Sökning: "Erland Källen"

Visar resultat 1 - 5 av 8 avhandlingar innehållade orden Erland Källen.

  1. 1. A study of atmospheric variations on climatic and medium range time scales using bifurcation theory

    Författare :Erland Källén; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis deals with atmospheric variability on the long and medium range time scales as described by simplified, low-order models. On the climatic time scale of 0 (103 years) an energy balance and an ice-sheet model are used to investigate some aspects of the climatic record. LÄS MER

  3. 2. Atmospheric circulation regimes and climate change

    Författare :Jenny Brandefelt; Erland Källén; Jonas Nycander; Vim Verkley; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; atmospheric large-scale circulation; greenhouse gas forcing; climate sensitivity; Meteorology; Meteorologi;

    Sammanfattning : The Earth's atmosphere is expected to warm in response to increasing atmospheric concentrations of greenhouse gases (GHG). The response of the Earth's complex and chaotic climate system to the GHG emissions is, however, difficult to assess. In this thesis, two issues of importance for the assessment of this response are studied. LÄS MER

  4. 3. On the recent Arctic Warming

    Författare :Rune Grand Graversen; Michael Tjernström; Erland Källén; John Walsh; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Climate change; atmospheric energy transport; Meteorology; Meteorologi; atmosfärvetenskap; Atmospheric Sciences;

    Sammanfattning : The Arctic region attracts considerable scientific interest in these years. Some of the Earth's most pronounced signs of the recent climate change are found here. The summer sea-ice cover is shrinking at an alarming rate. At the same time the region warms faster than the rest of the globe. LÄS MER

  5. 4. The use of a satellite-derived cloud climatology for studying cloud-aerosol processes and the performance of regional cloud climate simulations

    Författare :Karl-Göran Karlsson; Erland Källen; Jon-Egil Kristjansson; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Clouds and climate; satellite cloud climatology; validation of clouds; clouds and aerosols; Meteorology; Meteorologi;

    Sammanfattning : The entry of satellite-derived decadal cloud datasets with homogeneous coverage in time and space enables studies not possible before. This thesis presents two such applications. The first study deals with cloud-aerosol processes and the second with an evaluation of cloud simulations from a regional climate model. LÄS MER

  7. 5. On errors in meteorological data assimilation

    Författare :Magnus Lindskog; Erland Källen; Nils. Gustafsson; Florence Rabier; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Meteorology; Meteorologi; meteorologi; Meteorology;

    Sammanfattning : Data assimilation in Numerical Weather Prediction (NWP) optimally blends observations with atmospheric model data in order to obtain the best possible initial state for an atmospheric model prediction. Specification of error characteristics is an important part of data assimilation. LÄS MER