Sökning: "geomagnetic field"

Visar resultat 1 - 5 av 37 avhandlingar innehållade orden geomagnetic field.

  1. 1. Assessing Holocene and late Pleistocene geomagnetic dipole field variability

    Författare :Andreas Nilsson; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Geomagnetic field; palaeomagnetism; the Holocene; dipole tilt; dipole moment; cosmogenic radionuclides;

    Sammanfattning : Palaeomagnetic studies of continuous geological archives and archaeological artefacts are required to reconstruct geomagnetic field changes beyond the range of historical observations. In this thesis I assess the reliability of sedimentary palaeomagnetic data and Holocene dipole field reconstructions. LÄS MER

  2. 2. Magnetic map sense in animals: effects of geographic and magnetic displacements

    Författare :Jannika Boström; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Oenanthe oenanthe; skylight polarization; geomagnetic map; geomagnetic field; endogenous migration programme; migratory fuelling; orientation; animal navigation;

    Sammanfattning : Migration research is a large and diverse field and in my thesis I have focused on the impact of geomagnetic cues on animal orientation, navigation and migratory fuelling. Several animal species from widely different taxa possess the ability to sense and make use of geomagnetic information during migratory or homing events. LÄS MER

  3. 3. Avian migration: the role of geomagnetic cues

    Författare :Ian Henshaw; Cecilia Kullberg; Thomas Alerstam; Stockholms universitet; []
    Nyckelord :NATURAL SCIENCES; NATURVETENSKAP; geomagnetic cues; orientation; food intake; fuel deposition; corticosterone; endogenous time program; bird migration; Biology; Biologi; etologi; Ethology;

    Sammanfattning : The regularity and scale of bird migrations has impressed mankind for generations. Birds rely on an inherited migratory program to guide them during the journey; however, recent evidence suggests that additional external cues are necessary. LÄS MER

  4. 4. Improving archaeomagnetic dating through new data acquisition and method development

    Författare :Megan Allington; Kvartärgeologi; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Archaeomagnetism; Palaeomagnetism; Geomagnetic field; Archaeomagnetic dating;

    Sammanfattning : The Earth’s magnetic field (or geomagnetic field) has been measured for hundreds of years, starting with maritime observations from logbooks for navigation purposes to present day real-time recording by satellites. From these records, the geomagnetic field variation throughout recent time is well-understood. LÄS MER

  5. 5. Solar Wind and Geomagnetic Activity - Predictions Using Neural Networks

    Författare :Hans Gleisner; Astronomi - Genomgår omorganisation; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Geophysics; kosmisk kemi; rymdvetenskap; magnetosphere; solar wind; space weather; geomagnetic activity; geomagnetism; ring current; auroral electrojet; neural networks; forecasting; Astronomy; space research; Astronomi; cosmic chemistry; physical oceanography; meteorology; Geofysik; fysisk oceanografi; meteorologi; Fysicumarkivet A:2000:Gleisner;

    Sammanfattning : This thesis shows how artificial neural networks (ANNs) can be applied to predict geomagnetic activity from solar-wind data. It introduces and summarizes five papers where development of ANN models are reported, and where predictions of geomagnetic activity are discussed. LÄS MER