Sökning: "Atmospheric boundary layers"

Visar resultat 1 - 5 av 23 avhandlingar innehållade orden Atmospheric boundary layers.

  1. 1. Studies of stratocumulus-topped boundary layers using a numerical weather prediction model

    Författare :Robert Sigg; Peter Duynkereke; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; meteorologi; Meteorology;

    Sammanfattning : Persistent stratocumulus clouds are commonly observed in many areas on Earth. In general, stratocumulus clouds cool the Earth-atmosphere system due to their influence on the radiation budget. It is therefore essential to describe such clouds accurately in climate and numerical weather prediction models. 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. Large Eddy Simulation of Non-Local Turbulence and Integral Measures of Atmospheric Boundary Layers

    Författare :Igor Esau; Frans Nieuwstadt; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Meteorology; Planetary boundary layers; large eddy simulations; non-local turbulence; Meteorologi; Meteorology; Meteorologi; Meteorology; meteorologi;

    Sammanfattning : A new large eddy simulation (LES) code is developed and used to investigate non-local features of turbulent planetary boundary layers (PBLs). The LES code is based on filtered Navier-Stokes equations, which describe motions of incompressible, Boussinesq fluid at high Reynolds numbers. LÄS MER

  5. 4. Boundary Conditions for Spectral Simulations of Atmospheric Boundary Layers

    Författare :Erik Boström; Philipp Schlatter; Bernard J. Geurts; KTH; []
    Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY;

    Sammanfattning : An atmospheric boundary layer (ABL) is generally a very high Reynolds number boundary layer over a fully rough surface that is influenced by different external forces. Numerical simulations of ABLs are typically demanding, particularly due to the high Reynolds numbers. LÄS MER

  7. 5. 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