Sökning: "atmospheric flow"

Visar resultat 1 - 5 av 151 avhandlingar innehållade orden atmospheric flow.

1. 1. Mesoscale Simulations of Atmospheric Flow in Complex Terrain

   Författare :Matthias Mohr; Sergej Zilitinkevich; Leif Enger; Dieter P. Eppel; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Meteorology; Mesoscale modeling; Flow in complex terrain; Atmospheric dispersion; Model comparison; Boundary conditions; Numerical modeling; Atmospheric pressure; Gravity waves; Meteorologi; Meteorology; Meteorologi; Meteorology; meteorologi;

   Sammanfattning : The MIUU mesoscale model was further developed, in order to include information on large-scale atmospheric fields from global or regional atmospheric climate- and weather-prediction models. For this purpose, a new lateral boundary condition was developed and implemented into the model. LÄS MER

3. 2. Modelling of stably-stratified, convective and transitional atmospheric boundary layers using the explicit algebraic Reynolds-stress model

   Författare :Velibor Zeli; Gert Brethouwer; Arne V. Johansson; Stefan Wallin; Bert Holtslag; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; atmospheric turbulence; convective atmosphere; Reynolds-stress model; stably-stratified atmosphere; transitional atmosphere; Engineering Mechanics; Teknisk mekanik;

   Sammanfattning : The atmospheric boundary layer (ABL) is in continuous turbulent motion. The heating and cooling of the Earth’s surface drives mechanic and thermodynamic processes in the ABL through enhancing and damping of atmospheric turbulence. The surface forcing has a profound effect on the diurnal cycle of temperature,wind and related variables in the ABL. LÄS MER

4. 3. Near surface atmospheric flow over high latitude glaciers

   Författare :Oskar Parmhed; Erland Källén; Branko Grisogono; Haraldur Ólafsson; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Stable boundary layer; Ekman layer; Katabatic flow; gravity wave; low-level jets; Meteorology; Meteorologi;

   Sammanfattning : In this thesis various descriptions of the near surface atmospheric flow over a high latitude glacier is used in an effort to increase our understanding of the basic flow dynamics there. Through their contribution to sea-level change, mountain glaciers play a significant role in Earth’s climate system. LÄS MER

5. 4. Paths to improving atmospheric models across scales : The importance of the unresolved scales

   Författare :Kerstin Hartung; Gunilla Svensson; Rodrigo Caballero; Olof Runborg; Heikki Järvinen; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; global climate models; atmospheric blocking; topographic forcing; physical parametrizations; single-column model; atmosphere-ocean single-column model; air-sea interaction; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

   Sammanfattning : Correct representation of physical processes, the parametrizations, and their interaction with the resolved circulation is crucial for the performance of numerical models. Here, focus is put on understanding model biases and developing tools to alleviate existing biases. LÄS MER

7. 5. High Order Local Radial Basis Function Methods for Atmospheric Flow Simulations

   Författare :Erik Lehto; Elisabeth Larsson; Natasha Flyer; Tobin Driscoll; Uppsala universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Radial basis function; meshless method; high order finite difference; atmospheric flow; hyper-viscosity; stable algorithm; Scientific Computing; Beräkningsvetenskap;

   Sammanfattning : Since the introduction of modern computers, numerical methods for atmospheric simulations have routinely been applied for weather prediction, and in the last fifty years, there has been a steady improvement in the accuracy of forecasts. Accurate numerical models of the atmosphere are also becoming more important as researchers rely on global climate simulations to assess and understand the impact of global warming. LÄS MER