Sökning: "EARTHS EARLY ATMOSPHERE"
Visar resultat 1 - 5 av 6 avhandlingar innehållade orden EARTHS EARLY ATMOSPHERE.
1. Modelling the early to mid-Holocene Arctic climate
Sammanfattning : In the recent past it has become evident that the Earth's climate is changing, and that human activity play a significant role in these changes. One of the regions where the ongoing climate change has been most evident is in the Arctic: the surface temperature has increased twice as much in this region as compared to the global average, in addition, a significant decline in the Arctic sea-ice extent has been observed in the past decades. LÄS MER
2. Modelling the middle atmosphere and its sensitivity to climate change
Sammanfattning : The Earth's middle atmosphere at about 10-100 km has shown a substantial sensitivity to human activities. First, the ozone layer has been reduced since the the early 1980s due to man-made emissions of halogenated hydrocarbons. LÄS MER
3. Atmospheric dynamics and the hydrologic cycle in warm climates
Sammanfattning : Past warm climates represent one extreme of Earth's known climate states. Here, we study warm climates in both idealized simulations and full-complexity general circulation model (GCM) simulations of the early Eocene epoch, approximately 50 million years ago. LÄS MER
4. Ocean chemistry and the evolution of multicellularity
Sammanfattning : Oxygen has been assumed to be a vital trigger for the evolution of multicellular life forms on Earth, partly based on its power to promote substantial energy flux in cell respiration and partly as biosynthesis of compounds like collagen require oxygen. However, the co-evolution of large life and the Earth’s chemical environment is not well understood at present, and there is particular disagreement in the field about whether the Cambrian explosion of animal life forms was a chemical or biological event. LÄS MER
5. Factors influencing emission fluxes and bacterial enrichment in sea spray aerosols : Insights from laboratory and field studies
Sammanfattning : Sea spray aerosol (SSA) is one of the major natural aerosol sources and is produced when wave breaking entrains air into ocean surface water, which subsequently breaks up into bubbles. These bubbles rise to the surface and can scavenge biogenic material. LÄS MER