Visar resultat 1 - 5 av 23 avhandlingar innehållade ordet mesosphere.
Sammanfattning : Observing airglow emissions allows us to explore the chemical composition and dynamics of the upper mesosphere. The Odin satellite has routinely measured O2(a1∆g) and OH Meinel band airglow emissions from 2001 until 2015. In this thesis, the Odin/OSIRIS infrared imager data have been studied in some depth for the first time. LÄS MER
2. Empirical Modeling of Solar Induced Variations of Nitric Oxide in the Upper Mesosphere and Lower Thermosphere
Sammanfattning : Nitric Oxide (NO) is produced by solar photolysis and auroral activity in the upper mesosphere and lower thermosphere region and can, via transport processes, eventually impact the ozone layer in the stratosphere. This thesis uses measurements of NO taken between 2004 and 2016 by the Odin Sub Millimetre Radiometer (SMR) to build an empirical model which links the prevailing solar and auroral conditions with the measured number density of NO. LÄS MER
Sammanfattning : Water vapour is the most important greenhouse gas and plays a fundamental role in the climate system and for the chemistry of the Earth's atmosphere. This thesis presents observations of water vapour in the middle atmosphere with a particular focus on the mesosphere. LÄS MER
Sammanfattning : The forcing of the Sun on Earth's atmosphere manifests itself via solar radiation and energetic particle precipitation (EPP), which variations are most noticeable in the upper regions of the atmosphere. A key species in the lower thermosphere, which is influenced by solar forcing, is nitric oxide (NO). LÄS MER
5. Time series of mesospheric species measured using ground-based microwave spectrometry: Retrieval and Error estimation
Sammanfattning : As the human emission of greenhouse gases continue to increase, the atmosphere is changing. The mesosphere region is particularly interesting as the magnitude oftemperature change in this region is expected to be larger, than in the lower layers of the atmosphere. LÄS MER