Sökning: "Atmospheric mixing"

Visar resultat 1 - 5 av 55 avhandlingar innehållade orden Atmospheric mixing.

1. 1. Arctic Atmospheric Rivers : Eulerian and Lagrangian features, and trends over the last 40 years

   Författare :Cheng You; Michael Tjernström; Abhay Devasthale; Heikki Järvinen; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arctic; Atmospheric river; Stratocumulus; Blocking; Turbulence; Longwave irradiance; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

   Sammanfattning : Arctic Atmospheric rivers, termed ‘warm-and-moist intrusion’ (WaMAI) in this thesis, transporting heat and moisture into the Arctic from lower latitudes, is a key contributor to the amplified warming in the Arctic under global change (Arctic Amplification). However, the warming effect of WaMAIs and its transformation along the trajectories into high Arctic still remain unclear, as well as their relation with the large-scale atmospheric circulation. LÄS MER

3. 2. Fluxes and Mixing Processes in the Marine Atmospheric Boundary Layer

   Författare :Erik Olof Nilsson; Anna Rutgersson; Harm Jonker; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Waves; Growing sea; Swell; Marine boundary layer; Air-sea interaction; Mixing; Momentum flux; Wind stress; Flux attenuation; Sensor separation; Large eddy simulation; Multiresolution analysis; Coupling; Wave model; Climate model; Wave age; Meteorology; Meteorologi;

   Sammanfattning : Atmospheric models are strongly dependent on the turbulent exchange of momentum, sensible heat and moisture (latent heat) at the surface. Oceans cover about 70% of the Earth’s surface and understanding the processes that control air-sea exchange is of great importance in order to predict weather and climate. LÄS MER

4. 3. Introducing Surface Gravity Waves into Earth System Models

   Författare :Lichuan Wu; Anna Rutgersson; Erik Sahlée; Peter Janssen; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Surface gravity waves; Air-sea interaction; Earth-System Model; Atmospheric mixing; Upper-ocean turbulence; Meteorology; Meteorologi;

   Sammanfattning : Surface gravity waves alter the turbulence of the bottom atmosphere and the upper ocean. Accordingly, they can affect momentum flux, heat fluxes, gas exchange and atmospheric mixing. However, in most state-of-the-art Earth System Models (ESMs), surface wave influences are not fully considered or even included. LÄS MER

5. 4. Submicrometre aerosol emissions from sea spray and road traffic

   Författare :Monica Mårtensson; Douglas Nilsson; Christer Johansson; Michael Smith; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Eddy covariance method; aerosol emissions; submicrometre sea salt parameterisation; primary marine organic aerosols; sea spray; road traffic emission factors; air-sea exchange; aerosol dynamics model; internal aerosol mixing; combustion aerosols; Atmosphere and hydrosphere sciences; Atmosfärs- och hydrosfärsvetenskap; atmosfärvetenskap; Atmospheric Sciences;

   Sammanfattning : The uncertainty of the climate and health effects of aerosols is still large, one important reason being lack of knowledge of the primary emissions. This thesis combines laboratory and field experiments, and process modelling in an effort to better quantify the submicrometre aerosol emissions and to understand some of the processes in the atmosphere. LÄS MER

7. 5. Hygroscopic Growth of Atmospheric Aerosol Particles and Its Relation to Nucleation Scavenging in Clouds

   Författare :Birgitta Svenningsson; Kärnfysik; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; aerosol formation; atmospheric aerosols; hygroscopic growth; nucleation scavenging; cloud; water activity; external mixing; tandem differential mobility analyser; Kärnfysik; cloud condensation nuclei spectra; Nuclear physics; TDMA; Fysicumarkivet A:1997:Svenningsson; inorganic salts;

   Sammanfattning : Aerosol particles in the atmosphere are important in several aspects. Some major aerosol constituents that are deposited in ecosystems are acidic or fertilisers and some minor or trace constituents are toxic. LÄS MER