Sökning: "Boundary-layer meteorology"

Visar resultat 1 - 5 av 52 avhandlingar innehållade orden Boundary-layer meteorology.

  1. 1. Boundary Layer Parametrization in Numerical Weather Prediction Models

    Författare :Jacob Svensson; Gunilla Svensson; Michael Tjernström; Patrick Samuelsson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boundary-Layer Meteorology; Numerical Weather Prediction; Turbulence parametrization; COAMPS; IFS; meteorologi; Meteorology;

    Sammanfattning : Numerical weather prediction (NWP) and climate models have shown to have a challenge to correctly simulate stable boundary layers and diurnal cycles. This aim of this study is to evaluate, describe and give suggestions for improvements of the descriptions of stable boundary layers in operational NWP models. Two papers are included. LÄS MER

  3. 2. On the Arctic Boundary Layer : From Turbulence to Climate

    Författare :Thorsten Mauritsen; Gunilla Svensson; Joao Teixeira; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Atmospheric boundary layers; Turbulence; Stable stratification; Gravity waves; Mesoscale motion; Arctic climate; Meteorology; Meteorologi; atmosfärvetenskap; Atmospheric Sciences;

    Sammanfattning : The boundary layer is the part of the atmosphere that is in direct contact with the ground via turbulent motion. At mid-latitudes the boundary layer is usually one or a few kilometers deep, while in the Arctic it is much more shallow, typically a few hundred meters or less. LÄS MER

  4. 3. Mesoscale dynamics and boundary-layer structure in topographically forced low-level jets

    Författare :Stefan Söderberg; Michael Tjernström; Branko Grisogono; Douw G. Steyn; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; low-level jets; boundary layer; turbulence structure; Meteorology; Meteorologi;

    Sammanfattning : Two types of mesoscale wind-speed jet and their effects on boundary-layer structure were studied. The first is a coastal jet off the northern California coast, and the second is a katabatic jet over Vatnajökull, Iceland. LÄS MER

  5. 4. 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

  7. 5. Processes important for forecasting of clouds over snow

    Författare :Martin Hagman; Gunilla Svensson; Victoria Sinclair; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boundary-layer meteorology; WRF; Initialization; Stratocumulus clouds; Parameterization; Stable boundary layer; Single Column Model; meteorologi; Meteorology;

    Sammanfattning : The Swedish Armed Forces setup of the Weather Research and Forecasting Model (WRF) has problems to forecast low clouds in stably stratified conditions when the ground is covered by snow. The aim of this thesis is to understand what causes this deficit. LÄS MER