Sökning: "earth observations"

Visar resultat 16 - 20 av 339 avhandlingar innehållade orden earth observations.

  1. 16. Diurnal variation of stratospheric short-lived species

    Författare :Maryam Khosravi; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; chlorine monoxide; short-lived species; Arctic ClO; diurnal variation; tropical middle stratosphere; Arctic stratosphere;

    Sammanfattning : Diurnal variation of stratospheric short-lived speciesMaryam KhosraviChalmers University of TechnologyDepartment of Earth and Space SciencesAbstractThe depletion of ozone in the stratosphere has a direct impact on the amount of ultravioletradiation reaching the Earth’s surface. The ozone abundance and distributionis controlled by the photo-chemical reactions and catalytic cycles involving halogens(chlorine and bromine), odd hydrogen and odd nitrogen species as well as by atmospherictransport. LÄS MER

  3. 17. Motions in the Geodetic Reference Frame - GPS observations

    Författare :Martin Lidberg; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : .... LÄS MER

  4. 18. Measured and modelled long-term effects of whole-tree harvest : impact on soil and surface water acid-base status in boreal forests

    Författare :Therese Zetterberg; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : This thesis examines the impact of whole-tree harvest (WTH) on soils and surface waters acid-base status in coniferous forests compared with conventional harvesting (CH). A combination of field observations (up to four decades) and dynamic modelling was used to describe the impact on soil calcium (Ca²⁺) pools and surface water acid neutralizing capacity (ANC). LÄS MER

  5. 19. Evaluating Tropical Upper-tropospheric Water in Climate Models Using Satellite Data

    Författare :Marston Sheldon Johnston; Chalmers tekniska högskola; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ECHAM6; Humidity; Climate; CAM5; IWC; Clouds; EC-Earth;

    Sammanfattning : Measuring and simulating moist processes in the tropical upper troposphere are difficult tasks. Humidity in this region of the atmosphere is mainly supplied by deep convection and, problems with simulated convection areknown to be a major contributor to uncertainties in climate model projections. LÄS MER

  7. 20. Effect of Hyporheic Exchange on Conservative and Reactive Solute Transport in Streams : Model Assessments Based on Tracer Tests

    Författare :Karin Jonsson; Anders Wörman; Bernhard H. Schmid; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Earth sciences; conservative; hyporheic exchange; model; reactive; retention; solute; sorption kinetics; stream transport; temporal moments; tracer experiment; Geovetenskap; Earth sciences; Geovetenskap; Sedimentology; sedimentologi;

    Sammanfattning : Understanding of the processes affecting solute transport in flowing water is important for the possibility to predict the evolution with time of polluted stream systems. This thesis presents tracer experiment methodology and model developments for solute transport in streams, with special focus on retention processes and their effect on solute stream transport. LÄS MER