Sökning: "ice clouds"

Visar resultat 1 - 5 av 55 avhandlingar innehållade orden ice clouds.

1. 1. Mechanisms for the Influence from Ice Nucleus Aerosols on Clouds and their Indirect Effects: Cloud Modelling

   Författare :Deepak Waman; MERGE: ModElling the Regional and Global Earth system; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; clouds; Radiation; Ice Nuclei; Primary Biological Aerosol Particles; Ice particles; Secondary ice; primary ice; Aerosol particles; thunderstorm;

   Sammanfattning : The role of multiple groups of primary biological aerosol particles (PBAPs) as ice nucleating particles (INPs), and of ice formation processes such as time-dependent freezing of various INPs, and various secondary ice production(SIP) mechanisms in overall ice concentration has been evaluated in a range of cloud systems by simulating them numerically with the state-of-the-art ‘Aerosol-Cloud’ (AC) model in a 3D mesoscale domain. Also, the mechanismsof aerosol indirect effects (AIEs) arising from anthropogenic INPs, and the responses to these AIEs from time-dependent INP freezing and SIP processes are investigated in the simulated clouds. LÄS MER

3. 2. Secondary ice production : An empirical formulation and organization of mechanisms among simulated cloud-types

   Författare :Akash Deshmukh; MERGE: ModElling the Regional and Global Earth system; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; ice; collision; ice production; ice enhancement; secondary ice; sublimation; fragmentation;

   Sammanfattning : Clouds are essential elements within Earth's atmosphere, posing a challenge for cloud-resolving models in understanding the creation of new cloud ice particles from existing ice and liquid phases. Such ice initiation determines cloud microphysical and radiative properties, influencing cloud phase, precipitation and cloud extent/properties. LÄS MER

4. 3. Remote sensing of ice clouds : synergistic measurements and radiative transfer simulations

   Författare :Gerrit Holl; Gerald Mace; Luleå tekniska universitet; []
   Nyckelord :TEKNIK OCH TEKNOLOGIER; ENGINEERING AND TECHNOLOGY; Rymdteknik; Space Technology;

   Sammanfattning : This thesis primarily considers the spaceborne remote sensing of ice clouds and frozen precipitation. Ice clouds are important for hydrology and for the Earth’s radiation budget, but many properties are difficult to measure, in particular using spaceborne instruments. LÄS MER

5. 4. Bioaerosols and their importance for low-level Arctic clouds

   Författare :Gabriel Pereira Freitas; Paul Zieger; Radovan Krejci; Kevin J. Noone; Claudia Mohr; Martin Gallagher; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Bioaerosols; Aerosols; Clouds; Arctic; Cloud Condensation Nuclei; Ice Nucleating Particles; Sea Spray Aerosol; Environmental Sciences; miljövetenskap;

   Sammanfattning : Bioaerosols are microorganisms or functional parts of them or other biological matter suspended in air. Examples are bacteria, viruses, pollen, spores, or smaller plant debris. In the atmosphere, bioaerosols can play various functional roles, such as facilitating the spread of genetic material. LÄS MER

7. 5. Thin water and ice films on minerals : a molecular level study

   Författare :Merve Yeşilbaş; Jean-François Boily; Johannes Messinger; Grégory Lefèvre; Umeå universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; water; ice; cryosalt; minerals; rocks; atmosphere; Dynamic Vapour Sorption; FTIR; cryo-FESEM; fysikalisk kemi; Physical Chemistry;

   Sammanfattning : Minerals in Earth’s crust and suspended in the atmosphere form water or ice films as thin as a few nanometers to as thick as a few micrometers, and beyond. Mineral-bound water and ice films in terrestrial systems (e.g. LÄS MER