Sökning: "biogenic"

Visar resultat 1 - 5 av 103 avhandlingar innehållade ordet biogenic.

1. 1. The influence of biogenic organic compounds on cloud formation

   Författare :Sanna Ekström; Barbara Nozière; Tomas Alsberg; Hans-Christen Hansson; Ernest Weingartner; Stockholms universitet; []
   Nyckelord :biogenic; aerosol; CCN; water-soluble; microorganisms; surfactant; organosulfate; NATURAL SCIENCES; NATURVETENSKAP; Applied Environmental Science; tillämpad miljövetenskap;

   Sammanfattning : Aerosols and clouds provide the largest uncertainty in the atmospheric radiation budget. The main focus of this thesis was to investigate the ability of organic compounds in aerosol particles to form clouds, and more specifically those emitted by living organisms. LÄS MER

3. 2. On Biogenic Halocarbons in Antarctic Waters

   Författare :Erik Mattsson; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Volatile biogenic halocarbons; Antarctica; Southern Ocean; Sea ice; Snow; Air-sea exchange;

   Sammanfattning : Little is known regarding the distribution of naturally produced volatile halogenated organic compounds, halocarbons, in Antarctic waters and the contribution of these waters to the global atmospheric load of halogens. In the atmosphere, halocarbons are degraded by photolysis, and form reactive halogen radicals. LÄS MER

4. 3. Biogenic Halocarbons in Polar Sea Ice

   Författare :Anna Granfors; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Volatile biogenic halocarbons; Sea ice; Antarctica; ice-air flux; gases;

   Sammanfattning : Sea ice is to date a rather poorly investigated part of the cycling of volatile halogenated organic compounds, halocarbons. These compounds are natural sources of reactive iodine and bromine to the atmosphere, and are produced in the marine environment. LÄS MER

5. 4. Atmospheric Chemistry of Volatile Organic Compounds: Oxidation Products, Mechanisms and Secondary Organic Aerosol Formation

   Författare :Julia Hammes; Göteborgs universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; SOA; VOC; anthropogenic; biogenic; FIGAERO; CIMS; HOMs; ELVOCs; atmospheric oxidation; chemical mechanism; NOx; limonene; a-pinene; TMB; ozone; nitrate; OH; radical chemistry; RO2; G-FROST; GO:PAM;

   Sammanfattning : The results from this work are a piece in understanding the complex puzzle of atmospheric aerosol formation. Secondary organic aerosol (SOA) formed by the oxidation of volatile organic compounds (VOC) in the atmosphere is a key component of air pollution with a strong negative impact on human health and influence on climate, but its formation is poorly understood. LÄS MER

7. 5. 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