Sökning: "Erik Sahlée"

Visar resultat 6 - 10 av 12 avhandlingar innehållade orden Erik Sahlée.

  1. 6. Gas Exchange over Aquatic Interfaces and its Importance for Greenhouse Gas Emission

    Författare :Jovana Kokic; Sebastian Sobek; Erik Sahlée; Marcus B. Wallin; Anne Ojala; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; gas exchange; lake; stream; lake sediment; headwaters; carbon dioxide; methane; greenhouse gas emission; carbon; turbulence; Biology with specialization in Limnology; Biologi med inriktning mot limnologi;

    Sammanfattning : Aquatic ecosystems play a substantial role in global cycling of carbon (C), despite covering only about 4% of the earth surface. They emit large amounts of greenhouse gases (GHG) to the atmosphere, comparable to the amount of C stored annually in terrestrial ecosystems. In addition, C can be buried in lake sediments. LÄS MER

  3. 7. Air-Sea Fluxes of CO2 : Analysis Methods and Impact on Carbon Budget

    Författare :Maria Norman; Anna Rutgersson; Erik Sahlée; William Drennan; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; air-sea exchange; carbon dioxide; Baltic Sea; eddy-covariance method; inertial dissipation method; cospectral-peak method; Baltic Sea measurements; CO2 fluxes; Galathea 3 expedition; Baltic Sea modeling; water-side convection; coastal upwelling; carbon budget; Meteorology; Meteorologi;

    Sammanfattning : Carbon dioxide (CO2) is an important greenhouse gas, and the atmospheric concentration of CO2 has increased by more than 100 ppm since prior to the industrial revolution.  The global oceans are considered an important sink of atmospheric CO2, since approximately one third of the anthropogenic emissions are absorbed by the oceans. LÄS MER

  4. 8. Lake Fluxes of Methane and Carbon Dioxide

    Författare :Eva Podgrajsek; Erik Sahlée; Dennis Baldocchi; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; air-lake gas exchange; carbon dioxide; eddy covariance; floating chambers; methane; waterside convection; Meteorology; Meteorologi;

    Sammanfattning : Methane (CH4) and carbon dioxide (CO2) are two important greenhouse gases. Recent studies have shown that lakes, although they cover a small area of the globe, can be very important natural sources of atmospheric CH4 and CO2. LÄS MER

  5. 9. Mesoscale Processes over the Baltic Sea

    Författare :Nina Svensson; Erik Sahlée; Hans Bergström; Anna Rutgersson; Søren Larsen; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Boundary layer; Baltic Sea; stable conditions; low-level jet; sea breeze; boundary layer rolls; mesoscale effects; WRF; LIDAR;

    Sammanfattning : The objective of this thesis is to study mesoscale processes above the Baltic Sea, which is a small, semi-enclosed sea where land-sea interaction may have a large impact on the offshore conditions. It is only the last tens of years that offshore research has become more popular, and one reason for this is the increasing offshore wind energy, which poses the need for accurate estimates of wind speed and turbulence conditions in the marine environment. LÄS MER

  7. 10. Wind and atmospheric stability characteristics over the Baltic Sea

    Författare :Nina Svensson; Erik Sahlée; Hans Bergström; Anna Rutgersson; Xiaoli Guo Larsén; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; coastal transition; stable conditions; boundary layer rolls; low level jet; WRF; Baltic Sea; Meteorology; Meteorologi;

    Sammanfattning : In recent years there has been an increase in offshore wind energy, which poses the need for accurate wind speed estimates in the marine environment, especially in coastal areas where most wind turbines will be placed. This thesis is focused on the Baltic Sea, which is a small, semi-enclosed sea where land-sea interaction play an important role in explaining the wind patterns. LÄS MER