Search for dissertations about: "convection parameterization"

Showing result 1 - 5 of 6 swedish dissertations containing the words convection parameterization.

2. 1. Convection in large scale numerical models : parameterization and forecasts of precipitation probability

   Author : Ulla Hammarstrand; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES;

   Abstract : This thesis deals with the problem of including the effects of moist convection in the atmosphere in a large scale numerical forecast model and how to interpret and evaluate the predicted convective precipitation.Two methods for parameterizing convection in a large scale numerical forecast model are tested to find the most appropriate one for precipitation forecasts in the mid-latitudes. READ MORE

4. 2. On the representation of precipitation in high-resolution regional climate models

   Author : Petter Lind; Erik Kjellström; Michael Tjernström; Jan Erik Haugen; Anna Rutgersson; Abdel Hannachi; Stockholms universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Regional climate modeling; high-resolution; convection parameterization; precipitation; extremes; statistical analysis; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography; meteorologi; Meteorology;

   Abstract : Weather and climate models applied with sufficiently fine mesh grids to enable a large part of atmospheric deep convection to be explicitly resolved have shown a significantly improved representation of local, short-duration and intense precipitation events compared to coarser scale models. In this thesis, two studies are presented aimed at exploring the dependence of horizontal resolution and of parameterization of convection on the simulation of precipitation. READ MORE

5. 3. Estimating the Air-Water Gas Transfer Velocity during Low Wind Conditions

   Author : Sam Fredriksson; Göteborgs universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; Air.sea gas exchange; Turbulence; Heat flux; Natural convection; Shear; Direct numerical simulations; Gas transfer velocity; IR; Flux-chambers;

   Abstract : The abundances of atmospheric carbon dioxide, CO2, and methane, CH4, are increasing. These increases affect e.g., the global carbon cycle and the climate both regionally and globally. READ MORE

6. 4. Air-Sea Fluxes of CO2 : Analysis Methods and Impact on Carbon Budget

   Author : Maria Norman; Anna Rutgersson; Erik Sahlée; William Drennan; Uppsala universitet; []
   Keywords : NATURVETENSKAP; NATURAL SCIENCES; air-sea exchange; carbon dioxide; Baltic Sea; eddy-covariance method; inertial dissipation method; cospectral-peak method; Baltic Sea measurements; CO2 fluxes; Galathea 3 expedition; Baltic Sea modeling; water-side convection; coastal upwelling; carbon budget; Meteorology; Meteorologi;

   Abstract : Carbon dioxide (CO2) is an important greenhouse gas, and the atmospheric concentration of CO2 has increased by more than 100 ppm since prior to the industrial revolution.  The global oceans are considered an important sink of atmospheric CO2, since approximately one third of the anthropogenic emissions are absorbed by the oceans. READ MORE

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

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

   Abstract : 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. READ MORE