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Visar resultat 1 - 5 av 34 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Arctic Atmospheric Rivers : Eulerian and Lagrangian features, and trends over the last 40 years

   Författare :Cheng You; Michael Tjernström; Abhay Devasthale; Heikki Järvinen; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arctic; Atmospheric river; Stratocumulus; Blocking; Turbulence; Longwave irradiance; atmosfärvetenskap och oceanografi; Atmospheric Sciences and Oceanography;

   Sammanfattning : Arctic Atmospheric rivers, termed ‘warm-and-moist intrusion’ (WaMAI) in this thesis, transporting heat and moisture into the Arctic from lower latitudes, is a key contributor to the amplified warming in the Arctic under global change (Arctic Amplification). However, the warming effect of WaMAIs and its transformation along the trajectories into high Arctic still remain unclear, as well as their relation with the large-scale atmospheric circulation. LÄS MER

3. 2. On the recent Arctic Warming

   Författare :Rune Grand Graversen; Michael Tjernström; Erland Källén; John Walsh; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Climate change; atmospheric energy transport; Meteorology; Meteorologi; atmosfärvetenskap; Atmospheric Sciences;

   Sammanfattning : The Arctic region attracts considerable scientific interest in these years. Some of the Earth's most pronounced signs of the recent climate change are found here. The summer sea-ice cover is shrinking at an alarming rate. At the same time the region warms faster than the rest of the globe. LÄS MER

4. 3. On the atmospheric transport pathways of heat into the Arctic in winter and spring

   Författare :Sonja Murto; Rodrigo Caballero; Gunilla Svensson; Dörthe Handorf; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Arctic climate; Blocking; Warm-air intrusions; Surface energy budget; Melt onset; MOSAiC; Atmospheric Sciences and Oceanography; atmosfärvetenskap och oceanografi;

   Sammanfattning : The atmospheric meridional energy transport is an important component in the global climate system, as it transports moisture and heat from the midlatitudes into the Arctic, balancing the regional energy loss to space. Narrow and intense injections of warm and moist air, so-called warm-air intrusions, have a large local imprint on the surface through various processes acting on different scales, such as cloud formation, turbulent fluxes and atmospheric large-scale circulation. LÄS MER

5. 4. Tribology for Greener Combustion Engines : Scuffing in Marine Engines and a Lubricating Boric Acid Fuel Additive

   Författare :Petra Olander; Staffan Jacobson; Roland Larsson; Uppsala universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Friction; wear; lubrication; energy loss; atmospheric emissions; fuel efficiency; transport.; Teknisk fysik med inriktning mot tribomaterial; Engineering Science with specialization in Tribo Materials;

   Sammanfattning : This thesis aims at increased knowledge in two fields of tribological research; both related to making currently used combustion engines greener. The first field regards the possibilities of using a boric acid fuel additive to increase fuel efficiency. LÄS MER

7. 5. A large-eddy simulation perspective on Arctic airmass transformation and low-level cloud evolution

   Författare :Antonios Dimitrelos; Annica Ekman; Caballero Rodrigo; Rune Grand Graversen; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Arctic; mixed phase clouds; sea ice; Arctic amplification; atmospheric energy transport; CCN; Atmospheric Sciences and Oceanography; atmosfärvetenskap och oceanografi;

   Sammanfattning : The Arctic is currently warming faster than other regions of the Earth. Many processes and feedbacks contribute to the enhanced warming. Among these are the radiative effects of clouds. LÄS MER