cloud evolution

   Författare :Antonios Dimitrelos; Annica Ekman; Caballero Rodrigo; Rune Grand Graversen; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arctic; mixed phase clouds; sea ice; Arctic amplification; atmospheric energy transport; CCN; Atmospheric Sciences and Oceanography; atmosfärvetenskap och oceanografi;

   Sammanfattning : The Arctic is currently warming faster than other regions of the Earth. Many processes and feedbacks contribute to the enhanced warming. Among these are the radiative effects of clouds. LÄS MER

4. 18. Mechanisms for the Influence from Ice Nucleus Aerosols on Clouds and their Indirect Effects: Cloud Modelling

   Författare :Deepak Waman; MERGE: ModElling the Regional and Global Earth system; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; clouds; Radiation; Ice Nuclei; Primary Biological Aerosol Particles; Ice particles; Secondary ice; primary ice; Aerosol particles; thunderstorm;

   Sammanfattning : The role of multiple groups of primary biological aerosol particles (PBAPs) as ice nucleating particles (INPs), and of ice formation processes such as time-dependent freezing of various INPs, and various secondary ice production(SIP) mechanisms in overall ice concentration has been evaluated in a range of cloud systems by simulating them numerically with the state-of-the-art ‘Aerosol-Cloud’ (AC) model in a 3D mesoscale domain. Also, the mechanismsof aerosol indirect effects (AIEs) arising from anthropogenic INPs, and the responses to these AIEs from time-dependent INP freezing and SIP processes are investigated in the simulated clouds. LÄS MER

5. 19. Formation and Transformation of Atmospheric Brown Carbon (BrC)

   Författare :Kalyan Mitra; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; brown carbon BrC ; primary organic aerosol POA ; secondary organic aerosol SOA ; BrC bleaching; BrC browning; Toluene photo-oxidation; NOx; Ammonia; NH3; acidity effects; light absorption;

   Sammanfattning : Atmospheric brown carbon (BrC) aerosol absorbs light in the UV-Vis spectrum and has poorly constrained but potentially large climate forcing impacts. Most current climate models lack detailed chemistry and interlinked properties of atmospheric BrC, that induce large uncertainties in radiative forcing predictions. LÄS MER

7. 20. Formation, ageing and thermal properties of secondary organic aerosol

   Författare :Eva U. Emanuelsson; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; volatile organic compounds; biogenic; anthropogenic; secondary organic aerosol; troposphere; volatility; ozone;

   Sammanfattning : In order to properly represent and predict the effects of aerosol in climate systems, an accurate description of their formation and properties is needed. This thesis describes work done to increase the knowledge of processes and properties of atmospherically relevant secondary organic aerosol (SOA) from both biogenic and anthropogenic origin. LÄS MER